1 /* 2 ** 2001-09-15 3 ** 4 ** The author disclaims copyright to this source code. In place of 5 ** a legal notice, here is a blessing: 6 ** 7 ** May you do good and not evil. 8 ** May you find forgiveness for yourself and forgive others. 9 ** May you share freely, never taking more than you give. 10 ** 11 ************************************************************************* 12 ** This header file defines the interface that the SQLite library 13 ** presents to client programs. If a C-function, structure, datatype, 14 ** or constant definition does not appear in this file, then it is 15 ** not a published API of SQLite, is subject to change without 16 ** notice, and should not be referenced by programs that use SQLite. 17 ** 18 ** Some of the definitions that are in this file are marked as 19 ** "experimental". Experimental interfaces are normally new 20 ** features recently added to SQLite. We do not anticipate changes 21 ** to experimental interfaces but reserve the right to make minor changes 22 ** if experience from use "in the wild" suggest such changes are prudent. 23 ** 24 ** The official C-language API documentation for SQLite is derived 25 ** from comments in this file. This file is the authoritative source 26 ** on how SQLite interfaces are supposed to operate. 27 ** 28 ** The name of this file under configuration management is "sqlite.h.in". 29 ** The makefile makes some minor changes to this file (such as inserting 30 ** the version number) and changes its name to "sqlite3.h" as 31 ** part of the build process. 32 */ 33 #ifndef SQLITE3_H 34 #define SQLITE3_H 35 #include <stdarg.h> /* Needed for the definition of va_list */ 36 37 /* 38 ** Make sure we can call this stuff from C++. 39 */ 40 #ifdef __cplusplus 41 extern "C" { 42 #endif 43 44 45 /* 46 ** Provide the ability to override linkage features of the interface. 47 */ 48 #ifndef SQLITE_EXTERN 49 # define SQLITE_EXTERN extern 50 #endif 51 #ifndef SQLITE_API 52 # define SQLITE_API 53 #endif 54 #ifndef SQLITE_CDECL 55 # define SQLITE_CDECL 56 #endif 57 #ifndef SQLITE_APICALL 58 # define SQLITE_APICALL 59 #endif 60 #ifndef SQLITE_STDCALL 61 # define SQLITE_STDCALL SQLITE_APICALL 62 #endif 63 #ifndef SQLITE_CALLBACK 64 # define SQLITE_CALLBACK 65 #endif 66 #ifndef SQLITE_SYSAPI 67 # define SQLITE_SYSAPI 68 #endif 69 70 /* 71 ** These no-op macros are used in front of interfaces to mark those 72 ** interfaces as either deprecated or experimental. New applications 73 ** should not use deprecated interfaces - they are supported for backwards 74 ** compatibility only. Application writers should be aware that 75 ** experimental interfaces are subject to change in point releases. 76 ** 77 ** These macros used to resolve to various kinds of compiler magic that 78 ** would generate warning messages when they were used. But that 79 ** compiler magic ended up generating such a flurry of bug reports 80 ** that we have taken it all out and gone back to using simple 81 ** noop macros. 82 */ 83 #define SQLITE_DEPRECATED 84 #define SQLITE_EXPERIMENTAL 85 86 /* 87 ** Ensure these symbols were not defined by some previous header file. 88 */ 89 #ifdef SQLITE_VERSION 90 # undef SQLITE_VERSION 91 #endif 92 #ifdef SQLITE_VERSION_NUMBER 93 # undef SQLITE_VERSION_NUMBER 94 #endif 95 96 /* 97 ** CAPI3REF: Compile-Time Library Version Numbers 98 ** 99 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 100 ** evaluates to a string literal that is the SQLite version in the 101 ** format "X.Y.Z" where X is the major version number (always 3 for 102 ** SQLite3) and Y is the minor version number and Z is the release number.)^ 103 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 104 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 105 ** numbers used in [SQLITE_VERSION].)^ 106 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 107 ** be larger than the release from which it is derived. Either Y will 108 ** be held constant and Z will be incremented or else Y will be incremented 109 ** and Z will be reset to zero. 110 ** 111 ** Since [version 3.6.18] ([dateof:3.6.18]), 112 ** SQLite source code has been stored in the 113 ** <a href="http://www.fossil-scm.org/">Fossil configuration management 114 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 115 ** a string which identifies a particular check-in of SQLite 116 ** within its configuration management system. ^The SQLITE_SOURCE_ID 117 ** string contains the date and time of the check-in (UTC) and a SHA1 118 ** or SHA3-256 hash of the entire source tree. If the source code has 119 ** been edited in any way since it was last checked in, then the last 120 ** four hexadecimal digits of the hash may be modified. 121 ** 122 ** See also: [sqlite3_libversion()], 123 ** [sqlite3_libversion_number()], [sqlite3_sourceid()], 124 ** [sqlite_version()] and [sqlite_source_id()]. 125 */ 126 #define SQLITE_VERSION "3.28.0" 127 #define SQLITE_VERSION_NUMBER 3028000 128 #define SQLITE_SOURCE_ID "2019-04-16 19:49:53 884b4b7e502b4e991677b53971277adfaf0a04a284f8e483e2553d0f83156b50" 129 130 /* 131 ** CAPI3REF: Run-Time Library Version Numbers 132 ** KEYWORDS: sqlite3_version sqlite3_sourceid 133 ** 134 ** These interfaces provide the same information as the [SQLITE_VERSION], 135 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 136 ** but are associated with the library instead of the header file. ^(Cautious 137 ** programmers might include assert() statements in their application to 138 ** verify that values returned by these interfaces match the macros in 139 ** the header, and thus ensure that the application is 140 ** compiled with matching library and header files. 141 ** 142 ** <blockquote><pre> 143 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 144 ** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 ); 145 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 146 ** </pre></blockquote>)^ 147 ** 148 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 149 ** macro. ^The sqlite3_libversion() function returns a pointer to the 150 ** to the sqlite3_version[] string constant. The sqlite3_libversion() 151 ** function is provided for use in DLLs since DLL users usually do not have 152 ** direct access to string constants within the DLL. ^The 153 ** sqlite3_libversion_number() function returns an integer equal to 154 ** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns 155 ** a pointer to a string constant whose value is the same as the 156 ** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built 157 ** using an edited copy of [the amalgamation], then the last four characters 158 ** of the hash might be different from [SQLITE_SOURCE_ID].)^ 159 ** 160 ** See also: [sqlite_version()] and [sqlite_source_id()]. 161 */ 162 SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 163 SQLITE_API const char *sqlite3_libversion(void); 164 SQLITE_API const char *sqlite3_sourceid(void); 165 SQLITE_API int sqlite3_libversion_number(void); 166 167 /* 168 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics 169 ** 170 ** ^The sqlite3_compileoption_used() function returns 0 or 1 171 ** indicating whether the specified option was defined at 172 ** compile time. ^The SQLITE_ prefix may be omitted from the 173 ** option name passed to sqlite3_compileoption_used(). 174 ** 175 ** ^The sqlite3_compileoption_get() function allows iterating 176 ** over the list of options that were defined at compile time by 177 ** returning the N-th compile time option string. ^If N is out of range, 178 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 179 ** prefix is omitted from any strings returned by 180 ** sqlite3_compileoption_get(). 181 ** 182 ** ^Support for the diagnostic functions sqlite3_compileoption_used() 183 ** and sqlite3_compileoption_get() may be omitted by specifying the 184 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 185 ** 186 ** See also: SQL functions [sqlite_compileoption_used()] and 187 ** [sqlite_compileoption_get()] and the [compile_options pragma]. 188 */ 189 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 190 SQLITE_API int sqlite3_compileoption_used(const char *zOptName); 191 SQLITE_API const char *sqlite3_compileoption_get(int N); 192 #else 193 # define sqlite3_compileoption_used(X) 0 194 # define sqlite3_compileoption_get(X) ((void*)0) 195 #endif 196 197 /* 198 ** CAPI3REF: Test To See If The Library Is Threadsafe 199 ** 200 ** ^The sqlite3_threadsafe() function returns zero if and only if 201 ** SQLite was compiled with mutexing code omitted due to the 202 ** [SQLITE_THREADSAFE] compile-time option being set to 0. 203 ** 204 ** SQLite can be compiled with or without mutexes. When 205 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 206 ** are enabled and SQLite is threadsafe. When the 207 ** [SQLITE_THREADSAFE] macro is 0, 208 ** the mutexes are omitted. Without the mutexes, it is not safe 209 ** to use SQLite concurrently from more than one thread. 210 ** 211 ** Enabling mutexes incurs a measurable performance penalty. 212 ** So if speed is of utmost importance, it makes sense to disable 213 ** the mutexes. But for maximum safety, mutexes should be enabled. 214 ** ^The default behavior is for mutexes to be enabled. 215 ** 216 ** This interface can be used by an application to make sure that the 217 ** version of SQLite that it is linking against was compiled with 218 ** the desired setting of the [SQLITE_THREADSAFE] macro. 219 ** 220 ** This interface only reports on the compile-time mutex setting 221 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 222 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 223 ** can be fully or partially disabled using a call to [sqlite3_config()] 224 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 225 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 226 ** sqlite3_threadsafe() function shows only the compile-time setting of 227 ** thread safety, not any run-time changes to that setting made by 228 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 229 ** is unchanged by calls to sqlite3_config().)^ 230 ** 231 ** See the [threading mode] documentation for additional information. 232 */ 233 SQLITE_API int sqlite3_threadsafe(void); 234 235 /* 236 ** CAPI3REF: Database Connection Handle 237 ** KEYWORDS: {database connection} {database connections} 238 ** 239 ** Each open SQLite database is represented by a pointer to an instance of 240 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 241 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 242 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 243 ** and [sqlite3_close_v2()] are its destructors. There are many other 244 ** interfaces (such as 245 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 246 ** [sqlite3_busy_timeout()] to name but three) that are methods on an 247 ** sqlite3 object. 248 */ 249 typedef struct sqlite3 sqlite3; 250 251 /* 252 ** CAPI3REF: 64-Bit Integer Types 253 ** KEYWORDS: sqlite_int64 sqlite_uint64 254 ** 255 ** Because there is no cross-platform way to specify 64-bit integer types 256 ** SQLite includes typedefs for 64-bit signed and unsigned integers. 257 ** 258 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 259 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards 260 ** compatibility only. 261 ** 262 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values 263 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 264 ** sqlite3_uint64 and sqlite_uint64 types can store integer values 265 ** between 0 and +18446744073709551615 inclusive. 266 */ 267 #ifdef SQLITE_INT64_TYPE 268 typedef SQLITE_INT64_TYPE sqlite_int64; 269 # ifdef SQLITE_UINT64_TYPE 270 typedef SQLITE_UINT64_TYPE sqlite_uint64; 271 # else 272 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 273 # endif 274 #elif defined(_MSC_VER) || defined(__BORLANDC__) 275 typedef __int64 sqlite_int64; 276 typedef unsigned __int64 sqlite_uint64; 277 #else 278 typedef long long int sqlite_int64; 279 typedef unsigned long long int sqlite_uint64; 280 #endif 281 typedef sqlite_int64 sqlite3_int64; 282 typedef sqlite_uint64 sqlite3_uint64; 283 284 /* 285 ** If compiling for a processor that lacks floating point support, 286 ** substitute integer for floating-point. 287 */ 288 #ifdef SQLITE_OMIT_FLOATING_POINT 289 # define double sqlite3_int64 290 #endif 291 292 /* 293 ** CAPI3REF: Closing A Database Connection 294 ** DESTRUCTOR: sqlite3 295 ** 296 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 297 ** for the [sqlite3] object. 298 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 299 ** the [sqlite3] object is successfully destroyed and all associated 300 ** resources are deallocated. 301 ** 302 ** ^If the database connection is associated with unfinalized prepared 303 ** statements or unfinished sqlite3_backup objects then sqlite3_close() 304 ** will leave the database connection open and return [SQLITE_BUSY]. 305 ** ^If sqlite3_close_v2() is called with unfinalized prepared statements 306 ** and/or unfinished sqlite3_backups, then the database connection becomes 307 ** an unusable "zombie" which will automatically be deallocated when the 308 ** last prepared statement is finalized or the last sqlite3_backup is 309 ** finished. The sqlite3_close_v2() interface is intended for use with 310 ** host languages that are garbage collected, and where the order in which 311 ** destructors are called is arbitrary. 312 ** 313 ** Applications should [sqlite3_finalize | finalize] all [prepared statements], 314 ** [sqlite3_blob_close | close] all [BLOB handles], and 315 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 316 ** with the [sqlite3] object prior to attempting to close the object. ^If 317 ** sqlite3_close_v2() is called on a [database connection] that still has 318 ** outstanding [prepared statements], [BLOB handles], and/or 319 ** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 320 ** of resources is deferred until all [prepared statements], [BLOB handles], 321 ** and [sqlite3_backup] objects are also destroyed. 322 ** 323 ** ^If an [sqlite3] object is destroyed while a transaction is open, 324 ** the transaction is automatically rolled back. 325 ** 326 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 327 ** must be either a NULL 328 ** pointer or an [sqlite3] object pointer obtained 329 ** from [sqlite3_open()], [sqlite3_open16()], or 330 ** [sqlite3_open_v2()], and not previously closed. 331 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 332 ** argument is a harmless no-op. 333 */ 334 SQLITE_API int sqlite3_close(sqlite3*); 335 SQLITE_API int sqlite3_close_v2(sqlite3*); 336 337 /* 338 ** The type for a callback function. 339 ** This is legacy and deprecated. It is included for historical 340 ** compatibility and is not documented. 341 */ 342 typedef int (*sqlite3_callback)(void*,int,char**, char**); 343 344 /* 345 ** CAPI3REF: One-Step Query Execution Interface 346 ** METHOD: sqlite3 347 ** 348 ** The sqlite3_exec() interface is a convenience wrapper around 349 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 350 ** that allows an application to run multiple statements of SQL 351 ** without having to use a lot of C code. 352 ** 353 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 354 ** semicolon-separate SQL statements passed into its 2nd argument, 355 ** in the context of the [database connection] passed in as its 1st 356 ** argument. ^If the callback function of the 3rd argument to 357 ** sqlite3_exec() is not NULL, then it is invoked for each result row 358 ** coming out of the evaluated SQL statements. ^The 4th argument to 359 ** sqlite3_exec() is relayed through to the 1st argument of each 360 ** callback invocation. ^If the callback pointer to sqlite3_exec() 361 ** is NULL, then no callback is ever invoked and result rows are 362 ** ignored. 363 ** 364 ** ^If an error occurs while evaluating the SQL statements passed into 365 ** sqlite3_exec(), then execution of the current statement stops and 366 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 367 ** is not NULL then any error message is written into memory obtained 368 ** from [sqlite3_malloc()] and passed back through the 5th parameter. 369 ** To avoid memory leaks, the application should invoke [sqlite3_free()] 370 ** on error message strings returned through the 5th parameter of 371 ** sqlite3_exec() after the error message string is no longer needed. 372 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 373 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 374 ** NULL before returning. 375 ** 376 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 377 ** routine returns SQLITE_ABORT without invoking the callback again and 378 ** without running any subsequent SQL statements. 379 ** 380 ** ^The 2nd argument to the sqlite3_exec() callback function is the 381 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 382 ** callback is an array of pointers to strings obtained as if from 383 ** [sqlite3_column_text()], one for each column. ^If an element of a 384 ** result row is NULL then the corresponding string pointer for the 385 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 386 ** sqlite3_exec() callback is an array of pointers to strings where each 387 ** entry represents the name of corresponding result column as obtained 388 ** from [sqlite3_column_name()]. 389 ** 390 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 391 ** to an empty string, or a pointer that contains only whitespace and/or 392 ** SQL comments, then no SQL statements are evaluated and the database 393 ** is not changed. 394 ** 395 ** Restrictions: 396 ** 397 ** <ul> 398 ** <li> The application must ensure that the 1st parameter to sqlite3_exec() 399 ** is a valid and open [database connection]. 400 ** <li> The application must not close the [database connection] specified by 401 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 402 ** <li> The application must not modify the SQL statement text passed into 403 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 404 ** </ul> 405 */ 406 SQLITE_API int sqlite3_exec( 407 sqlite3*, /* An open database */ 408 const char *sql, /* SQL to be evaluated */ 409 int (*callback)(void*,int,char**,char**), /* Callback function */ 410 void *, /* 1st argument to callback */ 411 char **errmsg /* Error msg written here */ 412 ); 413 414 /* 415 ** CAPI3REF: Result Codes 416 ** KEYWORDS: {result code definitions} 417 ** 418 ** Many SQLite functions return an integer result code from the set shown 419 ** here in order to indicate success or failure. 420 ** 421 ** New error codes may be added in future versions of SQLite. 422 ** 423 ** See also: [extended result code definitions] 424 */ 425 #define SQLITE_OK 0 /* Successful result */ 426 /* beginning-of-error-codes */ 427 #define SQLITE_ERROR 1 /* Generic error */ 428 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 429 #define SQLITE_PERM 3 /* Access permission denied */ 430 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ 431 #define SQLITE_BUSY 5 /* The database file is locked */ 432 #define SQLITE_LOCKED 6 /* A table in the database is locked */ 433 #define SQLITE_NOMEM 7 /* A malloc() failed */ 434 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 435 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 436 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 437 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 438 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 439 #define SQLITE_FULL 13 /* Insertion failed because database is full */ 440 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 441 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 442 #define SQLITE_EMPTY 16 /* Internal use only */ 443 #define SQLITE_SCHEMA 17 /* The database schema changed */ 444 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 445 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 446 #define SQLITE_MISMATCH 20 /* Data type mismatch */ 447 #define SQLITE_MISUSE 21 /* Library used incorrectly */ 448 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 449 #define SQLITE_AUTH 23 /* Authorization denied */ 450 #define SQLITE_FORMAT 24 /* Not used */ 451 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 452 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ 453 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 454 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 455 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 456 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 457 /* end-of-error-codes */ 458 459 /* 460 ** CAPI3REF: Extended Result Codes 461 ** KEYWORDS: {extended result code definitions} 462 ** 463 ** In its default configuration, SQLite API routines return one of 30 integer 464 ** [result codes]. However, experience has shown that many of 465 ** these result codes are too coarse-grained. They do not provide as 466 ** much information about problems as programmers might like. In an effort to 467 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 468 ** and later) include 469 ** support for additional result codes that provide more detailed information 470 ** about errors. These [extended result codes] are enabled or disabled 471 ** on a per database connection basis using the 472 ** [sqlite3_extended_result_codes()] API. Or, the extended code for 473 ** the most recent error can be obtained using 474 ** [sqlite3_extended_errcode()]. 475 */ 476 #define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 477 #define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 478 #define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8)) 479 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 480 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 481 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 482 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 483 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 484 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 485 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 486 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 487 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 488 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 489 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 490 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 491 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 492 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 493 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 494 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 495 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 496 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 497 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 498 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 499 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 500 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 501 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 502 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 503 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 504 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 505 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 506 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 507 #define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 508 #define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 509 #define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 510 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 511 #define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 512 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 513 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 514 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 515 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 516 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 517 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 518 #define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 519 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 520 #define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 521 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 522 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 523 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 524 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 525 #define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 526 #define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 527 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 528 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 529 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 530 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 531 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 532 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 533 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 534 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 535 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 536 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 537 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 538 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 539 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 540 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 541 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 542 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 543 544 /* 545 ** CAPI3REF: Flags For File Open Operations 546 ** 547 ** These bit values are intended for use in the 548 ** 3rd parameter to the [sqlite3_open_v2()] interface and 549 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 550 */ 551 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 552 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 553 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 554 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 555 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 556 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 557 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 558 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 559 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 560 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 561 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 562 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 563 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 564 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 565 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 566 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 567 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 568 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 569 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 570 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 571 572 /* Reserved: 0x00F00000 */ 573 574 /* 575 ** CAPI3REF: Device Characteristics 576 ** 577 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 578 ** object returns an integer which is a vector of these 579 ** bit values expressing I/O characteristics of the mass storage 580 ** device that holds the file that the [sqlite3_io_methods] 581 ** refers to. 582 ** 583 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 584 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 585 ** mean that writes of blocks that are nnn bytes in size and 586 ** are aligned to an address which is an integer multiple of 587 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 588 ** that when data is appended to a file, the data is appended 589 ** first then the size of the file is extended, never the other 590 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 591 ** information is written to disk in the same order as calls 592 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 593 ** after reboot following a crash or power loss, the only bytes in a 594 ** file that were written at the application level might have changed 595 ** and that adjacent bytes, even bytes within the same sector are 596 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 597 ** flag indicates that a file cannot be deleted when open. The 598 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 599 ** read-only media and cannot be changed even by processes with 600 ** elevated privileges. 601 ** 602 ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 603 ** filesystem supports doing multiple write operations atomically when those 604 ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 605 ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 606 */ 607 #define SQLITE_IOCAP_ATOMIC 0x00000001 608 #define SQLITE_IOCAP_ATOMIC512 0x00000002 609 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 610 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 611 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 612 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 613 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 614 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 615 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 616 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 617 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 618 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 619 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 620 #define SQLITE_IOCAP_IMMUTABLE 0x00002000 621 #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 622 623 /* 624 ** CAPI3REF: File Locking Levels 625 ** 626 ** SQLite uses one of these integer values as the second 627 ** argument to calls it makes to the xLock() and xUnlock() methods 628 ** of an [sqlite3_io_methods] object. 629 */ 630 #define SQLITE_LOCK_NONE 0 631 #define SQLITE_LOCK_SHARED 1 632 #define SQLITE_LOCK_RESERVED 2 633 #define SQLITE_LOCK_PENDING 3 634 #define SQLITE_LOCK_EXCLUSIVE 4 635 636 /* 637 ** CAPI3REF: Synchronization Type Flags 638 ** 639 ** When SQLite invokes the xSync() method of an 640 ** [sqlite3_io_methods] object it uses a combination of 641 ** these integer values as the second argument. 642 ** 643 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 644 ** sync operation only needs to flush data to mass storage. Inode 645 ** information need not be flushed. If the lower four bits of the flag 646 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 647 ** If the lower four bits equal SQLITE_SYNC_FULL, that means 648 ** to use Mac OS X style fullsync instead of fsync(). 649 ** 650 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 651 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 652 ** settings. The [synchronous pragma] determines when calls to the 653 ** xSync VFS method occur and applies uniformly across all platforms. 654 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 655 ** energetic or rigorous or forceful the sync operations are and 656 ** only make a difference on Mac OSX for the default SQLite code. 657 ** (Third-party VFS implementations might also make the distinction 658 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 659 ** operating systems natively supported by SQLite, only Mac OSX 660 ** cares about the difference.) 661 */ 662 #define SQLITE_SYNC_NORMAL 0x00002 663 #define SQLITE_SYNC_FULL 0x00003 664 #define SQLITE_SYNC_DATAONLY 0x00010 665 666 /* 667 ** CAPI3REF: OS Interface Open File Handle 668 ** 669 ** An [sqlite3_file] object represents an open file in the 670 ** [sqlite3_vfs | OS interface layer]. Individual OS interface 671 ** implementations will 672 ** want to subclass this object by appending additional fields 673 ** for their own use. The pMethods entry is a pointer to an 674 ** [sqlite3_io_methods] object that defines methods for performing 675 ** I/O operations on the open file. 676 */ 677 typedef struct sqlite3_file sqlite3_file; 678 struct sqlite3_file { 679 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 680 }; 681 682 /* 683 ** CAPI3REF: OS Interface File Virtual Methods Object 684 ** 685 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 686 ** [sqlite3_file] object (or, more commonly, a subclass of the 687 ** [sqlite3_file] object) with a pointer to an instance of this object. 688 ** This object defines the methods used to perform various operations 689 ** against the open file represented by the [sqlite3_file] object. 690 ** 691 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 692 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 693 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 694 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 695 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 696 ** to NULL. 697 ** 698 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 699 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 700 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 701 ** flag may be ORed in to indicate that only the data of the file 702 ** and not its inode needs to be synced. 703 ** 704 ** The integer values to xLock() and xUnlock() are one of 705 ** <ul> 706 ** <li> [SQLITE_LOCK_NONE], 707 ** <li> [SQLITE_LOCK_SHARED], 708 ** <li> [SQLITE_LOCK_RESERVED], 709 ** <li> [SQLITE_LOCK_PENDING], or 710 ** <li> [SQLITE_LOCK_EXCLUSIVE]. 711 ** </ul> 712 ** xLock() increases the lock. xUnlock() decreases the lock. 713 ** The xCheckReservedLock() method checks whether any database connection, 714 ** either in this process or in some other process, is holding a RESERVED, 715 ** PENDING, or EXCLUSIVE lock on the file. It returns true 716 ** if such a lock exists and false otherwise. 717 ** 718 ** The xFileControl() method is a generic interface that allows custom 719 ** VFS implementations to directly control an open file using the 720 ** [sqlite3_file_control()] interface. The second "op" argument is an 721 ** integer opcode. The third argument is a generic pointer intended to 722 ** point to a structure that may contain arguments or space in which to 723 ** write return values. Potential uses for xFileControl() might be 724 ** functions to enable blocking locks with timeouts, to change the 725 ** locking strategy (for example to use dot-file locks), to inquire 726 ** about the status of a lock, or to break stale locks. The SQLite 727 ** core reserves all opcodes less than 100 for its own use. 728 ** A [file control opcodes | list of opcodes] less than 100 is available. 729 ** Applications that define a custom xFileControl method should use opcodes 730 ** greater than 100 to avoid conflicts. VFS implementations should 731 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 732 ** recognize. 733 ** 734 ** The xSectorSize() method returns the sector size of the 735 ** device that underlies the file. The sector size is the 736 ** minimum write that can be performed without disturbing 737 ** other bytes in the file. The xDeviceCharacteristics() 738 ** method returns a bit vector describing behaviors of the 739 ** underlying device: 740 ** 741 ** <ul> 742 ** <li> [SQLITE_IOCAP_ATOMIC] 743 ** <li> [SQLITE_IOCAP_ATOMIC512] 744 ** <li> [SQLITE_IOCAP_ATOMIC1K] 745 ** <li> [SQLITE_IOCAP_ATOMIC2K] 746 ** <li> [SQLITE_IOCAP_ATOMIC4K] 747 ** <li> [SQLITE_IOCAP_ATOMIC8K] 748 ** <li> [SQLITE_IOCAP_ATOMIC16K] 749 ** <li> [SQLITE_IOCAP_ATOMIC32K] 750 ** <li> [SQLITE_IOCAP_ATOMIC64K] 751 ** <li> [SQLITE_IOCAP_SAFE_APPEND] 752 ** <li> [SQLITE_IOCAP_SEQUENTIAL] 753 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 754 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 755 ** <li> [SQLITE_IOCAP_IMMUTABLE] 756 ** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 757 ** </ul> 758 ** 759 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 760 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 761 ** mean that writes of blocks that are nnn bytes in size and 762 ** are aligned to an address which is an integer multiple of 763 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 764 ** that when data is appended to a file, the data is appended 765 ** first then the size of the file is extended, never the other 766 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 767 ** information is written to disk in the same order as calls 768 ** to xWrite(). 769 ** 770 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 771 ** in the unread portions of the buffer with zeros. A VFS that 772 ** fails to zero-fill short reads might seem to work. However, 773 ** failure to zero-fill short reads will eventually lead to 774 ** database corruption. 775 */ 776 typedef struct sqlite3_io_methods sqlite3_io_methods; 777 struct sqlite3_io_methods { 778 int iVersion; 779 int (*xClose)(sqlite3_file*); 780 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 781 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 782 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 783 int (*xSync)(sqlite3_file*, int flags); 784 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 785 int (*xLock)(sqlite3_file*, int); 786 int (*xUnlock)(sqlite3_file*, int); 787 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 788 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 789 int (*xSectorSize)(sqlite3_file*); 790 int (*xDeviceCharacteristics)(sqlite3_file*); 791 /* Methods above are valid for version 1 */ 792 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 793 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 794 void (*xShmBarrier)(sqlite3_file*); 795 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 796 /* Methods above are valid for version 2 */ 797 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 798 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 799 /* Methods above are valid for version 3 */ 800 /* Additional methods may be added in future releases */ 801 }; 802 803 /* 804 ** CAPI3REF: Standard File Control Opcodes 805 ** KEYWORDS: {file control opcodes} {file control opcode} 806 ** 807 ** These integer constants are opcodes for the xFileControl method 808 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 809 ** interface. 810 ** 811 ** <ul> 812 ** <li>[[SQLITE_FCNTL_LOCKSTATE]] 813 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 814 ** opcode causes the xFileControl method to write the current state of 815 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 816 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 817 ** into an integer that the pArg argument points to. This capability 818 ** is used during testing and is only available when the SQLITE_TEST 819 ** compile-time option is used. 820 ** 821 ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 822 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 823 ** layer a hint of how large the database file will grow to be during the 824 ** current transaction. This hint is not guaranteed to be accurate but it 825 ** is often close. The underlying VFS might choose to preallocate database 826 ** file space based on this hint in order to help writes to the database 827 ** file run faster. 828 ** 829 ** <li>[[SQLITE_FCNTL_SIZE_LIMIT]] 830 ** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that 831 ** implements [sqlite3_deserialize()] to set an upper bound on the size 832 ** of the in-memory database. The argument is a pointer to a [sqlite3_int64]. 833 ** If the integer pointed to is negative, then it is filled in with the 834 ** current limit. Otherwise the limit is set to the larger of the value 835 ** of the integer pointed to and the current database size. The integer 836 ** pointed to is set to the new limit. 837 ** 838 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 839 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 840 ** extends and truncates the database file in chunks of a size specified 841 ** by the user. The fourth argument to [sqlite3_file_control()] should 842 ** point to an integer (type int) containing the new chunk-size to use 843 ** for the nominated database. Allocating database file space in large 844 ** chunks (say 1MB at a time), may reduce file-system fragmentation and 845 ** improve performance on some systems. 846 ** 847 ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 848 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 849 ** to the [sqlite3_file] object associated with a particular database 850 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 851 ** 852 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 853 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 854 ** to the [sqlite3_file] object associated with the journal file (either 855 ** the [rollback journal] or the [write-ahead log]) for a particular database 856 ** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 857 ** 858 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 859 ** No longer in use. 860 ** 861 ** <li>[[SQLITE_FCNTL_SYNC]] 862 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 863 ** sent to the VFS immediately before the xSync method is invoked on a 864 ** database file descriptor. Or, if the xSync method is not invoked 865 ** because the user has configured SQLite with 866 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 867 ** of the xSync method. In most cases, the pointer argument passed with 868 ** this file-control is NULL. However, if the database file is being synced 869 ** as part of a multi-database commit, the argument points to a nul-terminated 870 ** string containing the transactions master-journal file name. VFSes that 871 ** do not need this signal should silently ignore this opcode. Applications 872 ** should not call [sqlite3_file_control()] with this opcode as doing so may 873 ** disrupt the operation of the specialized VFSes that do require it. 874 ** 875 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 876 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 877 ** and sent to the VFS after a transaction has been committed immediately 878 ** but before the database is unlocked. VFSes that do not need this signal 879 ** should silently ignore this opcode. Applications should not call 880 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 881 ** operation of the specialized VFSes that do require it. 882 ** 883 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 884 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 885 ** retry counts and intervals for certain disk I/O operations for the 886 ** windows [VFS] in order to provide robustness in the presence of 887 ** anti-virus programs. By default, the windows VFS will retry file read, 888 ** file write, and file delete operations up to 10 times, with a delay 889 ** of 25 milliseconds before the first retry and with the delay increasing 890 ** by an additional 25 milliseconds with each subsequent retry. This 891 ** opcode allows these two values (10 retries and 25 milliseconds of delay) 892 ** to be adjusted. The values are changed for all database connections 893 ** within the same process. The argument is a pointer to an array of two 894 ** integers where the first integer is the new retry count and the second 895 ** integer is the delay. If either integer is negative, then the setting 896 ** is not changed but instead the prior value of that setting is written 897 ** into the array entry, allowing the current retry settings to be 898 ** interrogated. The zDbName parameter is ignored. 899 ** 900 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 901 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 902 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 903 ** write ahead log ([WAL file]) and shared memory 904 ** files used for transaction control 905 ** are automatically deleted when the latest connection to the database 906 ** closes. Setting persistent WAL mode causes those files to persist after 907 ** close. Persisting the files is useful when other processes that do not 908 ** have write permission on the directory containing the database file want 909 ** to read the database file, as the WAL and shared memory files must exist 910 ** in order for the database to be readable. The fourth parameter to 911 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 912 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 913 ** WAL mode. If the integer is -1, then it is overwritten with the current 914 ** WAL persistence setting. 915 ** 916 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 917 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 918 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 919 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 920 ** xDeviceCharacteristics methods. The fourth parameter to 921 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 922 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 923 ** mode. If the integer is -1, then it is overwritten with the current 924 ** zero-damage mode setting. 925 ** 926 ** <li>[[SQLITE_FCNTL_OVERWRITE]] 927 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 928 ** a write transaction to indicate that, unless it is rolled back for some 929 ** reason, the entire database file will be overwritten by the current 930 ** transaction. This is used by VACUUM operations. 931 ** 932 ** <li>[[SQLITE_FCNTL_VFSNAME]] 933 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 934 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the 935 ** final bottom-level VFS are written into memory obtained from 936 ** [sqlite3_malloc()] and the result is stored in the char* variable 937 ** that the fourth parameter of [sqlite3_file_control()] points to. 938 ** The caller is responsible for freeing the memory when done. As with 939 ** all file-control actions, there is no guarantee that this will actually 940 ** do anything. Callers should initialize the char* variable to a NULL 941 ** pointer in case this file-control is not implemented. This file-control 942 ** is intended for diagnostic use only. 943 ** 944 ** <li>[[SQLITE_FCNTL_VFS_POINTER]] 945 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 946 ** [VFSes] currently in use. ^(The argument X in 947 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 948 ** of type "[sqlite3_vfs] **". This opcodes will set *X 949 ** to a pointer to the top-level VFS.)^ 950 ** ^When there are multiple VFS shims in the stack, this opcode finds the 951 ** upper-most shim only. 952 ** 953 ** <li>[[SQLITE_FCNTL_PRAGMA]] 954 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 955 ** file control is sent to the open [sqlite3_file] object corresponding 956 ** to the database file to which the pragma statement refers. ^The argument 957 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 958 ** pointers to strings (char**) in which the second element of the array 959 ** is the name of the pragma and the third element is the argument to the 960 ** pragma or NULL if the pragma has no argument. ^The handler for an 961 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 962 ** of the char** argument point to a string obtained from [sqlite3_mprintf()] 963 ** or the equivalent and that string will become the result of the pragma or 964 ** the error message if the pragma fails. ^If the 965 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 966 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 967 ** file control returns [SQLITE_OK], then the parser assumes that the 968 ** VFS has handled the PRAGMA itself and the parser generates a no-op 969 ** prepared statement if result string is NULL, or that returns a copy 970 ** of the result string if the string is non-NULL. 971 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 972 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 973 ** that the VFS encountered an error while handling the [PRAGMA] and the 974 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 975 ** file control occurs at the beginning of pragma statement analysis and so 976 ** it is able to override built-in [PRAGMA] statements. 977 ** 978 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 979 ** ^The [SQLITE_FCNTL_BUSYHANDLER] 980 ** file-control may be invoked by SQLite on the database file handle 981 ** shortly after it is opened in order to provide a custom VFS with access 982 ** to the connections busy-handler callback. The argument is of type (void **) 983 ** - an array of two (void *) values. The first (void *) actually points 984 ** to a function of type (int (*)(void *)). In order to invoke the connections 985 ** busy-handler, this function should be invoked with the second (void *) in 986 ** the array as the only argument. If it returns non-zero, then the operation 987 ** should be retried. If it returns zero, the custom VFS should abandon the 988 ** current operation. 989 ** 990 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 991 ** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 992 ** to have SQLite generate a 993 ** temporary filename using the same algorithm that is followed to generate 994 ** temporary filenames for TEMP tables and other internal uses. The 995 ** argument should be a char** which will be filled with the filename 996 ** written into memory obtained from [sqlite3_malloc()]. The caller should 997 ** invoke [sqlite3_free()] on the result to avoid a memory leak. 998 ** 999 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 1000 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 1001 ** maximum number of bytes that will be used for memory-mapped I/O. 1002 ** The argument is a pointer to a value of type sqlite3_int64 that 1003 ** is an advisory maximum number of bytes in the file to memory map. The 1004 ** pointer is overwritten with the old value. The limit is not changed if 1005 ** the value originally pointed to is negative, and so the current limit 1006 ** can be queried by passing in a pointer to a negative number. This 1007 ** file-control is used internally to implement [PRAGMA mmap_size]. 1008 ** 1009 ** <li>[[SQLITE_FCNTL_TRACE]] 1010 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information 1011 ** to the VFS about what the higher layers of the SQLite stack are doing. 1012 ** This file control is used by some VFS activity tracing [shims]. 1013 ** The argument is a zero-terminated string. Higher layers in the 1014 ** SQLite stack may generate instances of this file control if 1015 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1016 ** 1017 ** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1018 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1019 ** pointer to an integer and it writes a boolean into that integer depending 1020 ** on whether or not the file has been renamed, moved, or deleted since it 1021 ** was first opened. 1022 ** 1023 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1024 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1025 ** underlying native file handle associated with a file handle. This file 1026 ** control interprets its argument as a pointer to a native file handle and 1027 ** writes the resulting value there. 1028 ** 1029 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1030 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1031 ** opcode causes the xFileControl method to swap the file handle with the one 1032 ** pointed to by the pArg argument. This capability is used during testing 1033 ** and only needs to be supported when SQLITE_TEST is defined. 1034 ** 1035 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1036 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1037 ** be advantageous to block on the next WAL lock if the lock is not immediately 1038 ** available. The WAL subsystem issues this signal during rare 1039 ** circumstances in order to fix a problem with priority inversion. 1040 ** Applications should <em>not</em> use this file-control. 1041 ** 1042 ** <li>[[SQLITE_FCNTL_ZIPVFS]] 1043 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1044 ** VFS should return SQLITE_NOTFOUND for this opcode. 1045 ** 1046 ** <li>[[SQLITE_FCNTL_RBU]] 1047 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1048 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1049 ** this opcode. 1050 ** 1051 ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1052 ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1053 ** the file descriptor is placed in "batch write mode", which 1054 ** means all subsequent write operations will be deferred and done 1055 ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1056 ** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1057 ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1058 ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1059 ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1060 ** no VFS interface calls on the same [sqlite3_file] file descriptor 1061 ** except for calls to the xWrite method and the xFileControl method 1062 ** with [SQLITE_FCNTL_SIZE_HINT]. 1063 ** 1064 ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1065 ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1066 ** operations since the previous successful call to 1067 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1068 ** This file control returns [SQLITE_OK] if and only if the writes were 1069 ** all performed successfully and have been committed to persistent storage. 1070 ** ^Regardless of whether or not it is successful, this file control takes 1071 ** the file descriptor out of batch write mode so that all subsequent 1072 ** write operations are independent. 1073 ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1074 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1075 ** 1076 ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1077 ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1078 ** operations since the previous successful call to 1079 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1080 ** ^This file control takes the file descriptor out of batch write mode 1081 ** so that all subsequent write operations are independent. 1082 ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1083 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1084 ** 1085 ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1086 ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode causes attempts to obtain 1087 ** a file lock using the xLock or xShmLock methods of the VFS to wait 1088 ** for up to M milliseconds before failing, where M is the single 1089 ** unsigned integer parameter. 1090 ** 1091 ** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1092 ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1093 ** a database file. The argument is a pointer to a 32-bit unsigned integer. 1094 ** The "data version" for the pager is written into the pointer. The 1095 ** "data version" changes whenever any change occurs to the corresponding 1096 ** database file, either through SQL statements on the same database 1097 ** connection or through transactions committed by separate database 1098 ** connections possibly in other processes. The [sqlite3_total_changes()] 1099 ** interface can be used to find if any database on the connection has changed, 1100 ** but that interface responds to changes on TEMP as well as MAIN and does 1101 ** not provide a mechanism to detect changes to MAIN only. Also, the 1102 ** [sqlite3_total_changes()] interface responds to internal changes only and 1103 ** omits changes made by other database connections. The 1104 ** [PRAGMA data_version] command provide a mechanism to detect changes to 1105 ** a single attached database that occur due to other database connections, 1106 ** but omits changes implemented by the database connection on which it is 1107 ** called. This file control is the only mechanism to detect changes that 1108 ** happen either internally or externally and that are associated with 1109 ** a particular attached database. 1110 ** </ul> 1111 */ 1112 #define SQLITE_FCNTL_LOCKSTATE 1 1113 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1114 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1115 #define SQLITE_FCNTL_LAST_ERRNO 4 1116 #define SQLITE_FCNTL_SIZE_HINT 5 1117 #define SQLITE_FCNTL_CHUNK_SIZE 6 1118 #define SQLITE_FCNTL_FILE_POINTER 7 1119 #define SQLITE_FCNTL_SYNC_OMITTED 8 1120 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 1121 #define SQLITE_FCNTL_PERSIST_WAL 10 1122 #define SQLITE_FCNTL_OVERWRITE 11 1123 #define SQLITE_FCNTL_VFSNAME 12 1124 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1125 #define SQLITE_FCNTL_PRAGMA 14 1126 #define SQLITE_FCNTL_BUSYHANDLER 15 1127 #define SQLITE_FCNTL_TEMPFILENAME 16 1128 #define SQLITE_FCNTL_MMAP_SIZE 18 1129 #define SQLITE_FCNTL_TRACE 19 1130 #define SQLITE_FCNTL_HAS_MOVED 20 1131 #define SQLITE_FCNTL_SYNC 21 1132 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 1133 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1134 #define SQLITE_FCNTL_WAL_BLOCK 24 1135 #define SQLITE_FCNTL_ZIPVFS 25 1136 #define SQLITE_FCNTL_RBU 26 1137 #define SQLITE_FCNTL_VFS_POINTER 27 1138 #define SQLITE_FCNTL_JOURNAL_POINTER 28 1139 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1140 #define SQLITE_FCNTL_PDB 30 1141 #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1142 #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1143 #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1144 #define SQLITE_FCNTL_LOCK_TIMEOUT 34 1145 #define SQLITE_FCNTL_DATA_VERSION 35 1146 #define SQLITE_FCNTL_SIZE_LIMIT 36 1147 1148 /* deprecated names */ 1149 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1150 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1151 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1152 1153 1154 /* 1155 ** CAPI3REF: Mutex Handle 1156 ** 1157 ** The mutex module within SQLite defines [sqlite3_mutex] to be an 1158 ** abstract type for a mutex object. The SQLite core never looks 1159 ** at the internal representation of an [sqlite3_mutex]. It only 1160 ** deals with pointers to the [sqlite3_mutex] object. 1161 ** 1162 ** Mutexes are created using [sqlite3_mutex_alloc()]. 1163 */ 1164 typedef struct sqlite3_mutex sqlite3_mutex; 1165 1166 /* 1167 ** CAPI3REF: Loadable Extension Thunk 1168 ** 1169 ** A pointer to the opaque sqlite3_api_routines structure is passed as 1170 ** the third parameter to entry points of [loadable extensions]. This 1171 ** structure must be typedefed in order to work around compiler warnings 1172 ** on some platforms. 1173 */ 1174 typedef struct sqlite3_api_routines sqlite3_api_routines; 1175 1176 /* 1177 ** CAPI3REF: OS Interface Object 1178 ** 1179 ** An instance of the sqlite3_vfs object defines the interface between 1180 ** the SQLite core and the underlying operating system. The "vfs" 1181 ** in the name of the object stands for "virtual file system". See 1182 ** the [VFS | VFS documentation] for further information. 1183 ** 1184 ** The VFS interface is sometimes extended by adding new methods onto 1185 ** the end. Each time such an extension occurs, the iVersion field 1186 ** is incremented. The iVersion value started out as 1 in 1187 ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1188 ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1189 ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1190 ** may be appended to the sqlite3_vfs object and the iVersion value 1191 ** may increase again in future versions of SQLite. 1192 ** Note that the structure 1193 ** of the sqlite3_vfs object changes in the transition from 1194 ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1195 ** and yet the iVersion field was not modified. 1196 ** 1197 ** The szOsFile field is the size of the subclassed [sqlite3_file] 1198 ** structure used by this VFS. mxPathname is the maximum length of 1199 ** a pathname in this VFS. 1200 ** 1201 ** Registered sqlite3_vfs objects are kept on a linked list formed by 1202 ** the pNext pointer. The [sqlite3_vfs_register()] 1203 ** and [sqlite3_vfs_unregister()] interfaces manage this list 1204 ** in a thread-safe way. The [sqlite3_vfs_find()] interface 1205 ** searches the list. Neither the application code nor the VFS 1206 ** implementation should use the pNext pointer. 1207 ** 1208 ** The pNext field is the only field in the sqlite3_vfs 1209 ** structure that SQLite will ever modify. SQLite will only access 1210 ** or modify this field while holding a particular static mutex. 1211 ** The application should never modify anything within the sqlite3_vfs 1212 ** object once the object has been registered. 1213 ** 1214 ** The zName field holds the name of the VFS module. The name must 1215 ** be unique across all VFS modules. 1216 ** 1217 ** [[sqlite3_vfs.xOpen]] 1218 ** ^SQLite guarantees that the zFilename parameter to xOpen 1219 ** is either a NULL pointer or string obtained 1220 ** from xFullPathname() with an optional suffix added. 1221 ** ^If a suffix is added to the zFilename parameter, it will 1222 ** consist of a single "-" character followed by no more than 1223 ** 11 alphanumeric and/or "-" characters. 1224 ** ^SQLite further guarantees that 1225 ** the string will be valid and unchanged until xClose() is 1226 ** called. Because of the previous sentence, 1227 ** the [sqlite3_file] can safely store a pointer to the 1228 ** filename if it needs to remember the filename for some reason. 1229 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1230 ** must invent its own temporary name for the file. ^Whenever the 1231 ** xFilename parameter is NULL it will also be the case that the 1232 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1233 ** 1234 ** The flags argument to xOpen() includes all bits set in 1235 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1236 ** or [sqlite3_open16()] is used, then flags includes at least 1237 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1238 ** If xOpen() opens a file read-only then it sets *pOutFlags to 1239 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1240 ** 1241 ** ^(SQLite will also add one of the following flags to the xOpen() 1242 ** call, depending on the object being opened: 1243 ** 1244 ** <ul> 1245 ** <li> [SQLITE_OPEN_MAIN_DB] 1246 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1247 ** <li> [SQLITE_OPEN_TEMP_DB] 1248 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1249 ** <li> [SQLITE_OPEN_TRANSIENT_DB] 1250 ** <li> [SQLITE_OPEN_SUBJOURNAL] 1251 ** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1252 ** <li> [SQLITE_OPEN_WAL] 1253 ** </ul>)^ 1254 ** 1255 ** The file I/O implementation can use the object type flags to 1256 ** change the way it deals with files. For example, an application 1257 ** that does not care about crash recovery or rollback might make 1258 ** the open of a journal file a no-op. Writes to this journal would 1259 ** also be no-ops, and any attempt to read the journal would return 1260 ** SQLITE_IOERR. Or the implementation might recognize that a database 1261 ** file will be doing page-aligned sector reads and writes in a random 1262 ** order and set up its I/O subsystem accordingly. 1263 ** 1264 ** SQLite might also add one of the following flags to the xOpen method: 1265 ** 1266 ** <ul> 1267 ** <li> [SQLITE_OPEN_DELETEONCLOSE] 1268 ** <li> [SQLITE_OPEN_EXCLUSIVE] 1269 ** </ul> 1270 ** 1271 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1272 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1273 ** will be set for TEMP databases and their journals, transient 1274 ** databases, and subjournals. 1275 ** 1276 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1277 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1278 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1279 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1280 ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1281 ** be created, and that it is an error if it already exists. 1282 ** It is <i>not</i> used to indicate the file should be opened 1283 ** for exclusive access. 1284 ** 1285 ** ^At least szOsFile bytes of memory are allocated by SQLite 1286 ** to hold the [sqlite3_file] structure passed as the third 1287 ** argument to xOpen. The xOpen method does not have to 1288 ** allocate the structure; it should just fill it in. Note that 1289 ** the xOpen method must set the sqlite3_file.pMethods to either 1290 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1291 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1292 ** element will be valid after xOpen returns regardless of the success 1293 ** or failure of the xOpen call. 1294 ** 1295 ** [[sqlite3_vfs.xAccess]] 1296 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1297 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1298 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1299 ** to test whether a file is at least readable. The file can be a 1300 ** directory. 1301 ** 1302 ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1303 ** output buffer xFullPathname. The exact size of the output buffer 1304 ** is also passed as a parameter to both methods. If the output buffer 1305 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1306 ** handled as a fatal error by SQLite, vfs implementations should endeavor 1307 ** to prevent this by setting mxPathname to a sufficiently large value. 1308 ** 1309 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1310 ** interfaces are not strictly a part of the filesystem, but they are 1311 ** included in the VFS structure for completeness. 1312 ** The xRandomness() function attempts to return nBytes bytes 1313 ** of good-quality randomness into zOut. The return value is 1314 ** the actual number of bytes of randomness obtained. 1315 ** The xSleep() method causes the calling thread to sleep for at 1316 ** least the number of microseconds given. ^The xCurrentTime() 1317 ** method returns a Julian Day Number for the current date and time as 1318 ** a floating point value. 1319 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1320 ** Day Number multiplied by 86400000 (the number of milliseconds in 1321 ** a 24-hour day). 1322 ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1323 ** date and time if that method is available (if iVersion is 2 or 1324 ** greater and the function pointer is not NULL) and will fall back 1325 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1326 ** 1327 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1328 ** are not used by the SQLite core. These optional interfaces are provided 1329 ** by some VFSes to facilitate testing of the VFS code. By overriding 1330 ** system calls with functions under its control, a test program can 1331 ** simulate faults and error conditions that would otherwise be difficult 1332 ** or impossible to induce. The set of system calls that can be overridden 1333 ** varies from one VFS to another, and from one version of the same VFS to the 1334 ** next. Applications that use these interfaces must be prepared for any 1335 ** or all of these interfaces to be NULL or for their behavior to change 1336 ** from one release to the next. Applications must not attempt to access 1337 ** any of these methods if the iVersion of the VFS is less than 3. 1338 */ 1339 typedef struct sqlite3_vfs sqlite3_vfs; 1340 typedef void (*sqlite3_syscall_ptr)(void); 1341 struct sqlite3_vfs { 1342 int iVersion; /* Structure version number (currently 3) */ 1343 int szOsFile; /* Size of subclassed sqlite3_file */ 1344 int mxPathname; /* Maximum file pathname length */ 1345 sqlite3_vfs *pNext; /* Next registered VFS */ 1346 const char *zName; /* Name of this virtual file system */ 1347 void *pAppData; /* Pointer to application-specific data */ 1348 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1349 int flags, int *pOutFlags); 1350 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1351 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1352 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1353 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1354 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1355 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1356 void (*xDlClose)(sqlite3_vfs*, void*); 1357 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1358 int (*xSleep)(sqlite3_vfs*, int microseconds); 1359 int (*xCurrentTime)(sqlite3_vfs*, double*); 1360 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1361 /* 1362 ** The methods above are in version 1 of the sqlite_vfs object 1363 ** definition. Those that follow are added in version 2 or later 1364 */ 1365 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1366 /* 1367 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1368 ** Those below are for version 3 and greater. 1369 */ 1370 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1371 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1372 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1373 /* 1374 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1375 ** New fields may be appended in future versions. The iVersion 1376 ** value will increment whenever this happens. 1377 */ 1378 }; 1379 1380 /* 1381 ** CAPI3REF: Flags for the xAccess VFS method 1382 ** 1383 ** These integer constants can be used as the third parameter to 1384 ** the xAccess method of an [sqlite3_vfs] object. They determine 1385 ** what kind of permissions the xAccess method is looking for. 1386 ** With SQLITE_ACCESS_EXISTS, the xAccess method 1387 ** simply checks whether the file exists. 1388 ** With SQLITE_ACCESS_READWRITE, the xAccess method 1389 ** checks whether the named directory is both readable and writable 1390 ** (in other words, if files can be added, removed, and renamed within 1391 ** the directory). 1392 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1393 ** [temp_store_directory pragma], though this could change in a future 1394 ** release of SQLite. 1395 ** With SQLITE_ACCESS_READ, the xAccess method 1396 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1397 ** currently unused, though it might be used in a future release of 1398 ** SQLite. 1399 */ 1400 #define SQLITE_ACCESS_EXISTS 0 1401 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1402 #define SQLITE_ACCESS_READ 2 /* Unused */ 1403 1404 /* 1405 ** CAPI3REF: Flags for the xShmLock VFS method 1406 ** 1407 ** These integer constants define the various locking operations 1408 ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1409 ** following are the only legal combinations of flags to the 1410 ** xShmLock method: 1411 ** 1412 ** <ul> 1413 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1414 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1415 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1416 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1417 ** </ul> 1418 ** 1419 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1420 ** was given on the corresponding lock. 1421 ** 1422 ** The xShmLock method can transition between unlocked and SHARED or 1423 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1424 ** and EXCLUSIVE. 1425 */ 1426 #define SQLITE_SHM_UNLOCK 1 1427 #define SQLITE_SHM_LOCK 2 1428 #define SQLITE_SHM_SHARED 4 1429 #define SQLITE_SHM_EXCLUSIVE 8 1430 1431 /* 1432 ** CAPI3REF: Maximum xShmLock index 1433 ** 1434 ** The xShmLock method on [sqlite3_io_methods] may use values 1435 ** between 0 and this upper bound as its "offset" argument. 1436 ** The SQLite core will never attempt to acquire or release a 1437 ** lock outside of this range 1438 */ 1439 #define SQLITE_SHM_NLOCK 8 1440 1441 1442 /* 1443 ** CAPI3REF: Initialize The SQLite Library 1444 ** 1445 ** ^The sqlite3_initialize() routine initializes the 1446 ** SQLite library. ^The sqlite3_shutdown() routine 1447 ** deallocates any resources that were allocated by sqlite3_initialize(). 1448 ** These routines are designed to aid in process initialization and 1449 ** shutdown on embedded systems. Workstation applications using 1450 ** SQLite normally do not need to invoke either of these routines. 1451 ** 1452 ** A call to sqlite3_initialize() is an "effective" call if it is 1453 ** the first time sqlite3_initialize() is invoked during the lifetime of 1454 ** the process, or if it is the first time sqlite3_initialize() is invoked 1455 ** following a call to sqlite3_shutdown(). ^(Only an effective call 1456 ** of sqlite3_initialize() does any initialization. All other calls 1457 ** are harmless no-ops.)^ 1458 ** 1459 ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1460 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1461 ** an effective call to sqlite3_shutdown() does any deinitialization. 1462 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1463 ** 1464 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1465 ** is not. The sqlite3_shutdown() interface must only be called from a 1466 ** single thread. All open [database connections] must be closed and all 1467 ** other SQLite resources must be deallocated prior to invoking 1468 ** sqlite3_shutdown(). 1469 ** 1470 ** Among other things, ^sqlite3_initialize() will invoke 1471 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1472 ** will invoke sqlite3_os_end(). 1473 ** 1474 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1475 ** ^If for some reason, sqlite3_initialize() is unable to initialize 1476 ** the library (perhaps it is unable to allocate a needed resource such 1477 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1478 ** 1479 ** ^The sqlite3_initialize() routine is called internally by many other 1480 ** SQLite interfaces so that an application usually does not need to 1481 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1482 ** calls sqlite3_initialize() so the SQLite library will be automatically 1483 ** initialized when [sqlite3_open()] is called if it has not be initialized 1484 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1485 ** compile-time option, then the automatic calls to sqlite3_initialize() 1486 ** are omitted and the application must call sqlite3_initialize() directly 1487 ** prior to using any other SQLite interface. For maximum portability, 1488 ** it is recommended that applications always invoke sqlite3_initialize() 1489 ** directly prior to using any other SQLite interface. Future releases 1490 ** of SQLite may require this. In other words, the behavior exhibited 1491 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1492 ** default behavior in some future release of SQLite. 1493 ** 1494 ** The sqlite3_os_init() routine does operating-system specific 1495 ** initialization of the SQLite library. The sqlite3_os_end() 1496 ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1497 ** performed by these routines include allocation or deallocation 1498 ** of static resources, initialization of global variables, 1499 ** setting up a default [sqlite3_vfs] module, or setting up 1500 ** a default configuration using [sqlite3_config()]. 1501 ** 1502 ** The application should never invoke either sqlite3_os_init() 1503 ** or sqlite3_os_end() directly. The application should only invoke 1504 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1505 ** interface is called automatically by sqlite3_initialize() and 1506 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1507 ** implementations for sqlite3_os_init() and sqlite3_os_end() 1508 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1509 ** When [custom builds | built for other platforms] 1510 ** (using the [SQLITE_OS_OTHER=1] compile-time 1511 ** option) the application must supply a suitable implementation for 1512 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1513 ** implementation of sqlite3_os_init() or sqlite3_os_end() 1514 ** must return [SQLITE_OK] on success and some other [error code] upon 1515 ** failure. 1516 */ 1517 SQLITE_API int sqlite3_initialize(void); 1518 SQLITE_API int sqlite3_shutdown(void); 1519 SQLITE_API int sqlite3_os_init(void); 1520 SQLITE_API int sqlite3_os_end(void); 1521 1522 /* 1523 ** CAPI3REF: Configuring The SQLite Library 1524 ** 1525 ** The sqlite3_config() interface is used to make global configuration 1526 ** changes to SQLite in order to tune SQLite to the specific needs of 1527 ** the application. The default configuration is recommended for most 1528 ** applications and so this routine is usually not necessary. It is 1529 ** provided to support rare applications with unusual needs. 1530 ** 1531 ** <b>The sqlite3_config() interface is not threadsafe. The application 1532 ** must ensure that no other SQLite interfaces are invoked by other 1533 ** threads while sqlite3_config() is running.</b> 1534 ** 1535 ** The sqlite3_config() interface 1536 ** may only be invoked prior to library initialization using 1537 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1538 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1539 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1540 ** Note, however, that ^sqlite3_config() can be called as part of the 1541 ** implementation of an application-defined [sqlite3_os_init()]. 1542 ** 1543 ** The first argument to sqlite3_config() is an integer 1544 ** [configuration option] that determines 1545 ** what property of SQLite is to be configured. Subsequent arguments 1546 ** vary depending on the [configuration option] 1547 ** in the first argument. 1548 ** 1549 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1550 ** ^If the option is unknown or SQLite is unable to set the option 1551 ** then this routine returns a non-zero [error code]. 1552 */ 1553 SQLITE_API int sqlite3_config(int, ...); 1554 1555 /* 1556 ** CAPI3REF: Configure database connections 1557 ** METHOD: sqlite3 1558 ** 1559 ** The sqlite3_db_config() interface is used to make configuration 1560 ** changes to a [database connection]. The interface is similar to 1561 ** [sqlite3_config()] except that the changes apply to a single 1562 ** [database connection] (specified in the first argument). 1563 ** 1564 ** The second argument to sqlite3_db_config(D,V,...) is the 1565 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1566 ** that indicates what aspect of the [database connection] is being configured. 1567 ** Subsequent arguments vary depending on the configuration verb. 1568 ** 1569 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1570 ** the call is considered successful. 1571 */ 1572 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1573 1574 /* 1575 ** CAPI3REF: Memory Allocation Routines 1576 ** 1577 ** An instance of this object defines the interface between SQLite 1578 ** and low-level memory allocation routines. 1579 ** 1580 ** This object is used in only one place in the SQLite interface. 1581 ** A pointer to an instance of this object is the argument to 1582 ** [sqlite3_config()] when the configuration option is 1583 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1584 ** By creating an instance of this object 1585 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1586 ** during configuration, an application can specify an alternative 1587 ** memory allocation subsystem for SQLite to use for all of its 1588 ** dynamic memory needs. 1589 ** 1590 ** Note that SQLite comes with several [built-in memory allocators] 1591 ** that are perfectly adequate for the overwhelming majority of applications 1592 ** and that this object is only useful to a tiny minority of applications 1593 ** with specialized memory allocation requirements. This object is 1594 ** also used during testing of SQLite in order to specify an alternative 1595 ** memory allocator that simulates memory out-of-memory conditions in 1596 ** order to verify that SQLite recovers gracefully from such 1597 ** conditions. 1598 ** 1599 ** The xMalloc, xRealloc, and xFree methods must work like the 1600 ** malloc(), realloc() and free() functions from the standard C library. 1601 ** ^SQLite guarantees that the second argument to 1602 ** xRealloc is always a value returned by a prior call to xRoundup. 1603 ** 1604 ** xSize should return the allocated size of a memory allocation 1605 ** previously obtained from xMalloc or xRealloc. The allocated size 1606 ** is always at least as big as the requested size but may be larger. 1607 ** 1608 ** The xRoundup method returns what would be the allocated size of 1609 ** a memory allocation given a particular requested size. Most memory 1610 ** allocators round up memory allocations at least to the next multiple 1611 ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1612 ** Every memory allocation request coming in through [sqlite3_malloc()] 1613 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1614 ** that causes the corresponding memory allocation to fail. 1615 ** 1616 ** The xInit method initializes the memory allocator. For example, 1617 ** it might allocate any require mutexes or initialize internal data 1618 ** structures. The xShutdown method is invoked (indirectly) by 1619 ** [sqlite3_shutdown()] and should deallocate any resources acquired 1620 ** by xInit. The pAppData pointer is used as the only parameter to 1621 ** xInit and xShutdown. 1622 ** 1623 ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1624 ** the xInit method, so the xInit method need not be threadsafe. The 1625 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1626 ** not need to be threadsafe either. For all other methods, SQLite 1627 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1628 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1629 ** it is by default) and so the methods are automatically serialized. 1630 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1631 ** methods must be threadsafe or else make their own arrangements for 1632 ** serialization. 1633 ** 1634 ** SQLite will never invoke xInit() more than once without an intervening 1635 ** call to xShutdown(). 1636 */ 1637 typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1638 struct sqlite3_mem_methods { 1639 void *(*xMalloc)(int); /* Memory allocation function */ 1640 void (*xFree)(void*); /* Free a prior allocation */ 1641 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1642 int (*xSize)(void*); /* Return the size of an allocation */ 1643 int (*xRoundup)(int); /* Round up request size to allocation size */ 1644 int (*xInit)(void*); /* Initialize the memory allocator */ 1645 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1646 void *pAppData; /* Argument to xInit() and xShutdown() */ 1647 }; 1648 1649 /* 1650 ** CAPI3REF: Configuration Options 1651 ** KEYWORDS: {configuration option} 1652 ** 1653 ** These constants are the available integer configuration options that 1654 ** can be passed as the first argument to the [sqlite3_config()] interface. 1655 ** 1656 ** New configuration options may be added in future releases of SQLite. 1657 ** Existing configuration options might be discontinued. Applications 1658 ** should check the return code from [sqlite3_config()] to make sure that 1659 ** the call worked. The [sqlite3_config()] interface will return a 1660 ** non-zero [error code] if a discontinued or unsupported configuration option 1661 ** is invoked. 1662 ** 1663 ** <dl> 1664 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1665 ** <dd>There are no arguments to this option. ^This option sets the 1666 ** [threading mode] to Single-thread. In other words, it disables 1667 ** all mutexing and puts SQLite into a mode where it can only be used 1668 ** by a single thread. ^If SQLite is compiled with 1669 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1670 ** it is not possible to change the [threading mode] from its default 1671 ** value of Single-thread and so [sqlite3_config()] will return 1672 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1673 ** configuration option.</dd> 1674 ** 1675 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1676 ** <dd>There are no arguments to this option. ^This option sets the 1677 ** [threading mode] to Multi-thread. In other words, it disables 1678 ** mutexing on [database connection] and [prepared statement] objects. 1679 ** The application is responsible for serializing access to 1680 ** [database connections] and [prepared statements]. But other mutexes 1681 ** are enabled so that SQLite will be safe to use in a multi-threaded 1682 ** environment as long as no two threads attempt to use the same 1683 ** [database connection] at the same time. ^If SQLite is compiled with 1684 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1685 ** it is not possible to set the Multi-thread [threading mode] and 1686 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1687 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1688 ** 1689 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1690 ** <dd>There are no arguments to this option. ^This option sets the 1691 ** [threading mode] to Serialized. In other words, this option enables 1692 ** all mutexes including the recursive 1693 ** mutexes on [database connection] and [prepared statement] objects. 1694 ** In this mode (which is the default when SQLite is compiled with 1695 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1696 ** to [database connections] and [prepared statements] so that the 1697 ** application is free to use the same [database connection] or the 1698 ** same [prepared statement] in different threads at the same time. 1699 ** ^If SQLite is compiled with 1700 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1701 ** it is not possible to set the Serialized [threading mode] and 1702 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1703 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1704 ** 1705 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1706 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1707 ** a pointer to an instance of the [sqlite3_mem_methods] structure. 1708 ** The argument specifies 1709 ** alternative low-level memory allocation routines to be used in place of 1710 ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1711 ** its own private copy of the content of the [sqlite3_mem_methods] structure 1712 ** before the [sqlite3_config()] call returns.</dd> 1713 ** 1714 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1715 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1716 ** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1717 ** The [sqlite3_mem_methods] 1718 ** structure is filled with the currently defined memory allocation routines.)^ 1719 ** This option can be used to overload the default memory allocation 1720 ** routines with a wrapper that simulations memory allocation failure or 1721 ** tracks memory usage, for example. </dd> 1722 ** 1723 ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1724 ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1725 ** type int, interpreted as a boolean, which if true provides a hint to 1726 ** SQLite that it should avoid large memory allocations if possible. 1727 ** SQLite will run faster if it is free to make large memory allocations, 1728 ** but some application might prefer to run slower in exchange for 1729 ** guarantees about memory fragmentation that are possible if large 1730 ** allocations are avoided. This hint is normally off. 1731 ** </dd> 1732 ** 1733 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1734 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1735 ** interpreted as a boolean, which enables or disables the collection of 1736 ** memory allocation statistics. ^(When memory allocation statistics are 1737 ** disabled, the following SQLite interfaces become non-operational: 1738 ** <ul> 1739 ** <li> [sqlite3_memory_used()] 1740 ** <li> [sqlite3_memory_highwater()] 1741 ** <li> [sqlite3_soft_heap_limit64()] 1742 ** <li> [sqlite3_status64()] 1743 ** </ul>)^ 1744 ** ^Memory allocation statistics are enabled by default unless SQLite is 1745 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1746 ** allocation statistics are disabled by default. 1747 ** </dd> 1748 ** 1749 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1750 ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1751 ** </dd> 1752 ** 1753 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1754 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1755 ** that SQLite can use for the database page cache with the default page 1756 ** cache implementation. 1757 ** This configuration option is a no-op if an application-define page 1758 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1759 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1760 ** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1761 ** and the number of cache lines (N). 1762 ** The sz argument should be the size of the largest database page 1763 ** (a power of two between 512 and 65536) plus some extra bytes for each 1764 ** page header. ^The number of extra bytes needed by the page header 1765 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1766 ** ^It is harmless, apart from the wasted memory, 1767 ** for the sz parameter to be larger than necessary. The pMem 1768 ** argument must be either a NULL pointer or a pointer to an 8-byte 1769 ** aligned block of memory of at least sz*N bytes, otherwise 1770 ** subsequent behavior is undefined. 1771 ** ^When pMem is not NULL, SQLite will strive to use the memory provided 1772 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1773 ** a page cache line is larger than sz bytes or if all of the pMem buffer 1774 ** is exhausted. 1775 ** ^If pMem is NULL and N is non-zero, then each database connection 1776 ** does an initial bulk allocation for page cache memory 1777 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1778 ** of -1024*N bytes if N is negative, . ^If additional 1779 ** page cache memory is needed beyond what is provided by the initial 1780 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1781 ** additional cache line. </dd> 1782 ** 1783 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1784 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1785 ** that SQLite will use for all of its dynamic memory allocation needs 1786 ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1787 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1788 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1789 ** [SQLITE_ERROR] if invoked otherwise. 1790 ** ^There are three arguments to SQLITE_CONFIG_HEAP: 1791 ** An 8-byte aligned pointer to the memory, 1792 ** the number of bytes in the memory buffer, and the minimum allocation size. 1793 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1794 ** to using its default memory allocator (the system malloc() implementation), 1795 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1796 ** memory pointer is not NULL then the alternative memory 1797 ** allocator is engaged to handle all of SQLites memory allocation needs. 1798 ** The first pointer (the memory pointer) must be aligned to an 8-byte 1799 ** boundary or subsequent behavior of SQLite will be undefined. 1800 ** The minimum allocation size is capped at 2**12. Reasonable values 1801 ** for the minimum allocation size are 2**5 through 2**8.</dd> 1802 ** 1803 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1804 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1805 ** pointer to an instance of the [sqlite3_mutex_methods] structure. 1806 ** The argument specifies alternative low-level mutex routines to be used 1807 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1808 ** the content of the [sqlite3_mutex_methods] structure before the call to 1809 ** [sqlite3_config()] returns. ^If SQLite is compiled with 1810 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1811 ** the entire mutexing subsystem is omitted from the build and hence calls to 1812 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1813 ** return [SQLITE_ERROR].</dd> 1814 ** 1815 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1816 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1817 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1818 ** [sqlite3_mutex_methods] 1819 ** structure is filled with the currently defined mutex routines.)^ 1820 ** This option can be used to overload the default mutex allocation 1821 ** routines with a wrapper used to track mutex usage for performance 1822 ** profiling or testing, for example. ^If SQLite is compiled with 1823 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1824 ** the entire mutexing subsystem is omitted from the build and hence calls to 1825 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1826 ** return [SQLITE_ERROR].</dd> 1827 ** 1828 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1829 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1830 ** the default size of lookaside memory on each [database connection]. 1831 ** The first argument is the 1832 ** size of each lookaside buffer slot and the second is the number of 1833 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1834 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1835 ** option to [sqlite3_db_config()] can be used to change the lookaside 1836 ** configuration on individual connections.)^ </dd> 1837 ** 1838 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1839 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1840 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1841 ** the interface to a custom page cache implementation.)^ 1842 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1843 ** 1844 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1845 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1846 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1847 ** the current page cache implementation into that object.)^ </dd> 1848 ** 1849 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1850 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1851 ** global [error log]. 1852 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1853 ** function with a call signature of void(*)(void*,int,const char*), 1854 ** and a pointer to void. ^If the function pointer is not NULL, it is 1855 ** invoked by [sqlite3_log()] to process each logging event. ^If the 1856 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1857 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1858 ** passed through as the first parameter to the application-defined logger 1859 ** function whenever that function is invoked. ^The second parameter to 1860 ** the logger function is a copy of the first parameter to the corresponding 1861 ** [sqlite3_log()] call and is intended to be a [result code] or an 1862 ** [extended result code]. ^The third parameter passed to the logger is 1863 ** log message after formatting via [sqlite3_snprintf()]. 1864 ** The SQLite logging interface is not reentrant; the logger function 1865 ** supplied by the application must not invoke any SQLite interface. 1866 ** In a multi-threaded application, the application-defined logger 1867 ** function must be threadsafe. </dd> 1868 ** 1869 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1870 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1871 ** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1872 ** then URI handling is globally disabled.)^ ^If URI handling is globally 1873 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1874 ** [sqlite3_open16()] or 1875 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1876 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1877 ** connection is opened. ^If it is globally disabled, filenames are 1878 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1879 ** database connection is opened. ^(By default, URI handling is globally 1880 ** disabled. The default value may be changed by compiling with the 1881 ** [SQLITE_USE_URI] symbol defined.)^ 1882 ** 1883 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1884 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1885 ** argument which is interpreted as a boolean in order to enable or disable 1886 ** the use of covering indices for full table scans in the query optimizer. 1887 ** ^The default setting is determined 1888 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1889 ** if that compile-time option is omitted. 1890 ** The ability to disable the use of covering indices for full table scans 1891 ** is because some incorrectly coded legacy applications might malfunction 1892 ** when the optimization is enabled. Providing the ability to 1893 ** disable the optimization allows the older, buggy application code to work 1894 ** without change even with newer versions of SQLite. 1895 ** 1896 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1897 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1898 ** <dd> These options are obsolete and should not be used by new code. 1899 ** They are retained for backwards compatibility but are now no-ops. 1900 ** </dd> 1901 ** 1902 ** [[SQLITE_CONFIG_SQLLOG]] 1903 ** <dt>SQLITE_CONFIG_SQLLOG 1904 ** <dd>This option is only available if sqlite is compiled with the 1905 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1906 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1907 ** The second should be of type (void*). The callback is invoked by the library 1908 ** in three separate circumstances, identified by the value passed as the 1909 ** fourth parameter. If the fourth parameter is 0, then the database connection 1910 ** passed as the second argument has just been opened. The third argument 1911 ** points to a buffer containing the name of the main database file. If the 1912 ** fourth parameter is 1, then the SQL statement that the third parameter 1913 ** points to has just been executed. Or, if the fourth parameter is 2, then 1914 ** the connection being passed as the second parameter is being closed. The 1915 ** third parameter is passed NULL In this case. An example of using this 1916 ** configuration option can be seen in the "test_sqllog.c" source file in 1917 ** the canonical SQLite source tree.</dd> 1918 ** 1919 ** [[SQLITE_CONFIG_MMAP_SIZE]] 1920 ** <dt>SQLITE_CONFIG_MMAP_SIZE 1921 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1922 ** that are the default mmap size limit (the default setting for 1923 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1924 ** ^The default setting can be overridden by each database connection using 1925 ** either the [PRAGMA mmap_size] command, or by using the 1926 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1927 ** will be silently truncated if necessary so that it does not exceed the 1928 ** compile-time maximum mmap size set by the 1929 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1930 ** ^If either argument to this option is negative, then that argument is 1931 ** changed to its compile-time default. 1932 ** 1933 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1934 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1935 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1936 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1937 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1938 ** that specifies the maximum size of the created heap. 1939 ** 1940 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1941 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1942 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1943 ** is a pointer to an integer and writes into that integer the number of extra 1944 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1945 ** The amount of extra space required can change depending on the compiler, 1946 ** target platform, and SQLite version. 1947 ** 1948 ** [[SQLITE_CONFIG_PMASZ]] 1949 ** <dt>SQLITE_CONFIG_PMASZ 1950 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1951 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1952 ** sorter to that integer. The default minimum PMA Size is set by the 1953 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1954 ** to help with sort operations when multithreaded sorting 1955 ** is enabled (using the [PRAGMA threads] command) and the amount of content 1956 ** to be sorted exceeds the page size times the minimum of the 1957 ** [PRAGMA cache_size] setting and this value. 1958 ** 1959 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1960 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1961 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1962 ** becomes the [statement journal] spill-to-disk threshold. 1963 ** [Statement journals] are held in memory until their size (in bytes) 1964 ** exceeds this threshold, at which point they are written to disk. 1965 ** Or if the threshold is -1, statement journals are always held 1966 ** exclusively in memory. 1967 ** Since many statement journals never become large, setting the spill 1968 ** threshold to a value such as 64KiB can greatly reduce the amount of 1969 ** I/O required to support statement rollback. 1970 ** The default value for this setting is controlled by the 1971 ** [SQLITE_STMTJRNL_SPILL] compile-time option. 1972 ** 1973 ** [[SQLITE_CONFIG_SORTERREF_SIZE]] 1974 ** <dt>SQLITE_CONFIG_SORTERREF_SIZE 1975 ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 1976 ** of type (int) - the new value of the sorter-reference size threshold. 1977 ** Usually, when SQLite uses an external sort to order records according 1978 ** to an ORDER BY clause, all fields required by the caller are present in the 1979 ** sorted records. However, if SQLite determines based on the declared type 1980 ** of a table column that its values are likely to be very large - larger 1981 ** than the configured sorter-reference size threshold - then a reference 1982 ** is stored in each sorted record and the required column values loaded 1983 ** from the database as records are returned in sorted order. The default 1984 ** value for this option is to never use this optimization. Specifying a 1985 ** negative value for this option restores the default behaviour. 1986 ** This option is only available if SQLite is compiled with the 1987 ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 1988 ** 1989 ** [[SQLITE_CONFIG_MEMDB_MAXSIZE]] 1990 ** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE 1991 ** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter 1992 ** [sqlite3_int64] parameter which is the default maximum size for an in-memory 1993 ** database created using [sqlite3_deserialize()]. This default maximum 1994 ** size can be adjusted up or down for individual databases using the 1995 ** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this 1996 ** configuration setting is never used, then the default maximum is determined 1997 ** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that 1998 ** compile-time option is not set, then the default maximum is 1073741824. 1999 ** </dl> 2000 */ 2001 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 2002 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 2003 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 2004 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 2005 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 2006 #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 2007 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 2008 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 2009 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 2010 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 2011 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 2012 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 2013 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 2014 #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 2015 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 2016 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 2017 #define SQLITE_CONFIG_URI 17 /* int */ 2018 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 2019 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 2020 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 2021 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 2022 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 2023 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 2024 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2025 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2026 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2027 #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2028 #define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2029 #define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */ 2030 2031 /* 2032 ** CAPI3REF: Database Connection Configuration Options 2033 ** 2034 ** These constants are the available integer configuration options that 2035 ** can be passed as the second argument to the [sqlite3_db_config()] interface. 2036 ** 2037 ** New configuration options may be added in future releases of SQLite. 2038 ** Existing configuration options might be discontinued. Applications 2039 ** should check the return code from [sqlite3_db_config()] to make sure that 2040 ** the call worked. ^The [sqlite3_db_config()] interface will return a 2041 ** non-zero [error code] if a discontinued or unsupported configuration option 2042 ** is invoked. 2043 ** 2044 ** <dl> 2045 ** [[SQLITE_DBCONFIG_LOOKASIDE]] 2046 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2047 ** <dd> ^This option takes three additional arguments that determine the 2048 ** [lookaside memory allocator] configuration for the [database connection]. 2049 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2050 ** pointer to a memory buffer to use for lookaside memory. 2051 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2052 ** may be NULL in which case SQLite will allocate the 2053 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2054 ** size of each lookaside buffer slot. ^The third argument is the number of 2055 ** slots. The size of the buffer in the first argument must be greater than 2056 ** or equal to the product of the second and third arguments. The buffer 2057 ** must be aligned to an 8-byte boundary. ^If the second argument to 2058 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2059 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2060 ** configuration for a database connection can only be changed when that 2061 ** connection is not currently using lookaside memory, or in other words 2062 ** when the "current value" returned by 2063 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 2064 ** Any attempt to change the lookaside memory configuration when lookaside 2065 ** memory is in use leaves the configuration unchanged and returns 2066 ** [SQLITE_BUSY].)^</dd> 2067 ** 2068 ** [[SQLITE_DBCONFIG_ENABLE_FKEY]] 2069 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2070 ** <dd> ^This option is used to enable or disable the enforcement of 2071 ** [foreign key constraints]. There should be two additional arguments. 2072 ** The first argument is an integer which is 0 to disable FK enforcement, 2073 ** positive to enable FK enforcement or negative to leave FK enforcement 2074 ** unchanged. The second parameter is a pointer to an integer into which 2075 ** is written 0 or 1 to indicate whether FK enforcement is off or on 2076 ** following this call. The second parameter may be a NULL pointer, in 2077 ** which case the FK enforcement setting is not reported back. </dd> 2078 ** 2079 ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] 2080 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2081 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2082 ** There should be two additional arguments. 2083 ** The first argument is an integer which is 0 to disable triggers, 2084 ** positive to enable triggers or negative to leave the setting unchanged. 2085 ** The second parameter is a pointer to an integer into which 2086 ** is written 0 or 1 to indicate whether triggers are disabled or enabled 2087 ** following this call. The second parameter may be a NULL pointer, in 2088 ** which case the trigger setting is not reported back. </dd> 2089 ** 2090 ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] 2091 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2092 ** <dd> ^This option is used to enable or disable the 2093 ** [fts3_tokenizer()] function which is part of the 2094 ** [FTS3] full-text search engine extension. 2095 ** There should be two additional arguments. 2096 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2097 ** positive to enable fts3_tokenizer() or negative to leave the setting 2098 ** unchanged. 2099 ** The second parameter is a pointer to an integer into which 2100 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2101 ** following this call. The second parameter may be a NULL pointer, in 2102 ** which case the new setting is not reported back. </dd> 2103 ** 2104 ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] 2105 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2106 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2107 ** interface independently of the [load_extension()] SQL function. 2108 ** The [sqlite3_enable_load_extension()] API enables or disables both the 2109 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2110 ** There should be two additional arguments. 2111 ** When the first argument to this interface is 1, then only the C-API is 2112 ** enabled and the SQL function remains disabled. If the first argument to 2113 ** this interface is 0, then both the C-API and the SQL function are disabled. 2114 ** If the first argument is -1, then no changes are made to state of either the 2115 ** C-API or the SQL function. 2116 ** The second parameter is a pointer to an integer into which 2117 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2118 ** is disabled or enabled following this call. The second parameter may 2119 ** be a NULL pointer, in which case the new setting is not reported back. 2120 ** </dd> 2121 ** 2122 ** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2123 ** <dd> ^This option is used to change the name of the "main" database 2124 ** schema. ^The sole argument is a pointer to a constant UTF8 string 2125 ** which will become the new schema name in place of "main". ^SQLite 2126 ** does not make a copy of the new main schema name string, so the application 2127 ** must ensure that the argument passed into this DBCONFIG option is unchanged 2128 ** until after the database connection closes. 2129 ** </dd> 2130 ** 2131 ** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] 2132 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2133 ** <dd> Usually, when a database in wal mode is closed or detached from a 2134 ** database handle, SQLite checks if this will mean that there are now no 2135 ** connections at all to the database. If so, it performs a checkpoint 2136 ** operation before closing the connection. This option may be used to 2137 ** override this behaviour. The first parameter passed to this operation 2138 ** is an integer - positive to disable checkpoints-on-close, or zero (the 2139 ** default) to enable them, and negative to leave the setting unchanged. 2140 ** The second parameter is a pointer to an integer 2141 ** into which is written 0 or 1 to indicate whether checkpoints-on-close 2142 ** have been disabled - 0 if they are not disabled, 1 if they are. 2143 ** </dd> 2144 ** 2145 ** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2146 ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2147 ** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2148 ** a single SQL query statement will always use the same algorithm regardless 2149 ** of values of [bound parameters].)^ The QPSG disables some query optimizations 2150 ** that look at the values of bound parameters, which can make some queries 2151 ** slower. But the QPSG has the advantage of more predictable behavior. With 2152 ** the QPSG active, SQLite will always use the same query plan in the field as 2153 ** was used during testing in the lab. 2154 ** The first argument to this setting is an integer which is 0 to disable 2155 ** the QPSG, positive to enable QPSG, or negative to leave the setting 2156 ** unchanged. The second parameter is a pointer to an integer into which 2157 ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2158 ** following this call. 2159 ** </dd> 2160 ** 2161 ** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2162 ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2163 ** include output for any operations performed by trigger programs. This 2164 ** option is used to set or clear (the default) a flag that governs this 2165 ** behavior. The first parameter passed to this operation is an integer - 2166 ** positive to enable output for trigger programs, or zero to disable it, 2167 ** or negative to leave the setting unchanged. 2168 ** The second parameter is a pointer to an integer into which is written 2169 ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2170 ** it is not disabled, 1 if it is. 2171 ** </dd> 2172 ** 2173 ** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2174 ** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2175 ** [VACUUM] in order to reset a database back to an empty database 2176 ** with no schema and no content. The following process works even for 2177 ** a badly corrupted database file: 2178 ** <ol> 2179 ** <li> If the database connection is newly opened, make sure it has read the 2180 ** database schema by preparing then discarding some query against the 2181 ** database, or calling sqlite3_table_column_metadata(), ignoring any 2182 ** errors. This step is only necessary if the application desires to keep 2183 ** the database in WAL mode after the reset if it was in WAL mode before 2184 ** the reset. 2185 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2186 ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2187 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2188 ** </ol> 2189 ** Because resetting a database is destructive and irreversible, the 2190 ** process requires the use of this obscure API and multiple steps to help 2191 ** ensure that it does not happen by accident. 2192 ** 2193 ** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt> 2194 ** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the 2195 ** "defensive" flag for a database connection. When the defensive 2196 ** flag is enabled, language features that allow ordinary SQL to 2197 ** deliberately corrupt the database file are disabled. The disabled 2198 ** features include but are not limited to the following: 2199 ** <ul> 2200 ** <li> The [PRAGMA writable_schema=ON] statement. 2201 ** <li> Writes to the [sqlite_dbpage] virtual table. 2202 ** <li> Direct writes to [shadow tables]. 2203 ** </ul> 2204 ** </dd> 2205 ** 2206 ** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt> 2207 ** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the 2208 ** "writable_schema" flag. This has the same effect and is logically equivalent 2209 ** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF]. 2210 ** The first argument to this setting is an integer which is 0 to disable 2211 ** the writable_schema, positive to enable writable_schema, or negative to 2212 ** leave the setting unchanged. The second parameter is a pointer to an 2213 ** integer into which is written 0 or 1 to indicate whether the writable_schema 2214 ** is enabled or disabled following this call. 2215 ** </dd> 2216 ** </dl> 2217 */ 2218 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2219 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2220 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2221 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2222 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2223 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2224 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2225 #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2226 #define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2227 #define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2228 #define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ 2229 #define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */ 2230 #define SQLITE_DBCONFIG_MAX 1011 /* Largest DBCONFIG */ 2231 2232 /* 2233 ** CAPI3REF: Enable Or Disable Extended Result Codes 2234 ** METHOD: sqlite3 2235 ** 2236 ** ^The sqlite3_extended_result_codes() routine enables or disables the 2237 ** [extended result codes] feature of SQLite. ^The extended result 2238 ** codes are disabled by default for historical compatibility. 2239 */ 2240 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 2241 2242 /* 2243 ** CAPI3REF: Last Insert Rowid 2244 ** METHOD: sqlite3 2245 ** 2246 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2247 ** has a unique 64-bit signed 2248 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2249 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2250 ** names are not also used by explicitly declared columns. ^If 2251 ** the table has a column of type [INTEGER PRIMARY KEY] then that column 2252 ** is another alias for the rowid. 2253 ** 2254 ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2255 ** the most recent successful [INSERT] into a rowid table or [virtual table] 2256 ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2257 ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2258 ** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2259 ** zero. 2260 ** 2261 ** As well as being set automatically as rows are inserted into database 2262 ** tables, the value returned by this function may be set explicitly by 2263 ** [sqlite3_set_last_insert_rowid()] 2264 ** 2265 ** Some virtual table implementations may INSERT rows into rowid tables as 2266 ** part of committing a transaction (e.g. to flush data accumulated in memory 2267 ** to disk). In this case subsequent calls to this function return the rowid 2268 ** associated with these internal INSERT operations, which leads to 2269 ** unintuitive results. Virtual table implementations that do write to rowid 2270 ** tables in this way can avoid this problem by restoring the original 2271 ** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2272 ** control to the user. 2273 ** 2274 ** ^(If an [INSERT] occurs within a trigger then this routine will 2275 ** return the [rowid] of the inserted row as long as the trigger is 2276 ** running. Once the trigger program ends, the value returned 2277 ** by this routine reverts to what it was before the trigger was fired.)^ 2278 ** 2279 ** ^An [INSERT] that fails due to a constraint violation is not a 2280 ** successful [INSERT] and does not change the value returned by this 2281 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2282 ** and INSERT OR ABORT make no changes to the return value of this 2283 ** routine when their insertion fails. ^(When INSERT OR REPLACE 2284 ** encounters a constraint violation, it does not fail. The 2285 ** INSERT continues to completion after deleting rows that caused 2286 ** the constraint problem so INSERT OR REPLACE will always change 2287 ** the return value of this interface.)^ 2288 ** 2289 ** ^For the purposes of this routine, an [INSERT] is considered to 2290 ** be successful even if it is subsequently rolled back. 2291 ** 2292 ** This function is accessible to SQL statements via the 2293 ** [last_insert_rowid() SQL function]. 2294 ** 2295 ** If a separate thread performs a new [INSERT] on the same 2296 ** database connection while the [sqlite3_last_insert_rowid()] 2297 ** function is running and thus changes the last insert [rowid], 2298 ** then the value returned by [sqlite3_last_insert_rowid()] is 2299 ** unpredictable and might not equal either the old or the new 2300 ** last insert [rowid]. 2301 */ 2302 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2303 2304 /* 2305 ** CAPI3REF: Set the Last Insert Rowid value. 2306 ** METHOD: sqlite3 2307 ** 2308 ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2309 ** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2310 ** without inserting a row into the database. 2311 */ 2312 SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2313 2314 /* 2315 ** CAPI3REF: Count The Number Of Rows Modified 2316 ** METHOD: sqlite3 2317 ** 2318 ** ^This function returns the number of rows modified, inserted or 2319 ** deleted by the most recently completed INSERT, UPDATE or DELETE 2320 ** statement on the database connection specified by the only parameter. 2321 ** ^Executing any other type of SQL statement does not modify the value 2322 ** returned by this function. 2323 ** 2324 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2325 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2326 ** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2327 ** 2328 ** Changes to a view that are intercepted by 2329 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2330 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2331 ** DELETE statement run on a view is always zero. Only changes made to real 2332 ** tables are counted. 2333 ** 2334 ** Things are more complicated if the sqlite3_changes() function is 2335 ** executed while a trigger program is running. This may happen if the 2336 ** program uses the [changes() SQL function], or if some other callback 2337 ** function invokes sqlite3_changes() directly. Essentially: 2338 ** 2339 ** <ul> 2340 ** <li> ^(Before entering a trigger program the value returned by 2341 ** sqlite3_changes() function is saved. After the trigger program 2342 ** has finished, the original value is restored.)^ 2343 ** 2344 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2345 ** statement sets the value returned by sqlite3_changes() 2346 ** upon completion as normal. Of course, this value will not include 2347 ** any changes performed by sub-triggers, as the sqlite3_changes() 2348 ** value will be saved and restored after each sub-trigger has run.)^ 2349 ** </ul> 2350 ** 2351 ** ^This means that if the changes() SQL function (or similar) is used 2352 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2353 ** returns the value as set when the calling statement began executing. 2354 ** ^If it is used by the second or subsequent such statement within a trigger 2355 ** program, the value returned reflects the number of rows modified by the 2356 ** previous INSERT, UPDATE or DELETE statement within the same trigger. 2357 ** 2358 ** If a separate thread makes changes on the same database connection 2359 ** while [sqlite3_changes()] is running then the value returned 2360 ** is unpredictable and not meaningful. 2361 ** 2362 ** See also: 2363 ** <ul> 2364 ** <li> the [sqlite3_total_changes()] interface 2365 ** <li> the [count_changes pragma] 2366 ** <li> the [changes() SQL function] 2367 ** <li> the [data_version pragma] 2368 ** </ul> 2369 */ 2370 SQLITE_API int sqlite3_changes(sqlite3*); 2371 2372 /* 2373 ** CAPI3REF: Total Number Of Rows Modified 2374 ** METHOD: sqlite3 2375 ** 2376 ** ^This function returns the total number of rows inserted, modified or 2377 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2378 ** since the database connection was opened, including those executed as 2379 ** part of trigger programs. ^Executing any other type of SQL statement 2380 ** does not affect the value returned by sqlite3_total_changes(). 2381 ** 2382 ** ^Changes made as part of [foreign key actions] are included in the 2383 ** count, but those made as part of REPLACE constraint resolution are 2384 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2385 ** are not counted. 2386 ** 2387 ** The [sqlite3_total_changes(D)] interface only reports the number 2388 ** of rows that changed due to SQL statement run against database 2389 ** connection D. Any changes by other database connections are ignored. 2390 ** To detect changes against a database file from other database 2391 ** connections use the [PRAGMA data_version] command or the 2392 ** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2393 ** 2394 ** If a separate thread makes changes on the same database connection 2395 ** while [sqlite3_total_changes()] is running then the value 2396 ** returned is unpredictable and not meaningful. 2397 ** 2398 ** See also: 2399 ** <ul> 2400 ** <li> the [sqlite3_changes()] interface 2401 ** <li> the [count_changes pragma] 2402 ** <li> the [changes() SQL function] 2403 ** <li> the [data_version pragma] 2404 ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2405 ** </ul> 2406 */ 2407 SQLITE_API int sqlite3_total_changes(sqlite3*); 2408 2409 /* 2410 ** CAPI3REF: Interrupt A Long-Running Query 2411 ** METHOD: sqlite3 2412 ** 2413 ** ^This function causes any pending database operation to abort and 2414 ** return at its earliest opportunity. This routine is typically 2415 ** called in response to a user action such as pressing "Cancel" 2416 ** or Ctrl-C where the user wants a long query operation to halt 2417 ** immediately. 2418 ** 2419 ** ^It is safe to call this routine from a thread different from the 2420 ** thread that is currently running the database operation. But it 2421 ** is not safe to call this routine with a [database connection] that 2422 ** is closed or might close before sqlite3_interrupt() returns. 2423 ** 2424 ** ^If an SQL operation is very nearly finished at the time when 2425 ** sqlite3_interrupt() is called, then it might not have an opportunity 2426 ** to be interrupted and might continue to completion. 2427 ** 2428 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2429 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2430 ** that is inside an explicit transaction, then the entire transaction 2431 ** will be rolled back automatically. 2432 ** 2433 ** ^The sqlite3_interrupt(D) call is in effect until all currently running 2434 ** SQL statements on [database connection] D complete. ^Any new SQL statements 2435 ** that are started after the sqlite3_interrupt() call and before the 2436 ** running statements reaches zero are interrupted as if they had been 2437 ** running prior to the sqlite3_interrupt() call. ^New SQL statements 2438 ** that are started after the running statement count reaches zero are 2439 ** not effected by the sqlite3_interrupt(). 2440 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2441 ** SQL statements is a no-op and has no effect on SQL statements 2442 ** that are started after the sqlite3_interrupt() call returns. 2443 */ 2444 SQLITE_API void sqlite3_interrupt(sqlite3*); 2445 2446 /* 2447 ** CAPI3REF: Determine If An SQL Statement Is Complete 2448 ** 2449 ** These routines are useful during command-line input to determine if the 2450 ** currently entered text seems to form a complete SQL statement or 2451 ** if additional input is needed before sending the text into 2452 ** SQLite for parsing. ^These routines return 1 if the input string 2453 ** appears to be a complete SQL statement. ^A statement is judged to be 2454 ** complete if it ends with a semicolon token and is not a prefix of a 2455 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2456 ** string literals or quoted identifier names or comments are not 2457 ** independent tokens (they are part of the token in which they are 2458 ** embedded) and thus do not count as a statement terminator. ^Whitespace 2459 ** and comments that follow the final semicolon are ignored. 2460 ** 2461 ** ^These routines return 0 if the statement is incomplete. ^If a 2462 ** memory allocation fails, then SQLITE_NOMEM is returned. 2463 ** 2464 ** ^These routines do not parse the SQL statements thus 2465 ** will not detect syntactically incorrect SQL. 2466 ** 2467 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2468 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2469 ** automatically by sqlite3_complete16(). If that initialization fails, 2470 ** then the return value from sqlite3_complete16() will be non-zero 2471 ** regardless of whether or not the input SQL is complete.)^ 2472 ** 2473 ** The input to [sqlite3_complete()] must be a zero-terminated 2474 ** UTF-8 string. 2475 ** 2476 ** The input to [sqlite3_complete16()] must be a zero-terminated 2477 ** UTF-16 string in native byte order. 2478 */ 2479 SQLITE_API int sqlite3_complete(const char *sql); 2480 SQLITE_API int sqlite3_complete16(const void *sql); 2481 2482 /* 2483 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2484 ** KEYWORDS: {busy-handler callback} {busy handler} 2485 ** METHOD: sqlite3 2486 ** 2487 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2488 ** that might be invoked with argument P whenever 2489 ** an attempt is made to access a database table associated with 2490 ** [database connection] D when another thread 2491 ** or process has the table locked. 2492 ** The sqlite3_busy_handler() interface is used to implement 2493 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2494 ** 2495 ** ^If the busy callback is NULL, then [SQLITE_BUSY] 2496 ** is returned immediately upon encountering the lock. ^If the busy callback 2497 ** is not NULL, then the callback might be invoked with two arguments. 2498 ** 2499 ** ^The first argument to the busy handler is a copy of the void* pointer which 2500 ** is the third argument to sqlite3_busy_handler(). ^The second argument to 2501 ** the busy handler callback is the number of times that the busy handler has 2502 ** been invoked previously for the same locking event. ^If the 2503 ** busy callback returns 0, then no additional attempts are made to 2504 ** access the database and [SQLITE_BUSY] is returned 2505 ** to the application. 2506 ** ^If the callback returns non-zero, then another attempt 2507 ** is made to access the database and the cycle repeats. 2508 ** 2509 ** The presence of a busy handler does not guarantee that it will be invoked 2510 ** when there is lock contention. ^If SQLite determines that invoking the busy 2511 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2512 ** to the application instead of invoking the 2513 ** busy handler. 2514 ** Consider a scenario where one process is holding a read lock that 2515 ** it is trying to promote to a reserved lock and 2516 ** a second process is holding a reserved lock that it is trying 2517 ** to promote to an exclusive lock. The first process cannot proceed 2518 ** because it is blocked by the second and the second process cannot 2519 ** proceed because it is blocked by the first. If both processes 2520 ** invoke the busy handlers, neither will make any progress. Therefore, 2521 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2522 ** will induce the first process to release its read lock and allow 2523 ** the second process to proceed. 2524 ** 2525 ** ^The default busy callback is NULL. 2526 ** 2527 ** ^(There can only be a single busy handler defined for each 2528 ** [database connection]. Setting a new busy handler clears any 2529 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2530 ** or evaluating [PRAGMA busy_timeout=N] will change the 2531 ** busy handler and thus clear any previously set busy handler. 2532 ** 2533 ** The busy callback should not take any actions which modify the 2534 ** database connection that invoked the busy handler. In other words, 2535 ** the busy handler is not reentrant. Any such actions 2536 ** result in undefined behavior. 2537 ** 2538 ** A busy handler must not close the database connection 2539 ** or [prepared statement] that invoked the busy handler. 2540 */ 2541 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2542 2543 /* 2544 ** CAPI3REF: Set A Busy Timeout 2545 ** METHOD: sqlite3 2546 ** 2547 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2548 ** for a specified amount of time when a table is locked. ^The handler 2549 ** will sleep multiple times until at least "ms" milliseconds of sleeping 2550 ** have accumulated. ^After at least "ms" milliseconds of sleeping, 2551 ** the handler returns 0 which causes [sqlite3_step()] to return 2552 ** [SQLITE_BUSY]. 2553 ** 2554 ** ^Calling this routine with an argument less than or equal to zero 2555 ** turns off all busy handlers. 2556 ** 2557 ** ^(There can only be a single busy handler for a particular 2558 ** [database connection] at any given moment. If another busy handler 2559 ** was defined (using [sqlite3_busy_handler()]) prior to calling 2560 ** this routine, that other busy handler is cleared.)^ 2561 ** 2562 ** See also: [PRAGMA busy_timeout] 2563 */ 2564 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2565 2566 /* 2567 ** CAPI3REF: Convenience Routines For Running Queries 2568 ** METHOD: sqlite3 2569 ** 2570 ** This is a legacy interface that is preserved for backwards compatibility. 2571 ** Use of this interface is not recommended. 2572 ** 2573 ** Definition: A <b>result table</b> is memory data structure created by the 2574 ** [sqlite3_get_table()] interface. A result table records the 2575 ** complete query results from one or more queries. 2576 ** 2577 ** The table conceptually has a number of rows and columns. But 2578 ** these numbers are not part of the result table itself. These 2579 ** numbers are obtained separately. Let N be the number of rows 2580 ** and M be the number of columns. 2581 ** 2582 ** A result table is an array of pointers to zero-terminated UTF-8 strings. 2583 ** There are (N+1)*M elements in the array. The first M pointers point 2584 ** to zero-terminated strings that contain the names of the columns. 2585 ** The remaining entries all point to query results. NULL values result 2586 ** in NULL pointers. All other values are in their UTF-8 zero-terminated 2587 ** string representation as returned by [sqlite3_column_text()]. 2588 ** 2589 ** A result table might consist of one or more memory allocations. 2590 ** It is not safe to pass a result table directly to [sqlite3_free()]. 2591 ** A result table should be deallocated using [sqlite3_free_table()]. 2592 ** 2593 ** ^(As an example of the result table format, suppose a query result 2594 ** is as follows: 2595 ** 2596 ** <blockquote><pre> 2597 ** Name | Age 2598 ** ----------------------- 2599 ** Alice | 43 2600 ** Bob | 28 2601 ** Cindy | 21 2602 ** </pre></blockquote> 2603 ** 2604 ** There are two column (M==2) and three rows (N==3). Thus the 2605 ** result table has 8 entries. Suppose the result table is stored 2606 ** in an array names azResult. Then azResult holds this content: 2607 ** 2608 ** <blockquote><pre> 2609 ** azResult[0] = "Name"; 2610 ** azResult[1] = "Age"; 2611 ** azResult[2] = "Alice"; 2612 ** azResult[3] = "43"; 2613 ** azResult[4] = "Bob"; 2614 ** azResult[5] = "28"; 2615 ** azResult[6] = "Cindy"; 2616 ** azResult[7] = "21"; 2617 ** </pre></blockquote>)^ 2618 ** 2619 ** ^The sqlite3_get_table() function evaluates one or more 2620 ** semicolon-separated SQL statements in the zero-terminated UTF-8 2621 ** string of its 2nd parameter and returns a result table to the 2622 ** pointer given in its 3rd parameter. 2623 ** 2624 ** After the application has finished with the result from sqlite3_get_table(), 2625 ** it must pass the result table pointer to sqlite3_free_table() in order to 2626 ** release the memory that was malloced. Because of the way the 2627 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2628 ** function must not try to call [sqlite3_free()] directly. Only 2629 ** [sqlite3_free_table()] is able to release the memory properly and safely. 2630 ** 2631 ** The sqlite3_get_table() interface is implemented as a wrapper around 2632 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2633 ** to any internal data structures of SQLite. It uses only the public 2634 ** interface defined here. As a consequence, errors that occur in the 2635 ** wrapper layer outside of the internal [sqlite3_exec()] call are not 2636 ** reflected in subsequent calls to [sqlite3_errcode()] or 2637 ** [sqlite3_errmsg()]. 2638 */ 2639 SQLITE_API int sqlite3_get_table( 2640 sqlite3 *db, /* An open database */ 2641 const char *zSql, /* SQL to be evaluated */ 2642 char ***pazResult, /* Results of the query */ 2643 int *pnRow, /* Number of result rows written here */ 2644 int *pnColumn, /* Number of result columns written here */ 2645 char **pzErrmsg /* Error msg written here */ 2646 ); 2647 SQLITE_API void sqlite3_free_table(char **result); 2648 2649 /* 2650 ** CAPI3REF: Formatted String Printing Functions 2651 ** 2652 ** These routines are work-alikes of the "printf()" family of functions 2653 ** from the standard C library. 2654 ** These routines understand most of the common formatting options from 2655 ** the standard library printf() 2656 ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2657 ** See the [built-in printf()] documentation for details. 2658 ** 2659 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2660 ** results into memory obtained from [sqlite3_malloc64()]. 2661 ** The strings returned by these two routines should be 2662 ** released by [sqlite3_free()]. ^Both routines return a 2663 ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2664 ** memory to hold the resulting string. 2665 ** 2666 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2667 ** the standard C library. The result is written into the 2668 ** buffer supplied as the second parameter whose size is given by 2669 ** the first parameter. Note that the order of the 2670 ** first two parameters is reversed from snprintf().)^ This is an 2671 ** historical accident that cannot be fixed without breaking 2672 ** backwards compatibility. ^(Note also that sqlite3_snprintf() 2673 ** returns a pointer to its buffer instead of the number of 2674 ** characters actually written into the buffer.)^ We admit that 2675 ** the number of characters written would be a more useful return 2676 ** value but we cannot change the implementation of sqlite3_snprintf() 2677 ** now without breaking compatibility. 2678 ** 2679 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2680 ** guarantees that the buffer is always zero-terminated. ^The first 2681 ** parameter "n" is the total size of the buffer, including space for 2682 ** the zero terminator. So the longest string that can be completely 2683 ** written will be n-1 characters. 2684 ** 2685 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2686 ** 2687 ** See also: [built-in printf()], [printf() SQL function] 2688 */ 2689 SQLITE_API char *sqlite3_mprintf(const char*,...); 2690 SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2691 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2692 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2693 2694 /* 2695 ** CAPI3REF: Memory Allocation Subsystem 2696 ** 2697 ** The SQLite core uses these three routines for all of its own 2698 ** internal memory allocation needs. "Core" in the previous sentence 2699 ** does not include operating-system specific VFS implementation. The 2700 ** Windows VFS uses native malloc() and free() for some operations. 2701 ** 2702 ** ^The sqlite3_malloc() routine returns a pointer to a block 2703 ** of memory at least N bytes in length, where N is the parameter. 2704 ** ^If sqlite3_malloc() is unable to obtain sufficient free 2705 ** memory, it returns a NULL pointer. ^If the parameter N to 2706 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2707 ** a NULL pointer. 2708 ** 2709 ** ^The sqlite3_malloc64(N) routine works just like 2710 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2711 ** of a signed 32-bit integer. 2712 ** 2713 ** ^Calling sqlite3_free() with a pointer previously returned 2714 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2715 ** that it might be reused. ^The sqlite3_free() routine is 2716 ** a no-op if is called with a NULL pointer. Passing a NULL pointer 2717 ** to sqlite3_free() is harmless. After being freed, memory 2718 ** should neither be read nor written. Even reading previously freed 2719 ** memory might result in a segmentation fault or other severe error. 2720 ** Memory corruption, a segmentation fault, or other severe error 2721 ** might result if sqlite3_free() is called with a non-NULL pointer that 2722 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2723 ** 2724 ** ^The sqlite3_realloc(X,N) interface attempts to resize a 2725 ** prior memory allocation X to be at least N bytes. 2726 ** ^If the X parameter to sqlite3_realloc(X,N) 2727 ** is a NULL pointer then its behavior is identical to calling 2728 ** sqlite3_malloc(N). 2729 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2730 ** negative then the behavior is exactly the same as calling 2731 ** sqlite3_free(X). 2732 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2733 ** of at least N bytes in size or NULL if insufficient memory is available. 2734 ** ^If M is the size of the prior allocation, then min(N,M) bytes 2735 ** of the prior allocation are copied into the beginning of buffer returned 2736 ** by sqlite3_realloc(X,N) and the prior allocation is freed. 2737 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2738 ** prior allocation is not freed. 2739 ** 2740 ** ^The sqlite3_realloc64(X,N) interfaces works the same as 2741 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2742 ** of a 32-bit signed integer. 2743 ** 2744 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2745 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2746 ** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2747 ** ^The value returned by sqlite3_msize(X) might be larger than the number 2748 ** of bytes requested when X was allocated. ^If X is a NULL pointer then 2749 ** sqlite3_msize(X) returns zero. If X points to something that is not 2750 ** the beginning of memory allocation, or if it points to a formerly 2751 ** valid memory allocation that has now been freed, then the behavior 2752 ** of sqlite3_msize(X) is undefined and possibly harmful. 2753 ** 2754 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2755 ** sqlite3_malloc64(), and sqlite3_realloc64() 2756 ** is always aligned to at least an 8 byte boundary, or to a 2757 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2758 ** option is used. 2759 ** 2760 ** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2761 ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2762 ** implementation of these routines to be omitted. That capability 2763 ** is no longer provided. Only built-in memory allocators can be used. 2764 ** 2765 ** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2766 ** the system malloc() and free() directly when converting 2767 ** filenames between the UTF-8 encoding used by SQLite 2768 ** and whatever filename encoding is used by the particular Windows 2769 ** installation. Memory allocation errors were detected, but 2770 ** they were reported back as [SQLITE_CANTOPEN] or 2771 ** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2772 ** 2773 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2774 ** must be either NULL or else pointers obtained from a prior 2775 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2776 ** not yet been released. 2777 ** 2778 ** The application must not read or write any part of 2779 ** a block of memory after it has been released using 2780 ** [sqlite3_free()] or [sqlite3_realloc()]. 2781 */ 2782 SQLITE_API void *sqlite3_malloc(int); 2783 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 2784 SQLITE_API void *sqlite3_realloc(void*, int); 2785 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 2786 SQLITE_API void sqlite3_free(void*); 2787 SQLITE_API sqlite3_uint64 sqlite3_msize(void*); 2788 2789 /* 2790 ** CAPI3REF: Memory Allocator Statistics 2791 ** 2792 ** SQLite provides these two interfaces for reporting on the status 2793 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2794 ** routines, which form the built-in memory allocation subsystem. 2795 ** 2796 ** ^The [sqlite3_memory_used()] routine returns the number of bytes 2797 ** of memory currently outstanding (malloced but not freed). 2798 ** ^The [sqlite3_memory_highwater()] routine returns the maximum 2799 ** value of [sqlite3_memory_used()] since the high-water mark 2800 ** was last reset. ^The values returned by [sqlite3_memory_used()] and 2801 ** [sqlite3_memory_highwater()] include any overhead 2802 ** added by SQLite in its implementation of [sqlite3_malloc()], 2803 ** but not overhead added by the any underlying system library 2804 ** routines that [sqlite3_malloc()] may call. 2805 ** 2806 ** ^The memory high-water mark is reset to the current value of 2807 ** [sqlite3_memory_used()] if and only if the parameter to 2808 ** [sqlite3_memory_highwater()] is true. ^The value returned 2809 ** by [sqlite3_memory_highwater(1)] is the high-water mark 2810 ** prior to the reset. 2811 */ 2812 SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 2813 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2814 2815 /* 2816 ** CAPI3REF: Pseudo-Random Number Generator 2817 ** 2818 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2819 ** select random [ROWID | ROWIDs] when inserting new records into a table that 2820 ** already uses the largest possible [ROWID]. The PRNG is also used for 2821 ** the build-in random() and randomblob() SQL functions. This interface allows 2822 ** applications to access the same PRNG for other purposes. 2823 ** 2824 ** ^A call to this routine stores N bytes of randomness into buffer P. 2825 ** ^The P parameter can be a NULL pointer. 2826 ** 2827 ** ^If this routine has not been previously called or if the previous 2828 ** call had N less than one or a NULL pointer for P, then the PRNG is 2829 ** seeded using randomness obtained from the xRandomness method of 2830 ** the default [sqlite3_vfs] object. 2831 ** ^If the previous call to this routine had an N of 1 or more and a 2832 ** non-NULL P then the pseudo-randomness is generated 2833 ** internally and without recourse to the [sqlite3_vfs] xRandomness 2834 ** method. 2835 */ 2836 SQLITE_API void sqlite3_randomness(int N, void *P); 2837 2838 /* 2839 ** CAPI3REF: Compile-Time Authorization Callbacks 2840 ** METHOD: sqlite3 2841 ** KEYWORDS: {authorizer callback} 2842 ** 2843 ** ^This routine registers an authorizer callback with a particular 2844 ** [database connection], supplied in the first argument. 2845 ** ^The authorizer callback is invoked as SQL statements are being compiled 2846 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2847 ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 2848 ** and [sqlite3_prepare16_v3()]. ^At various 2849 ** points during the compilation process, as logic is being created 2850 ** to perform various actions, the authorizer callback is invoked to 2851 ** see if those actions are allowed. ^The authorizer callback should 2852 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2853 ** specific action but allow the SQL statement to continue to be 2854 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2855 ** rejected with an error. ^If the authorizer callback returns 2856 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2857 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2858 ** the authorizer will fail with an error message. 2859 ** 2860 ** When the callback returns [SQLITE_OK], that means the operation 2861 ** requested is ok. ^When the callback returns [SQLITE_DENY], the 2862 ** [sqlite3_prepare_v2()] or equivalent call that triggered the 2863 ** authorizer will fail with an error message explaining that 2864 ** access is denied. 2865 ** 2866 ** ^The first parameter to the authorizer callback is a copy of the third 2867 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2868 ** to the callback is an integer [SQLITE_COPY | action code] that specifies 2869 ** the particular action to be authorized. ^The third through sixth parameters 2870 ** to the callback are either NULL pointers or zero-terminated strings 2871 ** that contain additional details about the action to be authorized. 2872 ** Applications must always be prepared to encounter a NULL pointer in any 2873 ** of the third through the sixth parameters of the authorization callback. 2874 ** 2875 ** ^If the action code is [SQLITE_READ] 2876 ** and the callback returns [SQLITE_IGNORE] then the 2877 ** [prepared statement] statement is constructed to substitute 2878 ** a NULL value in place of the table column that would have 2879 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2880 ** return can be used to deny an untrusted user access to individual 2881 ** columns of a table. 2882 ** ^When a table is referenced by a [SELECT] but no column values are 2883 ** extracted from that table (for example in a query like 2884 ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 2885 ** is invoked once for that table with a column name that is an empty string. 2886 ** ^If the action code is [SQLITE_DELETE] and the callback returns 2887 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2888 ** [truncate optimization] is disabled and all rows are deleted individually. 2889 ** 2890 ** An authorizer is used when [sqlite3_prepare | preparing] 2891 ** SQL statements from an untrusted source, to ensure that the SQL statements 2892 ** do not try to access data they are not allowed to see, or that they do not 2893 ** try to execute malicious statements that damage the database. For 2894 ** example, an application may allow a user to enter arbitrary 2895 ** SQL queries for evaluation by a database. But the application does 2896 ** not want the user to be able to make arbitrary changes to the 2897 ** database. An authorizer could then be put in place while the 2898 ** user-entered SQL is being [sqlite3_prepare | prepared] that 2899 ** disallows everything except [SELECT] statements. 2900 ** 2901 ** Applications that need to process SQL from untrusted sources 2902 ** might also consider lowering resource limits using [sqlite3_limit()] 2903 ** and limiting database size using the [max_page_count] [PRAGMA] 2904 ** in addition to using an authorizer. 2905 ** 2906 ** ^(Only a single authorizer can be in place on a database connection 2907 ** at a time. Each call to sqlite3_set_authorizer overrides the 2908 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2909 ** The authorizer is disabled by default. 2910 ** 2911 ** The authorizer callback must not do anything that will modify 2912 ** the database connection that invoked the authorizer callback. 2913 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2914 ** database connections for the meaning of "modify" in this paragraph. 2915 ** 2916 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2917 ** statement might be re-prepared during [sqlite3_step()] due to a 2918 ** schema change. Hence, the application should ensure that the 2919 ** correct authorizer callback remains in place during the [sqlite3_step()]. 2920 ** 2921 ** ^Note that the authorizer callback is invoked only during 2922 ** [sqlite3_prepare()] or its variants. Authorization is not 2923 ** performed during statement evaluation in [sqlite3_step()], unless 2924 ** as stated in the previous paragraph, sqlite3_step() invokes 2925 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2926 */ 2927 SQLITE_API int sqlite3_set_authorizer( 2928 sqlite3*, 2929 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2930 void *pUserData 2931 ); 2932 2933 /* 2934 ** CAPI3REF: Authorizer Return Codes 2935 ** 2936 ** The [sqlite3_set_authorizer | authorizer callback function] must 2937 ** return either [SQLITE_OK] or one of these two constants in order 2938 ** to signal SQLite whether or not the action is permitted. See the 2939 ** [sqlite3_set_authorizer | authorizer documentation] for additional 2940 ** information. 2941 ** 2942 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2943 ** returned from the [sqlite3_vtab_on_conflict()] interface. 2944 */ 2945 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2946 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2947 2948 /* 2949 ** CAPI3REF: Authorizer Action Codes 2950 ** 2951 ** The [sqlite3_set_authorizer()] interface registers a callback function 2952 ** that is invoked to authorize certain SQL statement actions. The 2953 ** second parameter to the callback is an integer code that specifies 2954 ** what action is being authorized. These are the integer action codes that 2955 ** the authorizer callback may be passed. 2956 ** 2957 ** These action code values signify what kind of operation is to be 2958 ** authorized. The 3rd and 4th parameters to the authorization 2959 ** callback function will be parameters or NULL depending on which of these 2960 ** codes is used as the second parameter. ^(The 5th parameter to the 2961 ** authorizer callback is the name of the database ("main", "temp", 2962 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2963 ** is the name of the inner-most trigger or view that is responsible for 2964 ** the access attempt or NULL if this access attempt is directly from 2965 ** top-level SQL code. 2966 */ 2967 /******************************************* 3rd ************ 4th ***********/ 2968 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2969 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2970 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2971 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2972 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2973 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2974 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2975 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2976 #define SQLITE_DELETE 9 /* Table Name NULL */ 2977 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2978 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2979 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2980 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2981 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2982 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2983 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2984 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2985 #define SQLITE_INSERT 18 /* Table Name NULL */ 2986 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2987 #define SQLITE_READ 20 /* Table Name Column Name */ 2988 #define SQLITE_SELECT 21 /* NULL NULL */ 2989 #define SQLITE_TRANSACTION 22 /* Operation NULL */ 2990 #define SQLITE_UPDATE 23 /* Table Name Column Name */ 2991 #define SQLITE_ATTACH 24 /* Filename NULL */ 2992 #define SQLITE_DETACH 25 /* Database Name NULL */ 2993 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2994 #define SQLITE_REINDEX 27 /* Index Name NULL */ 2995 #define SQLITE_ANALYZE 28 /* Table Name NULL */ 2996 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2997 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2998 #define SQLITE_FUNCTION 31 /* NULL Function Name */ 2999 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 3000 #define SQLITE_COPY 0 /* No longer used */ 3001 #define SQLITE_RECURSIVE 33 /* NULL NULL */ 3002 3003 /* 3004 ** CAPI3REF: Tracing And Profiling Functions 3005 ** METHOD: sqlite3 3006 ** 3007 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 3008 ** instead of the routines described here. 3009 ** 3010 ** These routines register callback functions that can be used for 3011 ** tracing and profiling the execution of SQL statements. 3012 ** 3013 ** ^The callback function registered by sqlite3_trace() is invoked at 3014 ** various times when an SQL statement is being run by [sqlite3_step()]. 3015 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 3016 ** SQL statement text as the statement first begins executing. 3017 ** ^(Additional sqlite3_trace() callbacks might occur 3018 ** as each triggered subprogram is entered. The callbacks for triggers 3019 ** contain a UTF-8 SQL comment that identifies the trigger.)^ 3020 ** 3021 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 3022 ** the length of [bound parameter] expansion in the output of sqlite3_trace(). 3023 ** 3024 ** ^The callback function registered by sqlite3_profile() is invoked 3025 ** as each SQL statement finishes. ^The profile callback contains 3026 ** the original statement text and an estimate of wall-clock time 3027 ** of how long that statement took to run. ^The profile callback 3028 ** time is in units of nanoseconds, however the current implementation 3029 ** is only capable of millisecond resolution so the six least significant 3030 ** digits in the time are meaningless. Future versions of SQLite 3031 ** might provide greater resolution on the profiler callback. Invoking 3032 ** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the 3033 ** profile callback. 3034 */ 3035 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 3036 void(*xTrace)(void*,const char*), void*); 3037 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 3038 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 3039 3040 /* 3041 ** CAPI3REF: SQL Trace Event Codes 3042 ** KEYWORDS: SQLITE_TRACE 3043 ** 3044 ** These constants identify classes of events that can be monitored 3045 ** using the [sqlite3_trace_v2()] tracing logic. The M argument 3046 ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 3047 ** the following constants. ^The first argument to the trace callback 3048 ** is one of the following constants. 3049 ** 3050 ** New tracing constants may be added in future releases. 3051 ** 3052 ** ^A trace callback has four arguments: xCallback(T,C,P,X). 3053 ** ^The T argument is one of the integer type codes above. 3054 ** ^The C argument is a copy of the context pointer passed in as the 3055 ** fourth argument to [sqlite3_trace_v2()]. 3056 ** The P and X arguments are pointers whose meanings depend on T. 3057 ** 3058 ** <dl> 3059 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3060 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3061 ** first begins running and possibly at other times during the 3062 ** execution of the prepared statement, such as at the start of each 3063 ** trigger subprogram. ^The P argument is a pointer to the 3064 ** [prepared statement]. ^The X argument is a pointer to a string which 3065 ** is the unexpanded SQL text of the prepared statement or an SQL comment 3066 ** that indicates the invocation of a trigger. ^The callback can compute 3067 ** the same text that would have been returned by the legacy [sqlite3_trace()] 3068 ** interface by using the X argument when X begins with "--" and invoking 3069 ** [sqlite3_expanded_sql(P)] otherwise. 3070 ** 3071 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3072 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3073 ** information as is provided by the [sqlite3_profile()] callback. 3074 ** ^The P argument is a pointer to the [prepared statement] and the 3075 ** X argument points to a 64-bit integer which is the estimated of 3076 ** the number of nanosecond that the prepared statement took to run. 3077 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3078 ** 3079 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3080 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3081 ** statement generates a single row of result. 3082 ** ^The P argument is a pointer to the [prepared statement] and the 3083 ** X argument is unused. 3084 ** 3085 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3086 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3087 ** connection closes. 3088 ** ^The P argument is a pointer to the [database connection] object 3089 ** and the X argument is unused. 3090 ** </dl> 3091 */ 3092 #define SQLITE_TRACE_STMT 0x01 3093 #define SQLITE_TRACE_PROFILE 0x02 3094 #define SQLITE_TRACE_ROW 0x04 3095 #define SQLITE_TRACE_CLOSE 0x08 3096 3097 /* 3098 ** CAPI3REF: SQL Trace Hook 3099 ** METHOD: sqlite3 3100 ** 3101 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3102 ** function X against [database connection] D, using property mask M 3103 ** and context pointer P. ^If the X callback is 3104 ** NULL or if the M mask is zero, then tracing is disabled. The 3105 ** M argument should be the bitwise OR-ed combination of 3106 ** zero or more [SQLITE_TRACE] constants. 3107 ** 3108 ** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3109 ** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3110 ** 3111 ** ^The X callback is invoked whenever any of the events identified by 3112 ** mask M occur. ^The integer return value from the callback is currently 3113 ** ignored, though this may change in future releases. Callback 3114 ** implementations should return zero to ensure future compatibility. 3115 ** 3116 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3117 ** ^The T argument is one of the [SQLITE_TRACE] 3118 ** constants to indicate why the callback was invoked. 3119 ** ^The C argument is a copy of the context pointer. 3120 ** The P and X arguments are pointers whose meanings depend on T. 3121 ** 3122 ** The sqlite3_trace_v2() interface is intended to replace the legacy 3123 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3124 ** are deprecated. 3125 */ 3126 SQLITE_API int sqlite3_trace_v2( 3127 sqlite3*, 3128 unsigned uMask, 3129 int(*xCallback)(unsigned,void*,void*,void*), 3130 void *pCtx 3131 ); 3132 3133 /* 3134 ** CAPI3REF: Query Progress Callbacks 3135 ** METHOD: sqlite3 3136 ** 3137 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3138 ** function X to be invoked periodically during long running calls to 3139 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3140 ** database connection D. An example use for this 3141 ** interface is to keep a GUI updated during a large query. 3142 ** 3143 ** ^The parameter P is passed through as the only parameter to the 3144 ** callback function X. ^The parameter N is the approximate number of 3145 ** [virtual machine instructions] that are evaluated between successive 3146 ** invocations of the callback X. ^If N is less than one then the progress 3147 ** handler is disabled. 3148 ** 3149 ** ^Only a single progress handler may be defined at one time per 3150 ** [database connection]; setting a new progress handler cancels the 3151 ** old one. ^Setting parameter X to NULL disables the progress handler. 3152 ** ^The progress handler is also disabled by setting N to a value less 3153 ** than 1. 3154 ** 3155 ** ^If the progress callback returns non-zero, the operation is 3156 ** interrupted. This feature can be used to implement a 3157 ** "Cancel" button on a GUI progress dialog box. 3158 ** 3159 ** The progress handler callback must not do anything that will modify 3160 ** the database connection that invoked the progress handler. 3161 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3162 ** database connections for the meaning of "modify" in this paragraph. 3163 ** 3164 */ 3165 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3166 3167 /* 3168 ** CAPI3REF: Opening A New Database Connection 3169 ** CONSTRUCTOR: sqlite3 3170 ** 3171 ** ^These routines open an SQLite database file as specified by the 3172 ** filename argument. ^The filename argument is interpreted as UTF-8 for 3173 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3174 ** order for sqlite3_open16(). ^(A [database connection] handle is usually 3175 ** returned in *ppDb, even if an error occurs. The only exception is that 3176 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3177 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3178 ** object.)^ ^(If the database is opened (and/or created) successfully, then 3179 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3180 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3181 ** an English language description of the error following a failure of any 3182 ** of the sqlite3_open() routines. 3183 ** 3184 ** ^The default encoding will be UTF-8 for databases created using 3185 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3186 ** created using sqlite3_open16() will be UTF-16 in the native byte order. 3187 ** 3188 ** Whether or not an error occurs when it is opened, resources 3189 ** associated with the [database connection] handle should be released by 3190 ** passing it to [sqlite3_close()] when it is no longer required. 3191 ** 3192 ** The sqlite3_open_v2() interface works like sqlite3_open() 3193 ** except that it accepts two additional parameters for additional control 3194 ** over the new database connection. ^(The flags parameter to 3195 ** sqlite3_open_v2() can take one of 3196 ** the following three values, optionally combined with the 3197 ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 3198 ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 3199 ** 3200 ** <dl> 3201 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3202 ** <dd>The database is opened in read-only mode. If the database does not 3203 ** already exist, an error is returned.</dd>)^ 3204 ** 3205 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3206 ** <dd>The database is opened for reading and writing if possible, or reading 3207 ** only if the file is write protected by the operating system. In either 3208 ** case the database must already exist, otherwise an error is returned.</dd>)^ 3209 ** 3210 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3211 ** <dd>The database is opened for reading and writing, and is created if 3212 ** it does not already exist. This is the behavior that is always used for 3213 ** sqlite3_open() and sqlite3_open16().</dd>)^ 3214 ** </dl> 3215 ** 3216 ** If the 3rd parameter to sqlite3_open_v2() is not one of the 3217 ** combinations shown above optionally combined with other 3218 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3219 ** then the behavior is undefined. 3220 ** 3221 ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 3222 ** opens in the multi-thread [threading mode] as long as the single-thread 3223 ** mode has not been set at compile-time or start-time. ^If the 3224 ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 3225 ** in the serialized [threading mode] unless single-thread was 3226 ** previously selected at compile-time or start-time. 3227 ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 3228 ** eligible to use [shared cache mode], regardless of whether or not shared 3229 ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 3230 ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 3231 ** participate in [shared cache mode] even if it is enabled. 3232 ** 3233 ** ^The fourth parameter to sqlite3_open_v2() is the name of the 3234 ** [sqlite3_vfs] object that defines the operating system interface that 3235 ** the new database connection should use. ^If the fourth parameter is 3236 ** a NULL pointer then the default [sqlite3_vfs] object is used. 3237 ** 3238 ** ^If the filename is ":memory:", then a private, temporary in-memory database 3239 ** is created for the connection. ^This in-memory database will vanish when 3240 ** the database connection is closed. Future versions of SQLite might 3241 ** make use of additional special filenames that begin with the ":" character. 3242 ** It is recommended that when a database filename actually does begin with 3243 ** a ":" character you should prefix the filename with a pathname such as 3244 ** "./" to avoid ambiguity. 3245 ** 3246 ** ^If the filename is an empty string, then a private, temporary 3247 ** on-disk database will be created. ^This private database will be 3248 ** automatically deleted as soon as the database connection is closed. 3249 ** 3250 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3251 ** 3252 ** ^If [URI filename] interpretation is enabled, and the filename argument 3253 ** begins with "file:", then the filename is interpreted as a URI. ^URI 3254 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3255 ** set in the third argument to sqlite3_open_v2(), or if it has 3256 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3257 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3258 ** URI filename interpretation is turned off 3259 ** by default, but future releases of SQLite might enable URI filename 3260 ** interpretation by default. See "[URI filenames]" for additional 3261 ** information. 3262 ** 3263 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3264 ** authority, then it must be either an empty string or the string 3265 ** "localhost". ^If the authority is not an empty string or "localhost", an 3266 ** error is returned to the caller. ^The fragment component of a URI, if 3267 ** present, is ignored. 3268 ** 3269 ** ^SQLite uses the path component of the URI as the name of the disk file 3270 ** which contains the database. ^If the path begins with a '/' character, 3271 ** then it is interpreted as an absolute path. ^If the path does not begin 3272 ** with a '/' (meaning that the authority section is omitted from the URI) 3273 ** then the path is interpreted as a relative path. 3274 ** ^(On windows, the first component of an absolute path 3275 ** is a drive specification (e.g. "C:").)^ 3276 ** 3277 ** [[core URI query parameters]] 3278 ** The query component of a URI may contain parameters that are interpreted 3279 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3280 ** SQLite and its built-in [VFSes] interpret the 3281 ** following query parameters: 3282 ** 3283 ** <ul> 3284 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3285 ** a VFS object that provides the operating system interface that should 3286 ** be used to access the database file on disk. ^If this option is set to 3287 ** an empty string the default VFS object is used. ^Specifying an unknown 3288 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3289 ** present, then the VFS specified by the option takes precedence over 3290 ** the value passed as the fourth parameter to sqlite3_open_v2(). 3291 ** 3292 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3293 ** "rwc", or "memory". Attempting to set it to any other value is 3294 ** an error)^. 3295 ** ^If "ro" is specified, then the database is opened for read-only 3296 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3297 ** third argument to sqlite3_open_v2(). ^If the mode option is set to 3298 ** "rw", then the database is opened for read-write (but not create) 3299 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3300 ** been set. ^Value "rwc" is equivalent to setting both 3301 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3302 ** set to "memory" then a pure [in-memory database] that never reads 3303 ** or writes from disk is used. ^It is an error to specify a value for 3304 ** the mode parameter that is less restrictive than that specified by 3305 ** the flags passed in the third parameter to sqlite3_open_v2(). 3306 ** 3307 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3308 ** "private". ^Setting it to "shared" is equivalent to setting the 3309 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3310 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3311 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3312 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3313 ** a URI filename, its value overrides any behavior requested by setting 3314 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3315 ** 3316 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3317 ** [powersafe overwrite] property does or does not apply to the 3318 ** storage media on which the database file resides. 3319 ** 3320 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3321 ** which if set disables file locking in rollback journal modes. This 3322 ** is useful for accessing a database on a filesystem that does not 3323 ** support locking. Caution: Database corruption might result if two 3324 ** or more processes write to the same database and any one of those 3325 ** processes uses nolock=1. 3326 ** 3327 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3328 ** parameter that indicates that the database file is stored on 3329 ** read-only media. ^When immutable is set, SQLite assumes that the 3330 ** database file cannot be changed, even by a process with higher 3331 ** privilege, and so the database is opened read-only and all locking 3332 ** and change detection is disabled. Caution: Setting the immutable 3333 ** property on a database file that does in fact change can result 3334 ** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3335 ** See also: [SQLITE_IOCAP_IMMUTABLE]. 3336 ** 3337 ** </ul> 3338 ** 3339 ** ^Specifying an unknown parameter in the query component of a URI is not an 3340 ** error. Future versions of SQLite might understand additional query 3341 ** parameters. See "[query parameters with special meaning to SQLite]" for 3342 ** additional information. 3343 ** 3344 ** [[URI filename examples]] <h3>URI filename examples</h3> 3345 ** 3346 ** <table border="1" align=center cellpadding=5> 3347 ** <tr><th> URI filenames <th> Results 3348 ** <tr><td> file:data.db <td> 3349 ** Open the file "data.db" in the current directory. 3350 ** <tr><td> file:/home/fred/data.db<br> 3351 ** file:///home/fred/data.db <br> 3352 ** file://localhost/home/fred/data.db <br> <td> 3353 ** Open the database file "/home/fred/data.db". 3354 ** <tr><td> file://darkstar/home/fred/data.db <td> 3355 ** An error. "darkstar" is not a recognized authority. 3356 ** <tr><td style="white-space:nowrap"> 3357 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3358 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3359 ** C:. Note that the %20 escaping in this example is not strictly 3360 ** necessary - space characters can be used literally 3361 ** in URI filenames. 3362 ** <tr><td> file:data.db?mode=ro&cache=private <td> 3363 ** Open file "data.db" in the current directory for read-only access. 3364 ** Regardless of whether or not shared-cache mode is enabled by 3365 ** default, use a private cache. 3366 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3367 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3368 ** that uses dot-files in place of posix advisory locking. 3369 ** <tr><td> file:data.db?mode=readonly <td> 3370 ** An error. "readonly" is not a valid option for the "mode" parameter. 3371 ** </table> 3372 ** 3373 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3374 ** query components of a URI. A hexadecimal escape sequence consists of a 3375 ** percent sign - "%" - followed by exactly two hexadecimal digits 3376 ** specifying an octet value. ^Before the path or query components of a 3377 ** URI filename are interpreted, they are encoded using UTF-8 and all 3378 ** hexadecimal escape sequences replaced by a single byte containing the 3379 ** corresponding octet. If this process generates an invalid UTF-8 encoding, 3380 ** the results are undefined. 3381 ** 3382 ** <b>Note to Windows users:</b> The encoding used for the filename argument 3383 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3384 ** codepage is currently defined. Filenames containing international 3385 ** characters must be converted to UTF-8 prior to passing them into 3386 ** sqlite3_open() or sqlite3_open_v2(). 3387 ** 3388 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3389 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3390 ** features that require the use of temporary files may fail. 3391 ** 3392 ** See also: [sqlite3_temp_directory] 3393 */ 3394 SQLITE_API int sqlite3_open( 3395 const char *filename, /* Database filename (UTF-8) */ 3396 sqlite3 **ppDb /* OUT: SQLite db handle */ 3397 ); 3398 SQLITE_API int sqlite3_open16( 3399 const void *filename, /* Database filename (UTF-16) */ 3400 sqlite3 **ppDb /* OUT: SQLite db handle */ 3401 ); 3402 SQLITE_API int sqlite3_open_v2( 3403 const char *filename, /* Database filename (UTF-8) */ 3404 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3405 int flags, /* Flags */ 3406 const char *zVfs /* Name of VFS module to use */ 3407 ); 3408 3409 /* 3410 ** CAPI3REF: Obtain Values For URI Parameters 3411 ** 3412 ** These are utility routines, useful to VFS implementations, that check 3413 ** to see if a database file was a URI that contained a specific query 3414 ** parameter, and if so obtains the value of that query parameter. 3415 ** 3416 ** If F is the database filename pointer passed into the xOpen() method of 3417 ** a VFS implementation when the flags parameter to xOpen() has one or 3418 ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 3419 ** P is the name of the query parameter, then 3420 ** sqlite3_uri_parameter(F,P) returns the value of the P 3421 ** parameter if it exists or a NULL pointer if P does not appear as a 3422 ** query parameter on F. If P is a query parameter of F 3423 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3424 ** a pointer to an empty string. 3425 ** 3426 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3427 ** parameter and returns true (1) or false (0) according to the value 3428 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3429 ** value of query parameter P is one of "yes", "true", or "on" in any 3430 ** case or if the value begins with a non-zero number. The 3431 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3432 ** query parameter P is one of "no", "false", or "off" in any case or 3433 ** if the value begins with a numeric zero. If P is not a query 3434 ** parameter on F or if the value of P is does not match any of the 3435 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3436 ** 3437 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3438 ** 64-bit signed integer and returns that integer, or D if P does not 3439 ** exist. If the value of P is something other than an integer, then 3440 ** zero is returned. 3441 ** 3442 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3443 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3444 ** is not a database file pathname pointer that SQLite passed into the xOpen 3445 ** VFS method, then the behavior of this routine is undefined and probably 3446 ** undesirable. 3447 ** 3448 ** See the [URI filename] documentation for additional information. 3449 */ 3450 SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3451 SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3452 SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3453 3454 3455 /* 3456 ** CAPI3REF: Error Codes And Messages 3457 ** METHOD: sqlite3 3458 ** 3459 ** ^If the most recent sqlite3_* API call associated with 3460 ** [database connection] D failed, then the sqlite3_errcode(D) interface 3461 ** returns the numeric [result code] or [extended result code] for that 3462 ** API call. 3463 ** ^The sqlite3_extended_errcode() 3464 ** interface is the same except that it always returns the 3465 ** [extended result code] even when extended result codes are 3466 ** disabled. 3467 ** 3468 ** The values returned by sqlite3_errcode() and/or 3469 ** sqlite3_extended_errcode() might change with each API call. 3470 ** Except, there are some interfaces that are guaranteed to never 3471 ** change the value of the error code. The error-code preserving 3472 ** interfaces are: 3473 ** 3474 ** <ul> 3475 ** <li> sqlite3_errcode() 3476 ** <li> sqlite3_extended_errcode() 3477 ** <li> sqlite3_errmsg() 3478 ** <li> sqlite3_errmsg16() 3479 ** </ul> 3480 ** 3481 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3482 ** text that describes the error, as either UTF-8 or UTF-16 respectively. 3483 ** ^(Memory to hold the error message string is managed internally. 3484 ** The application does not need to worry about freeing the result. 3485 ** However, the error string might be overwritten or deallocated by 3486 ** subsequent calls to other SQLite interface functions.)^ 3487 ** 3488 ** ^The sqlite3_errstr() interface returns the English-language text 3489 ** that describes the [result code], as UTF-8. 3490 ** ^(Memory to hold the error message string is managed internally 3491 ** and must not be freed by the application)^. 3492 ** 3493 ** When the serialized [threading mode] is in use, it might be the 3494 ** case that a second error occurs on a separate thread in between 3495 ** the time of the first error and the call to these interfaces. 3496 ** When that happens, the second error will be reported since these 3497 ** interfaces always report the most recent result. To avoid 3498 ** this, each thread can obtain exclusive use of the [database connection] D 3499 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3500 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3501 ** all calls to the interfaces listed here are completed. 3502 ** 3503 ** If an interface fails with SQLITE_MISUSE, that means the interface 3504 ** was invoked incorrectly by the application. In that case, the 3505 ** error code and message may or may not be set. 3506 */ 3507 SQLITE_API int sqlite3_errcode(sqlite3 *db); 3508 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 3509 SQLITE_API const char *sqlite3_errmsg(sqlite3*); 3510 SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 3511 SQLITE_API const char *sqlite3_errstr(int); 3512 3513 /* 3514 ** CAPI3REF: Prepared Statement Object 3515 ** KEYWORDS: {prepared statement} {prepared statements} 3516 ** 3517 ** An instance of this object represents a single SQL statement that 3518 ** has been compiled into binary form and is ready to be evaluated. 3519 ** 3520 ** Think of each SQL statement as a separate computer program. The 3521 ** original SQL text is source code. A prepared statement object 3522 ** is the compiled object code. All SQL must be converted into a 3523 ** prepared statement before it can be run. 3524 ** 3525 ** The life-cycle of a prepared statement object usually goes like this: 3526 ** 3527 ** <ol> 3528 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3529 ** <li> Bind values to [parameters] using the sqlite3_bind_*() 3530 ** interfaces. 3531 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3532 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3533 ** to step 2. Do this zero or more times. 3534 ** <li> Destroy the object using [sqlite3_finalize()]. 3535 ** </ol> 3536 */ 3537 typedef struct sqlite3_stmt sqlite3_stmt; 3538 3539 /* 3540 ** CAPI3REF: Run-time Limits 3541 ** METHOD: sqlite3 3542 ** 3543 ** ^(This interface allows the size of various constructs to be limited 3544 ** on a connection by connection basis. The first parameter is the 3545 ** [database connection] whose limit is to be set or queried. The 3546 ** second parameter is one of the [limit categories] that define a 3547 ** class of constructs to be size limited. The third parameter is the 3548 ** new limit for that construct.)^ 3549 ** 3550 ** ^If the new limit is a negative number, the limit is unchanged. 3551 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3552 ** [limits | hard upper bound] 3553 ** set at compile-time by a C preprocessor macro called 3554 ** [limits | SQLITE_MAX_<i>NAME</i>]. 3555 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3556 ** ^Attempts to increase a limit above its hard upper bound are 3557 ** silently truncated to the hard upper bound. 3558 ** 3559 ** ^Regardless of whether or not the limit was changed, the 3560 ** [sqlite3_limit()] interface returns the prior value of the limit. 3561 ** ^Hence, to find the current value of a limit without changing it, 3562 ** simply invoke this interface with the third parameter set to -1. 3563 ** 3564 ** Run-time limits are intended for use in applications that manage 3565 ** both their own internal database and also databases that are controlled 3566 ** by untrusted external sources. An example application might be a 3567 ** web browser that has its own databases for storing history and 3568 ** separate databases controlled by JavaScript applications downloaded 3569 ** off the Internet. The internal databases can be given the 3570 ** large, default limits. Databases managed by external sources can 3571 ** be given much smaller limits designed to prevent a denial of service 3572 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3573 ** interface to further control untrusted SQL. The size of the database 3574 ** created by an untrusted script can be contained using the 3575 ** [max_page_count] [PRAGMA]. 3576 ** 3577 ** New run-time limit categories may be added in future releases. 3578 */ 3579 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 3580 3581 /* 3582 ** CAPI3REF: Run-Time Limit Categories 3583 ** KEYWORDS: {limit category} {*limit categories} 3584 ** 3585 ** These constants define various performance limits 3586 ** that can be lowered at run-time using [sqlite3_limit()]. 3587 ** The synopsis of the meanings of the various limits is shown below. 3588 ** Additional information is available at [limits | Limits in SQLite]. 3589 ** 3590 ** <dl> 3591 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3592 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3593 ** 3594 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3595 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3596 ** 3597 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3598 ** <dd>The maximum number of columns in a table definition or in the 3599 ** result set of a [SELECT] or the maximum number of columns in an index 3600 ** or in an ORDER BY or GROUP BY clause.</dd>)^ 3601 ** 3602 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3603 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3604 ** 3605 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3606 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3607 ** 3608 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3609 ** <dd>The maximum number of instructions in a virtual machine program 3610 ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 3611 ** the equivalent tries to allocate space for more than this many opcodes 3612 ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 3613 ** 3614 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3615 ** <dd>The maximum number of arguments on a function.</dd>)^ 3616 ** 3617 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3618 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3619 ** 3620 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3621 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3622 ** <dd>The maximum length of the pattern argument to the [LIKE] or 3623 ** [GLOB] operators.</dd>)^ 3624 ** 3625 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3626 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3627 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3628 ** 3629 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3630 ** <dd>The maximum depth of recursion for triggers.</dd>)^ 3631 ** 3632 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3633 ** <dd>The maximum number of auxiliary worker threads that a single 3634 ** [prepared statement] may start.</dd>)^ 3635 ** </dl> 3636 */ 3637 #define SQLITE_LIMIT_LENGTH 0 3638 #define SQLITE_LIMIT_SQL_LENGTH 1 3639 #define SQLITE_LIMIT_COLUMN 2 3640 #define SQLITE_LIMIT_EXPR_DEPTH 3 3641 #define SQLITE_LIMIT_COMPOUND_SELECT 4 3642 #define SQLITE_LIMIT_VDBE_OP 5 3643 #define SQLITE_LIMIT_FUNCTION_ARG 6 3644 #define SQLITE_LIMIT_ATTACHED 7 3645 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3646 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 3647 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 3648 #define SQLITE_LIMIT_WORKER_THREADS 11 3649 3650 /* 3651 ** CAPI3REF: Prepare Flags 3652 ** 3653 ** These constants define various flags that can be passed into 3654 ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 3655 ** [sqlite3_prepare16_v3()] interfaces. 3656 ** 3657 ** New flags may be added in future releases of SQLite. 3658 ** 3659 ** <dl> 3660 ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 3661 ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 3662 ** that the prepared statement will be retained for a long time and 3663 ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 3664 ** and [sqlite3_prepare16_v3()] assume that the prepared statement will 3665 ** be used just once or at most a few times and then destroyed using 3666 ** [sqlite3_finalize()] relatively soon. The current implementation acts 3667 ** on this hint by avoiding the use of [lookaside memory] so as not to 3668 ** deplete the limited store of lookaside memory. Future versions of 3669 ** SQLite may act on this hint differently. 3670 ** 3671 ** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt> 3672 ** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used 3673 ** to be required for any prepared statement that wanted to use the 3674 ** [sqlite3_normalized_sql()] interface. However, the 3675 ** [sqlite3_normalized_sql()] interface is now available to all 3676 ** prepared statements, regardless of whether or not they use this 3677 ** flag. 3678 ** 3679 ** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt> 3680 ** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler 3681 ** to return an error (error code SQLITE_ERROR) if the statement uses 3682 ** any virtual tables. 3683 ** </dl> 3684 */ 3685 #define SQLITE_PREPARE_PERSISTENT 0x01 3686 #define SQLITE_PREPARE_NORMALIZE 0x02 3687 #define SQLITE_PREPARE_NO_VTAB 0x04 3688 3689 /* 3690 ** CAPI3REF: Compiling An SQL Statement 3691 ** KEYWORDS: {SQL statement compiler} 3692 ** METHOD: sqlite3 3693 ** CONSTRUCTOR: sqlite3_stmt 3694 ** 3695 ** To execute an SQL statement, it must first be compiled into a byte-code 3696 ** program using one of these routines. Or, in other words, these routines 3697 ** are constructors for the [prepared statement] object. 3698 ** 3699 ** The preferred routine to use is [sqlite3_prepare_v2()]. The 3700 ** [sqlite3_prepare()] interface is legacy and should be avoided. 3701 ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 3702 ** for special purposes. 3703 ** 3704 ** The use of the UTF-8 interfaces is preferred, as SQLite currently 3705 ** does all parsing using UTF-8. The UTF-16 interfaces are provided 3706 ** as a convenience. The UTF-16 interfaces work by converting the 3707 ** input text into UTF-8, then invoking the corresponding UTF-8 interface. 3708 ** 3709 ** The first argument, "db", is a [database connection] obtained from a 3710 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3711 ** [sqlite3_open16()]. The database connection must not have been closed. 3712 ** 3713 ** The second argument, "zSql", is the statement to be compiled, encoded 3714 ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 3715 ** and sqlite3_prepare_v3() 3716 ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 3717 ** and sqlite3_prepare16_v3() use UTF-16. 3718 ** 3719 ** ^If the nByte argument is negative, then zSql is read up to the 3720 ** first zero terminator. ^If nByte is positive, then it is the 3721 ** number of bytes read from zSql. ^If nByte is zero, then no prepared 3722 ** statement is generated. 3723 ** If the caller knows that the supplied string is nul-terminated, then 3724 ** there is a small performance advantage to passing an nByte parameter that 3725 ** is the number of bytes in the input string <i>including</i> 3726 ** the nul-terminator. 3727 ** 3728 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3729 ** past the end of the first SQL statement in zSql. These routines only 3730 ** compile the first statement in zSql, so *pzTail is left pointing to 3731 ** what remains uncompiled. 3732 ** 3733 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3734 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3735 ** to NULL. ^If the input text contains no SQL (if the input is an empty 3736 ** string or a comment) then *ppStmt is set to NULL. 3737 ** The calling procedure is responsible for deleting the compiled 3738 ** SQL statement using [sqlite3_finalize()] after it has finished with it. 3739 ** ppStmt may not be NULL. 3740 ** 3741 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3742 ** otherwise an [error code] is returned. 3743 ** 3744 ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 3745 ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 3746 ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 3747 ** are retained for backwards compatibility, but their use is discouraged. 3748 ** ^In the "vX" interfaces, the prepared statement 3749 ** that is returned (the [sqlite3_stmt] object) contains a copy of the 3750 ** original SQL text. This causes the [sqlite3_step()] interface to 3751 ** behave differently in three ways: 3752 ** 3753 ** <ol> 3754 ** <li> 3755 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3756 ** always used to do, [sqlite3_step()] will automatically recompile the SQL 3757 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3758 ** retries will occur before sqlite3_step() gives up and returns an error. 3759 ** </li> 3760 ** 3761 ** <li> 3762 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3763 ** [error codes] or [extended error codes]. ^The legacy behavior was that 3764 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3765 ** and the application would have to make a second call to [sqlite3_reset()] 3766 ** in order to find the underlying cause of the problem. With the "v2" prepare 3767 ** interfaces, the underlying reason for the error is returned immediately. 3768 ** </li> 3769 ** 3770 ** <li> 3771 ** ^If the specific value bound to [parameter | host parameter] in the 3772 ** WHERE clause might influence the choice of query plan for a statement, 3773 ** then the statement will be automatically recompiled, as if there had been 3774 ** a schema change, on the first [sqlite3_step()] call following any change 3775 ** to the [sqlite3_bind_text | bindings] of that [parameter]. 3776 ** ^The specific value of WHERE-clause [parameter] might influence the 3777 ** choice of query plan if the parameter is the left-hand side of a [LIKE] 3778 ** or [GLOB] operator or if the parameter is compared to an indexed column 3779 ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3780 ** </li> 3781 ** </ol> 3782 ** 3783 ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 3784 ** the extra prepFlags parameter, which is a bit array consisting of zero or 3785 ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 3786 ** sqlite3_prepare_v2() interface works exactly the same as 3787 ** sqlite3_prepare_v3() with a zero prepFlags parameter. 3788 */ 3789 SQLITE_API int sqlite3_prepare( 3790 sqlite3 *db, /* Database handle */ 3791 const char *zSql, /* SQL statement, UTF-8 encoded */ 3792 int nByte, /* Maximum length of zSql in bytes. */ 3793 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3794 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3795 ); 3796 SQLITE_API int sqlite3_prepare_v2( 3797 sqlite3 *db, /* Database handle */ 3798 const char *zSql, /* SQL statement, UTF-8 encoded */ 3799 int nByte, /* Maximum length of zSql in bytes. */ 3800 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3801 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3802 ); 3803 SQLITE_API int sqlite3_prepare_v3( 3804 sqlite3 *db, /* Database handle */ 3805 const char *zSql, /* SQL statement, UTF-8 encoded */ 3806 int nByte, /* Maximum length of zSql in bytes. */ 3807 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3808 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3809 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3810 ); 3811 SQLITE_API int sqlite3_prepare16( 3812 sqlite3 *db, /* Database handle */ 3813 const void *zSql, /* SQL statement, UTF-16 encoded */ 3814 int nByte, /* Maximum length of zSql in bytes. */ 3815 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3816 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3817 ); 3818 SQLITE_API int sqlite3_prepare16_v2( 3819 sqlite3 *db, /* Database handle */ 3820 const void *zSql, /* SQL statement, UTF-16 encoded */ 3821 int nByte, /* Maximum length of zSql in bytes. */ 3822 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3823 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3824 ); 3825 SQLITE_API int sqlite3_prepare16_v3( 3826 sqlite3 *db, /* Database handle */ 3827 const void *zSql, /* SQL statement, UTF-16 encoded */ 3828 int nByte, /* Maximum length of zSql in bytes. */ 3829 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3830 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3831 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3832 ); 3833 3834 /* 3835 ** CAPI3REF: Retrieving Statement SQL 3836 ** METHOD: sqlite3_stmt 3837 ** 3838 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 3839 ** SQL text used to create [prepared statement] P if P was 3840 ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 3841 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 3842 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 3843 ** string containing the SQL text of prepared statement P with 3844 ** [bound parameters] expanded. 3845 ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 3846 ** string containing the normalized SQL text of prepared statement P. The 3847 ** semantics used to normalize a SQL statement are unspecified and subject 3848 ** to change. At a minimum, literal values will be replaced with suitable 3849 ** placeholders. 3850 ** 3851 ** ^(For example, if a prepared statement is created using the SQL 3852 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 3853 ** and parameter :xyz is unbound, then sqlite3_sql() will return 3854 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 3855 ** will return "SELECT 2345,NULL".)^ 3856 ** 3857 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 3858 ** is available to hold the result, or if the result would exceed the 3859 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 3860 ** 3861 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 3862 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 3863 ** option causes sqlite3_expanded_sql() to always return NULL. 3864 ** 3865 ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) 3866 ** are managed by SQLite and are automatically freed when the prepared 3867 ** statement is finalized. 3868 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 3869 ** is obtained from [sqlite3_malloc()] and must be free by the application 3870 ** by passing it to [sqlite3_free()]. 3871 */ 3872 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 3873 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 3874 SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); 3875 3876 /* 3877 ** CAPI3REF: Determine If An SQL Statement Writes The Database 3878 ** METHOD: sqlite3_stmt 3879 ** 3880 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3881 ** and only if the [prepared statement] X makes no direct changes to 3882 ** the content of the database file. 3883 ** 3884 ** Note that [application-defined SQL functions] or 3885 ** [virtual tables] might change the database indirectly as a side effect. 3886 ** ^(For example, if an application defines a function "eval()" that 3887 ** calls [sqlite3_exec()], then the following SQL statement would 3888 ** change the database file through side-effects: 3889 ** 3890 ** <blockquote><pre> 3891 ** SELECT eval('DELETE FROM t1') FROM t2; 3892 ** </pre></blockquote> 3893 ** 3894 ** But because the [SELECT] statement does not change the database file 3895 ** directly, sqlite3_stmt_readonly() would still return true.)^ 3896 ** 3897 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3898 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3899 ** since the statements themselves do not actually modify the database but 3900 ** rather they control the timing of when other statements modify the 3901 ** database. ^The [ATTACH] and [DETACH] statements also cause 3902 ** sqlite3_stmt_readonly() to return true since, while those statements 3903 ** change the configuration of a database connection, they do not make 3904 ** changes to the content of the database files on disk. 3905 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 3906 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 3907 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 3908 ** sqlite3_stmt_readonly() returns false for those commands. 3909 */ 3910 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3911 3912 /* 3913 ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement 3914 ** METHOD: sqlite3_stmt 3915 ** 3916 ** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the 3917 ** prepared statement S is an EXPLAIN statement, or 2 if the 3918 ** statement S is an EXPLAIN QUERY PLAN. 3919 ** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is 3920 ** an ordinary statement or a NULL pointer. 3921 */ 3922 SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt); 3923 3924 /* 3925 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3926 ** METHOD: sqlite3_stmt 3927 ** 3928 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3929 ** [prepared statement] S has been stepped at least once using 3930 ** [sqlite3_step(S)] but has neither run to completion (returned 3931 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor 3932 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3933 ** interface returns false if S is a NULL pointer. If S is not a 3934 ** NULL pointer and is not a pointer to a valid [prepared statement] 3935 ** object, then the behavior is undefined and probably undesirable. 3936 ** 3937 ** This interface can be used in combination [sqlite3_next_stmt()] 3938 ** to locate all prepared statements associated with a database 3939 ** connection that are in need of being reset. This can be used, 3940 ** for example, in diagnostic routines to search for prepared 3941 ** statements that are holding a transaction open. 3942 */ 3943 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 3944 3945 /* 3946 ** CAPI3REF: Dynamically Typed Value Object 3947 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3948 ** 3949 ** SQLite uses the sqlite3_value object to represent all values 3950 ** that can be stored in a database table. SQLite uses dynamic typing 3951 ** for the values it stores. ^Values stored in sqlite3_value objects 3952 ** can be integers, floating point values, strings, BLOBs, or NULL. 3953 ** 3954 ** An sqlite3_value object may be either "protected" or "unprotected". 3955 ** Some interfaces require a protected sqlite3_value. Other interfaces 3956 ** will accept either a protected or an unprotected sqlite3_value. 3957 ** Every interface that accepts sqlite3_value arguments specifies 3958 ** whether or not it requires a protected sqlite3_value. The 3959 ** [sqlite3_value_dup()] interface can be used to construct a new 3960 ** protected sqlite3_value from an unprotected sqlite3_value. 3961 ** 3962 ** The terms "protected" and "unprotected" refer to whether or not 3963 ** a mutex is held. An internal mutex is held for a protected 3964 ** sqlite3_value object but no mutex is held for an unprotected 3965 ** sqlite3_value object. If SQLite is compiled to be single-threaded 3966 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3967 ** or if SQLite is run in one of reduced mutex modes 3968 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3969 ** then there is no distinction between protected and unprotected 3970 ** sqlite3_value objects and they can be used interchangeably. However, 3971 ** for maximum code portability it is recommended that applications 3972 ** still make the distinction between protected and unprotected 3973 ** sqlite3_value objects even when not strictly required. 3974 ** 3975 ** ^The sqlite3_value objects that are passed as parameters into the 3976 ** implementation of [application-defined SQL functions] are protected. 3977 ** ^The sqlite3_value object returned by 3978 ** [sqlite3_column_value()] is unprotected. 3979 ** Unprotected sqlite3_value objects may only be used as arguments 3980 ** to [sqlite3_result_value()], [sqlite3_bind_value()], and 3981 ** [sqlite3_value_dup()]. 3982 ** The [sqlite3_value_blob | sqlite3_value_type()] family of 3983 ** interfaces require protected sqlite3_value objects. 3984 */ 3985 typedef struct sqlite3_value sqlite3_value; 3986 3987 /* 3988 ** CAPI3REF: SQL Function Context Object 3989 ** 3990 ** The context in which an SQL function executes is stored in an 3991 ** sqlite3_context object. ^A pointer to an sqlite3_context object 3992 ** is always first parameter to [application-defined SQL functions]. 3993 ** The application-defined SQL function implementation will pass this 3994 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3995 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3996 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3997 ** and/or [sqlite3_set_auxdata()]. 3998 */ 3999 typedef struct sqlite3_context sqlite3_context; 4000 4001 /* 4002 ** CAPI3REF: Binding Values To Prepared Statements 4003 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 4004 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 4005 ** METHOD: sqlite3_stmt 4006 ** 4007 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 4008 ** literals may be replaced by a [parameter] that matches one of following 4009 ** templates: 4010 ** 4011 ** <ul> 4012 ** <li> ? 4013 ** <li> ?NNN 4014 ** <li> :VVV 4015 ** <li> @VVV 4016 ** <li> $VVV 4017 ** </ul> 4018 ** 4019 ** In the templates above, NNN represents an integer literal, 4020 ** and VVV represents an alphanumeric identifier.)^ ^The values of these 4021 ** parameters (also called "host parameter names" or "SQL parameters") 4022 ** can be set using the sqlite3_bind_*() routines defined here. 4023 ** 4024 ** ^The first argument to the sqlite3_bind_*() routines is always 4025 ** a pointer to the [sqlite3_stmt] object returned from 4026 ** [sqlite3_prepare_v2()] or its variants. 4027 ** 4028 ** ^The second argument is the index of the SQL parameter to be set. 4029 ** ^The leftmost SQL parameter has an index of 1. ^When the same named 4030 ** SQL parameter is used more than once, second and subsequent 4031 ** occurrences have the same index as the first occurrence. 4032 ** ^The index for named parameters can be looked up using the 4033 ** [sqlite3_bind_parameter_index()] API if desired. ^The index 4034 ** for "?NNN" parameters is the value of NNN. 4035 ** ^The NNN value must be between 1 and the [sqlite3_limit()] 4036 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 4037 ** 4038 ** ^The third argument is the value to bind to the parameter. 4039 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4040 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 4041 ** is ignored and the end result is the same as sqlite3_bind_null(). 4042 ** 4043 ** ^(In those routines that have a fourth argument, its value is the 4044 ** number of bytes in the parameter. To be clear: the value is the 4045 ** number of <u>bytes</u> in the value, not the number of characters.)^ 4046 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4047 ** is negative, then the length of the string is 4048 ** the number of bytes up to the first zero terminator. 4049 ** If the fourth parameter to sqlite3_bind_blob() is negative, then 4050 ** the behavior is undefined. 4051 ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 4052 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then 4053 ** that parameter must be the byte offset 4054 ** where the NUL terminator would occur assuming the string were NUL 4055 ** terminated. If any NUL characters occur at byte offsets less than 4056 ** the value of the fourth parameter then the resulting string value will 4057 ** contain embedded NULs. The result of expressions involving strings 4058 ** with embedded NULs is undefined. 4059 ** 4060 ** ^The fifth argument to the BLOB and string binding interfaces 4061 ** is a destructor used to dispose of the BLOB or 4062 ** string after SQLite has finished with it. ^The destructor is called 4063 ** to dispose of the BLOB or string even if the call to the bind API fails, 4064 ** except the destructor is not called if the third parameter is a NULL 4065 ** pointer or the fourth parameter is negative. 4066 ** ^If the fifth argument is 4067 ** the special value [SQLITE_STATIC], then SQLite assumes that the 4068 ** information is in static, unmanaged space and does not need to be freed. 4069 ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 4070 ** SQLite makes its own private copy of the data immediately, before 4071 ** the sqlite3_bind_*() routine returns. 4072 ** 4073 ** ^The sixth argument to sqlite3_bind_text64() must be one of 4074 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 4075 ** to specify the encoding of the text in the third parameter. If 4076 ** the sixth argument to sqlite3_bind_text64() is not one of the 4077 ** allowed values shown above, or if the text encoding is different 4078 ** from the encoding specified by the sixth parameter, then the behavior 4079 ** is undefined. 4080 ** 4081 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 4082 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 4083 ** (just an integer to hold its size) while it is being processed. 4084 ** Zeroblobs are intended to serve as placeholders for BLOBs whose 4085 ** content is later written using 4086 ** [sqlite3_blob_open | incremental BLOB I/O] routines. 4087 ** ^A negative value for the zeroblob results in a zero-length BLOB. 4088 ** 4089 ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 4090 ** [prepared statement] S to have an SQL value of NULL, but to also be 4091 ** associated with the pointer P of type T. ^D is either a NULL pointer or 4092 ** a pointer to a destructor function for P. ^SQLite will invoke the 4093 ** destructor D with a single argument of P when it is finished using 4094 ** P. The T parameter should be a static string, preferably a string 4095 ** literal. The sqlite3_bind_pointer() routine is part of the 4096 ** [pointer passing interface] added for SQLite 3.20.0. 4097 ** 4098 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4099 ** for the [prepared statement] or with a prepared statement for which 4100 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4101 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4102 ** routine is passed a [prepared statement] that has been finalized, the 4103 ** result is undefined and probably harmful. 4104 ** 4105 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4106 ** ^Unbound parameters are interpreted as NULL. 4107 ** 4108 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4109 ** [error code] if anything goes wrong. 4110 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4111 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4112 ** [SQLITE_MAX_LENGTH]. 4113 ** ^[SQLITE_RANGE] is returned if the parameter 4114 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4115 ** 4116 ** See also: [sqlite3_bind_parameter_count()], 4117 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4118 */ 4119 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4120 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4121 void(*)(void*)); 4122 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 4123 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 4124 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4125 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 4126 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4127 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4128 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4129 void(*)(void*), unsigned char encoding); 4130 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4131 SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4132 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4133 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4134 4135 /* 4136 ** CAPI3REF: Number Of SQL Parameters 4137 ** METHOD: sqlite3_stmt 4138 ** 4139 ** ^This routine can be used to find the number of [SQL parameters] 4140 ** in a [prepared statement]. SQL parameters are tokens of the 4141 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4142 ** placeholders for values that are [sqlite3_bind_blob | bound] 4143 ** to the parameters at a later time. 4144 ** 4145 ** ^(This routine actually returns the index of the largest (rightmost) 4146 ** parameter. For all forms except ?NNN, this will correspond to the 4147 ** number of unique parameters. If parameters of the ?NNN form are used, 4148 ** there may be gaps in the list.)^ 4149 ** 4150 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4151 ** [sqlite3_bind_parameter_name()], and 4152 ** [sqlite3_bind_parameter_index()]. 4153 */ 4154 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 4155 4156 /* 4157 ** CAPI3REF: Name Of A Host Parameter 4158 ** METHOD: sqlite3_stmt 4159 ** 4160 ** ^The sqlite3_bind_parameter_name(P,N) interface returns 4161 ** the name of the N-th [SQL parameter] in the [prepared statement] P. 4162 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4163 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4164 ** respectively. 4165 ** In other words, the initial ":" or "$" or "@" or "?" 4166 ** is included as part of the name.)^ 4167 ** ^Parameters of the form "?" without a following integer have no name 4168 ** and are referred to as "nameless" or "anonymous parameters". 4169 ** 4170 ** ^The first host parameter has an index of 1, not 0. 4171 ** 4172 ** ^If the value N is out of range or if the N-th parameter is 4173 ** nameless, then NULL is returned. ^The returned string is 4174 ** always in UTF-8 encoding even if the named parameter was 4175 ** originally specified as UTF-16 in [sqlite3_prepare16()], 4176 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4177 ** 4178 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4179 ** [sqlite3_bind_parameter_count()], and 4180 ** [sqlite3_bind_parameter_index()]. 4181 */ 4182 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4183 4184 /* 4185 ** CAPI3REF: Index Of A Parameter With A Given Name 4186 ** METHOD: sqlite3_stmt 4187 ** 4188 ** ^Return the index of an SQL parameter given its name. ^The 4189 ** index value returned is suitable for use as the second 4190 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4191 ** is returned if no matching parameter is found. ^The parameter 4192 ** name must be given in UTF-8 even if the original statement 4193 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4194 ** [sqlite3_prepare16_v3()]. 4195 ** 4196 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4197 ** [sqlite3_bind_parameter_count()], and 4198 ** [sqlite3_bind_parameter_name()]. 4199 */ 4200 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4201 4202 /* 4203 ** CAPI3REF: Reset All Bindings On A Prepared Statement 4204 ** METHOD: sqlite3_stmt 4205 ** 4206 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4207 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4208 ** ^Use this routine to reset all host parameters to NULL. 4209 */ 4210 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 4211 4212 /* 4213 ** CAPI3REF: Number Of Columns In A Result Set 4214 ** METHOD: sqlite3_stmt 4215 ** 4216 ** ^Return the number of columns in the result set returned by the 4217 ** [prepared statement]. ^If this routine returns 0, that means the 4218 ** [prepared statement] returns no data (for example an [UPDATE]). 4219 ** ^However, just because this routine returns a positive number does not 4220 ** mean that one or more rows of data will be returned. ^A SELECT statement 4221 ** will always have a positive sqlite3_column_count() but depending on the 4222 ** WHERE clause constraints and the table content, it might return no rows. 4223 ** 4224 ** See also: [sqlite3_data_count()] 4225 */ 4226 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 4227 4228 /* 4229 ** CAPI3REF: Column Names In A Result Set 4230 ** METHOD: sqlite3_stmt 4231 ** 4232 ** ^These routines return the name assigned to a particular column 4233 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4234 ** interface returns a pointer to a zero-terminated UTF-8 string 4235 ** and sqlite3_column_name16() returns a pointer to a zero-terminated 4236 ** UTF-16 string. ^The first parameter is the [prepared statement] 4237 ** that implements the [SELECT] statement. ^The second parameter is the 4238 ** column number. ^The leftmost column is number 0. 4239 ** 4240 ** ^The returned string pointer is valid until either the [prepared statement] 4241 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4242 ** reprepared by the first call to [sqlite3_step()] for a particular run 4243 ** or until the next call to 4244 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4245 ** 4246 ** ^If sqlite3_malloc() fails during the processing of either routine 4247 ** (for example during a conversion from UTF-8 to UTF-16) then a 4248 ** NULL pointer is returned. 4249 ** 4250 ** ^The name of a result column is the value of the "AS" clause for 4251 ** that column, if there is an AS clause. If there is no AS clause 4252 ** then the name of the column is unspecified and may change from 4253 ** one release of SQLite to the next. 4254 */ 4255 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 4256 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4257 4258 /* 4259 ** CAPI3REF: Source Of Data In A Query Result 4260 ** METHOD: sqlite3_stmt 4261 ** 4262 ** ^These routines provide a means to determine the database, table, and 4263 ** table column that is the origin of a particular result column in 4264 ** [SELECT] statement. 4265 ** ^The name of the database or table or column can be returned as 4266 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4267 ** the database name, the _table_ routines return the table name, and 4268 ** the origin_ routines return the column name. 4269 ** ^The returned string is valid until the [prepared statement] is destroyed 4270 ** using [sqlite3_finalize()] or until the statement is automatically 4271 ** reprepared by the first call to [sqlite3_step()] for a particular run 4272 ** or until the same information is requested 4273 ** again in a different encoding. 4274 ** 4275 ** ^The names returned are the original un-aliased names of the 4276 ** database, table, and column. 4277 ** 4278 ** ^The first argument to these interfaces is a [prepared statement]. 4279 ** ^These functions return information about the Nth result column returned by 4280 ** the statement, where N is the second function argument. 4281 ** ^The left-most column is column 0 for these routines. 4282 ** 4283 ** ^If the Nth column returned by the statement is an expression or 4284 ** subquery and is not a column value, then all of these functions return 4285 ** NULL. ^These routine might also return NULL if a memory allocation error 4286 ** occurs. ^Otherwise, they return the name of the attached database, table, 4287 ** or column that query result column was extracted from. 4288 ** 4289 ** ^As with all other SQLite APIs, those whose names end with "16" return 4290 ** UTF-16 encoded strings and the other functions return UTF-8. 4291 ** 4292 ** ^These APIs are only available if the library was compiled with the 4293 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4294 ** 4295 ** If two or more threads call one or more of these routines against the same 4296 ** prepared statement and column at the same time then the results are 4297 ** undefined. 4298 ** 4299 ** If two or more threads call one or more 4300 ** [sqlite3_column_database_name | column metadata interfaces] 4301 ** for the same [prepared statement] and result column 4302 ** at the same time then the results are undefined. 4303 */ 4304 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4305 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4306 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4307 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4308 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4309 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4310 4311 /* 4312 ** CAPI3REF: Declared Datatype Of A Query Result 4313 ** METHOD: sqlite3_stmt 4314 ** 4315 ** ^(The first parameter is a [prepared statement]. 4316 ** If this statement is a [SELECT] statement and the Nth column of the 4317 ** returned result set of that [SELECT] is a table column (not an 4318 ** expression or subquery) then the declared type of the table 4319 ** column is returned.)^ ^If the Nth column of the result set is an 4320 ** expression or subquery, then a NULL pointer is returned. 4321 ** ^The returned string is always UTF-8 encoded. 4322 ** 4323 ** ^(For example, given the database schema: 4324 ** 4325 ** CREATE TABLE t1(c1 VARIANT); 4326 ** 4327 ** and the following statement to be compiled: 4328 ** 4329 ** SELECT c1 + 1, c1 FROM t1; 4330 ** 4331 ** this routine would return the string "VARIANT" for the second result 4332 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4333 ** 4334 ** ^SQLite uses dynamic run-time typing. ^So just because a column 4335 ** is declared to contain a particular type does not mean that the 4336 ** data stored in that column is of the declared type. SQLite is 4337 ** strongly typed, but the typing is dynamic not static. ^Type 4338 ** is associated with individual values, not with the containers 4339 ** used to hold those values. 4340 */ 4341 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4342 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4343 4344 /* 4345 ** CAPI3REF: Evaluate An SQL Statement 4346 ** METHOD: sqlite3_stmt 4347 ** 4348 ** After a [prepared statement] has been prepared using any of 4349 ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4350 ** or [sqlite3_prepare16_v3()] or one of the legacy 4351 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4352 ** must be called one or more times to evaluate the statement. 4353 ** 4354 ** The details of the behavior of the sqlite3_step() interface depend 4355 ** on whether the statement was prepared using the newer "vX" interfaces 4356 ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4357 ** [sqlite3_prepare16_v2()] or the older legacy 4358 ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4359 ** new "vX" interface is recommended for new applications but the legacy 4360 ** interface will continue to be supported. 4361 ** 4362 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4363 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4364 ** ^With the "v2" interface, any of the other [result codes] or 4365 ** [extended result codes] might be returned as well. 4366 ** 4367 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4368 ** database locks it needs to do its job. ^If the statement is a [COMMIT] 4369 ** or occurs outside of an explicit transaction, then you can retry the 4370 ** statement. If the statement is not a [COMMIT] and occurs within an 4371 ** explicit transaction then you should rollback the transaction before 4372 ** continuing. 4373 ** 4374 ** ^[SQLITE_DONE] means that the statement has finished executing 4375 ** successfully. sqlite3_step() should not be called again on this virtual 4376 ** machine without first calling [sqlite3_reset()] to reset the virtual 4377 ** machine back to its initial state. 4378 ** 4379 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4380 ** is returned each time a new row of data is ready for processing by the 4381 ** caller. The values may be accessed using the [column access functions]. 4382 ** sqlite3_step() is called again to retrieve the next row of data. 4383 ** 4384 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4385 ** violation) has occurred. sqlite3_step() should not be called again on 4386 ** the VM. More information may be found by calling [sqlite3_errmsg()]. 4387 ** ^With the legacy interface, a more specific error code (for example, 4388 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4389 ** can be obtained by calling [sqlite3_reset()] on the 4390 ** [prepared statement]. ^In the "v2" interface, 4391 ** the more specific error code is returned directly by sqlite3_step(). 4392 ** 4393 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4394 ** Perhaps it was called on a [prepared statement] that has 4395 ** already been [sqlite3_finalize | finalized] or on one that had 4396 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4397 ** be the case that the same database connection is being used by two or 4398 ** more threads at the same moment in time. 4399 ** 4400 ** For all versions of SQLite up to and including 3.6.23.1, a call to 4401 ** [sqlite3_reset()] was required after sqlite3_step() returned anything 4402 ** other than [SQLITE_ROW] before any subsequent invocation of 4403 ** sqlite3_step(). Failure to reset the prepared statement using 4404 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4405 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4406 ** sqlite3_step() began 4407 ** calling [sqlite3_reset()] automatically in this circumstance rather 4408 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4409 ** break because any application that ever receives an SQLITE_MISUSE error 4410 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4411 ** can be used to restore the legacy behavior. 4412 ** 4413 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4414 ** API always returns a generic error code, [SQLITE_ERROR], following any 4415 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4416 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4417 ** specific [error codes] that better describes the error. 4418 ** We admit that this is a goofy design. The problem has been fixed 4419 ** with the "v2" interface. If you prepare all of your SQL statements 4420 ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4421 ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4422 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4423 ** then the more specific [error codes] are returned directly 4424 ** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4425 */ 4426 SQLITE_API int sqlite3_step(sqlite3_stmt*); 4427 4428 /* 4429 ** CAPI3REF: Number of columns in a result set 4430 ** METHOD: sqlite3_stmt 4431 ** 4432 ** ^The sqlite3_data_count(P) interface returns the number of columns in the 4433 ** current row of the result set of [prepared statement] P. 4434 ** ^If prepared statement P does not have results ready to return 4435 ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 4436 ** interfaces) then sqlite3_data_count(P) returns 0. 4437 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4438 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4439 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4440 ** will return non-zero if previous call to [sqlite3_step](P) returned 4441 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4442 ** where it always returns zero since each step of that multi-step 4443 ** pragma returns 0 columns of data. 4444 ** 4445 ** See also: [sqlite3_column_count()] 4446 */ 4447 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 4448 4449 /* 4450 ** CAPI3REF: Fundamental Datatypes 4451 ** KEYWORDS: SQLITE_TEXT 4452 ** 4453 ** ^(Every value in SQLite has one of five fundamental datatypes: 4454 ** 4455 ** <ul> 4456 ** <li> 64-bit signed integer 4457 ** <li> 64-bit IEEE floating point number 4458 ** <li> string 4459 ** <li> BLOB 4460 ** <li> NULL 4461 ** </ul>)^ 4462 ** 4463 ** These constants are codes for each of those types. 4464 ** 4465 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4466 ** for a completely different meaning. Software that links against both 4467 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4468 ** SQLITE_TEXT. 4469 */ 4470 #define SQLITE_INTEGER 1 4471 #define SQLITE_FLOAT 2 4472 #define SQLITE_BLOB 4 4473 #define SQLITE_NULL 5 4474 #ifdef SQLITE_TEXT 4475 # undef SQLITE_TEXT 4476 #else 4477 # define SQLITE_TEXT 3 4478 #endif 4479 #define SQLITE3_TEXT 3 4480 4481 /* 4482 ** CAPI3REF: Result Values From A Query 4483 ** KEYWORDS: {column access functions} 4484 ** METHOD: sqlite3_stmt 4485 ** 4486 ** <b>Summary:</b> 4487 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4488 ** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 4489 ** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 4490 ** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 4491 ** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 4492 ** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 4493 ** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 4494 ** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 4495 ** [sqlite3_value|unprotected sqlite3_value] object. 4496 ** <tr><td> <td> <td> 4497 ** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 4498 ** or a UTF-8 TEXT result in bytes 4499 ** <tr><td><b>sqlite3_column_bytes16 </b> 4500 ** <td>→ <td>Size of UTF-16 4501 ** TEXT in bytes 4502 ** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 4503 ** datatype of the result 4504 ** </table></blockquote> 4505 ** 4506 ** <b>Details:</b> 4507 ** 4508 ** ^These routines return information about a single column of the current 4509 ** result row of a query. ^In every case the first argument is a pointer 4510 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4511 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4512 ** and the second argument is the index of the column for which information 4513 ** should be returned. ^The leftmost column of the result set has the index 0. 4514 ** ^The number of columns in the result can be determined using 4515 ** [sqlite3_column_count()]. 4516 ** 4517 ** If the SQL statement does not currently point to a valid row, or if the 4518 ** column index is out of range, the result is undefined. 4519 ** These routines may only be called when the most recent call to 4520 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4521 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4522 ** If any of these routines are called after [sqlite3_reset()] or 4523 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4524 ** something other than [SQLITE_ROW], the results are undefined. 4525 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4526 ** are called from a different thread while any of these routines 4527 ** are pending, then the results are undefined. 4528 ** 4529 ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 4530 ** each return the value of a result column in a specific data format. If 4531 ** the result column is not initially in the requested format (for example, 4532 ** if the query returns an integer but the sqlite3_column_text() interface 4533 ** is used to extract the value) then an automatic type conversion is performed. 4534 ** 4535 ** ^The sqlite3_column_type() routine returns the 4536 ** [SQLITE_INTEGER | datatype code] for the initial data type 4537 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4538 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 4539 ** The return value of sqlite3_column_type() can be used to decide which 4540 ** of the first six interface should be used to extract the column value. 4541 ** The value returned by sqlite3_column_type() is only meaningful if no 4542 ** automatic type conversions have occurred for the value in question. 4543 ** After a type conversion, the result of calling sqlite3_column_type() 4544 ** is undefined, though harmless. Future 4545 ** versions of SQLite may change the behavior of sqlite3_column_type() 4546 ** following a type conversion. 4547 ** 4548 ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 4549 ** or sqlite3_column_bytes16() interfaces can be used to determine the size 4550 ** of that BLOB or string. 4551 ** 4552 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4553 ** routine returns the number of bytes in that BLOB or string. 4554 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4555 ** the string to UTF-8 and then returns the number of bytes. 4556 ** ^If the result is a numeric value then sqlite3_column_bytes() uses 4557 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4558 ** the number of bytes in that string. 4559 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4560 ** 4561 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4562 ** routine returns the number of bytes in that BLOB or string. 4563 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4564 ** the string to UTF-16 and then returns the number of bytes. 4565 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4566 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4567 ** the number of bytes in that string. 4568 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4569 ** 4570 ** ^The values returned by [sqlite3_column_bytes()] and 4571 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4572 ** of the string. ^For clarity: the values returned by 4573 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4574 ** bytes in the string, not the number of characters. 4575 ** 4576 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4577 ** even empty strings, are always zero-terminated. ^The return 4578 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4579 ** 4580 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4581 ** [unprotected sqlite3_value] object. In a multithreaded environment, 4582 ** an unprotected sqlite3_value object may only be used safely with 4583 ** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4584 ** If the [unprotected sqlite3_value] object returned by 4585 ** [sqlite3_column_value()] is used in any other way, including calls 4586 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4587 ** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4588 ** Hence, the sqlite3_column_value() interface 4589 ** is normally only useful within the implementation of 4590 ** [application-defined SQL functions] or [virtual tables], not within 4591 ** top-level application code. 4592 ** 4593 ** The these routines may attempt to convert the datatype of the result. 4594 ** ^For example, if the internal representation is FLOAT and a text result 4595 ** is requested, [sqlite3_snprintf()] is used internally to perform the 4596 ** conversion automatically. ^(The following table details the conversions 4597 ** that are applied: 4598 ** 4599 ** <blockquote> 4600 ** <table border="1"> 4601 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4602 ** 4603 ** <tr><td> NULL <td> INTEGER <td> Result is 0 4604 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4605 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4606 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4607 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4608 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4609 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4610 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4611 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4612 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4613 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4614 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4615 ** <tr><td> TEXT <td> BLOB <td> No change 4616 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4617 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4618 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4619 ** </table> 4620 ** </blockquote>)^ 4621 ** 4622 ** Note that when type conversions occur, pointers returned by prior 4623 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4624 ** sqlite3_column_text16() may be invalidated. 4625 ** Type conversions and pointer invalidations might occur 4626 ** in the following cases: 4627 ** 4628 ** <ul> 4629 ** <li> The initial content is a BLOB and sqlite3_column_text() or 4630 ** sqlite3_column_text16() is called. A zero-terminator might 4631 ** need to be added to the string.</li> 4632 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4633 ** sqlite3_column_text16() is called. The content must be converted 4634 ** to UTF-16.</li> 4635 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4636 ** sqlite3_column_text() is called. The content must be converted 4637 ** to UTF-8.</li> 4638 ** </ul> 4639 ** 4640 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4641 ** not invalidate a prior pointer, though of course the content of the buffer 4642 ** that the prior pointer references will have been modified. Other kinds 4643 ** of conversion are done in place when it is possible, but sometimes they 4644 ** are not possible and in those cases prior pointers are invalidated. 4645 ** 4646 ** The safest policy is to invoke these routines 4647 ** in one of the following ways: 4648 ** 4649 ** <ul> 4650 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4651 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4652 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4653 ** </ul> 4654 ** 4655 ** In other words, you should call sqlite3_column_text(), 4656 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4657 ** into the desired format, then invoke sqlite3_column_bytes() or 4658 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4659 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4660 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4661 ** with calls to sqlite3_column_bytes(). 4662 ** 4663 ** ^The pointers returned are valid until a type conversion occurs as 4664 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4665 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4666 ** and BLOBs is freed automatically. Do not pass the pointers returned 4667 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4668 ** [sqlite3_free()]. 4669 ** 4670 ** As long as the input parameters are correct, these routines will only 4671 ** fail if an out-of-memory error occurs during a format conversion. 4672 ** Only the following subset of interfaces are subject to out-of-memory 4673 ** errors: 4674 ** 4675 ** <ul> 4676 ** <li> sqlite3_column_blob() 4677 ** <li> sqlite3_column_text() 4678 ** <li> sqlite3_column_text16() 4679 ** <li> sqlite3_column_bytes() 4680 ** <li> sqlite3_column_bytes16() 4681 ** </ul> 4682 ** 4683 ** If an out-of-memory error occurs, then the return value from these 4684 ** routines is the same as if the column had contained an SQL NULL value. 4685 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 4686 ** by invoking the [sqlite3_errcode()] immediately after the suspect 4687 ** return value is obtained and before any 4688 ** other SQLite interface is called on the same [database connection]. 4689 */ 4690 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4691 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 4692 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 4693 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4694 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4695 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4696 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4697 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4698 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4699 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 4700 4701 /* 4702 ** CAPI3REF: Destroy A Prepared Statement Object 4703 ** DESTRUCTOR: sqlite3_stmt 4704 ** 4705 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4706 ** ^If the most recent evaluation of the statement encountered no errors 4707 ** or if the statement is never been evaluated, then sqlite3_finalize() returns 4708 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4709 ** sqlite3_finalize(S) returns the appropriate [error code] or 4710 ** [extended error code]. 4711 ** 4712 ** ^The sqlite3_finalize(S) routine can be called at any point during 4713 ** the life cycle of [prepared statement] S: 4714 ** before statement S is ever evaluated, after 4715 ** one or more calls to [sqlite3_reset()], or after any call 4716 ** to [sqlite3_step()] regardless of whether or not the statement has 4717 ** completed execution. 4718 ** 4719 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4720 ** 4721 ** The application must finalize every [prepared statement] in order to avoid 4722 ** resource leaks. It is a grievous error for the application to try to use 4723 ** a prepared statement after it has been finalized. Any use of a prepared 4724 ** statement after it has been finalized can result in undefined and 4725 ** undesirable behavior such as segfaults and heap corruption. 4726 */ 4727 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 4728 4729 /* 4730 ** CAPI3REF: Reset A Prepared Statement Object 4731 ** METHOD: sqlite3_stmt 4732 ** 4733 ** The sqlite3_reset() function is called to reset a [prepared statement] 4734 ** object back to its initial state, ready to be re-executed. 4735 ** ^Any SQL statement variables that had values bound to them using 4736 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4737 ** Use [sqlite3_clear_bindings()] to reset the bindings. 4738 ** 4739 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4740 ** back to the beginning of its program. 4741 ** 4742 ** ^If the most recent call to [sqlite3_step(S)] for the 4743 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4744 ** or if [sqlite3_step(S)] has never before been called on S, 4745 ** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4746 ** 4747 ** ^If the most recent call to [sqlite3_step(S)] for the 4748 ** [prepared statement] S indicated an error, then 4749 ** [sqlite3_reset(S)] returns an appropriate [error code]. 4750 ** 4751 ** ^The [sqlite3_reset(S)] interface does not change the values 4752 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4753 */ 4754 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 4755 4756 /* 4757 ** CAPI3REF: Create Or Redefine SQL Functions 4758 ** KEYWORDS: {function creation routines} 4759 ** KEYWORDS: {application-defined SQL function} 4760 ** KEYWORDS: {application-defined SQL functions} 4761 ** METHOD: sqlite3 4762 ** 4763 ** ^These functions (collectively known as "function creation routines") 4764 ** are used to add SQL functions or aggregates or to redefine the behavior 4765 ** of existing SQL functions or aggregates. The only differences between 4766 ** the three "sqlite3_create_function*" routines are the text encoding 4767 ** expected for the second parameter (the name of the function being 4768 ** created) and the presence or absence of a destructor callback for 4769 ** the application data pointer. Function sqlite3_create_window_function() 4770 ** is similar, but allows the user to supply the extra callback functions 4771 ** needed by [aggregate window functions]. 4772 ** 4773 ** ^The first parameter is the [database connection] to which the SQL 4774 ** function is to be added. ^If an application uses more than one database 4775 ** connection then application-defined SQL functions must be added 4776 ** to each database connection separately. 4777 ** 4778 ** ^The second parameter is the name of the SQL function to be created or 4779 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4780 ** representation, exclusive of the zero-terminator. ^Note that the name 4781 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4782 ** ^Any attempt to create a function with a longer name 4783 ** will result in [SQLITE_MISUSE] being returned. 4784 ** 4785 ** ^The third parameter (nArg) 4786 ** is the number of arguments that the SQL function or 4787 ** aggregate takes. ^If this parameter is -1, then the SQL function or 4788 ** aggregate may take any number of arguments between 0 and the limit 4789 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4790 ** parameter is less than -1 or greater than 127 then the behavior is 4791 ** undefined. 4792 ** 4793 ** ^The fourth parameter, eTextRep, specifies what 4794 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4795 ** its parameters. The application should set this parameter to 4796 ** [SQLITE_UTF16LE] if the function implementation invokes 4797 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4798 ** implementation invokes [sqlite3_value_text16be()] on an input, or 4799 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4800 ** otherwise. ^The same SQL function may be registered multiple times using 4801 ** different preferred text encodings, with different implementations for 4802 ** each encoding. 4803 ** ^When multiple implementations of the same function are available, SQLite 4804 ** will pick the one that involves the least amount of data conversion. 4805 ** 4806 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4807 ** to signal that the function will always return the same result given 4808 ** the same inputs within a single SQL statement. Most SQL functions are 4809 ** deterministic. The built-in [random()] SQL function is an example of a 4810 ** function that is not deterministic. The SQLite query planner is able to 4811 ** perform additional optimizations on deterministic functions, so use 4812 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4813 ** 4814 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4815 ** function can gain access to this pointer using [sqlite3_user_data()].)^ 4816 ** 4817 ** ^The sixth, seventh and eighth parameters passed to the three 4818 ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 4819 ** pointers to C-language functions that implement the SQL function or 4820 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4821 ** callback only; NULL pointers must be passed as the xStep and xFinal 4822 ** parameters. ^An aggregate SQL function requires an implementation of xStep 4823 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4824 ** SQL function or aggregate, pass NULL pointers for all three function 4825 ** callbacks. 4826 ** 4827 ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 4828 ** and xInverse) passed to sqlite3_create_window_function are pointers to 4829 ** C-language callbacks that implement the new function. xStep and xFinal 4830 ** must both be non-NULL. xValue and xInverse may either both be NULL, in 4831 ** which case a regular aggregate function is created, or must both be 4832 ** non-NULL, in which case the new function may be used as either an aggregate 4833 ** or aggregate window function. More details regarding the implementation 4834 ** of aggregate window functions are 4835 ** [user-defined window functions|available here]. 4836 ** 4837 ** ^(If the final parameter to sqlite3_create_function_v2() or 4838 ** sqlite3_create_window_function() is not NULL, then it is destructor for 4839 ** the application data pointer. The destructor is invoked when the function 4840 ** is deleted, either by being overloaded or when the database connection 4841 ** closes.)^ ^The destructor is also invoked if the call to 4842 ** sqlite3_create_function_v2() fails. ^When the destructor callback is 4843 ** invoked, it is passed a single argument which is a copy of the application 4844 ** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 4845 ** 4846 ** ^It is permitted to register multiple implementations of the same 4847 ** functions with the same name but with either differing numbers of 4848 ** arguments or differing preferred text encodings. ^SQLite will use 4849 ** the implementation that most closely matches the way in which the 4850 ** SQL function is used. ^A function implementation with a non-negative 4851 ** nArg parameter is a better match than a function implementation with 4852 ** a negative nArg. ^A function where the preferred text encoding 4853 ** matches the database encoding is a better 4854 ** match than a function where the encoding is different. 4855 ** ^A function where the encoding difference is between UTF16le and UTF16be 4856 ** is a closer match than a function where the encoding difference is 4857 ** between UTF8 and UTF16. 4858 ** 4859 ** ^Built-in functions may be overloaded by new application-defined functions. 4860 ** 4861 ** ^An application-defined function is permitted to call other 4862 ** SQLite interfaces. However, such calls must not 4863 ** close the database connection nor finalize or reset the prepared 4864 ** statement in which the function is running. 4865 */ 4866 SQLITE_API int sqlite3_create_function( 4867 sqlite3 *db, 4868 const char *zFunctionName, 4869 int nArg, 4870 int eTextRep, 4871 void *pApp, 4872 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4873 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4874 void (*xFinal)(sqlite3_context*) 4875 ); 4876 SQLITE_API int sqlite3_create_function16( 4877 sqlite3 *db, 4878 const void *zFunctionName, 4879 int nArg, 4880 int eTextRep, 4881 void *pApp, 4882 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4883 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4884 void (*xFinal)(sqlite3_context*) 4885 ); 4886 SQLITE_API int sqlite3_create_function_v2( 4887 sqlite3 *db, 4888 const char *zFunctionName, 4889 int nArg, 4890 int eTextRep, 4891 void *pApp, 4892 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4893 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4894 void (*xFinal)(sqlite3_context*), 4895 void(*xDestroy)(void*) 4896 ); 4897 SQLITE_API int sqlite3_create_window_function( 4898 sqlite3 *db, 4899 const char *zFunctionName, 4900 int nArg, 4901 int eTextRep, 4902 void *pApp, 4903 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4904 void (*xFinal)(sqlite3_context*), 4905 void (*xValue)(sqlite3_context*), 4906 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 4907 void(*xDestroy)(void*) 4908 ); 4909 4910 /* 4911 ** CAPI3REF: Text Encodings 4912 ** 4913 ** These constant define integer codes that represent the various 4914 ** text encodings supported by SQLite. 4915 */ 4916 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4917 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4918 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4919 #define SQLITE_UTF16 4 /* Use native byte order */ 4920 #define SQLITE_ANY 5 /* Deprecated */ 4921 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4922 4923 /* 4924 ** CAPI3REF: Function Flags 4925 ** 4926 ** These constants may be ORed together with the 4927 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4928 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4929 ** [sqlite3_create_function_v2()]. 4930 */ 4931 #define SQLITE_DETERMINISTIC 0x800 4932 4933 /* 4934 ** CAPI3REF: Deprecated Functions 4935 ** DEPRECATED 4936 ** 4937 ** These functions are [deprecated]. In order to maintain 4938 ** backwards compatibility with older code, these functions continue 4939 ** to be supported. However, new applications should avoid 4940 ** the use of these functions. To encourage programmers to avoid 4941 ** these functions, we will not explain what they do. 4942 */ 4943 #ifndef SQLITE_OMIT_DEPRECATED 4944 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 4945 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 4946 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4947 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 4948 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 4949 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4950 void*,sqlite3_int64); 4951 #endif 4952 4953 /* 4954 ** CAPI3REF: Obtaining SQL Values 4955 ** METHOD: sqlite3_value 4956 ** 4957 ** <b>Summary:</b> 4958 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4959 ** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 4960 ** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 4961 ** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 4962 ** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 4963 ** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 4964 ** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 4965 ** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 4966 ** the native byteorder 4967 ** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 4968 ** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 4969 ** <tr><td> <td> <td> 4970 ** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 4971 ** or a UTF-8 TEXT in bytes 4972 ** <tr><td><b>sqlite3_value_bytes16 </b> 4973 ** <td>→ <td>Size of UTF-16 4974 ** TEXT in bytes 4975 ** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 4976 ** datatype of the value 4977 ** <tr><td><b>sqlite3_value_numeric_type </b> 4978 ** <td>→ <td>Best numeric datatype of the value 4979 ** <tr><td><b>sqlite3_value_nochange </b> 4980 ** <td>→ <td>True if the column is unchanged in an UPDATE 4981 ** against a virtual table. 4982 ** <tr><td><b>sqlite3_value_frombind </b> 4983 ** <td>→ <td>True if value originated from a [bound parameter] 4984 ** </table></blockquote> 4985 ** 4986 ** <b>Details:</b> 4987 ** 4988 ** These routines extract type, size, and content information from 4989 ** [protected sqlite3_value] objects. Protected sqlite3_value objects 4990 ** are used to pass parameter information into implementation of 4991 ** [application-defined SQL functions] and [virtual tables]. 4992 ** 4993 ** These routines work only with [protected sqlite3_value] objects. 4994 ** Any attempt to use these routines on an [unprotected sqlite3_value] 4995 ** is not threadsafe. 4996 ** 4997 ** ^These routines work just like the corresponding [column access functions] 4998 ** except that these routines take a single [protected sqlite3_value] object 4999 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 5000 ** 5001 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 5002 ** in the native byte-order of the host machine. ^The 5003 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 5004 ** extract UTF-16 strings as big-endian and little-endian respectively. 5005 ** 5006 ** ^If [sqlite3_value] object V was initialized 5007 ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 5008 ** and if X and Y are strings that compare equal according to strcmp(X,Y), 5009 ** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 5010 ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 5011 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5012 ** 5013 ** ^(The sqlite3_value_type(V) interface returns the 5014 ** [SQLITE_INTEGER | datatype code] for the initial datatype of the 5015 ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 5016 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 5017 ** Other interfaces might change the datatype for an sqlite3_value object. 5018 ** For example, if the datatype is initially SQLITE_INTEGER and 5019 ** sqlite3_value_text(V) is called to extract a text value for that 5020 ** integer, then subsequent calls to sqlite3_value_type(V) might return 5021 ** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 5022 ** occurs is undefined and may change from one release of SQLite to the next. 5023 ** 5024 ** ^(The sqlite3_value_numeric_type() interface attempts to apply 5025 ** numeric affinity to the value. This means that an attempt is 5026 ** made to convert the value to an integer or floating point. If 5027 ** such a conversion is possible without loss of information (in other 5028 ** words, if the value is a string that looks like a number) 5029 ** then the conversion is performed. Otherwise no conversion occurs. 5030 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 5031 ** 5032 ** ^Within the [xUpdate] method of a [virtual table], the 5033 ** sqlite3_value_nochange(X) interface returns true if and only if 5034 ** the column corresponding to X is unchanged by the UPDATE operation 5035 ** that the xUpdate method call was invoked to implement and if 5036 ** and the prior [xColumn] method call that was invoked to extracted 5037 ** the value for that column returned without setting a result (probably 5038 ** because it queried [sqlite3_vtab_nochange()] and found that the column 5039 ** was unchanging). ^Within an [xUpdate] method, any value for which 5040 ** sqlite3_value_nochange(X) is true will in all other respects appear 5041 ** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 5042 ** than within an [xUpdate] method call for an UPDATE statement, then 5043 ** the return value is arbitrary and meaningless. 5044 ** 5045 ** ^The sqlite3_value_frombind(X) interface returns non-zero if the 5046 ** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()] 5047 ** interfaces. ^If X comes from an SQL literal value, or a table column, 5048 ** and expression, then sqlite3_value_frombind(X) returns zero. 5049 ** 5050 ** Please pay particular attention to the fact that the pointer returned 5051 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 5052 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 5053 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 5054 ** or [sqlite3_value_text16()]. 5055 ** 5056 ** These routines must be called from the same thread as 5057 ** the SQL function that supplied the [sqlite3_value*] parameters. 5058 ** 5059 ** As long as the input parameter is correct, these routines can only 5060 ** fail if an out-of-memory error occurs during a format conversion. 5061 ** Only the following subset of interfaces are subject to out-of-memory 5062 ** errors: 5063 ** 5064 ** <ul> 5065 ** <li> sqlite3_value_blob() 5066 ** <li> sqlite3_value_text() 5067 ** <li> sqlite3_value_text16() 5068 ** <li> sqlite3_value_text16le() 5069 ** <li> sqlite3_value_text16be() 5070 ** <li> sqlite3_value_bytes() 5071 ** <li> sqlite3_value_bytes16() 5072 ** </ul> 5073 ** 5074 ** If an out-of-memory error occurs, then the return value from these 5075 ** routines is the same as if the column had contained an SQL NULL value. 5076 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 5077 ** by invoking the [sqlite3_errcode()] immediately after the suspect 5078 ** return value is obtained and before any 5079 ** other SQLite interface is called on the same [database connection]. 5080 */ 5081 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 5082 SQLITE_API double sqlite3_value_double(sqlite3_value*); 5083 SQLITE_API int sqlite3_value_int(sqlite3_value*); 5084 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 5085 SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*); 5086 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 5087 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 5088 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 5089 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 5090 SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 5091 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 5092 SQLITE_API int sqlite3_value_type(sqlite3_value*); 5093 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 5094 SQLITE_API int sqlite3_value_nochange(sqlite3_value*); 5095 SQLITE_API int sqlite3_value_frombind(sqlite3_value*); 5096 5097 /* 5098 ** CAPI3REF: Finding The Subtype Of SQL Values 5099 ** METHOD: sqlite3_value 5100 ** 5101 ** The sqlite3_value_subtype(V) function returns the subtype for 5102 ** an [application-defined SQL function] argument V. The subtype 5103 ** information can be used to pass a limited amount of context from 5104 ** one SQL function to another. Use the [sqlite3_result_subtype()] 5105 ** routine to set the subtype for the return value of an SQL function. 5106 */ 5107 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); 5108 5109 /* 5110 ** CAPI3REF: Copy And Free SQL Values 5111 ** METHOD: sqlite3_value 5112 ** 5113 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 5114 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 5115 ** is a [protected sqlite3_value] object even if the input is not. 5116 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 5117 ** memory allocation fails. 5118 ** 5119 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 5120 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 5121 ** then sqlite3_value_free(V) is a harmless no-op. 5122 */ 5123 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 5124 SQLITE_API void sqlite3_value_free(sqlite3_value*); 5125 5126 /* 5127 ** CAPI3REF: Obtain Aggregate Function Context 5128 ** METHOD: sqlite3_context 5129 ** 5130 ** Implementations of aggregate SQL functions use this 5131 ** routine to allocate memory for storing their state. 5132 ** 5133 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 5134 ** for a particular aggregate function, SQLite 5135 ** allocates N of memory, zeroes out that memory, and returns a pointer 5136 ** to the new memory. ^On second and subsequent calls to 5137 ** sqlite3_aggregate_context() for the same aggregate function instance, 5138 ** the same buffer is returned. Sqlite3_aggregate_context() is normally 5139 ** called once for each invocation of the xStep callback and then one 5140 ** last time when the xFinal callback is invoked. ^(When no rows match 5141 ** an aggregate query, the xStep() callback of the aggregate function 5142 ** implementation is never called and xFinal() is called exactly once. 5143 ** In those cases, sqlite3_aggregate_context() might be called for the 5144 ** first time from within xFinal().)^ 5145 ** 5146 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5147 ** when first called if N is less than or equal to zero or if a memory 5148 ** allocate error occurs. 5149 ** 5150 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 5151 ** determined by the N parameter on first successful call. Changing the 5152 ** value of N in subsequent call to sqlite3_aggregate_context() within 5153 ** the same aggregate function instance will not resize the memory 5154 ** allocation.)^ Within the xFinal callback, it is customary to set 5155 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5156 ** pointless memory allocations occur. 5157 ** 5158 ** ^SQLite automatically frees the memory allocated by 5159 ** sqlite3_aggregate_context() when the aggregate query concludes. 5160 ** 5161 ** The first parameter must be a copy of the 5162 ** [sqlite3_context | SQL function context] that is the first parameter 5163 ** to the xStep or xFinal callback routine that implements the aggregate 5164 ** function. 5165 ** 5166 ** This routine must be called from the same thread in which 5167 ** the aggregate SQL function is running. 5168 */ 5169 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 5170 5171 /* 5172 ** CAPI3REF: User Data For Functions 5173 ** METHOD: sqlite3_context 5174 ** 5175 ** ^The sqlite3_user_data() interface returns a copy of 5176 ** the pointer that was the pUserData parameter (the 5th parameter) 5177 ** of the [sqlite3_create_function()] 5178 ** and [sqlite3_create_function16()] routines that originally 5179 ** registered the application defined function. 5180 ** 5181 ** This routine must be called from the same thread in which 5182 ** the application-defined function is running. 5183 */ 5184 SQLITE_API void *sqlite3_user_data(sqlite3_context*); 5185 5186 /* 5187 ** CAPI3REF: Database Connection For Functions 5188 ** METHOD: sqlite3_context 5189 ** 5190 ** ^The sqlite3_context_db_handle() interface returns a copy of 5191 ** the pointer to the [database connection] (the 1st parameter) 5192 ** of the [sqlite3_create_function()] 5193 ** and [sqlite3_create_function16()] routines that originally 5194 ** registered the application defined function. 5195 */ 5196 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5197 5198 /* 5199 ** CAPI3REF: Function Auxiliary Data 5200 ** METHOD: sqlite3_context 5201 ** 5202 ** These functions may be used by (non-aggregate) SQL functions to 5203 ** associate metadata with argument values. If the same value is passed to 5204 ** multiple invocations of the same SQL function during query execution, under 5205 ** some circumstances the associated metadata may be preserved. An example 5206 ** of where this might be useful is in a regular-expression matching 5207 ** function. The compiled version of the regular expression can be stored as 5208 ** metadata associated with the pattern string. 5209 ** Then as long as the pattern string remains the same, 5210 ** the compiled regular expression can be reused on multiple 5211 ** invocations of the same function. 5212 ** 5213 ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 5214 ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5215 ** value to the application-defined function. ^N is zero for the left-most 5216 ** function argument. ^If there is no metadata 5217 ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5218 ** returns a NULL pointer. 5219 ** 5220 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 5221 ** argument of the application-defined function. ^Subsequent 5222 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5223 ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 5224 ** NULL if the metadata has been discarded. 5225 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5226 ** SQLite will invoke the destructor function X with parameter P exactly 5227 ** once, when the metadata is discarded. 5228 ** SQLite is free to discard the metadata at any time, including: <ul> 5229 ** <li> ^(when the corresponding function parameter changes)^, or 5230 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5231 ** SQL statement)^, or 5232 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5233 ** parameter)^, or 5234 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5235 ** allocation error occurs.)^ </ul> 5236 ** 5237 ** Note the last bullet in particular. The destructor X in 5238 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5239 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5240 ** should be called near the end of the function implementation and the 5241 ** function implementation should not make any use of P after 5242 ** sqlite3_set_auxdata() has been called. 5243 ** 5244 ** ^(In practice, metadata is preserved between function calls for 5245 ** function parameters that are compile-time constants, including literal 5246 ** values and [parameters] and expressions composed from the same.)^ 5247 ** 5248 ** The value of the N parameter to these interfaces should be non-negative. 5249 ** Future enhancements may make use of negative N values to define new 5250 ** kinds of function caching behavior. 5251 ** 5252 ** These routines must be called from the same thread in which 5253 ** the SQL function is running. 5254 */ 5255 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 5256 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5257 5258 5259 /* 5260 ** CAPI3REF: Constants Defining Special Destructor Behavior 5261 ** 5262 ** These are special values for the destructor that is passed in as the 5263 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5264 ** argument is SQLITE_STATIC, it means that the content pointer is constant 5265 ** and will never change. It does not need to be destroyed. ^The 5266 ** SQLITE_TRANSIENT value means that the content will likely change in 5267 ** the near future and that SQLite should make its own private copy of 5268 ** the content before returning. 5269 ** 5270 ** The typedef is necessary to work around problems in certain 5271 ** C++ compilers. 5272 */ 5273 typedef void (*sqlite3_destructor_type)(void*); 5274 #define SQLITE_STATIC ((sqlite3_destructor_type)0) 5275 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5276 5277 /* 5278 ** CAPI3REF: Setting The Result Of An SQL Function 5279 ** METHOD: sqlite3_context 5280 ** 5281 ** These routines are used by the xFunc or xFinal callbacks that 5282 ** implement SQL functions and aggregates. See 5283 ** [sqlite3_create_function()] and [sqlite3_create_function16()] 5284 ** for additional information. 5285 ** 5286 ** These functions work very much like the [parameter binding] family of 5287 ** functions used to bind values to host parameters in prepared statements. 5288 ** Refer to the [SQL parameter] documentation for additional information. 5289 ** 5290 ** ^The sqlite3_result_blob() interface sets the result from 5291 ** an application-defined function to be the BLOB whose content is pointed 5292 ** to by the second parameter and which is N bytes long where N is the 5293 ** third parameter. 5294 ** 5295 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5296 ** interfaces set the result of the application-defined function to be 5297 ** a BLOB containing all zero bytes and N bytes in size. 5298 ** 5299 ** ^The sqlite3_result_double() interface sets the result from 5300 ** an application-defined function to be a floating point value specified 5301 ** by its 2nd argument. 5302 ** 5303 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5304 ** cause the implemented SQL function to throw an exception. 5305 ** ^SQLite uses the string pointed to by the 5306 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5307 ** as the text of an error message. ^SQLite interprets the error 5308 ** message string from sqlite3_result_error() as UTF-8. ^SQLite 5309 ** interprets the string from sqlite3_result_error16() as UTF-16 in native 5310 ** byte order. ^If the third parameter to sqlite3_result_error() 5311 ** or sqlite3_result_error16() is negative then SQLite takes as the error 5312 ** message all text up through the first zero character. 5313 ** ^If the third parameter to sqlite3_result_error() or 5314 ** sqlite3_result_error16() is non-negative then SQLite takes that many 5315 ** bytes (not characters) from the 2nd parameter as the error message. 5316 ** ^The sqlite3_result_error() and sqlite3_result_error16() 5317 ** routines make a private copy of the error message text before 5318 ** they return. Hence, the calling function can deallocate or 5319 ** modify the text after they return without harm. 5320 ** ^The sqlite3_result_error_code() function changes the error code 5321 ** returned by SQLite as a result of an error in a function. ^By default, 5322 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5323 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5324 ** 5325 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5326 ** error indicating that a string or BLOB is too long to represent. 5327 ** 5328 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5329 ** error indicating that a memory allocation failed. 5330 ** 5331 ** ^The sqlite3_result_int() interface sets the return value 5332 ** of the application-defined function to be the 32-bit signed integer 5333 ** value given in the 2nd argument. 5334 ** ^The sqlite3_result_int64() interface sets the return value 5335 ** of the application-defined function to be the 64-bit signed integer 5336 ** value given in the 2nd argument. 5337 ** 5338 ** ^The sqlite3_result_null() interface sets the return value 5339 ** of the application-defined function to be NULL. 5340 ** 5341 ** ^The sqlite3_result_text(), sqlite3_result_text16(), 5342 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5343 ** set the return value of the application-defined function to be 5344 ** a text string which is represented as UTF-8, UTF-16 native byte order, 5345 ** UTF-16 little endian, or UTF-16 big endian, respectively. 5346 ** ^The sqlite3_result_text64() interface sets the return value of an 5347 ** application-defined function to be a text string in an encoding 5348 ** specified by the fifth (and last) parameter, which must be one 5349 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5350 ** ^SQLite takes the text result from the application from 5351 ** the 2nd parameter of the sqlite3_result_text* interfaces. 5352 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5353 ** is negative, then SQLite takes result text from the 2nd parameter 5354 ** through the first zero character. 5355 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5356 ** is non-negative, then as many bytes (not characters) of the text 5357 ** pointed to by the 2nd parameter are taken as the application-defined 5358 ** function result. If the 3rd parameter is non-negative, then it 5359 ** must be the byte offset into the string where the NUL terminator would 5360 ** appear if the string where NUL terminated. If any NUL characters occur 5361 ** in the string at a byte offset that is less than the value of the 3rd 5362 ** parameter, then the resulting string will contain embedded NULs and the 5363 ** result of expressions operating on strings with embedded NULs is undefined. 5364 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 5365 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5366 ** function as the destructor on the text or BLOB result when it has 5367 ** finished using that result. 5368 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5369 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 5370 ** assumes that the text or BLOB result is in constant space and does not 5371 ** copy the content of the parameter nor call a destructor on the content 5372 ** when it has finished using that result. 5373 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 5374 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 5375 ** then SQLite makes a copy of the result into space obtained 5376 ** from [sqlite3_malloc()] before it returns. 5377 ** 5378 ** ^The sqlite3_result_value() interface sets the result of 5379 ** the application-defined function to be a copy of the 5380 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 5381 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 5382 ** so that the [sqlite3_value] specified in the parameter may change or 5383 ** be deallocated after sqlite3_result_value() returns without harm. 5384 ** ^A [protected sqlite3_value] object may always be used where an 5385 ** [unprotected sqlite3_value] object is required, so either 5386 ** kind of [sqlite3_value] object can be used with this interface. 5387 ** 5388 ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 5389 ** SQL NULL value, just like [sqlite3_result_null(C)], except that it 5390 ** also associates the host-language pointer P or type T with that 5391 ** NULL value such that the pointer can be retrieved within an 5392 ** [application-defined SQL function] using [sqlite3_value_pointer()]. 5393 ** ^If the D parameter is not NULL, then it is a pointer to a destructor 5394 ** for the P parameter. ^SQLite invokes D with P as its only argument 5395 ** when SQLite is finished with P. The T parameter should be a static 5396 ** string and preferably a string literal. The sqlite3_result_pointer() 5397 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5398 ** 5399 ** If these routines are called from within the different thread 5400 ** than the one containing the application-defined function that received 5401 ** the [sqlite3_context] pointer, the results are undefined. 5402 */ 5403 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 5404 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 5405 sqlite3_uint64,void(*)(void*)); 5406 SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 5407 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 5408 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 5409 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 5410 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 5411 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 5412 SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 5413 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5414 SQLITE_API void sqlite3_result_null(sqlite3_context*); 5415 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5416 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5417 void(*)(void*), unsigned char encoding); 5418 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5419 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5420 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5421 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5422 SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 5423 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 5424 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 5425 5426 5427 /* 5428 ** CAPI3REF: Setting The Subtype Of An SQL Function 5429 ** METHOD: sqlite3_context 5430 ** 5431 ** The sqlite3_result_subtype(C,T) function causes the subtype of 5432 ** the result from the [application-defined SQL function] with 5433 ** [sqlite3_context] C to be the value T. Only the lower 8 bits 5434 ** of the subtype T are preserved in current versions of SQLite; 5435 ** higher order bits are discarded. 5436 ** The number of subtype bytes preserved by SQLite might increase 5437 ** in future releases of SQLite. 5438 */ 5439 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); 5440 5441 /* 5442 ** CAPI3REF: Define New Collating Sequences 5443 ** METHOD: sqlite3 5444 ** 5445 ** ^These functions add, remove, or modify a [collation] associated 5446 ** with the [database connection] specified as the first argument. 5447 ** 5448 ** ^The name of the collation is a UTF-8 string 5449 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 5450 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 5451 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 5452 ** considered to be the same name. 5453 ** 5454 ** ^(The third argument (eTextRep) must be one of the constants: 5455 ** <ul> 5456 ** <li> [SQLITE_UTF8], 5457 ** <li> [SQLITE_UTF16LE], 5458 ** <li> [SQLITE_UTF16BE], 5459 ** <li> [SQLITE_UTF16], or 5460 ** <li> [SQLITE_UTF16_ALIGNED]. 5461 ** </ul>)^ 5462 ** ^The eTextRep argument determines the encoding of strings passed 5463 ** to the collating function callback, xCallback. 5464 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 5465 ** force strings to be UTF16 with native byte order. 5466 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 5467 ** on an even byte address. 5468 ** 5469 ** ^The fourth argument, pArg, is an application data pointer that is passed 5470 ** through as the first argument to the collating function callback. 5471 ** 5472 ** ^The fifth argument, xCallback, is a pointer to the collating function. 5473 ** ^Multiple collating functions can be registered using the same name but 5474 ** with different eTextRep parameters and SQLite will use whichever 5475 ** function requires the least amount of data transformation. 5476 ** ^If the xCallback argument is NULL then the collating function is 5477 ** deleted. ^When all collating functions having the same name are deleted, 5478 ** that collation is no longer usable. 5479 ** 5480 ** ^The collating function callback is invoked with a copy of the pArg 5481 ** application data pointer and with two strings in the encoding specified 5482 ** by the eTextRep argument. The collating function must return an 5483 ** integer that is negative, zero, or positive 5484 ** if the first string is less than, equal to, or greater than the second, 5485 ** respectively. A collating function must always return the same answer 5486 ** given the same inputs. If two or more collating functions are registered 5487 ** to the same collation name (using different eTextRep values) then all 5488 ** must give an equivalent answer when invoked with equivalent strings. 5489 ** The collating function must obey the following properties for all 5490 ** strings A, B, and C: 5491 ** 5492 ** <ol> 5493 ** <li> If A==B then B==A. 5494 ** <li> If A==B and B==C then A==C. 5495 ** <li> If A<B THEN B>A. 5496 ** <li> If A<B and B<C then A<C. 5497 ** </ol> 5498 ** 5499 ** If a collating function fails any of the above constraints and that 5500 ** collating function is registered and used, then the behavior of SQLite 5501 ** is undefined. 5502 ** 5503 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 5504 ** with the addition that the xDestroy callback is invoked on pArg when 5505 ** the collating function is deleted. 5506 ** ^Collating functions are deleted when they are overridden by later 5507 ** calls to the collation creation functions or when the 5508 ** [database connection] is closed using [sqlite3_close()]. 5509 ** 5510 ** ^The xDestroy callback is <u>not</u> called if the 5511 ** sqlite3_create_collation_v2() function fails. Applications that invoke 5512 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5513 ** check the return code and dispose of the application data pointer 5514 ** themselves rather than expecting SQLite to deal with it for them. 5515 ** This is different from every other SQLite interface. The inconsistency 5516 ** is unfortunate but cannot be changed without breaking backwards 5517 ** compatibility. 5518 ** 5519 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5520 */ 5521 SQLITE_API int sqlite3_create_collation( 5522 sqlite3*, 5523 const char *zName, 5524 int eTextRep, 5525 void *pArg, 5526 int(*xCompare)(void*,int,const void*,int,const void*) 5527 ); 5528 SQLITE_API int sqlite3_create_collation_v2( 5529 sqlite3*, 5530 const char *zName, 5531 int eTextRep, 5532 void *pArg, 5533 int(*xCompare)(void*,int,const void*,int,const void*), 5534 void(*xDestroy)(void*) 5535 ); 5536 SQLITE_API int sqlite3_create_collation16( 5537 sqlite3*, 5538 const void *zName, 5539 int eTextRep, 5540 void *pArg, 5541 int(*xCompare)(void*,int,const void*,int,const void*) 5542 ); 5543 5544 /* 5545 ** CAPI3REF: Collation Needed Callbacks 5546 ** METHOD: sqlite3 5547 ** 5548 ** ^To avoid having to register all collation sequences before a database 5549 ** can be used, a single callback function may be registered with the 5550 ** [database connection] to be invoked whenever an undefined collation 5551 ** sequence is required. 5552 ** 5553 ** ^If the function is registered using the sqlite3_collation_needed() API, 5554 ** then it is passed the names of undefined collation sequences as strings 5555 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5556 ** the names are passed as UTF-16 in machine native byte order. 5557 ** ^A call to either function replaces the existing collation-needed callback. 5558 ** 5559 ** ^(When the callback is invoked, the first argument passed is a copy 5560 ** of the second argument to sqlite3_collation_needed() or 5561 ** sqlite3_collation_needed16(). The second argument is the database 5562 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5563 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5564 ** sequence function required. The fourth parameter is the name of the 5565 ** required collation sequence.)^ 5566 ** 5567 ** The callback function should register the desired collation using 5568 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5569 ** [sqlite3_create_collation_v2()]. 5570 */ 5571 SQLITE_API int sqlite3_collation_needed( 5572 sqlite3*, 5573 void*, 5574 void(*)(void*,sqlite3*,int eTextRep,const char*) 5575 ); 5576 SQLITE_API int sqlite3_collation_needed16( 5577 sqlite3*, 5578 void*, 5579 void(*)(void*,sqlite3*,int eTextRep,const void*) 5580 ); 5581 5582 #ifdef SQLITE_HAS_CODEC 5583 /* 5584 ** Specify the key for an encrypted database. This routine should be 5585 ** called right after sqlite3_open(). 5586 ** 5587 ** The code to implement this API is not available in the public release 5588 ** of SQLite. 5589 */ 5590 SQLITE_API int sqlite3_key( 5591 sqlite3 *db, /* Database to be rekeyed */ 5592 const void *pKey, int nKey /* The key */ 5593 ); 5594 SQLITE_API int sqlite3_key_v2( 5595 sqlite3 *db, /* Database to be rekeyed */ 5596 const char *zDbName, /* Name of the database */ 5597 const void *pKey, int nKey /* The key */ 5598 ); 5599 5600 /* 5601 ** Change the key on an open database. If the current database is not 5602 ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 5603 ** database is decrypted. 5604 ** 5605 ** The code to implement this API is not available in the public release 5606 ** of SQLite. 5607 */ 5608 SQLITE_API int sqlite3_rekey( 5609 sqlite3 *db, /* Database to be rekeyed */ 5610 const void *pKey, int nKey /* The new key */ 5611 ); 5612 SQLITE_API int sqlite3_rekey_v2( 5613 sqlite3 *db, /* Database to be rekeyed */ 5614 const char *zDbName, /* Name of the database */ 5615 const void *pKey, int nKey /* The new key */ 5616 ); 5617 5618 /* 5619 ** Specify the activation key for a SEE database. Unless 5620 ** activated, none of the SEE routines will work. 5621 */ 5622 SQLITE_API void sqlite3_activate_see( 5623 const char *zPassPhrase /* Activation phrase */ 5624 ); 5625 #endif 5626 5627 #ifdef SQLITE_ENABLE_CEROD 5628 /* 5629 ** Specify the activation key for a CEROD database. Unless 5630 ** activated, none of the CEROD routines will work. 5631 */ 5632 SQLITE_API void sqlite3_activate_cerod( 5633 const char *zPassPhrase /* Activation phrase */ 5634 ); 5635 #endif 5636 5637 /* 5638 ** CAPI3REF: Suspend Execution For A Short Time 5639 ** 5640 ** The sqlite3_sleep() function causes the current thread to suspend execution 5641 ** for at least a number of milliseconds specified in its parameter. 5642 ** 5643 ** If the operating system does not support sleep requests with 5644 ** millisecond time resolution, then the time will be rounded up to 5645 ** the nearest second. The number of milliseconds of sleep actually 5646 ** requested from the operating system is returned. 5647 ** 5648 ** ^SQLite implements this interface by calling the xSleep() 5649 ** method of the default [sqlite3_vfs] object. If the xSleep() method 5650 ** of the default VFS is not implemented correctly, or not implemented at 5651 ** all, then the behavior of sqlite3_sleep() may deviate from the description 5652 ** in the previous paragraphs. 5653 */ 5654 SQLITE_API int sqlite3_sleep(int); 5655 5656 /* 5657 ** CAPI3REF: Name Of The Folder Holding Temporary Files 5658 ** 5659 ** ^(If this global variable is made to point to a string which is 5660 ** the name of a folder (a.k.a. directory), then all temporary files 5661 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 5662 ** will be placed in that directory.)^ ^If this variable 5663 ** is a NULL pointer, then SQLite performs a search for an appropriate 5664 ** temporary file directory. 5665 ** 5666 ** Applications are strongly discouraged from using this global variable. 5667 ** It is required to set a temporary folder on Windows Runtime (WinRT). 5668 ** But for all other platforms, it is highly recommended that applications 5669 ** neither read nor write this variable. This global variable is a relic 5670 ** that exists for backwards compatibility of legacy applications and should 5671 ** be avoided in new projects. 5672 ** 5673 ** It is not safe to read or modify this variable in more than one 5674 ** thread at a time. It is not safe to read or modify this variable 5675 ** if a [database connection] is being used at the same time in a separate 5676 ** thread. 5677 ** It is intended that this variable be set once 5678 ** as part of process initialization and before any SQLite interface 5679 ** routines have been called and that this variable remain unchanged 5680 ** thereafter. 5681 ** 5682 ** ^The [temp_store_directory pragma] may modify this variable and cause 5683 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5684 ** the [temp_store_directory pragma] always assumes that any string 5685 ** that this variable points to is held in memory obtained from 5686 ** [sqlite3_malloc] and the pragma may attempt to free that memory 5687 ** using [sqlite3_free]. 5688 ** Hence, if this variable is modified directly, either it should be 5689 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 5690 ** or else the use of the [temp_store_directory pragma] should be avoided. 5691 ** Except when requested by the [temp_store_directory pragma], SQLite 5692 ** does not free the memory that sqlite3_temp_directory points to. If 5693 ** the application wants that memory to be freed, it must do 5694 ** so itself, taking care to only do so after all [database connection] 5695 ** objects have been destroyed. 5696 ** 5697 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 5698 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 5699 ** features that require the use of temporary files may fail. Here is an 5700 ** example of how to do this using C++ with the Windows Runtime: 5701 ** 5702 ** <blockquote><pre> 5703 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 5704 ** TemporaryFolder->Path->Data(); 5705 ** char zPathBuf[MAX_PATH + 1]; 5706 ** memset(zPathBuf, 0, sizeof(zPathBuf)); 5707 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 5708 ** NULL, NULL); 5709 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 5710 ** </pre></blockquote> 5711 */ 5712 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 5713 5714 /* 5715 ** CAPI3REF: Name Of The Folder Holding Database Files 5716 ** 5717 ** ^(If this global variable is made to point to a string which is 5718 ** the name of a folder (a.k.a. directory), then all database files 5719 ** specified with a relative pathname and created or accessed by 5720 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 5721 ** to be relative to that directory.)^ ^If this variable is a NULL 5722 ** pointer, then SQLite assumes that all database files specified 5723 ** with a relative pathname are relative to the current directory 5724 ** for the process. Only the windows VFS makes use of this global 5725 ** variable; it is ignored by the unix VFS. 5726 ** 5727 ** Changing the value of this variable while a database connection is 5728 ** open can result in a corrupt database. 5729 ** 5730 ** It is not safe to read or modify this variable in more than one 5731 ** thread at a time. It is not safe to read or modify this variable 5732 ** if a [database connection] is being used at the same time in a separate 5733 ** thread. 5734 ** It is intended that this variable be set once 5735 ** as part of process initialization and before any SQLite interface 5736 ** routines have been called and that this variable remain unchanged 5737 ** thereafter. 5738 ** 5739 ** ^The [data_store_directory pragma] may modify this variable and cause 5740 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5741 ** the [data_store_directory pragma] always assumes that any string 5742 ** that this variable points to is held in memory obtained from 5743 ** [sqlite3_malloc] and the pragma may attempt to free that memory 5744 ** using [sqlite3_free]. 5745 ** Hence, if this variable is modified directly, either it should be 5746 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 5747 ** or else the use of the [data_store_directory pragma] should be avoided. 5748 */ 5749 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 5750 5751 /* 5752 ** CAPI3REF: Win32 Specific Interface 5753 ** 5754 ** These interfaces are available only on Windows. The 5755 ** [sqlite3_win32_set_directory] interface is used to set the value associated 5756 ** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 5757 ** zValue, depending on the value of the type parameter. The zValue parameter 5758 ** should be NULL to cause the previous value to be freed via [sqlite3_free]; 5759 ** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 5760 ** prior to being used. The [sqlite3_win32_set_directory] interface returns 5761 ** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 5762 ** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 5763 ** [sqlite3_data_directory] variable is intended to act as a replacement for 5764 ** the current directory on the sub-platforms of Win32 where that concept is 5765 ** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 5766 ** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 5767 ** sqlite3_win32_set_directory interface except the string parameter must be 5768 ** UTF-8 or UTF-16, respectively. 5769 */ 5770 SQLITE_API int sqlite3_win32_set_directory( 5771 unsigned long type, /* Identifier for directory being set or reset */ 5772 void *zValue /* New value for directory being set or reset */ 5773 ); 5774 SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 5775 SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 5776 5777 /* 5778 ** CAPI3REF: Win32 Directory Types 5779 ** 5780 ** These macros are only available on Windows. They define the allowed values 5781 ** for the type argument to the [sqlite3_win32_set_directory] interface. 5782 */ 5783 #define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 5784 #define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 5785 5786 /* 5787 ** CAPI3REF: Test For Auto-Commit Mode 5788 ** KEYWORDS: {autocommit mode} 5789 ** METHOD: sqlite3 5790 ** 5791 ** ^The sqlite3_get_autocommit() interface returns non-zero or 5792 ** zero if the given database connection is or is not in autocommit mode, 5793 ** respectively. ^Autocommit mode is on by default. 5794 ** ^Autocommit mode is disabled by a [BEGIN] statement. 5795 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 5796 ** 5797 ** If certain kinds of errors occur on a statement within a multi-statement 5798 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 5799 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 5800 ** transaction might be rolled back automatically. The only way to 5801 ** find out whether SQLite automatically rolled back the transaction after 5802 ** an error is to use this function. 5803 ** 5804 ** If another thread changes the autocommit status of the database 5805 ** connection while this routine is running, then the return value 5806 ** is undefined. 5807 */ 5808 SQLITE_API int sqlite3_get_autocommit(sqlite3*); 5809 5810 /* 5811 ** CAPI3REF: Find The Database Handle Of A Prepared Statement 5812 ** METHOD: sqlite3_stmt 5813 ** 5814 ** ^The sqlite3_db_handle interface returns the [database connection] handle 5815 ** to which a [prepared statement] belongs. ^The [database connection] 5816 ** returned by sqlite3_db_handle is the same [database connection] 5817 ** that was the first argument 5818 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 5819 ** create the statement in the first place. 5820 */ 5821 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 5822 5823 /* 5824 ** CAPI3REF: Return The Filename For A Database Connection 5825 ** METHOD: sqlite3 5826 ** 5827 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 5828 ** associated with database N of connection D. ^The main database file 5829 ** has the name "main". If there is no attached database N on the database 5830 ** connection D, or if database N is a temporary or in-memory database, then 5831 ** this function will return either a NULL pointer or an empty string. 5832 ** 5833 ** ^The filename returned by this function is the output of the 5834 ** xFullPathname method of the [VFS]. ^In other words, the filename 5835 ** will be an absolute pathname, even if the filename used 5836 ** to open the database originally was a URI or relative pathname. 5837 */ 5838 SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 5839 5840 /* 5841 ** CAPI3REF: Determine if a database is read-only 5842 ** METHOD: sqlite3 5843 ** 5844 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 5845 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not 5846 ** the name of a database on connection D. 5847 */ 5848 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 5849 5850 /* 5851 ** CAPI3REF: Find the next prepared statement 5852 ** METHOD: sqlite3 5853 ** 5854 ** ^This interface returns a pointer to the next [prepared statement] after 5855 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 5856 ** then this interface returns a pointer to the first prepared statement 5857 ** associated with the database connection pDb. ^If no prepared statement 5858 ** satisfies the conditions of this routine, it returns NULL. 5859 ** 5860 ** The [database connection] pointer D in a call to 5861 ** [sqlite3_next_stmt(D,S)] must refer to an open database 5862 ** connection and in particular must not be a NULL pointer. 5863 */ 5864 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 5865 5866 /* 5867 ** CAPI3REF: Commit And Rollback Notification Callbacks 5868 ** METHOD: sqlite3 5869 ** 5870 ** ^The sqlite3_commit_hook() interface registers a callback 5871 ** function to be invoked whenever a transaction is [COMMIT | committed]. 5872 ** ^Any callback set by a previous call to sqlite3_commit_hook() 5873 ** for the same database connection is overridden. 5874 ** ^The sqlite3_rollback_hook() interface registers a callback 5875 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 5876 ** ^Any callback set by a previous call to sqlite3_rollback_hook() 5877 ** for the same database connection is overridden. 5878 ** ^The pArg argument is passed through to the callback. 5879 ** ^If the callback on a commit hook function returns non-zero, 5880 ** then the commit is converted into a rollback. 5881 ** 5882 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 5883 ** return the P argument from the previous call of the same function 5884 ** on the same [database connection] D, or NULL for 5885 ** the first call for each function on D. 5886 ** 5887 ** The commit and rollback hook callbacks are not reentrant. 5888 ** The callback implementation must not do anything that will modify 5889 ** the database connection that invoked the callback. Any actions 5890 ** to modify the database connection must be deferred until after the 5891 ** completion of the [sqlite3_step()] call that triggered the commit 5892 ** or rollback hook in the first place. 5893 ** Note that running any other SQL statements, including SELECT statements, 5894 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5895 ** the database connections for the meaning of "modify" in this paragraph. 5896 ** 5897 ** ^Registering a NULL function disables the callback. 5898 ** 5899 ** ^When the commit hook callback routine returns zero, the [COMMIT] 5900 ** operation is allowed to continue normally. ^If the commit hook 5901 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5902 ** ^The rollback hook is invoked on a rollback that results from a commit 5903 ** hook returning non-zero, just as it would be with any other rollback. 5904 ** 5905 ** ^For the purposes of this API, a transaction is said to have been 5906 ** rolled back if an explicit "ROLLBACK" statement is executed, or 5907 ** an error or constraint causes an implicit rollback to occur. 5908 ** ^The rollback callback is not invoked if a transaction is 5909 ** automatically rolled back because the database connection is closed. 5910 ** 5911 ** See also the [sqlite3_update_hook()] interface. 5912 */ 5913 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5914 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5915 5916 /* 5917 ** CAPI3REF: Data Change Notification Callbacks 5918 ** METHOD: sqlite3 5919 ** 5920 ** ^The sqlite3_update_hook() interface registers a callback function 5921 ** with the [database connection] identified by the first argument 5922 ** to be invoked whenever a row is updated, inserted or deleted in 5923 ** a [rowid table]. 5924 ** ^Any callback set by a previous call to this function 5925 ** for the same database connection is overridden. 5926 ** 5927 ** ^The second argument is a pointer to the function to invoke when a 5928 ** row is updated, inserted or deleted in a rowid table. 5929 ** ^The first argument to the callback is a copy of the third argument 5930 ** to sqlite3_update_hook(). 5931 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 5932 ** or [SQLITE_UPDATE], depending on the operation that caused the callback 5933 ** to be invoked. 5934 ** ^The third and fourth arguments to the callback contain pointers to the 5935 ** database and table name containing the affected row. 5936 ** ^The final callback parameter is the [rowid] of the row. 5937 ** ^In the case of an update, this is the [rowid] after the update takes place. 5938 ** 5939 ** ^(The update hook is not invoked when internal system tables are 5940 ** modified (i.e. sqlite_master and sqlite_sequence).)^ 5941 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 5942 ** 5943 ** ^In the current implementation, the update hook 5944 ** is not invoked when conflicting rows are deleted because of an 5945 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 5946 ** invoked when rows are deleted using the [truncate optimization]. 5947 ** The exceptions defined in this paragraph might change in a future 5948 ** release of SQLite. 5949 ** 5950 ** The update hook implementation must not do anything that will modify 5951 ** the database connection that invoked the update hook. Any actions 5952 ** to modify the database connection must be deferred until after the 5953 ** completion of the [sqlite3_step()] call that triggered the update hook. 5954 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 5955 ** database connections for the meaning of "modify" in this paragraph. 5956 ** 5957 ** ^The sqlite3_update_hook(D,C,P) function 5958 ** returns the P argument from the previous call 5959 ** on the same [database connection] D, or NULL for 5960 ** the first call on D. 5961 ** 5962 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 5963 ** and [sqlite3_preupdate_hook()] interfaces. 5964 */ 5965 SQLITE_API void *sqlite3_update_hook( 5966 sqlite3*, 5967 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 5968 void* 5969 ); 5970 5971 /* 5972 ** CAPI3REF: Enable Or Disable Shared Pager Cache 5973 ** 5974 ** ^(This routine enables or disables the sharing of the database cache 5975 ** and schema data structures between [database connection | connections] 5976 ** to the same database. Sharing is enabled if the argument is true 5977 ** and disabled if the argument is false.)^ 5978 ** 5979 ** ^Cache sharing is enabled and disabled for an entire process. 5980 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 5981 ** In prior versions of SQLite, 5982 ** sharing was enabled or disabled for each thread separately. 5983 ** 5984 ** ^(The cache sharing mode set by this interface effects all subsequent 5985 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 5986 ** Existing database connections continue use the sharing mode 5987 ** that was in effect at the time they were opened.)^ 5988 ** 5989 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 5990 ** successfully. An [error code] is returned otherwise.)^ 5991 ** 5992 ** ^Shared cache is disabled by default. But this might change in 5993 ** future releases of SQLite. Applications that care about shared 5994 ** cache setting should set it explicitly. 5995 ** 5996 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 5997 ** and will always return SQLITE_MISUSE. On those systems, 5998 ** shared cache mode should be enabled per-database connection via 5999 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 6000 ** 6001 ** This interface is threadsafe on processors where writing a 6002 ** 32-bit integer is atomic. 6003 ** 6004 ** See Also: [SQLite Shared-Cache Mode] 6005 */ 6006 SQLITE_API int sqlite3_enable_shared_cache(int); 6007 6008 /* 6009 ** CAPI3REF: Attempt To Free Heap Memory 6010 ** 6011 ** ^The sqlite3_release_memory() interface attempts to free N bytes 6012 ** of heap memory by deallocating non-essential memory allocations 6013 ** held by the database library. Memory used to cache database 6014 ** pages to improve performance is an example of non-essential memory. 6015 ** ^sqlite3_release_memory() returns the number of bytes actually freed, 6016 ** which might be more or less than the amount requested. 6017 ** ^The sqlite3_release_memory() routine is a no-op returning zero 6018 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 6019 ** 6020 ** See also: [sqlite3_db_release_memory()] 6021 */ 6022 SQLITE_API int sqlite3_release_memory(int); 6023 6024 /* 6025 ** CAPI3REF: Free Memory Used By A Database Connection 6026 ** METHOD: sqlite3 6027 ** 6028 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 6029 ** memory as possible from database connection D. Unlike the 6030 ** [sqlite3_release_memory()] interface, this interface is in effect even 6031 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 6032 ** omitted. 6033 ** 6034 ** See also: [sqlite3_release_memory()] 6035 */ 6036 SQLITE_API int sqlite3_db_release_memory(sqlite3*); 6037 6038 /* 6039 ** CAPI3REF: Impose A Limit On Heap Size 6040 ** 6041 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 6042 ** soft limit on the amount of heap memory that may be allocated by SQLite. 6043 ** ^SQLite strives to keep heap memory utilization below the soft heap 6044 ** limit by reducing the number of pages held in the page cache 6045 ** as heap memory usages approaches the limit. 6046 ** ^The soft heap limit is "soft" because even though SQLite strives to stay 6047 ** below the limit, it will exceed the limit rather than generate 6048 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 6049 ** is advisory only. 6050 ** 6051 ** ^The return value from sqlite3_soft_heap_limit64() is the size of 6052 ** the soft heap limit prior to the call, or negative in the case of an 6053 ** error. ^If the argument N is negative 6054 ** then no change is made to the soft heap limit. Hence, the current 6055 ** size of the soft heap limit can be determined by invoking 6056 ** sqlite3_soft_heap_limit64() with a negative argument. 6057 ** 6058 ** ^If the argument N is zero then the soft heap limit is disabled. 6059 ** 6060 ** ^(The soft heap limit is not enforced in the current implementation 6061 ** if one or more of following conditions are true: 6062 ** 6063 ** <ul> 6064 ** <li> The soft heap limit is set to zero. 6065 ** <li> Memory accounting is disabled using a combination of the 6066 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 6067 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 6068 ** <li> An alternative page cache implementation is specified using 6069 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 6070 ** <li> The page cache allocates from its own memory pool supplied 6071 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 6072 ** from the heap. 6073 ** </ul>)^ 6074 ** 6075 ** Beginning with SQLite [version 3.7.3] ([dateof:3.7.3]), 6076 ** the soft heap limit is enforced 6077 ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 6078 ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 6079 ** the soft heap limit is enforced on every memory allocation. Without 6080 ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 6081 ** when memory is allocated by the page cache. Testing suggests that because 6082 ** the page cache is the predominate memory user in SQLite, most 6083 ** applications will achieve adequate soft heap limit enforcement without 6084 ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 6085 ** 6086 ** The circumstances under which SQLite will enforce the soft heap limit may 6087 ** changes in future releases of SQLite. 6088 */ 6089 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 6090 6091 /* 6092 ** CAPI3REF: Deprecated Soft Heap Limit Interface 6093 ** DEPRECATED 6094 ** 6095 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 6096 ** interface. This routine is provided for historical compatibility 6097 ** only. All new applications should use the 6098 ** [sqlite3_soft_heap_limit64()] interface rather than this one. 6099 */ 6100 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 6101 6102 6103 /* 6104 ** CAPI3REF: Extract Metadata About A Column Of A Table 6105 ** METHOD: sqlite3 6106 ** 6107 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 6108 ** information about column C of table T in database D 6109 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 6110 ** interface returns SQLITE_OK and fills in the non-NULL pointers in 6111 ** the final five arguments with appropriate values if the specified 6112 ** column exists. ^The sqlite3_table_column_metadata() interface returns 6113 ** SQLITE_ERROR and if the specified column does not exist. 6114 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a 6115 ** NULL pointer, then this routine simply checks for the existence of the 6116 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 6117 ** does not. If the table name parameter T in a call to 6118 ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 6119 ** undefined behavior. 6120 ** 6121 ** ^The column is identified by the second, third and fourth parameters to 6122 ** this function. ^(The second parameter is either the name of the database 6123 ** (i.e. "main", "temp", or an attached database) containing the specified 6124 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched 6125 ** for the table using the same algorithm used by the database engine to 6126 ** resolve unqualified table references. 6127 ** 6128 ** ^The third and fourth parameters to this function are the table and column 6129 ** name of the desired column, respectively. 6130 ** 6131 ** ^Metadata is returned by writing to the memory locations passed as the 5th 6132 ** and subsequent parameters to this function. ^Any of these arguments may be 6133 ** NULL, in which case the corresponding element of metadata is omitted. 6134 ** 6135 ** ^(<blockquote> 6136 ** <table border="1"> 6137 ** <tr><th> Parameter <th> Output<br>Type <th> Description 6138 ** 6139 ** <tr><td> 5th <td> const char* <td> Data type 6140 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 6141 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 6142 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 6143 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 6144 ** </table> 6145 ** </blockquote>)^ 6146 ** 6147 ** ^The memory pointed to by the character pointers returned for the 6148 ** declaration type and collation sequence is valid until the next 6149 ** call to any SQLite API function. 6150 ** 6151 ** ^If the specified table is actually a view, an [error code] is returned. 6152 ** 6153 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 6154 ** is not a [WITHOUT ROWID] table and an 6155 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 6156 ** parameters are set for the explicitly declared column. ^(If there is no 6157 ** [INTEGER PRIMARY KEY] column, then the outputs 6158 ** for the [rowid] are set as follows: 6159 ** 6160 ** <pre> 6161 ** data type: "INTEGER" 6162 ** collation sequence: "BINARY" 6163 ** not null: 0 6164 ** primary key: 1 6165 ** auto increment: 0 6166 ** </pre>)^ 6167 ** 6168 ** ^This function causes all database schemas to be read from disk and 6169 ** parsed, if that has not already been done, and returns an error if 6170 ** any errors are encountered while loading the schema. 6171 */ 6172 SQLITE_API int sqlite3_table_column_metadata( 6173 sqlite3 *db, /* Connection handle */ 6174 const char *zDbName, /* Database name or NULL */ 6175 const char *zTableName, /* Table name */ 6176 const char *zColumnName, /* Column name */ 6177 char const **pzDataType, /* OUTPUT: Declared data type */ 6178 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 6179 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 6180 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 6181 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 6182 ); 6183 6184 /* 6185 ** CAPI3REF: Load An Extension 6186 ** METHOD: sqlite3 6187 ** 6188 ** ^This interface loads an SQLite extension library from the named file. 6189 ** 6190 ** ^The sqlite3_load_extension() interface attempts to load an 6191 ** [SQLite extension] library contained in the file zFile. If 6192 ** the file cannot be loaded directly, attempts are made to load 6193 ** with various operating-system specific extensions added. 6194 ** So for example, if "samplelib" cannot be loaded, then names like 6195 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 6196 ** be tried also. 6197 ** 6198 ** ^The entry point is zProc. 6199 ** ^(zProc may be 0, in which case SQLite will try to come up with an 6200 ** entry point name on its own. It first tries "sqlite3_extension_init". 6201 ** If that does not work, it constructs a name "sqlite3_X_init" where the 6202 ** X is consists of the lower-case equivalent of all ASCII alphabetic 6203 ** characters in the filename from the last "/" to the first following 6204 ** "." and omitting any initial "lib".)^ 6205 ** ^The sqlite3_load_extension() interface returns 6206 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 6207 ** ^If an error occurs and pzErrMsg is not 0, then the 6208 ** [sqlite3_load_extension()] interface shall attempt to 6209 ** fill *pzErrMsg with error message text stored in memory 6210 ** obtained from [sqlite3_malloc()]. The calling function 6211 ** should free this memory by calling [sqlite3_free()]. 6212 ** 6213 ** ^Extension loading must be enabled using 6214 ** [sqlite3_enable_load_extension()] or 6215 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 6216 ** prior to calling this API, 6217 ** otherwise an error will be returned. 6218 ** 6219 ** <b>Security warning:</b> It is recommended that the 6220 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 6221 ** interface. The use of the [sqlite3_enable_load_extension()] interface 6222 ** should be avoided. This will keep the SQL function [load_extension()] 6223 ** disabled and prevent SQL injections from giving attackers 6224 ** access to extension loading capabilities. 6225 ** 6226 ** See also the [load_extension() SQL function]. 6227 */ 6228 SQLITE_API int sqlite3_load_extension( 6229 sqlite3 *db, /* Load the extension into this database connection */ 6230 const char *zFile, /* Name of the shared library containing extension */ 6231 const char *zProc, /* Entry point. Derived from zFile if 0 */ 6232 char **pzErrMsg /* Put error message here if not 0 */ 6233 ); 6234 6235 /* 6236 ** CAPI3REF: Enable Or Disable Extension Loading 6237 ** METHOD: sqlite3 6238 ** 6239 ** ^So as not to open security holes in older applications that are 6240 ** unprepared to deal with [extension loading], and as a means of disabling 6241 ** [extension loading] while evaluating user-entered SQL, the following API 6242 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 6243 ** 6244 ** ^Extension loading is off by default. 6245 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 6246 ** to turn extension loading on and call it with onoff==0 to turn 6247 ** it back off again. 6248 ** 6249 ** ^This interface enables or disables both the C-API 6250 ** [sqlite3_load_extension()] and the SQL function [load_extension()]. 6251 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 6252 ** to enable or disable only the C-API.)^ 6253 ** 6254 ** <b>Security warning:</b> It is recommended that extension loading 6255 ** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 6256 ** rather than this interface, so the [load_extension()] SQL function 6257 ** remains disabled. This will prevent SQL injections from giving attackers 6258 ** access to extension loading capabilities. 6259 */ 6260 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 6261 6262 /* 6263 ** CAPI3REF: Automatically Load Statically Linked Extensions 6264 ** 6265 ** ^This interface causes the xEntryPoint() function to be invoked for 6266 ** each new [database connection] that is created. The idea here is that 6267 ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 6268 ** that is to be automatically loaded into all new database connections. 6269 ** 6270 ** ^(Even though the function prototype shows that xEntryPoint() takes 6271 ** no arguments and returns void, SQLite invokes xEntryPoint() with three 6272 ** arguments and expects an integer result as if the signature of the 6273 ** entry point where as follows: 6274 ** 6275 ** <blockquote><pre> 6276 ** int xEntryPoint( 6277 ** sqlite3 *db, 6278 ** const char **pzErrMsg, 6279 ** const struct sqlite3_api_routines *pThunk 6280 ** ); 6281 ** </pre></blockquote>)^ 6282 ** 6283 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 6284 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 6285 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 6286 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 6287 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 6288 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 6289 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 6290 ** 6291 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 6292 ** on the list of automatic extensions is a harmless no-op. ^No entry point 6293 ** will be called more than once for each database connection that is opened. 6294 ** 6295 ** See also: [sqlite3_reset_auto_extension()] 6296 ** and [sqlite3_cancel_auto_extension()] 6297 */ 6298 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void)); 6299 6300 /* 6301 ** CAPI3REF: Cancel Automatic Extension Loading 6302 ** 6303 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 6304 ** initialization routine X that was registered using a prior call to 6305 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 6306 ** routine returns 1 if initialization routine X was successfully 6307 ** unregistered and it returns 0 if X was not on the list of initialization 6308 ** routines. 6309 */ 6310 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 6311 6312 /* 6313 ** CAPI3REF: Reset Automatic Extension Loading 6314 ** 6315 ** ^This interface disables all automatic extensions previously 6316 ** registered using [sqlite3_auto_extension()]. 6317 */ 6318 SQLITE_API void sqlite3_reset_auto_extension(void); 6319 6320 /* 6321 ** The interface to the virtual-table mechanism is currently considered 6322 ** to be experimental. The interface might change in incompatible ways. 6323 ** If this is a problem for you, do not use the interface at this time. 6324 ** 6325 ** When the virtual-table mechanism stabilizes, we will declare the 6326 ** interface fixed, support it indefinitely, and remove this comment. 6327 */ 6328 6329 /* 6330 ** Structures used by the virtual table interface 6331 */ 6332 typedef struct sqlite3_vtab sqlite3_vtab; 6333 typedef struct sqlite3_index_info sqlite3_index_info; 6334 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 6335 typedef struct sqlite3_module sqlite3_module; 6336 6337 /* 6338 ** CAPI3REF: Virtual Table Object 6339 ** KEYWORDS: sqlite3_module {virtual table module} 6340 ** 6341 ** This structure, sometimes called a "virtual table module", 6342 ** defines the implementation of a [virtual tables]. 6343 ** This structure consists mostly of methods for the module. 6344 ** 6345 ** ^A virtual table module is created by filling in a persistent 6346 ** instance of this structure and passing a pointer to that instance 6347 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 6348 ** ^The registration remains valid until it is replaced by a different 6349 ** module or until the [database connection] closes. The content 6350 ** of this structure must not change while it is registered with 6351 ** any database connection. 6352 */ 6353 struct sqlite3_module { 6354 int iVersion; 6355 int (*xCreate)(sqlite3*, void *pAux, 6356 int argc, const char *const*argv, 6357 sqlite3_vtab **ppVTab, char**); 6358 int (*xConnect)(sqlite3*, void *pAux, 6359 int argc, const char *const*argv, 6360 sqlite3_vtab **ppVTab, char**); 6361 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 6362 int (*xDisconnect)(sqlite3_vtab *pVTab); 6363 int (*xDestroy)(sqlite3_vtab *pVTab); 6364 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 6365 int (*xClose)(sqlite3_vtab_cursor*); 6366 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 6367 int argc, sqlite3_value **argv); 6368 int (*xNext)(sqlite3_vtab_cursor*); 6369 int (*xEof)(sqlite3_vtab_cursor*); 6370 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 6371 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 6372 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 6373 int (*xBegin)(sqlite3_vtab *pVTab); 6374 int (*xSync)(sqlite3_vtab *pVTab); 6375 int (*xCommit)(sqlite3_vtab *pVTab); 6376 int (*xRollback)(sqlite3_vtab *pVTab); 6377 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 6378 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 6379 void **ppArg); 6380 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 6381 /* The methods above are in version 1 of the sqlite_module object. Those 6382 ** below are for version 2 and greater. */ 6383 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 6384 int (*xRelease)(sqlite3_vtab *pVTab, int); 6385 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 6386 /* The methods above are in versions 1 and 2 of the sqlite_module object. 6387 ** Those below are for version 3 and greater. */ 6388 int (*xShadowName)(const char*); 6389 }; 6390 6391 /* 6392 ** CAPI3REF: Virtual Table Indexing Information 6393 ** KEYWORDS: sqlite3_index_info 6394 ** 6395 ** The sqlite3_index_info structure and its substructures is used as part 6396 ** of the [virtual table] interface to 6397 ** pass information into and receive the reply from the [xBestIndex] 6398 ** method of a [virtual table module]. The fields under **Inputs** are the 6399 ** inputs to xBestIndex and are read-only. xBestIndex inserts its 6400 ** results into the **Outputs** fields. 6401 ** 6402 ** ^(The aConstraint[] array records WHERE clause constraints of the form: 6403 ** 6404 ** <blockquote>column OP expr</blockquote> 6405 ** 6406 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 6407 ** stored in aConstraint[].op using one of the 6408 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 6409 ** ^(The index of the column is stored in 6410 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 6411 ** expr on the right-hand side can be evaluated (and thus the constraint 6412 ** is usable) and false if it cannot.)^ 6413 ** 6414 ** ^The optimizer automatically inverts terms of the form "expr OP column" 6415 ** and makes other simplifications to the WHERE clause in an attempt to 6416 ** get as many WHERE clause terms into the form shown above as possible. 6417 ** ^The aConstraint[] array only reports WHERE clause terms that are 6418 ** relevant to the particular virtual table being queried. 6419 ** 6420 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 6421 ** ^Each term of aOrderBy records a column of the ORDER BY clause. 6422 ** 6423 ** The colUsed field indicates which columns of the virtual table may be 6424 ** required by the current scan. Virtual table columns are numbered from 6425 ** zero in the order in which they appear within the CREATE TABLE statement 6426 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 6427 ** the corresponding bit is set within the colUsed mask if the column may be 6428 ** required by SQLite. If the table has at least 64 columns and any column 6429 ** to the right of the first 63 is required, then bit 63 of colUsed is also 6430 ** set. In other words, column iCol may be required if the expression 6431 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 6432 ** non-zero. 6433 ** 6434 ** The [xBestIndex] method must fill aConstraintUsage[] with information 6435 ** about what parameters to pass to xFilter. ^If argvIndex>0 then 6436 ** the right-hand side of the corresponding aConstraint[] is evaluated 6437 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 6438 ** is true, then the constraint is assumed to be fully handled by the 6439 ** virtual table and is not checked again by SQLite.)^ 6440 ** 6441 ** ^The idxNum and idxPtr values are recorded and passed into the 6442 ** [xFilter] method. 6443 ** ^[sqlite3_free()] is used to free idxPtr if and only if 6444 ** needToFreeIdxPtr is true. 6445 ** 6446 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 6447 ** the correct order to satisfy the ORDER BY clause so that no separate 6448 ** sorting step is required. 6449 ** 6450 ** ^The estimatedCost value is an estimate of the cost of a particular 6451 ** strategy. A cost of N indicates that the cost of the strategy is similar 6452 ** to a linear scan of an SQLite table with N rows. A cost of log(N) 6453 ** indicates that the expense of the operation is similar to that of a 6454 ** binary search on a unique indexed field of an SQLite table with N rows. 6455 ** 6456 ** ^The estimatedRows value is an estimate of the number of rows that 6457 ** will be returned by the strategy. 6458 ** 6459 ** The xBestIndex method may optionally populate the idxFlags field with a 6460 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 6461 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 6462 ** assumes that the strategy may visit at most one row. 6463 ** 6464 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 6465 ** SQLite also assumes that if a call to the xUpdate() method is made as 6466 ** part of the same statement to delete or update a virtual table row and the 6467 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 6468 ** any database changes. In other words, if the xUpdate() returns 6469 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were 6470 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 6471 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 6472 ** the xUpdate method are automatically rolled back by SQLite. 6473 ** 6474 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 6475 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 6476 ** If a virtual table extension is 6477 ** used with an SQLite version earlier than 3.8.2, the results of attempting 6478 ** to read or write the estimatedRows field are undefined (but are likely 6479 ** to included crashing the application). The estimatedRows field should 6480 ** therefore only be used if [sqlite3_libversion_number()] returns a 6481 ** value greater than or equal to 3008002. Similarly, the idxFlags field 6482 ** was added for [version 3.9.0] ([dateof:3.9.0]). 6483 ** It may therefore only be used if 6484 ** sqlite3_libversion_number() returns a value greater than or equal to 6485 ** 3009000. 6486 */ 6487 struct sqlite3_index_info { 6488 /* Inputs */ 6489 int nConstraint; /* Number of entries in aConstraint */ 6490 struct sqlite3_index_constraint { 6491 int iColumn; /* Column constrained. -1 for ROWID */ 6492 unsigned char op; /* Constraint operator */ 6493 unsigned char usable; /* True if this constraint is usable */ 6494 int iTermOffset; /* Used internally - xBestIndex should ignore */ 6495 } *aConstraint; /* Table of WHERE clause constraints */ 6496 int nOrderBy; /* Number of terms in the ORDER BY clause */ 6497 struct sqlite3_index_orderby { 6498 int iColumn; /* Column number */ 6499 unsigned char desc; /* True for DESC. False for ASC. */ 6500 } *aOrderBy; /* The ORDER BY clause */ 6501 /* Outputs */ 6502 struct sqlite3_index_constraint_usage { 6503 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 6504 unsigned char omit; /* Do not code a test for this constraint */ 6505 } *aConstraintUsage; 6506 int idxNum; /* Number used to identify the index */ 6507 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 6508 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 6509 int orderByConsumed; /* True if output is already ordered */ 6510 double estimatedCost; /* Estimated cost of using this index */ 6511 /* Fields below are only available in SQLite 3.8.2 and later */ 6512 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 6513 /* Fields below are only available in SQLite 3.9.0 and later */ 6514 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 6515 /* Fields below are only available in SQLite 3.10.0 and later */ 6516 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 6517 }; 6518 6519 /* 6520 ** CAPI3REF: Virtual Table Scan Flags 6521 ** 6522 ** Virtual table implementations are allowed to set the 6523 ** [sqlite3_index_info].idxFlags field to some combination of 6524 ** these bits. 6525 */ 6526 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 6527 6528 /* 6529 ** CAPI3REF: Virtual Table Constraint Operator Codes 6530 ** 6531 ** These macros defined the allowed values for the 6532 ** [sqlite3_index_info].aConstraint[].op field. Each value represents 6533 ** an operator that is part of a constraint term in the wHERE clause of 6534 ** a query that uses a [virtual table]. 6535 */ 6536 #define SQLITE_INDEX_CONSTRAINT_EQ 2 6537 #define SQLITE_INDEX_CONSTRAINT_GT 4 6538 #define SQLITE_INDEX_CONSTRAINT_LE 8 6539 #define SQLITE_INDEX_CONSTRAINT_LT 16 6540 #define SQLITE_INDEX_CONSTRAINT_GE 32 6541 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 6542 #define SQLITE_INDEX_CONSTRAINT_LIKE 65 6543 #define SQLITE_INDEX_CONSTRAINT_GLOB 66 6544 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67 6545 #define SQLITE_INDEX_CONSTRAINT_NE 68 6546 #define SQLITE_INDEX_CONSTRAINT_ISNOT 69 6547 #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 6548 #define SQLITE_INDEX_CONSTRAINT_ISNULL 71 6549 #define SQLITE_INDEX_CONSTRAINT_IS 72 6550 #define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 6551 6552 /* 6553 ** CAPI3REF: Register A Virtual Table Implementation 6554 ** METHOD: sqlite3 6555 ** 6556 ** ^These routines are used to register a new [virtual table module] name. 6557 ** ^Module names must be registered before 6558 ** creating a new [virtual table] using the module and before using a 6559 ** preexisting [virtual table] for the module. 6560 ** 6561 ** ^The module name is registered on the [database connection] specified 6562 ** by the first parameter. ^The name of the module is given by the 6563 ** second parameter. ^The third parameter is a pointer to 6564 ** the implementation of the [virtual table module]. ^The fourth 6565 ** parameter is an arbitrary client data pointer that is passed through 6566 ** into the [xCreate] and [xConnect] methods of the virtual table module 6567 ** when a new virtual table is be being created or reinitialized. 6568 ** 6569 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 6570 ** is a pointer to a destructor for the pClientData. ^SQLite will 6571 ** invoke the destructor function (if it is not NULL) when SQLite 6572 ** no longer needs the pClientData pointer. ^The destructor will also 6573 ** be invoked if the call to sqlite3_create_module_v2() fails. 6574 ** ^The sqlite3_create_module() 6575 ** interface is equivalent to sqlite3_create_module_v2() with a NULL 6576 ** destructor. 6577 */ 6578 SQLITE_API int sqlite3_create_module( 6579 sqlite3 *db, /* SQLite connection to register module with */ 6580 const char *zName, /* Name of the module */ 6581 const sqlite3_module *p, /* Methods for the module */ 6582 void *pClientData /* Client data for xCreate/xConnect */ 6583 ); 6584 SQLITE_API int sqlite3_create_module_v2( 6585 sqlite3 *db, /* SQLite connection to register module with */ 6586 const char *zName, /* Name of the module */ 6587 const sqlite3_module *p, /* Methods for the module */ 6588 void *pClientData, /* Client data for xCreate/xConnect */ 6589 void(*xDestroy)(void*) /* Module destructor function */ 6590 ); 6591 6592 /* 6593 ** CAPI3REF: Virtual Table Instance Object 6594 ** KEYWORDS: sqlite3_vtab 6595 ** 6596 ** Every [virtual table module] implementation uses a subclass 6597 ** of this object to describe a particular instance 6598 ** of the [virtual table]. Each subclass will 6599 ** be tailored to the specific needs of the module implementation. 6600 ** The purpose of this superclass is to define certain fields that are 6601 ** common to all module implementations. 6602 ** 6603 ** ^Virtual tables methods can set an error message by assigning a 6604 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 6605 ** take care that any prior string is freed by a call to [sqlite3_free()] 6606 ** prior to assigning a new string to zErrMsg. ^After the error message 6607 ** is delivered up to the client application, the string will be automatically 6608 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 6609 */ 6610 struct sqlite3_vtab { 6611 const sqlite3_module *pModule; /* The module for this virtual table */ 6612 int nRef; /* Number of open cursors */ 6613 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 6614 /* Virtual table implementations will typically add additional fields */ 6615 }; 6616 6617 /* 6618 ** CAPI3REF: Virtual Table Cursor Object 6619 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 6620 ** 6621 ** Every [virtual table module] implementation uses a subclass of the 6622 ** following structure to describe cursors that point into the 6623 ** [virtual table] and are used 6624 ** to loop through the virtual table. Cursors are created using the 6625 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 6626 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 6627 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 6628 ** of the module. Each module implementation will define 6629 ** the content of a cursor structure to suit its own needs. 6630 ** 6631 ** This superclass exists in order to define fields of the cursor that 6632 ** are common to all implementations. 6633 */ 6634 struct sqlite3_vtab_cursor { 6635 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 6636 /* Virtual table implementations will typically add additional fields */ 6637 }; 6638 6639 /* 6640 ** CAPI3REF: Declare The Schema Of A Virtual Table 6641 ** 6642 ** ^The [xCreate] and [xConnect] methods of a 6643 ** [virtual table module] call this interface 6644 ** to declare the format (the names and datatypes of the columns) of 6645 ** the virtual tables they implement. 6646 */ 6647 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 6648 6649 /* 6650 ** CAPI3REF: Overload A Function For A Virtual Table 6651 ** METHOD: sqlite3 6652 ** 6653 ** ^(Virtual tables can provide alternative implementations of functions 6654 ** using the [xFindFunction] method of the [virtual table module]. 6655 ** But global versions of those functions 6656 ** must exist in order to be overloaded.)^ 6657 ** 6658 ** ^(This API makes sure a global version of a function with a particular 6659 ** name and number of parameters exists. If no such function exists 6660 ** before this API is called, a new function is created.)^ ^The implementation 6661 ** of the new function always causes an exception to be thrown. So 6662 ** the new function is not good for anything by itself. Its only 6663 ** purpose is to be a placeholder function that can be overloaded 6664 ** by a [virtual table]. 6665 */ 6666 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 6667 6668 /* 6669 ** The interface to the virtual-table mechanism defined above (back up 6670 ** to a comment remarkably similar to this one) is currently considered 6671 ** to be experimental. The interface might change in incompatible ways. 6672 ** If this is a problem for you, do not use the interface at this time. 6673 ** 6674 ** When the virtual-table mechanism stabilizes, we will declare the 6675 ** interface fixed, support it indefinitely, and remove this comment. 6676 */ 6677 6678 /* 6679 ** CAPI3REF: A Handle To An Open BLOB 6680 ** KEYWORDS: {BLOB handle} {BLOB handles} 6681 ** 6682 ** An instance of this object represents an open BLOB on which 6683 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 6684 ** ^Objects of this type are created by [sqlite3_blob_open()] 6685 ** and destroyed by [sqlite3_blob_close()]. 6686 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 6687 ** can be used to read or write small subsections of the BLOB. 6688 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 6689 */ 6690 typedef struct sqlite3_blob sqlite3_blob; 6691 6692 /* 6693 ** CAPI3REF: Open A BLOB For Incremental I/O 6694 ** METHOD: sqlite3 6695 ** CONSTRUCTOR: sqlite3_blob 6696 ** 6697 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 6698 ** in row iRow, column zColumn, table zTable in database zDb; 6699 ** in other words, the same BLOB that would be selected by: 6700 ** 6701 ** <pre> 6702 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 6703 ** </pre>)^ 6704 ** 6705 ** ^(Parameter zDb is not the filename that contains the database, but 6706 ** rather the symbolic name of the database. For attached databases, this is 6707 ** the name that appears after the AS keyword in the [ATTACH] statement. 6708 ** For the main database file, the database name is "main". For TEMP 6709 ** tables, the database name is "temp".)^ 6710 ** 6711 ** ^If the flags parameter is non-zero, then the BLOB is opened for read 6712 ** and write access. ^If the flags parameter is zero, the BLOB is opened for 6713 ** read-only access. 6714 ** 6715 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 6716 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error 6717 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 6718 ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 6719 ** on *ppBlob after this function it returns. 6720 ** 6721 ** This function fails with SQLITE_ERROR if any of the following are true: 6722 ** <ul> 6723 ** <li> ^(Database zDb does not exist)^, 6724 ** <li> ^(Table zTable does not exist within database zDb)^, 6725 ** <li> ^(Table zTable is a WITHOUT ROWID table)^, 6726 ** <li> ^(Column zColumn does not exist)^, 6727 ** <li> ^(Row iRow is not present in the table)^, 6728 ** <li> ^(The specified column of row iRow contains a value that is not 6729 ** a TEXT or BLOB value)^, 6730 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 6731 ** constraint and the blob is being opened for read/write access)^, 6732 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 6733 ** column zColumn is part of a [child key] definition and the blob is 6734 ** being opened for read/write access)^. 6735 ** </ul> 6736 ** 6737 ** ^Unless it returns SQLITE_MISUSE, this function sets the 6738 ** [database connection] error code and message accessible via 6739 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6740 ** 6741 ** A BLOB referenced by sqlite3_blob_open() may be read using the 6742 ** [sqlite3_blob_read()] interface and modified by using 6743 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 6744 ** different row of the same table using the [sqlite3_blob_reopen()] 6745 ** interface. However, the column, table, or database of a [BLOB handle] 6746 ** cannot be changed after the [BLOB handle] is opened. 6747 ** 6748 ** ^(If the row that a BLOB handle points to is modified by an 6749 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 6750 ** then the BLOB handle is marked as "expired". 6751 ** This is true if any column of the row is changed, even a column 6752 ** other than the one the BLOB handle is open on.)^ 6753 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 6754 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 6755 ** ^(Changes written into a BLOB prior to the BLOB expiring are not 6756 ** rolled back by the expiration of the BLOB. Such changes will eventually 6757 ** commit if the transaction continues to completion.)^ 6758 ** 6759 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 6760 ** the opened blob. ^The size of a blob may not be changed by this 6761 ** interface. Use the [UPDATE] SQL command to change the size of a 6762 ** blob. 6763 ** 6764 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 6765 ** and the built-in [zeroblob] SQL function may be used to create a 6766 ** zero-filled blob to read or write using the incremental-blob interface. 6767 ** 6768 ** To avoid a resource leak, every open [BLOB handle] should eventually 6769 ** be released by a call to [sqlite3_blob_close()]. 6770 ** 6771 ** See also: [sqlite3_blob_close()], 6772 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 6773 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 6774 */ 6775 SQLITE_API int sqlite3_blob_open( 6776 sqlite3*, 6777 const char *zDb, 6778 const char *zTable, 6779 const char *zColumn, 6780 sqlite3_int64 iRow, 6781 int flags, 6782 sqlite3_blob **ppBlob 6783 ); 6784 6785 /* 6786 ** CAPI3REF: Move a BLOB Handle to a New Row 6787 ** METHOD: sqlite3_blob 6788 ** 6789 ** ^This function is used to move an existing [BLOB handle] so that it points 6790 ** to a different row of the same database table. ^The new row is identified 6791 ** by the rowid value passed as the second argument. Only the row can be 6792 ** changed. ^The database, table and column on which the blob handle is open 6793 ** remain the same. Moving an existing [BLOB handle] to a new row is 6794 ** faster than closing the existing handle and opening a new one. 6795 ** 6796 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 6797 ** it must exist and there must be either a blob or text value stored in 6798 ** the nominated column.)^ ^If the new row is not present in the table, or if 6799 ** it does not contain a blob or text value, or if another error occurs, an 6800 ** SQLite error code is returned and the blob handle is considered aborted. 6801 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 6802 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 6803 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 6804 ** always returns zero. 6805 ** 6806 ** ^This function sets the database handle error code and message. 6807 */ 6808 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 6809 6810 /* 6811 ** CAPI3REF: Close A BLOB Handle 6812 ** DESTRUCTOR: sqlite3_blob 6813 ** 6814 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 6815 ** unconditionally. Even if this routine returns an error code, the 6816 ** handle is still closed.)^ 6817 ** 6818 ** ^If the blob handle being closed was opened for read-write access, and if 6819 ** the database is in auto-commit mode and there are no other open read-write 6820 ** blob handles or active write statements, the current transaction is 6821 ** committed. ^If an error occurs while committing the transaction, an error 6822 ** code is returned and the transaction rolled back. 6823 ** 6824 ** Calling this function with an argument that is not a NULL pointer or an 6825 ** open blob handle results in undefined behaviour. ^Calling this routine 6826 ** with a null pointer (such as would be returned by a failed call to 6827 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 6828 ** is passed a valid open blob handle, the values returned by the 6829 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 6830 */ 6831 SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 6832 6833 /* 6834 ** CAPI3REF: Return The Size Of An Open BLOB 6835 ** METHOD: sqlite3_blob 6836 ** 6837 ** ^Returns the size in bytes of the BLOB accessible via the 6838 ** successfully opened [BLOB handle] in its only argument. ^The 6839 ** incremental blob I/O routines can only read or overwriting existing 6840 ** blob content; they cannot change the size of a blob. 6841 ** 6842 ** This routine only works on a [BLOB handle] which has been created 6843 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6844 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6845 ** to this routine results in undefined and probably undesirable behavior. 6846 */ 6847 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 6848 6849 /* 6850 ** CAPI3REF: Read Data From A BLOB Incrementally 6851 ** METHOD: sqlite3_blob 6852 ** 6853 ** ^(This function is used to read data from an open [BLOB handle] into a 6854 ** caller-supplied buffer. N bytes of data are copied into buffer Z 6855 ** from the open BLOB, starting at offset iOffset.)^ 6856 ** 6857 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 6858 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 6859 ** less than zero, [SQLITE_ERROR] is returned and no data is read. 6860 ** ^The size of the blob (and hence the maximum value of N+iOffset) 6861 ** can be determined using the [sqlite3_blob_bytes()] interface. 6862 ** 6863 ** ^An attempt to read from an expired [BLOB handle] fails with an 6864 ** error code of [SQLITE_ABORT]. 6865 ** 6866 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 6867 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 6868 ** 6869 ** This routine only works on a [BLOB handle] which has been created 6870 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6871 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6872 ** to this routine results in undefined and probably undesirable behavior. 6873 ** 6874 ** See also: [sqlite3_blob_write()]. 6875 */ 6876 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 6877 6878 /* 6879 ** CAPI3REF: Write Data Into A BLOB Incrementally 6880 ** METHOD: sqlite3_blob 6881 ** 6882 ** ^(This function is used to write data into an open [BLOB handle] from a 6883 ** caller-supplied buffer. N bytes of data are copied from the buffer Z 6884 ** into the open BLOB, starting at offset iOffset.)^ 6885 ** 6886 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 6887 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 6888 ** ^Unless SQLITE_MISUSE is returned, this function sets the 6889 ** [database connection] error code and message accessible via 6890 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6891 ** 6892 ** ^If the [BLOB handle] passed as the first argument was not opened for 6893 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 6894 ** this function returns [SQLITE_READONLY]. 6895 ** 6896 ** This function may only modify the contents of the BLOB; it is 6897 ** not possible to increase the size of a BLOB using this API. 6898 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 6899 ** [SQLITE_ERROR] is returned and no data is written. The size of the 6900 ** BLOB (and hence the maximum value of N+iOffset) can be determined 6901 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 6902 ** than zero [SQLITE_ERROR] is returned and no data is written. 6903 ** 6904 ** ^An attempt to write to an expired [BLOB handle] fails with an 6905 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 6906 ** before the [BLOB handle] expired are not rolled back by the 6907 ** expiration of the handle, though of course those changes might 6908 ** have been overwritten by the statement that expired the BLOB handle 6909 ** or by other independent statements. 6910 ** 6911 ** This routine only works on a [BLOB handle] which has been created 6912 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6913 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6914 ** to this routine results in undefined and probably undesirable behavior. 6915 ** 6916 ** See also: [sqlite3_blob_read()]. 6917 */ 6918 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 6919 6920 /* 6921 ** CAPI3REF: Virtual File System Objects 6922 ** 6923 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 6924 ** that SQLite uses to interact 6925 ** with the underlying operating system. Most SQLite builds come with a 6926 ** single default VFS that is appropriate for the host computer. 6927 ** New VFSes can be registered and existing VFSes can be unregistered. 6928 ** The following interfaces are provided. 6929 ** 6930 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 6931 ** ^Names are case sensitive. 6932 ** ^Names are zero-terminated UTF-8 strings. 6933 ** ^If there is no match, a NULL pointer is returned. 6934 ** ^If zVfsName is NULL then the default VFS is returned. 6935 ** 6936 ** ^New VFSes are registered with sqlite3_vfs_register(). 6937 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 6938 ** ^The same VFS can be registered multiple times without injury. 6939 ** ^To make an existing VFS into the default VFS, register it again 6940 ** with the makeDflt flag set. If two different VFSes with the 6941 ** same name are registered, the behavior is undefined. If a 6942 ** VFS is registered with a name that is NULL or an empty string, 6943 ** then the behavior is undefined. 6944 ** 6945 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 6946 ** ^(If the default VFS is unregistered, another VFS is chosen as 6947 ** the default. The choice for the new VFS is arbitrary.)^ 6948 */ 6949 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 6950 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 6951 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 6952 6953 /* 6954 ** CAPI3REF: Mutexes 6955 ** 6956 ** The SQLite core uses these routines for thread 6957 ** synchronization. Though they are intended for internal 6958 ** use by SQLite, code that links against SQLite is 6959 ** permitted to use any of these routines. 6960 ** 6961 ** The SQLite source code contains multiple implementations 6962 ** of these mutex routines. An appropriate implementation 6963 ** is selected automatically at compile-time. The following 6964 ** implementations are available in the SQLite core: 6965 ** 6966 ** <ul> 6967 ** <li> SQLITE_MUTEX_PTHREADS 6968 ** <li> SQLITE_MUTEX_W32 6969 ** <li> SQLITE_MUTEX_NOOP 6970 ** </ul> 6971 ** 6972 ** The SQLITE_MUTEX_NOOP implementation is a set of routines 6973 ** that does no real locking and is appropriate for use in 6974 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 6975 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 6976 ** and Windows. 6977 ** 6978 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 6979 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 6980 ** implementation is included with the library. In this case the 6981 ** application must supply a custom mutex implementation using the 6982 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 6983 ** before calling sqlite3_initialize() or any other public sqlite3_ 6984 ** function that calls sqlite3_initialize(). 6985 ** 6986 ** ^The sqlite3_mutex_alloc() routine allocates a new 6987 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 6988 ** routine returns NULL if it is unable to allocate the requested 6989 ** mutex. The argument to sqlite3_mutex_alloc() must one of these 6990 ** integer constants: 6991 ** 6992 ** <ul> 6993 ** <li> SQLITE_MUTEX_FAST 6994 ** <li> SQLITE_MUTEX_RECURSIVE 6995 ** <li> SQLITE_MUTEX_STATIC_MASTER 6996 ** <li> SQLITE_MUTEX_STATIC_MEM 6997 ** <li> SQLITE_MUTEX_STATIC_OPEN 6998 ** <li> SQLITE_MUTEX_STATIC_PRNG 6999 ** <li> SQLITE_MUTEX_STATIC_LRU 7000 ** <li> SQLITE_MUTEX_STATIC_PMEM 7001 ** <li> SQLITE_MUTEX_STATIC_APP1 7002 ** <li> SQLITE_MUTEX_STATIC_APP2 7003 ** <li> SQLITE_MUTEX_STATIC_APP3 7004 ** <li> SQLITE_MUTEX_STATIC_VFS1 7005 ** <li> SQLITE_MUTEX_STATIC_VFS2 7006 ** <li> SQLITE_MUTEX_STATIC_VFS3 7007 ** </ul> 7008 ** 7009 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 7010 ** cause sqlite3_mutex_alloc() to create 7011 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 7012 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 7013 ** The mutex implementation does not need to make a distinction 7014 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 7015 ** not want to. SQLite will only request a recursive mutex in 7016 ** cases where it really needs one. If a faster non-recursive mutex 7017 ** implementation is available on the host platform, the mutex subsystem 7018 ** might return such a mutex in response to SQLITE_MUTEX_FAST. 7019 ** 7020 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 7021 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 7022 ** a pointer to a static preexisting mutex. ^Nine static mutexes are 7023 ** used by the current version of SQLite. Future versions of SQLite 7024 ** may add additional static mutexes. Static mutexes are for internal 7025 ** use by SQLite only. Applications that use SQLite mutexes should 7026 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 7027 ** SQLITE_MUTEX_RECURSIVE. 7028 ** 7029 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 7030 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 7031 ** returns a different mutex on every call. ^For the static 7032 ** mutex types, the same mutex is returned on every call that has 7033 ** the same type number. 7034 ** 7035 ** ^The sqlite3_mutex_free() routine deallocates a previously 7036 ** allocated dynamic mutex. Attempting to deallocate a static 7037 ** mutex results in undefined behavior. 7038 ** 7039 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 7040 ** to enter a mutex. ^If another thread is already within the mutex, 7041 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 7042 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 7043 ** upon successful entry. ^(Mutexes created using 7044 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 7045 ** In such cases, the 7046 ** mutex must be exited an equal number of times before another thread 7047 ** can enter.)^ If the same thread tries to enter any mutex other 7048 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 7049 ** 7050 ** ^(Some systems (for example, Windows 95) do not support the operation 7051 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 7052 ** will always return SQLITE_BUSY. The SQLite core only ever uses 7053 ** sqlite3_mutex_try() as an optimization so this is acceptable 7054 ** behavior.)^ 7055 ** 7056 ** ^The sqlite3_mutex_leave() routine exits a mutex that was 7057 ** previously entered by the same thread. The behavior 7058 ** is undefined if the mutex is not currently entered by the 7059 ** calling thread or is not currently allocated. 7060 ** 7061 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 7062 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines 7063 ** behave as no-ops. 7064 ** 7065 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 7066 */ 7067 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 7068 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 7069 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 7070 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 7071 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 7072 7073 /* 7074 ** CAPI3REF: Mutex Methods Object 7075 ** 7076 ** An instance of this structure defines the low-level routines 7077 ** used to allocate and use mutexes. 7078 ** 7079 ** Usually, the default mutex implementations provided by SQLite are 7080 ** sufficient, however the application has the option of substituting a custom 7081 ** implementation for specialized deployments or systems for which SQLite 7082 ** does not provide a suitable implementation. In this case, the application 7083 ** creates and populates an instance of this structure to pass 7084 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 7085 ** Additionally, an instance of this structure can be used as an 7086 ** output variable when querying the system for the current mutex 7087 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 7088 ** 7089 ** ^The xMutexInit method defined by this structure is invoked as 7090 ** part of system initialization by the sqlite3_initialize() function. 7091 ** ^The xMutexInit routine is called by SQLite exactly once for each 7092 ** effective call to [sqlite3_initialize()]. 7093 ** 7094 ** ^The xMutexEnd method defined by this structure is invoked as 7095 ** part of system shutdown by the sqlite3_shutdown() function. The 7096 ** implementation of this method is expected to release all outstanding 7097 ** resources obtained by the mutex methods implementation, especially 7098 ** those obtained by the xMutexInit method. ^The xMutexEnd() 7099 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 7100 ** 7101 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 7102 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 7103 ** xMutexNotheld) implement the following interfaces (respectively): 7104 ** 7105 ** <ul> 7106 ** <li> [sqlite3_mutex_alloc()] </li> 7107 ** <li> [sqlite3_mutex_free()] </li> 7108 ** <li> [sqlite3_mutex_enter()] </li> 7109 ** <li> [sqlite3_mutex_try()] </li> 7110 ** <li> [sqlite3_mutex_leave()] </li> 7111 ** <li> [sqlite3_mutex_held()] </li> 7112 ** <li> [sqlite3_mutex_notheld()] </li> 7113 ** </ul>)^ 7114 ** 7115 ** The only difference is that the public sqlite3_XXX functions enumerated 7116 ** above silently ignore any invocations that pass a NULL pointer instead 7117 ** of a valid mutex handle. The implementations of the methods defined 7118 ** by this structure are not required to handle this case, the results 7119 ** of passing a NULL pointer instead of a valid mutex handle are undefined 7120 ** (i.e. it is acceptable to provide an implementation that segfaults if 7121 ** it is passed a NULL pointer). 7122 ** 7123 ** The xMutexInit() method must be threadsafe. It must be harmless to 7124 ** invoke xMutexInit() multiple times within the same process and without 7125 ** intervening calls to xMutexEnd(). Second and subsequent calls to 7126 ** xMutexInit() must be no-ops. 7127 ** 7128 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 7129 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 7130 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 7131 ** memory allocation for a fast or recursive mutex. 7132 ** 7133 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 7134 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 7135 ** If xMutexInit fails in any way, it is expected to clean up after itself 7136 ** prior to returning. 7137 */ 7138 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 7139 struct sqlite3_mutex_methods { 7140 int (*xMutexInit)(void); 7141 int (*xMutexEnd)(void); 7142 sqlite3_mutex *(*xMutexAlloc)(int); 7143 void (*xMutexFree)(sqlite3_mutex *); 7144 void (*xMutexEnter)(sqlite3_mutex *); 7145 int (*xMutexTry)(sqlite3_mutex *); 7146 void (*xMutexLeave)(sqlite3_mutex *); 7147 int (*xMutexHeld)(sqlite3_mutex *); 7148 int (*xMutexNotheld)(sqlite3_mutex *); 7149 }; 7150 7151 /* 7152 ** CAPI3REF: Mutex Verification Routines 7153 ** 7154 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 7155 ** are intended for use inside assert() statements. The SQLite core 7156 ** never uses these routines except inside an assert() and applications 7157 ** are advised to follow the lead of the core. The SQLite core only 7158 ** provides implementations for these routines when it is compiled 7159 ** with the SQLITE_DEBUG flag. External mutex implementations 7160 ** are only required to provide these routines if SQLITE_DEBUG is 7161 ** defined and if NDEBUG is not defined. 7162 ** 7163 ** These routines should return true if the mutex in their argument 7164 ** is held or not held, respectively, by the calling thread. 7165 ** 7166 ** The implementation is not required to provide versions of these 7167 ** routines that actually work. If the implementation does not provide working 7168 ** versions of these routines, it should at least provide stubs that always 7169 ** return true so that one does not get spurious assertion failures. 7170 ** 7171 ** If the argument to sqlite3_mutex_held() is a NULL pointer then 7172 ** the routine should return 1. This seems counter-intuitive since 7173 ** clearly the mutex cannot be held if it does not exist. But 7174 ** the reason the mutex does not exist is because the build is not 7175 ** using mutexes. And we do not want the assert() containing the 7176 ** call to sqlite3_mutex_held() to fail, so a non-zero return is 7177 ** the appropriate thing to do. The sqlite3_mutex_notheld() 7178 ** interface should also return 1 when given a NULL pointer. 7179 */ 7180 #ifndef NDEBUG 7181 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 7182 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 7183 #endif 7184 7185 /* 7186 ** CAPI3REF: Mutex Types 7187 ** 7188 ** The [sqlite3_mutex_alloc()] interface takes a single argument 7189 ** which is one of these integer constants. 7190 ** 7191 ** The set of static mutexes may change from one SQLite release to the 7192 ** next. Applications that override the built-in mutex logic must be 7193 ** prepared to accommodate additional static mutexes. 7194 */ 7195 #define SQLITE_MUTEX_FAST 0 7196 #define SQLITE_MUTEX_RECURSIVE 1 7197 #define SQLITE_MUTEX_STATIC_MASTER 2 7198 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 7199 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 7200 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 7201 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 7202 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 7203 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 7204 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 7205 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 7206 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 7207 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 7208 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 7209 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 7210 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 7211 7212 /* 7213 ** CAPI3REF: Retrieve the mutex for a database connection 7214 ** METHOD: sqlite3 7215 ** 7216 ** ^This interface returns a pointer the [sqlite3_mutex] object that 7217 ** serializes access to the [database connection] given in the argument 7218 ** when the [threading mode] is Serialized. 7219 ** ^If the [threading mode] is Single-thread or Multi-thread then this 7220 ** routine returns a NULL pointer. 7221 */ 7222 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 7223 7224 /* 7225 ** CAPI3REF: Low-Level Control Of Database Files 7226 ** METHOD: sqlite3 7227 ** KEYWORDS: {file control} 7228 ** 7229 ** ^The [sqlite3_file_control()] interface makes a direct call to the 7230 ** xFileControl method for the [sqlite3_io_methods] object associated 7231 ** with a particular database identified by the second argument. ^The 7232 ** name of the database is "main" for the main database or "temp" for the 7233 ** TEMP database, or the name that appears after the AS keyword for 7234 ** databases that are added using the [ATTACH] SQL command. 7235 ** ^A NULL pointer can be used in place of "main" to refer to the 7236 ** main database file. 7237 ** ^The third and fourth parameters to this routine 7238 ** are passed directly through to the second and third parameters of 7239 ** the xFileControl method. ^The return value of the xFileControl 7240 ** method becomes the return value of this routine. 7241 ** 7242 ** A few opcodes for [sqlite3_file_control()] are handled directly 7243 ** by the SQLite core and never invoke the 7244 ** sqlite3_io_methods.xFileControl method. 7245 ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 7246 ** a pointer to the underlying [sqlite3_file] object to be written into 7247 ** the space pointed to by the 4th parameter. The 7248 ** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 7249 ** the [sqlite3_file] object associated with the journal file instead of 7250 ** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 7251 ** a pointer to the underlying [sqlite3_vfs] object for the file. 7252 ** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 7253 ** from the pager. 7254 ** 7255 ** ^If the second parameter (zDbName) does not match the name of any 7256 ** open database file, then SQLITE_ERROR is returned. ^This error 7257 ** code is not remembered and will not be recalled by [sqlite3_errcode()] 7258 ** or [sqlite3_errmsg()]. The underlying xFileControl method might 7259 ** also return SQLITE_ERROR. There is no way to distinguish between 7260 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 7261 ** xFileControl method. 7262 ** 7263 ** See also: [file control opcodes] 7264 */ 7265 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 7266 7267 /* 7268 ** CAPI3REF: Testing Interface 7269 ** 7270 ** ^The sqlite3_test_control() interface is used to read out internal 7271 ** state of SQLite and to inject faults into SQLite for testing 7272 ** purposes. ^The first parameter is an operation code that determines 7273 ** the number, meaning, and operation of all subsequent parameters. 7274 ** 7275 ** This interface is not for use by applications. It exists solely 7276 ** for verifying the correct operation of the SQLite library. Depending 7277 ** on how the SQLite library is compiled, this interface might not exist. 7278 ** 7279 ** The details of the operation codes, their meanings, the parameters 7280 ** they take, and what they do are all subject to change without notice. 7281 ** Unlike most of the SQLite API, this function is not guaranteed to 7282 ** operate consistently from one release to the next. 7283 */ 7284 SQLITE_API int sqlite3_test_control(int op, ...); 7285 7286 /* 7287 ** CAPI3REF: Testing Interface Operation Codes 7288 ** 7289 ** These constants are the valid operation code parameters used 7290 ** as the first argument to [sqlite3_test_control()]. 7291 ** 7292 ** These parameters and their meanings are subject to change 7293 ** without notice. These values are for testing purposes only. 7294 ** Applications should not use any of these parameters or the 7295 ** [sqlite3_test_control()] interface. 7296 */ 7297 #define SQLITE_TESTCTRL_FIRST 5 7298 #define SQLITE_TESTCTRL_PRNG_SAVE 5 7299 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 7300 #define SQLITE_TESTCTRL_PRNG_RESET 7 7301 #define SQLITE_TESTCTRL_BITVEC_TEST 8 7302 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 7303 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 7304 #define SQLITE_TESTCTRL_PENDING_BYTE 11 7305 #define SQLITE_TESTCTRL_ASSERT 12 7306 #define SQLITE_TESTCTRL_ALWAYS 13 7307 #define SQLITE_TESTCTRL_RESERVE 14 7308 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 7309 #define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 7310 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 7311 #define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 7312 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 7313 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 7314 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 7315 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 7316 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 7317 #define SQLITE_TESTCTRL_BYTEORDER 22 7318 #define SQLITE_TESTCTRL_ISINIT 23 7319 #define SQLITE_TESTCTRL_SORTER_MMAP 24 7320 #define SQLITE_TESTCTRL_IMPOSTER 25 7321 #define SQLITE_TESTCTRL_PARSER_COVERAGE 26 7322 #define SQLITE_TESTCTRL_LAST 26 /* Largest TESTCTRL */ 7323 7324 /* 7325 ** CAPI3REF: SQL Keyword Checking 7326 ** 7327 ** These routines provide access to the set of SQL language keywords 7328 ** recognized by SQLite. Applications can uses these routines to determine 7329 ** whether or not a specific identifier needs to be escaped (for example, 7330 ** by enclosing in double-quotes) so as not to confuse the parser. 7331 ** 7332 ** The sqlite3_keyword_count() interface returns the number of distinct 7333 ** keywords understood by SQLite. 7334 ** 7335 ** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 7336 ** makes *Z point to that keyword expressed as UTF8 and writes the number 7337 ** of bytes in the keyword into *L. The string that *Z points to is not 7338 ** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 7339 ** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 7340 ** or L are NULL or invalid pointers then calls to 7341 ** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 7342 ** 7343 ** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 7344 ** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 7345 ** if it is and zero if not. 7346 ** 7347 ** The parser used by SQLite is forgiving. It is often possible to use 7348 ** a keyword as an identifier as long as such use does not result in a 7349 ** parsing ambiguity. For example, the statement 7350 ** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 7351 ** creates a new table named "BEGIN" with three columns named 7352 ** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 7353 ** using keywords as identifiers. Common techniques used to avoid keyword 7354 ** name collisions include: 7355 ** <ul> 7356 ** <li> Put all identifier names inside double-quotes. This is the official 7357 ** SQL way to escape identifier names. 7358 ** <li> Put identifier names inside [...]. This is not standard SQL, 7359 ** but it is what SQL Server does and so lots of programmers use this 7360 ** technique. 7361 ** <li> Begin every identifier with the letter "Z" as no SQL keywords start 7362 ** with "Z". 7363 ** <li> Include a digit somewhere in every identifier name. 7364 ** </ul> 7365 ** 7366 ** Note that the number of keywords understood by SQLite can depend on 7367 ** compile-time options. For example, "VACUUM" is not a keyword if 7368 ** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 7369 ** new keywords may be added to future releases of SQLite. 7370 */ 7371 SQLITE_API int sqlite3_keyword_count(void); 7372 SQLITE_API int sqlite3_keyword_name(int,const char**,int*); 7373 SQLITE_API int sqlite3_keyword_check(const char*,int); 7374 7375 /* 7376 ** CAPI3REF: Dynamic String Object 7377 ** KEYWORDS: {dynamic string} 7378 ** 7379 ** An instance of the sqlite3_str object contains a dynamically-sized 7380 ** string under construction. 7381 ** 7382 ** The lifecycle of an sqlite3_str object is as follows: 7383 ** <ol> 7384 ** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 7385 ** <li> ^Text is appended to the sqlite3_str object using various 7386 ** methods, such as [sqlite3_str_appendf()]. 7387 ** <li> ^The sqlite3_str object is destroyed and the string it created 7388 ** is returned using the [sqlite3_str_finish()] interface. 7389 ** </ol> 7390 */ 7391 typedef struct sqlite3_str sqlite3_str; 7392 7393 /* 7394 ** CAPI3REF: Create A New Dynamic String Object 7395 ** CONSTRUCTOR: sqlite3_str 7396 ** 7397 ** ^The [sqlite3_str_new(D)] interface allocates and initializes 7398 ** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 7399 ** [sqlite3_str_new()] must be freed by a subsequent call to 7400 ** [sqlite3_str_finish(X)]. 7401 ** 7402 ** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 7403 ** valid [sqlite3_str] object, though in the event of an out-of-memory 7404 ** error the returned object might be a special singleton that will 7405 ** silently reject new text, always return SQLITE_NOMEM from 7406 ** [sqlite3_str_errcode()], always return 0 for 7407 ** [sqlite3_str_length()], and always return NULL from 7408 ** [sqlite3_str_finish(X)]. It is always safe to use the value 7409 ** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 7410 ** to any of the other [sqlite3_str] methods. 7411 ** 7412 ** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 7413 ** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 7414 ** length of the string contained in the [sqlite3_str] object will be 7415 ** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 7416 ** of [SQLITE_MAX_LENGTH]. 7417 */ 7418 SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*); 7419 7420 /* 7421 ** CAPI3REF: Finalize A Dynamic String 7422 ** DESTRUCTOR: sqlite3_str 7423 ** 7424 ** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 7425 ** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 7426 ** that contains the constructed string. The calling application should 7427 ** pass the returned value to [sqlite3_free()] to avoid a memory leak. 7428 ** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 7429 ** errors were encountered during construction of the string. ^The 7430 ** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 7431 ** string in [sqlite3_str] object X is zero bytes long. 7432 */ 7433 SQLITE_API char *sqlite3_str_finish(sqlite3_str*); 7434 7435 /* 7436 ** CAPI3REF: Add Content To A Dynamic String 7437 ** METHOD: sqlite3_str 7438 ** 7439 ** These interfaces add content to an sqlite3_str object previously obtained 7440 ** from [sqlite3_str_new()]. 7441 ** 7442 ** ^The [sqlite3_str_appendf(X,F,...)] and 7443 ** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 7444 ** functionality of SQLite to append formatted text onto the end of 7445 ** [sqlite3_str] object X. 7446 ** 7447 ** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 7448 ** onto the end of the [sqlite3_str] object X. N must be non-negative. 7449 ** S must contain at least N non-zero bytes of content. To append a 7450 ** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 7451 ** method instead. 7452 ** 7453 ** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 7454 ** zero-terminated string S onto the end of [sqlite3_str] object X. 7455 ** 7456 ** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 7457 ** single-byte character C onto the end of [sqlite3_str] object X. 7458 ** ^This method can be used, for example, to add whitespace indentation. 7459 ** 7460 ** ^The [sqlite3_str_reset(X)] method resets the string under construction 7461 ** inside [sqlite3_str] object X back to zero bytes in length. 7462 ** 7463 ** These methods do not return a result code. ^If an error occurs, that fact 7464 ** is recorded in the [sqlite3_str] object and can be recovered by a 7465 ** subsequent call to [sqlite3_str_errcode(X)]. 7466 */ 7467 SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 7468 SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 7469 SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 7470 SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 7471 SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 7472 SQLITE_API void sqlite3_str_reset(sqlite3_str*); 7473 7474 /* 7475 ** CAPI3REF: Status Of A Dynamic String 7476 ** METHOD: sqlite3_str 7477 ** 7478 ** These interfaces return the current status of an [sqlite3_str] object. 7479 ** 7480 ** ^If any prior errors have occurred while constructing the dynamic string 7481 ** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 7482 ** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 7483 ** [SQLITE_NOMEM] following any out-of-memory error, or 7484 ** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 7485 ** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 7486 ** 7487 ** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 7488 ** of the dynamic string under construction in [sqlite3_str] object X. 7489 ** ^The length returned by [sqlite3_str_length(X)] does not include the 7490 ** zero-termination byte. 7491 ** 7492 ** ^The [sqlite3_str_value(X)] method returns a pointer to the current 7493 ** content of the dynamic string under construction in X. The value 7494 ** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 7495 ** and might be freed or altered by any subsequent method on the same 7496 ** [sqlite3_str] object. Applications must not used the pointer returned 7497 ** [sqlite3_str_value(X)] after any subsequent method call on the same 7498 ** object. ^Applications may change the content of the string returned 7499 ** by [sqlite3_str_value(X)] as long as they do not write into any bytes 7500 ** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 7501 ** write any byte after any subsequent sqlite3_str method call. 7502 */ 7503 SQLITE_API int sqlite3_str_errcode(sqlite3_str*); 7504 SQLITE_API int sqlite3_str_length(sqlite3_str*); 7505 SQLITE_API char *sqlite3_str_value(sqlite3_str*); 7506 7507 /* 7508 ** CAPI3REF: SQLite Runtime Status 7509 ** 7510 ** ^These interfaces are used to retrieve runtime status information 7511 ** about the performance of SQLite, and optionally to reset various 7512 ** highwater marks. ^The first argument is an integer code for 7513 ** the specific parameter to measure. ^(Recognized integer codes 7514 ** are of the form [status parameters | SQLITE_STATUS_...].)^ 7515 ** ^The current value of the parameter is returned into *pCurrent. 7516 ** ^The highest recorded value is returned in *pHighwater. ^If the 7517 ** resetFlag is true, then the highest record value is reset after 7518 ** *pHighwater is written. ^(Some parameters do not record the highest 7519 ** value. For those parameters 7520 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 7521 ** ^(Other parameters record only the highwater mark and not the current 7522 ** value. For these latter parameters nothing is written into *pCurrent.)^ 7523 ** 7524 ** ^The sqlite3_status() and sqlite3_status64() routines return 7525 ** SQLITE_OK on success and a non-zero [error code] on failure. 7526 ** 7527 ** If either the current value or the highwater mark is too large to 7528 ** be represented by a 32-bit integer, then the values returned by 7529 ** sqlite3_status() are undefined. 7530 ** 7531 ** See also: [sqlite3_db_status()] 7532 */ 7533 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 7534 SQLITE_API int sqlite3_status64( 7535 int op, 7536 sqlite3_int64 *pCurrent, 7537 sqlite3_int64 *pHighwater, 7538 int resetFlag 7539 ); 7540 7541 7542 /* 7543 ** CAPI3REF: Status Parameters 7544 ** KEYWORDS: {status parameters} 7545 ** 7546 ** These integer constants designate various run-time status parameters 7547 ** that can be returned by [sqlite3_status()]. 7548 ** 7549 ** <dl> 7550 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 7551 ** <dd>This parameter is the current amount of memory checked out 7552 ** using [sqlite3_malloc()], either directly or indirectly. The 7553 ** figure includes calls made to [sqlite3_malloc()] by the application 7554 ** and internal memory usage by the SQLite library. Auxiliary page-cache 7555 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 7556 ** this parameter. The amount returned is the sum of the allocation 7557 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 7558 ** 7559 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 7560 ** <dd>This parameter records the largest memory allocation request 7561 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 7562 ** internal equivalents). Only the value returned in the 7563 ** *pHighwater parameter to [sqlite3_status()] is of interest. 7564 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 7565 ** 7566 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 7567 ** <dd>This parameter records the number of separate memory allocations 7568 ** currently checked out.</dd>)^ 7569 ** 7570 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 7571 ** <dd>This parameter returns the number of pages used out of the 7572 ** [pagecache memory allocator] that was configured using 7573 ** [SQLITE_CONFIG_PAGECACHE]. The 7574 ** value returned is in pages, not in bytes.</dd>)^ 7575 ** 7576 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 7577 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 7578 ** <dd>This parameter returns the number of bytes of page cache 7579 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 7580 ** buffer and where forced to overflow to [sqlite3_malloc()]. The 7581 ** returned value includes allocations that overflowed because they 7582 ** where too large (they were larger than the "sz" parameter to 7583 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 7584 ** no space was left in the page cache.</dd>)^ 7585 ** 7586 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 7587 ** <dd>This parameter records the largest memory allocation request 7588 ** handed to [pagecache memory allocator]. Only the value returned in the 7589 ** *pHighwater parameter to [sqlite3_status()] is of interest. 7590 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 7591 ** 7592 ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 7593 ** <dd>No longer used.</dd> 7594 ** 7595 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 7596 ** <dd>No longer used.</dd> 7597 ** 7598 ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 7599 ** <dd>No longer used.</dd> 7600 ** 7601 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 7602 ** <dd>The *pHighwater parameter records the deepest parser stack. 7603 ** The *pCurrent value is undefined. The *pHighwater value is only 7604 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 7605 ** </dl> 7606 ** 7607 ** New status parameters may be added from time to time. 7608 */ 7609 #define SQLITE_STATUS_MEMORY_USED 0 7610 #define SQLITE_STATUS_PAGECACHE_USED 1 7611 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 7612 #define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 7613 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 7614 #define SQLITE_STATUS_MALLOC_SIZE 5 7615 #define SQLITE_STATUS_PARSER_STACK 6 7616 #define SQLITE_STATUS_PAGECACHE_SIZE 7 7617 #define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 7618 #define SQLITE_STATUS_MALLOC_COUNT 9 7619 7620 /* 7621 ** CAPI3REF: Database Connection Status 7622 ** METHOD: sqlite3 7623 ** 7624 ** ^This interface is used to retrieve runtime status information 7625 ** about a single [database connection]. ^The first argument is the 7626 ** database connection object to be interrogated. ^The second argument 7627 ** is an integer constant, taken from the set of 7628 ** [SQLITE_DBSTATUS options], that 7629 ** determines the parameter to interrogate. The set of 7630 ** [SQLITE_DBSTATUS options] is likely 7631 ** to grow in future releases of SQLite. 7632 ** 7633 ** ^The current value of the requested parameter is written into *pCur 7634 ** and the highest instantaneous value is written into *pHiwtr. ^If 7635 ** the resetFlg is true, then the highest instantaneous value is 7636 ** reset back down to the current value. 7637 ** 7638 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 7639 ** non-zero [error code] on failure. 7640 ** 7641 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 7642 */ 7643 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 7644 7645 /* 7646 ** CAPI3REF: Status Parameters for database connections 7647 ** KEYWORDS: {SQLITE_DBSTATUS options} 7648 ** 7649 ** These constants are the available integer "verbs" that can be passed as 7650 ** the second argument to the [sqlite3_db_status()] interface. 7651 ** 7652 ** New verbs may be added in future releases of SQLite. Existing verbs 7653 ** might be discontinued. Applications should check the return code from 7654 ** [sqlite3_db_status()] to make sure that the call worked. 7655 ** The [sqlite3_db_status()] interface will return a non-zero error code 7656 ** if a discontinued or unsupported verb is invoked. 7657 ** 7658 ** <dl> 7659 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 7660 ** <dd>This parameter returns the number of lookaside memory slots currently 7661 ** checked out.</dd>)^ 7662 ** 7663 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 7664 ** <dd>This parameter returns the number malloc attempts that were 7665 ** satisfied using lookaside memory. Only the high-water value is meaningful; 7666 ** the current value is always zero.)^ 7667 ** 7668 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 7669 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 7670 ** <dd>This parameter returns the number malloc attempts that might have 7671 ** been satisfied using lookaside memory but failed due to the amount of 7672 ** memory requested being larger than the lookaside slot size. 7673 ** Only the high-water value is meaningful; 7674 ** the current value is always zero.)^ 7675 ** 7676 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 7677 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 7678 ** <dd>This parameter returns the number malloc attempts that might have 7679 ** been satisfied using lookaside memory but failed due to all lookaside 7680 ** memory already being in use. 7681 ** Only the high-water value is meaningful; 7682 ** the current value is always zero.)^ 7683 ** 7684 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 7685 ** <dd>This parameter returns the approximate number of bytes of heap 7686 ** memory used by all pager caches associated with the database connection.)^ 7687 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 7688 ** 7689 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 7690 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 7691 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 7692 ** pager cache is shared between two or more connections the bytes of heap 7693 ** memory used by that pager cache is divided evenly between the attached 7694 ** connections.)^ In other words, if none of the pager caches associated 7695 ** with the database connection are shared, this request returns the same 7696 ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 7697 ** shared, the value returned by this call will be smaller than that returned 7698 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 7699 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 7700 ** 7701 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 7702 ** <dd>This parameter returns the approximate number of bytes of heap 7703 ** memory used to store the schema for all databases associated 7704 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 7705 ** ^The full amount of memory used by the schemas is reported, even if the 7706 ** schema memory is shared with other database connections due to 7707 ** [shared cache mode] being enabled. 7708 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 7709 ** 7710 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 7711 ** <dd>This parameter returns the approximate number of bytes of heap 7712 ** and lookaside memory used by all prepared statements associated with 7713 ** the database connection.)^ 7714 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 7715 ** </dd> 7716 ** 7717 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 7718 ** <dd>This parameter returns the number of pager cache hits that have 7719 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 7720 ** is always 0. 7721 ** </dd> 7722 ** 7723 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 7724 ** <dd>This parameter returns the number of pager cache misses that have 7725 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 7726 ** is always 0. 7727 ** </dd> 7728 ** 7729 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 7730 ** <dd>This parameter returns the number of dirty cache entries that have 7731 ** been written to disk. Specifically, the number of pages written to the 7732 ** wal file in wal mode databases, or the number of pages written to the 7733 ** database file in rollback mode databases. Any pages written as part of 7734 ** transaction rollback or database recovery operations are not included. 7735 ** If an IO or other error occurs while writing a page to disk, the effect 7736 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 7737 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 7738 ** </dd> 7739 ** 7740 ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 7741 ** <dd>This parameter returns the number of dirty cache entries that have 7742 ** been written to disk in the middle of a transaction due to the page 7743 ** cache overflowing. Transactions are more efficient if they are written 7744 ** to disk all at once. When pages spill mid-transaction, that introduces 7745 ** additional overhead. This parameter can be used help identify 7746 ** inefficiencies that can be resolve by increasing the cache size. 7747 ** </dd> 7748 ** 7749 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 7750 ** <dd>This parameter returns zero for the current value if and only if 7751 ** all foreign key constraints (deferred or immediate) have been 7752 ** resolved.)^ ^The highwater mark is always 0. 7753 ** </dd> 7754 ** </dl> 7755 */ 7756 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 7757 #define SQLITE_DBSTATUS_CACHE_USED 1 7758 #define SQLITE_DBSTATUS_SCHEMA_USED 2 7759 #define SQLITE_DBSTATUS_STMT_USED 3 7760 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 7761 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 7762 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 7763 #define SQLITE_DBSTATUS_CACHE_HIT 7 7764 #define SQLITE_DBSTATUS_CACHE_MISS 8 7765 #define SQLITE_DBSTATUS_CACHE_WRITE 9 7766 #define SQLITE_DBSTATUS_DEFERRED_FKS 10 7767 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 7768 #define SQLITE_DBSTATUS_CACHE_SPILL 12 7769 #define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 7770 7771 7772 /* 7773 ** CAPI3REF: Prepared Statement Status 7774 ** METHOD: sqlite3_stmt 7775 ** 7776 ** ^(Each prepared statement maintains various 7777 ** [SQLITE_STMTSTATUS counters] that measure the number 7778 ** of times it has performed specific operations.)^ These counters can 7779 ** be used to monitor the performance characteristics of the prepared 7780 ** statements. For example, if the number of table steps greatly exceeds 7781 ** the number of table searches or result rows, that would tend to indicate 7782 ** that the prepared statement is using a full table scan rather than 7783 ** an index. 7784 ** 7785 ** ^(This interface is used to retrieve and reset counter values from 7786 ** a [prepared statement]. The first argument is the prepared statement 7787 ** object to be interrogated. The second argument 7788 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 7789 ** to be interrogated.)^ 7790 ** ^The current value of the requested counter is returned. 7791 ** ^If the resetFlg is true, then the counter is reset to zero after this 7792 ** interface call returns. 7793 ** 7794 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 7795 */ 7796 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 7797 7798 /* 7799 ** CAPI3REF: Status Parameters for prepared statements 7800 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 7801 ** 7802 ** These preprocessor macros define integer codes that name counter 7803 ** values associated with the [sqlite3_stmt_status()] interface. 7804 ** The meanings of the various counters are as follows: 7805 ** 7806 ** <dl> 7807 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 7808 ** <dd>^This is the number of times that SQLite has stepped forward in 7809 ** a table as part of a full table scan. Large numbers for this counter 7810 ** may indicate opportunities for performance improvement through 7811 ** careful use of indices.</dd> 7812 ** 7813 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 7814 ** <dd>^This is the number of sort operations that have occurred. 7815 ** A non-zero value in this counter may indicate an opportunity to 7816 ** improvement performance through careful use of indices.</dd> 7817 ** 7818 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 7819 ** <dd>^This is the number of rows inserted into transient indices that 7820 ** were created automatically in order to help joins run faster. 7821 ** A non-zero value in this counter may indicate an opportunity to 7822 ** improvement performance by adding permanent indices that do not 7823 ** need to be reinitialized each time the statement is run.</dd> 7824 ** 7825 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 7826 ** <dd>^This is the number of virtual machine operations executed 7827 ** by the prepared statement if that number is less than or equal 7828 ** to 2147483647. The number of virtual machine operations can be 7829 ** used as a proxy for the total work done by the prepared statement. 7830 ** If the number of virtual machine operations exceeds 2147483647 7831 ** then the value returned by this statement status code is undefined. 7832 ** 7833 ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 7834 ** <dd>^This is the number of times that the prepare statement has been 7835 ** automatically regenerated due to schema changes or change to 7836 ** [bound parameters] that might affect the query plan. 7837 ** 7838 ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 7839 ** <dd>^This is the number of times that the prepared statement has 7840 ** been run. A single "run" for the purposes of this counter is one 7841 ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 7842 ** The counter is incremented on the first [sqlite3_step()] call of each 7843 ** cycle. 7844 ** 7845 ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 7846 ** <dd>^This is the approximate number of bytes of heap memory 7847 ** used to store the prepared statement. ^This value is not actually 7848 ** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 7849 ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 7850 ** </dd> 7851 ** </dl> 7852 */ 7853 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 7854 #define SQLITE_STMTSTATUS_SORT 2 7855 #define SQLITE_STMTSTATUS_AUTOINDEX 3 7856 #define SQLITE_STMTSTATUS_VM_STEP 4 7857 #define SQLITE_STMTSTATUS_REPREPARE 5 7858 #define SQLITE_STMTSTATUS_RUN 6 7859 #define SQLITE_STMTSTATUS_MEMUSED 99 7860 7861 /* 7862 ** CAPI3REF: Custom Page Cache Object 7863 ** 7864 ** The sqlite3_pcache type is opaque. It is implemented by 7865 ** the pluggable module. The SQLite core has no knowledge of 7866 ** its size or internal structure and never deals with the 7867 ** sqlite3_pcache object except by holding and passing pointers 7868 ** to the object. 7869 ** 7870 ** See [sqlite3_pcache_methods2] for additional information. 7871 */ 7872 typedef struct sqlite3_pcache sqlite3_pcache; 7873 7874 /* 7875 ** CAPI3REF: Custom Page Cache Object 7876 ** 7877 ** The sqlite3_pcache_page object represents a single page in the 7878 ** page cache. The page cache will allocate instances of this 7879 ** object. Various methods of the page cache use pointers to instances 7880 ** of this object as parameters or as their return value. 7881 ** 7882 ** See [sqlite3_pcache_methods2] for additional information. 7883 */ 7884 typedef struct sqlite3_pcache_page sqlite3_pcache_page; 7885 struct sqlite3_pcache_page { 7886 void *pBuf; /* The content of the page */ 7887 void *pExtra; /* Extra information associated with the page */ 7888 }; 7889 7890 /* 7891 ** CAPI3REF: Application Defined Page Cache. 7892 ** KEYWORDS: {page cache} 7893 ** 7894 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 7895 ** register an alternative page cache implementation by passing in an 7896 ** instance of the sqlite3_pcache_methods2 structure.)^ 7897 ** In many applications, most of the heap memory allocated by 7898 ** SQLite is used for the page cache. 7899 ** By implementing a 7900 ** custom page cache using this API, an application can better control 7901 ** the amount of memory consumed by SQLite, the way in which 7902 ** that memory is allocated and released, and the policies used to 7903 ** determine exactly which parts of a database file are cached and for 7904 ** how long. 7905 ** 7906 ** The alternative page cache mechanism is an 7907 ** extreme measure that is only needed by the most demanding applications. 7908 ** The built-in page cache is recommended for most uses. 7909 ** 7910 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 7911 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 7912 ** the application may discard the parameter after the call to 7913 ** [sqlite3_config()] returns.)^ 7914 ** 7915 ** [[the xInit() page cache method]] 7916 ** ^(The xInit() method is called once for each effective 7917 ** call to [sqlite3_initialize()])^ 7918 ** (usually only once during the lifetime of the process). ^(The xInit() 7919 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 7920 ** The intent of the xInit() method is to set up global data structures 7921 ** required by the custom page cache implementation. 7922 ** ^(If the xInit() method is NULL, then the 7923 ** built-in default page cache is used instead of the application defined 7924 ** page cache.)^ 7925 ** 7926 ** [[the xShutdown() page cache method]] 7927 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 7928 ** It can be used to clean up 7929 ** any outstanding resources before process shutdown, if required. 7930 ** ^The xShutdown() method may be NULL. 7931 ** 7932 ** ^SQLite automatically serializes calls to the xInit method, 7933 ** so the xInit method need not be threadsafe. ^The 7934 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 7935 ** not need to be threadsafe either. All other methods must be threadsafe 7936 ** in multithreaded applications. 7937 ** 7938 ** ^SQLite will never invoke xInit() more than once without an intervening 7939 ** call to xShutdown(). 7940 ** 7941 ** [[the xCreate() page cache methods]] 7942 ** ^SQLite invokes the xCreate() method to construct a new cache instance. 7943 ** SQLite will typically create one cache instance for each open database file, 7944 ** though this is not guaranteed. ^The 7945 ** first parameter, szPage, is the size in bytes of the pages that must 7946 ** be allocated by the cache. ^szPage will always a power of two. ^The 7947 ** second parameter szExtra is a number of bytes of extra storage 7948 ** associated with each page cache entry. ^The szExtra parameter will 7949 ** a number less than 250. SQLite will use the 7950 ** extra szExtra bytes on each page to store metadata about the underlying 7951 ** database page on disk. The value passed into szExtra depends 7952 ** on the SQLite version, the target platform, and how SQLite was compiled. 7953 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 7954 ** created will be used to cache database pages of a file stored on disk, or 7955 ** false if it is used for an in-memory database. The cache implementation 7956 ** does not have to do anything special based with the value of bPurgeable; 7957 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 7958 ** never invoke xUnpin() except to deliberately delete a page. 7959 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 7960 ** false will always have the "discard" flag set to true. 7961 ** ^Hence, a cache created with bPurgeable false will 7962 ** never contain any unpinned pages. 7963 ** 7964 ** [[the xCachesize() page cache method]] 7965 ** ^(The xCachesize() method may be called at any time by SQLite to set the 7966 ** suggested maximum cache-size (number of pages stored by) the cache 7967 ** instance passed as the first argument. This is the value configured using 7968 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 7969 ** parameter, the implementation is not required to do anything with this 7970 ** value; it is advisory only. 7971 ** 7972 ** [[the xPagecount() page cache methods]] 7973 ** The xPagecount() method must return the number of pages currently 7974 ** stored in the cache, both pinned and unpinned. 7975 ** 7976 ** [[the xFetch() page cache methods]] 7977 ** The xFetch() method locates a page in the cache and returns a pointer to 7978 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 7979 ** The pBuf element of the returned sqlite3_pcache_page object will be a 7980 ** pointer to a buffer of szPage bytes used to store the content of a 7981 ** single database page. The pExtra element of sqlite3_pcache_page will be 7982 ** a pointer to the szExtra bytes of extra storage that SQLite has requested 7983 ** for each entry in the page cache. 7984 ** 7985 ** The page to be fetched is determined by the key. ^The minimum key value 7986 ** is 1. After it has been retrieved using xFetch, the page is considered 7987 ** to be "pinned". 7988 ** 7989 ** If the requested page is already in the page cache, then the page cache 7990 ** implementation must return a pointer to the page buffer with its content 7991 ** intact. If the requested page is not already in the cache, then the 7992 ** cache implementation should use the value of the createFlag 7993 ** parameter to help it determined what action to take: 7994 ** 7995 ** <table border=1 width=85% align=center> 7996 ** <tr><th> createFlag <th> Behavior when page is not already in cache 7997 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 7998 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 7999 ** Otherwise return NULL. 8000 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 8001 ** NULL if allocating a new page is effectively impossible. 8002 ** </table> 8003 ** 8004 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 8005 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 8006 ** failed.)^ In between the to xFetch() calls, SQLite may 8007 ** attempt to unpin one or more cache pages by spilling the content of 8008 ** pinned pages to disk and synching the operating system disk cache. 8009 ** 8010 ** [[the xUnpin() page cache method]] 8011 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 8012 ** as its second argument. If the third parameter, discard, is non-zero, 8013 ** then the page must be evicted from the cache. 8014 ** ^If the discard parameter is 8015 ** zero, then the page may be discarded or retained at the discretion of 8016 ** page cache implementation. ^The page cache implementation 8017 ** may choose to evict unpinned pages at any time. 8018 ** 8019 ** The cache must not perform any reference counting. A single 8020 ** call to xUnpin() unpins the page regardless of the number of prior calls 8021 ** to xFetch(). 8022 ** 8023 ** [[the xRekey() page cache methods]] 8024 ** The xRekey() method is used to change the key value associated with the 8025 ** page passed as the second argument. If the cache 8026 ** previously contains an entry associated with newKey, it must be 8027 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 8028 ** to be pinned. 8029 ** 8030 ** When SQLite calls the xTruncate() method, the cache must discard all 8031 ** existing cache entries with page numbers (keys) greater than or equal 8032 ** to the value of the iLimit parameter passed to xTruncate(). If any 8033 ** of these pages are pinned, they are implicitly unpinned, meaning that 8034 ** they can be safely discarded. 8035 ** 8036 ** [[the xDestroy() page cache method]] 8037 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 8038 ** All resources associated with the specified cache should be freed. ^After 8039 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 8040 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 8041 ** functions. 8042 ** 8043 ** [[the xShrink() page cache method]] 8044 ** ^SQLite invokes the xShrink() method when it wants the page cache to 8045 ** free up as much of heap memory as possible. The page cache implementation 8046 ** is not obligated to free any memory, but well-behaved implementations should 8047 ** do their best. 8048 */ 8049 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 8050 struct sqlite3_pcache_methods2 { 8051 int iVersion; 8052 void *pArg; 8053 int (*xInit)(void*); 8054 void (*xShutdown)(void*); 8055 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 8056 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8057 int (*xPagecount)(sqlite3_pcache*); 8058 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8059 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 8060 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 8061 unsigned oldKey, unsigned newKey); 8062 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8063 void (*xDestroy)(sqlite3_pcache*); 8064 void (*xShrink)(sqlite3_pcache*); 8065 }; 8066 8067 /* 8068 ** This is the obsolete pcache_methods object that has now been replaced 8069 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 8070 ** retained in the header file for backwards compatibility only. 8071 */ 8072 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 8073 struct sqlite3_pcache_methods { 8074 void *pArg; 8075 int (*xInit)(void*); 8076 void (*xShutdown)(void*); 8077 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 8078 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8079 int (*xPagecount)(sqlite3_pcache*); 8080 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8081 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 8082 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 8083 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8084 void (*xDestroy)(sqlite3_pcache*); 8085 }; 8086 8087 8088 /* 8089 ** CAPI3REF: Online Backup Object 8090 ** 8091 ** The sqlite3_backup object records state information about an ongoing 8092 ** online backup operation. ^The sqlite3_backup object is created by 8093 ** a call to [sqlite3_backup_init()] and is destroyed by a call to 8094 ** [sqlite3_backup_finish()]. 8095 ** 8096 ** See Also: [Using the SQLite Online Backup API] 8097 */ 8098 typedef struct sqlite3_backup sqlite3_backup; 8099 8100 /* 8101 ** CAPI3REF: Online Backup API. 8102 ** 8103 ** The backup API copies the content of one database into another. 8104 ** It is useful either for creating backups of databases or 8105 ** for copying in-memory databases to or from persistent files. 8106 ** 8107 ** See Also: [Using the SQLite Online Backup API] 8108 ** 8109 ** ^SQLite holds a write transaction open on the destination database file 8110 ** for the duration of the backup operation. 8111 ** ^The source database is read-locked only while it is being read; 8112 ** it is not locked continuously for the entire backup operation. 8113 ** ^Thus, the backup may be performed on a live source database without 8114 ** preventing other database connections from 8115 ** reading or writing to the source database while the backup is underway. 8116 ** 8117 ** ^(To perform a backup operation: 8118 ** <ol> 8119 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 8120 ** backup, 8121 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 8122 ** the data between the two databases, and finally 8123 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 8124 ** associated with the backup operation. 8125 ** </ol>)^ 8126 ** There should be exactly one call to sqlite3_backup_finish() for each 8127 ** successful call to sqlite3_backup_init(). 8128 ** 8129 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 8130 ** 8131 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 8132 ** [database connection] associated with the destination database 8133 ** and the database name, respectively. 8134 ** ^The database name is "main" for the main database, "temp" for the 8135 ** temporary database, or the name specified after the AS keyword in 8136 ** an [ATTACH] statement for an attached database. 8137 ** ^The S and M arguments passed to 8138 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 8139 ** and database name of the source database, respectively. 8140 ** ^The source and destination [database connections] (parameters S and D) 8141 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 8142 ** an error. 8143 ** 8144 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if 8145 ** there is already a read or read-write transaction open on the 8146 ** destination database. 8147 ** 8148 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 8149 ** returned and an error code and error message are stored in the 8150 ** destination [database connection] D. 8151 ** ^The error code and message for the failed call to sqlite3_backup_init() 8152 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 8153 ** [sqlite3_errmsg16()] functions. 8154 ** ^A successful call to sqlite3_backup_init() returns a pointer to an 8155 ** [sqlite3_backup] object. 8156 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 8157 ** sqlite3_backup_finish() functions to perform the specified backup 8158 ** operation. 8159 ** 8160 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 8161 ** 8162 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 8163 ** the source and destination databases specified by [sqlite3_backup] object B. 8164 ** ^If N is negative, all remaining source pages are copied. 8165 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 8166 ** are still more pages to be copied, then the function returns [SQLITE_OK]. 8167 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 8168 ** from source to destination, then it returns [SQLITE_DONE]. 8169 ** ^If an error occurs while running sqlite3_backup_step(B,N), 8170 ** then an [error code] is returned. ^As well as [SQLITE_OK] and 8171 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 8172 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 8173 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 8174 ** 8175 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 8176 ** <ol> 8177 ** <li> the destination database was opened read-only, or 8178 ** <li> the destination database is using write-ahead-log journaling 8179 ** and the destination and source page sizes differ, or 8180 ** <li> the destination database is an in-memory database and the 8181 ** destination and source page sizes differ. 8182 ** </ol>)^ 8183 ** 8184 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 8185 ** the [sqlite3_busy_handler | busy-handler function] 8186 ** is invoked (if one is specified). ^If the 8187 ** busy-handler returns non-zero before the lock is available, then 8188 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 8189 ** sqlite3_backup_step() can be retried later. ^If the source 8190 ** [database connection] 8191 ** is being used to write to the source database when sqlite3_backup_step() 8192 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 8193 ** case the call to sqlite3_backup_step() can be retried later on. ^(If 8194 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 8195 ** [SQLITE_READONLY] is returned, then 8196 ** there is no point in retrying the call to sqlite3_backup_step(). These 8197 ** errors are considered fatal.)^ The application must accept 8198 ** that the backup operation has failed and pass the backup operation handle 8199 ** to the sqlite3_backup_finish() to release associated resources. 8200 ** 8201 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 8202 ** on the destination file. ^The exclusive lock is not released until either 8203 ** sqlite3_backup_finish() is called or the backup operation is complete 8204 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 8205 ** sqlite3_backup_step() obtains a [shared lock] on the source database that 8206 ** lasts for the duration of the sqlite3_backup_step() call. 8207 ** ^Because the source database is not locked between calls to 8208 ** sqlite3_backup_step(), the source database may be modified mid-way 8209 ** through the backup process. ^If the source database is modified by an 8210 ** external process or via a database connection other than the one being 8211 ** used by the backup operation, then the backup will be automatically 8212 ** restarted by the next call to sqlite3_backup_step(). ^If the source 8213 ** database is modified by the using the same database connection as is used 8214 ** by the backup operation, then the backup database is automatically 8215 ** updated at the same time. 8216 ** 8217 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 8218 ** 8219 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 8220 ** application wishes to abandon the backup operation, the application 8221 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 8222 ** ^The sqlite3_backup_finish() interfaces releases all 8223 ** resources associated with the [sqlite3_backup] object. 8224 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 8225 ** active write-transaction on the destination database is rolled back. 8226 ** The [sqlite3_backup] object is invalid 8227 ** and may not be used following a call to sqlite3_backup_finish(). 8228 ** 8229 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 8230 ** sqlite3_backup_step() errors occurred, regardless or whether or not 8231 ** sqlite3_backup_step() completed. 8232 ** ^If an out-of-memory condition or IO error occurred during any prior 8233 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 8234 ** sqlite3_backup_finish() returns the corresponding [error code]. 8235 ** 8236 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 8237 ** is not a permanent error and does not affect the return value of 8238 ** sqlite3_backup_finish(). 8239 ** 8240 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 8241 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 8242 ** 8243 ** ^The sqlite3_backup_remaining() routine returns the number of pages still 8244 ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 8245 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages 8246 ** in the source database at the conclusion of the most recent 8247 ** sqlite3_backup_step(). 8248 ** ^(The values returned by these functions are only updated by 8249 ** sqlite3_backup_step(). If the source database is modified in a way that 8250 ** changes the size of the source database or the number of pages remaining, 8251 ** those changes are not reflected in the output of sqlite3_backup_pagecount() 8252 ** and sqlite3_backup_remaining() until after the next 8253 ** sqlite3_backup_step().)^ 8254 ** 8255 ** <b>Concurrent Usage of Database Handles</b> 8256 ** 8257 ** ^The source [database connection] may be used by the application for other 8258 ** purposes while a backup operation is underway or being initialized. 8259 ** ^If SQLite is compiled and configured to support threadsafe database 8260 ** connections, then the source database connection may be used concurrently 8261 ** from within other threads. 8262 ** 8263 ** However, the application must guarantee that the destination 8264 ** [database connection] is not passed to any other API (by any thread) after 8265 ** sqlite3_backup_init() is called and before the corresponding call to 8266 ** sqlite3_backup_finish(). SQLite does not currently check to see 8267 ** if the application incorrectly accesses the destination [database connection] 8268 ** and so no error code is reported, but the operations may malfunction 8269 ** nevertheless. Use of the destination database connection while a 8270 ** backup is in progress might also also cause a mutex deadlock. 8271 ** 8272 ** If running in [shared cache mode], the application must 8273 ** guarantee that the shared cache used by the destination database 8274 ** is not accessed while the backup is running. In practice this means 8275 ** that the application must guarantee that the disk file being 8276 ** backed up to is not accessed by any connection within the process, 8277 ** not just the specific connection that was passed to sqlite3_backup_init(). 8278 ** 8279 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 8280 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 8281 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 8282 ** APIs are not strictly speaking threadsafe. If they are invoked at the 8283 ** same time as another thread is invoking sqlite3_backup_step() it is 8284 ** possible that they return invalid values. 8285 */ 8286 SQLITE_API sqlite3_backup *sqlite3_backup_init( 8287 sqlite3 *pDest, /* Destination database handle */ 8288 const char *zDestName, /* Destination database name */ 8289 sqlite3 *pSource, /* Source database handle */ 8290 const char *zSourceName /* Source database name */ 8291 ); 8292 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 8293 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 8294 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 8295 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 8296 8297 /* 8298 ** CAPI3REF: Unlock Notification 8299 ** METHOD: sqlite3 8300 ** 8301 ** ^When running in shared-cache mode, a database operation may fail with 8302 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 8303 ** individual tables within the shared-cache cannot be obtained. See 8304 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 8305 ** ^This API may be used to register a callback that SQLite will invoke 8306 ** when the connection currently holding the required lock relinquishes it. 8307 ** ^This API is only available if the library was compiled with the 8308 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 8309 ** 8310 ** See Also: [Using the SQLite Unlock Notification Feature]. 8311 ** 8312 ** ^Shared-cache locks are released when a database connection concludes 8313 ** its current transaction, either by committing it or rolling it back. 8314 ** 8315 ** ^When a connection (known as the blocked connection) fails to obtain a 8316 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 8317 ** identity of the database connection (the blocking connection) that 8318 ** has locked the required resource is stored internally. ^After an 8319 ** application receives an SQLITE_LOCKED error, it may call the 8320 ** sqlite3_unlock_notify() method with the blocked connection handle as 8321 ** the first argument to register for a callback that will be invoked 8322 ** when the blocking connections current transaction is concluded. ^The 8323 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 8324 ** call that concludes the blocking connections transaction. 8325 ** 8326 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 8327 ** there is a chance that the blocking connection will have already 8328 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 8329 ** If this happens, then the specified callback is invoked immediately, 8330 ** from within the call to sqlite3_unlock_notify().)^ 8331 ** 8332 ** ^If the blocked connection is attempting to obtain a write-lock on a 8333 ** shared-cache table, and more than one other connection currently holds 8334 ** a read-lock on the same table, then SQLite arbitrarily selects one of 8335 ** the other connections to use as the blocking connection. 8336 ** 8337 ** ^(There may be at most one unlock-notify callback registered by a 8338 ** blocked connection. If sqlite3_unlock_notify() is called when the 8339 ** blocked connection already has a registered unlock-notify callback, 8340 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 8341 ** called with a NULL pointer as its second argument, then any existing 8342 ** unlock-notify callback is canceled. ^The blocked connections 8343 ** unlock-notify callback may also be canceled by closing the blocked 8344 ** connection using [sqlite3_close()]. 8345 ** 8346 ** The unlock-notify callback is not reentrant. If an application invokes 8347 ** any sqlite3_xxx API functions from within an unlock-notify callback, a 8348 ** crash or deadlock may be the result. 8349 ** 8350 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 8351 ** returns SQLITE_OK. 8352 ** 8353 ** <b>Callback Invocation Details</b> 8354 ** 8355 ** When an unlock-notify callback is registered, the application provides a 8356 ** single void* pointer that is passed to the callback when it is invoked. 8357 ** However, the signature of the callback function allows SQLite to pass 8358 ** it an array of void* context pointers. The first argument passed to 8359 ** an unlock-notify callback is a pointer to an array of void* pointers, 8360 ** and the second is the number of entries in the array. 8361 ** 8362 ** When a blocking connections transaction is concluded, there may be 8363 ** more than one blocked connection that has registered for an unlock-notify 8364 ** callback. ^If two or more such blocked connections have specified the 8365 ** same callback function, then instead of invoking the callback function 8366 ** multiple times, it is invoked once with the set of void* context pointers 8367 ** specified by the blocked connections bundled together into an array. 8368 ** This gives the application an opportunity to prioritize any actions 8369 ** related to the set of unblocked database connections. 8370 ** 8371 ** <b>Deadlock Detection</b> 8372 ** 8373 ** Assuming that after registering for an unlock-notify callback a 8374 ** database waits for the callback to be issued before taking any further 8375 ** action (a reasonable assumption), then using this API may cause the 8376 ** application to deadlock. For example, if connection X is waiting for 8377 ** connection Y's transaction to be concluded, and similarly connection 8378 ** Y is waiting on connection X's transaction, then neither connection 8379 ** will proceed and the system may remain deadlocked indefinitely. 8380 ** 8381 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 8382 ** detection. ^If a given call to sqlite3_unlock_notify() would put the 8383 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 8384 ** unlock-notify callback is registered. The system is said to be in 8385 ** a deadlocked state if connection A has registered for an unlock-notify 8386 ** callback on the conclusion of connection B's transaction, and connection 8387 ** B has itself registered for an unlock-notify callback when connection 8388 ** A's transaction is concluded. ^Indirect deadlock is also detected, so 8389 ** the system is also considered to be deadlocked if connection B has 8390 ** registered for an unlock-notify callback on the conclusion of connection 8391 ** C's transaction, where connection C is waiting on connection A. ^Any 8392 ** number of levels of indirection are allowed. 8393 ** 8394 ** <b>The "DROP TABLE" Exception</b> 8395 ** 8396 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 8397 ** always appropriate to call sqlite3_unlock_notify(). There is however, 8398 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 8399 ** SQLite checks if there are any currently executing SELECT statements 8400 ** that belong to the same connection. If there are, SQLITE_LOCKED is 8401 ** returned. In this case there is no "blocking connection", so invoking 8402 ** sqlite3_unlock_notify() results in the unlock-notify callback being 8403 ** invoked immediately. If the application then re-attempts the "DROP TABLE" 8404 ** or "DROP INDEX" query, an infinite loop might be the result. 8405 ** 8406 ** One way around this problem is to check the extended error code returned 8407 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 8408 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 8409 ** the special "DROP TABLE/INDEX" case, the extended error code is just 8410 ** SQLITE_LOCKED.)^ 8411 */ 8412 SQLITE_API int sqlite3_unlock_notify( 8413 sqlite3 *pBlocked, /* Waiting connection */ 8414 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 8415 void *pNotifyArg /* Argument to pass to xNotify */ 8416 ); 8417 8418 8419 /* 8420 ** CAPI3REF: String Comparison 8421 ** 8422 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 8423 ** and extensions to compare the contents of two buffers containing UTF-8 8424 ** strings in a case-independent fashion, using the same definition of "case 8425 ** independence" that SQLite uses internally when comparing identifiers. 8426 */ 8427 SQLITE_API int sqlite3_stricmp(const char *, const char *); 8428 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 8429 8430 /* 8431 ** CAPI3REF: String Globbing 8432 * 8433 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 8434 ** string X matches the [GLOB] pattern P. 8435 ** ^The definition of [GLOB] pattern matching used in 8436 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 8437 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 8438 ** is case sensitive. 8439 ** 8440 ** Note that this routine returns zero on a match and non-zero if the strings 8441 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8442 ** 8443 ** See also: [sqlite3_strlike()]. 8444 */ 8445 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 8446 8447 /* 8448 ** CAPI3REF: String LIKE Matching 8449 * 8450 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 8451 ** string X matches the [LIKE] pattern P with escape character E. 8452 ** ^The definition of [LIKE] pattern matching used in 8453 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 8454 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 8455 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 8456 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 8457 ** insensitive - equivalent upper and lower case ASCII characters match 8458 ** one another. 8459 ** 8460 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 8461 ** only ASCII characters are case folded. 8462 ** 8463 ** Note that this routine returns zero on a match and non-zero if the strings 8464 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8465 ** 8466 ** See also: [sqlite3_strglob()]. 8467 */ 8468 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 8469 8470 /* 8471 ** CAPI3REF: Error Logging Interface 8472 ** 8473 ** ^The [sqlite3_log()] interface writes a message into the [error log] 8474 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 8475 ** ^If logging is enabled, the zFormat string and subsequent arguments are 8476 ** used with [sqlite3_snprintf()] to generate the final output string. 8477 ** 8478 ** The sqlite3_log() interface is intended for use by extensions such as 8479 ** virtual tables, collating functions, and SQL functions. While there is 8480 ** nothing to prevent an application from calling sqlite3_log(), doing so 8481 ** is considered bad form. 8482 ** 8483 ** The zFormat string must not be NULL. 8484 ** 8485 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 8486 ** will not use dynamically allocated memory. The log message is stored in 8487 ** a fixed-length buffer on the stack. If the log message is longer than 8488 ** a few hundred characters, it will be truncated to the length of the 8489 ** buffer. 8490 */ 8491 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 8492 8493 /* 8494 ** CAPI3REF: Write-Ahead Log Commit Hook 8495 ** METHOD: sqlite3 8496 ** 8497 ** ^The [sqlite3_wal_hook()] function is used to register a callback that 8498 ** is invoked each time data is committed to a database in wal mode. 8499 ** 8500 ** ^(The callback is invoked by SQLite after the commit has taken place and 8501 ** the associated write-lock on the database released)^, so the implementation 8502 ** may read, write or [checkpoint] the database as required. 8503 ** 8504 ** ^The first parameter passed to the callback function when it is invoked 8505 ** is a copy of the third parameter passed to sqlite3_wal_hook() when 8506 ** registering the callback. ^The second is a copy of the database handle. 8507 ** ^The third parameter is the name of the database that was written to - 8508 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 8509 ** is the number of pages currently in the write-ahead log file, 8510 ** including those that were just committed. 8511 ** 8512 ** The callback function should normally return [SQLITE_OK]. ^If an error 8513 ** code is returned, that error will propagate back up through the 8514 ** SQLite code base to cause the statement that provoked the callback 8515 ** to report an error, though the commit will have still occurred. If the 8516 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 8517 ** that does not correspond to any valid SQLite error code, the results 8518 ** are undefined. 8519 ** 8520 ** A single database handle may have at most a single write-ahead log callback 8521 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 8522 ** previously registered write-ahead log callback. ^Note that the 8523 ** [sqlite3_wal_autocheckpoint()] interface and the 8524 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 8525 ** overwrite any prior [sqlite3_wal_hook()] settings. 8526 */ 8527 SQLITE_API void *sqlite3_wal_hook( 8528 sqlite3*, 8529 int(*)(void *,sqlite3*,const char*,int), 8530 void* 8531 ); 8532 8533 /* 8534 ** CAPI3REF: Configure an auto-checkpoint 8535 ** METHOD: sqlite3 8536 ** 8537 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 8538 ** [sqlite3_wal_hook()] that causes any database on [database connection] D 8539 ** to automatically [checkpoint] 8540 ** after committing a transaction if there are N or 8541 ** more frames in the [write-ahead log] file. ^Passing zero or 8542 ** a negative value as the nFrame parameter disables automatic 8543 ** checkpoints entirely. 8544 ** 8545 ** ^The callback registered by this function replaces any existing callback 8546 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 8547 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 8548 ** configured by this function. 8549 ** 8550 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 8551 ** from SQL. 8552 ** 8553 ** ^Checkpoints initiated by this mechanism are 8554 ** [sqlite3_wal_checkpoint_v2|PASSIVE]. 8555 ** 8556 ** ^Every new [database connection] defaults to having the auto-checkpoint 8557 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 8558 ** pages. The use of this interface 8559 ** is only necessary if the default setting is found to be suboptimal 8560 ** for a particular application. 8561 */ 8562 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 8563 8564 /* 8565 ** CAPI3REF: Checkpoint a database 8566 ** METHOD: sqlite3 8567 ** 8568 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 8569 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 8570 ** 8571 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 8572 ** [write-ahead log] for database X on [database connection] D to be 8573 ** transferred into the database file and for the write-ahead log to 8574 ** be reset. See the [checkpointing] documentation for addition 8575 ** information. 8576 ** 8577 ** This interface used to be the only way to cause a checkpoint to 8578 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 8579 ** interface was added. This interface is retained for backwards 8580 ** compatibility and as a convenience for applications that need to manually 8581 ** start a callback but which do not need the full power (and corresponding 8582 ** complication) of [sqlite3_wal_checkpoint_v2()]. 8583 */ 8584 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 8585 8586 /* 8587 ** CAPI3REF: Checkpoint a database 8588 ** METHOD: sqlite3 8589 ** 8590 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 8591 ** operation on database X of [database connection] D in mode M. Status 8592 ** information is written back into integers pointed to by L and C.)^ 8593 ** ^(The M parameter must be a valid [checkpoint mode]:)^ 8594 ** 8595 ** <dl> 8596 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 8597 ** ^Checkpoint as many frames as possible without waiting for any database 8598 ** readers or writers to finish, then sync the database file if all frames 8599 ** in the log were checkpointed. ^The [busy-handler callback] 8600 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 8601 ** ^On the other hand, passive mode might leave the checkpoint unfinished 8602 ** if there are concurrent readers or writers. 8603 ** 8604 ** <dt>SQLITE_CHECKPOINT_FULL<dd> 8605 ** ^This mode blocks (it invokes the 8606 ** [sqlite3_busy_handler|busy-handler callback]) until there is no 8607 ** database writer and all readers are reading from the most recent database 8608 ** snapshot. ^It then checkpoints all frames in the log file and syncs the 8609 ** database file. ^This mode blocks new database writers while it is pending, 8610 ** but new database readers are allowed to continue unimpeded. 8611 ** 8612 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 8613 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 8614 ** that after checkpointing the log file it blocks (calls the 8615 ** [busy-handler callback]) 8616 ** until all readers are reading from the database file only. ^This ensures 8617 ** that the next writer will restart the log file from the beginning. 8618 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 8619 ** database writer attempts while it is pending, but does not impede readers. 8620 ** 8621 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 8622 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 8623 ** addition that it also truncates the log file to zero bytes just prior 8624 ** to a successful return. 8625 ** </dl> 8626 ** 8627 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 8628 ** the log file or to -1 if the checkpoint could not run because 8629 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 8630 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 8631 ** log file (including any that were already checkpointed before the function 8632 ** was called) or to -1 if the checkpoint could not run due to an error or 8633 ** because the database is not in WAL mode. ^Note that upon successful 8634 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 8635 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 8636 ** 8637 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 8638 ** any other process is running a checkpoint operation at the same time, the 8639 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 8640 ** busy-handler configured, it will not be invoked in this case. 8641 ** 8642 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 8643 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be 8644 ** obtained immediately, and a busy-handler is configured, it is invoked and 8645 ** the writer lock retried until either the busy-handler returns 0 or the lock 8646 ** is successfully obtained. ^The busy-handler is also invoked while waiting for 8647 ** database readers as described above. ^If the busy-handler returns 0 before 8648 ** the writer lock is obtained or while waiting for database readers, the 8649 ** checkpoint operation proceeds from that point in the same way as 8650 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 8651 ** without blocking any further. ^SQLITE_BUSY is returned in this case. 8652 ** 8653 ** ^If parameter zDb is NULL or points to a zero length string, then the 8654 ** specified operation is attempted on all WAL databases [attached] to 8655 ** [database connection] db. In this case the 8656 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 8657 ** an SQLITE_BUSY error is encountered when processing one or more of the 8658 ** attached WAL databases, the operation is still attempted on any remaining 8659 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other 8660 ** error occurs while processing an attached database, processing is abandoned 8661 ** and the error code is returned to the caller immediately. ^If no error 8662 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 8663 ** databases, SQLITE_OK is returned. 8664 ** 8665 ** ^If database zDb is the name of an attached database that is not in WAL 8666 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 8667 ** zDb is not NULL (or a zero length string) and is not the name of any 8668 ** attached database, SQLITE_ERROR is returned to the caller. 8669 ** 8670 ** ^Unless it returns SQLITE_MISUSE, 8671 ** the sqlite3_wal_checkpoint_v2() interface 8672 ** sets the error information that is queried by 8673 ** [sqlite3_errcode()] and [sqlite3_errmsg()]. 8674 ** 8675 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 8676 ** from SQL. 8677 */ 8678 SQLITE_API int sqlite3_wal_checkpoint_v2( 8679 sqlite3 *db, /* Database handle */ 8680 const char *zDb, /* Name of attached database (or NULL) */ 8681 int eMode, /* SQLITE_CHECKPOINT_* value */ 8682 int *pnLog, /* OUT: Size of WAL log in frames */ 8683 int *pnCkpt /* OUT: Total number of frames checkpointed */ 8684 ); 8685 8686 /* 8687 ** CAPI3REF: Checkpoint Mode Values 8688 ** KEYWORDS: {checkpoint mode} 8689 ** 8690 ** These constants define all valid values for the "checkpoint mode" passed 8691 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 8692 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 8693 ** meaning of each of these checkpoint modes. 8694 */ 8695 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 8696 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 8697 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 8698 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 8699 8700 /* 8701 ** CAPI3REF: Virtual Table Interface Configuration 8702 ** 8703 ** This function may be called by either the [xConnect] or [xCreate] method 8704 ** of a [virtual table] implementation to configure 8705 ** various facets of the virtual table interface. 8706 ** 8707 ** If this interface is invoked outside the context of an xConnect or 8708 ** xCreate virtual table method then the behavior is undefined. 8709 ** 8710 ** At present, there is only one option that may be configured using 8711 ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 8712 ** may be added in the future. 8713 */ 8714 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 8715 8716 /* 8717 ** CAPI3REF: Virtual Table Configuration Options 8718 ** 8719 ** These macros define the various options to the 8720 ** [sqlite3_vtab_config()] interface that [virtual table] implementations 8721 ** can use to customize and optimize their behavior. 8722 ** 8723 ** <dl> 8724 ** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] 8725 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 8726 ** <dd>Calls of the form 8727 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 8728 ** where X is an integer. If X is zero, then the [virtual table] whose 8729 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 8730 ** support constraints. In this configuration (which is the default) if 8731 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 8732 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 8733 ** specified as part of the users SQL statement, regardless of the actual 8734 ** ON CONFLICT mode specified. 8735 ** 8736 ** If X is non-zero, then the virtual table implementation guarantees 8737 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 8738 ** any modifications to internal or persistent data structures have been made. 8739 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 8740 ** is able to roll back a statement or database transaction, and abandon 8741 ** or continue processing the current SQL statement as appropriate. 8742 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 8743 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 8744 ** had been ABORT. 8745 ** 8746 ** Virtual table implementations that are required to handle OR REPLACE 8747 ** must do so within the [xUpdate] method. If a call to the 8748 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 8749 ** CONFLICT policy is REPLACE, the virtual table implementation should 8750 ** silently replace the appropriate rows within the xUpdate callback and 8751 ** return SQLITE_OK. Or, if this is not possible, it may return 8752 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 8753 ** constraint handling. 8754 ** </dl> 8755 */ 8756 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 8757 8758 /* 8759 ** CAPI3REF: Determine The Virtual Table Conflict Policy 8760 ** 8761 ** This function may only be called from within a call to the [xUpdate] method 8762 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 8763 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 8764 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 8765 ** of the SQL statement that triggered the call to the [xUpdate] method of the 8766 ** [virtual table]. 8767 */ 8768 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 8769 8770 /* 8771 ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 8772 ** 8773 ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 8774 ** method of a [virtual table], then it returns true if and only if the 8775 ** column is being fetched as part of an UPDATE operation during which the 8776 ** column value will not change. Applications might use this to substitute 8777 ** a return value that is less expensive to compute and that the corresponding 8778 ** [xUpdate] method understands as a "no-change" value. 8779 ** 8780 ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 8781 ** the column is not changed by the UPDATE statement, then the xColumn 8782 ** method can optionally return without setting a result, without calling 8783 ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 8784 ** In that case, [sqlite3_value_nochange(X)] will return true for the 8785 ** same column in the [xUpdate] method. 8786 */ 8787 SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*); 8788 8789 /* 8790 ** CAPI3REF: Determine The Collation For a Virtual Table Constraint 8791 ** 8792 ** This function may only be called from within a call to the [xBestIndex] 8793 ** method of a [virtual table]. 8794 ** 8795 ** The first argument must be the sqlite3_index_info object that is the 8796 ** first parameter to the xBestIndex() method. The second argument must be 8797 ** an index into the aConstraint[] array belonging to the sqlite3_index_info 8798 ** structure passed to xBestIndex. This function returns a pointer to a buffer 8799 ** containing the name of the collation sequence for the corresponding 8800 ** constraint. 8801 */ 8802 SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 8803 8804 /* 8805 ** CAPI3REF: Conflict resolution modes 8806 ** KEYWORDS: {conflict resolution mode} 8807 ** 8808 ** These constants are returned by [sqlite3_vtab_on_conflict()] to 8809 ** inform a [virtual table] implementation what the [ON CONFLICT] mode 8810 ** is for the SQL statement being evaluated. 8811 ** 8812 ** Note that the [SQLITE_IGNORE] constant is also used as a potential 8813 ** return value from the [sqlite3_set_authorizer()] callback and that 8814 ** [SQLITE_ABORT] is also a [result code]. 8815 */ 8816 #define SQLITE_ROLLBACK 1 8817 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 8818 #define SQLITE_FAIL 3 8819 /* #define SQLITE_ABORT 4 // Also an error code */ 8820 #define SQLITE_REPLACE 5 8821 8822 /* 8823 ** CAPI3REF: Prepared Statement Scan Status Opcodes 8824 ** KEYWORDS: {scanstatus options} 8825 ** 8826 ** The following constants can be used for the T parameter to the 8827 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 8828 ** different metric for sqlite3_stmt_scanstatus() to return. 8829 ** 8830 ** When the value returned to V is a string, space to hold that string is 8831 ** managed by the prepared statement S and will be automatically freed when 8832 ** S is finalized. 8833 ** 8834 ** <dl> 8835 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 8836 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 8837 ** set to the total number of times that the X-th loop has run.</dd> 8838 ** 8839 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 8840 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 8841 ** to the total number of rows examined by all iterations of the X-th loop.</dd> 8842 ** 8843 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 8844 ** <dd>^The "double" variable pointed to by the T parameter will be set to the 8845 ** query planner's estimate for the average number of rows output from each 8846 ** iteration of the X-th loop. If the query planner's estimates was accurate, 8847 ** then this value will approximate the quotient NVISIT/NLOOP and the 8848 ** product of this value for all prior loops with the same SELECTID will 8849 ** be the NLOOP value for the current loop. 8850 ** 8851 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 8852 ** <dd>^The "const char *" variable pointed to by the T parameter will be set 8853 ** to a zero-terminated UTF-8 string containing the name of the index or table 8854 ** used for the X-th loop. 8855 ** 8856 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 8857 ** <dd>^The "const char *" variable pointed to by the T parameter will be set 8858 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 8859 ** description for the X-th loop. 8860 ** 8861 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 8862 ** <dd>^The "int" variable pointed to by the T parameter will be set to the 8863 ** "select-id" for the X-th loop. The select-id identifies which query or 8864 ** subquery the loop is part of. The main query has a select-id of zero. 8865 ** The select-id is the same value as is output in the first column 8866 ** of an [EXPLAIN QUERY PLAN] query. 8867 ** </dl> 8868 */ 8869 #define SQLITE_SCANSTAT_NLOOP 0 8870 #define SQLITE_SCANSTAT_NVISIT 1 8871 #define SQLITE_SCANSTAT_EST 2 8872 #define SQLITE_SCANSTAT_NAME 3 8873 #define SQLITE_SCANSTAT_EXPLAIN 4 8874 #define SQLITE_SCANSTAT_SELECTID 5 8875 8876 /* 8877 ** CAPI3REF: Prepared Statement Scan Status 8878 ** METHOD: sqlite3_stmt 8879 ** 8880 ** This interface returns information about the predicted and measured 8881 ** performance for pStmt. Advanced applications can use this 8882 ** interface to compare the predicted and the measured performance and 8883 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 8884 ** 8885 ** Since this interface is expected to be rarely used, it is only 8886 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 8887 ** compile-time option. 8888 ** 8889 ** The "iScanStatusOp" parameter determines which status information to return. 8890 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 8891 ** of this interface is undefined. 8892 ** ^The requested measurement is written into a variable pointed to by 8893 ** the "pOut" parameter. 8894 ** Parameter "idx" identifies the specific loop to retrieve statistics for. 8895 ** Loops are numbered starting from zero. ^If idx is out of range - less than 8896 ** zero or greater than or equal to the total number of loops used to implement 8897 ** the statement - a non-zero value is returned and the variable that pOut 8898 ** points to is unchanged. 8899 ** 8900 ** ^Statistics might not be available for all loops in all statements. ^In cases 8901 ** where there exist loops with no available statistics, this function behaves 8902 ** as if the loop did not exist - it returns non-zero and leave the variable 8903 ** that pOut points to unchanged. 8904 ** 8905 ** See also: [sqlite3_stmt_scanstatus_reset()] 8906 */ 8907 SQLITE_API int sqlite3_stmt_scanstatus( 8908 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 8909 int idx, /* Index of loop to report on */ 8910 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 8911 void *pOut /* Result written here */ 8912 ); 8913 8914 /* 8915 ** CAPI3REF: Zero Scan-Status Counters 8916 ** METHOD: sqlite3_stmt 8917 ** 8918 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 8919 ** 8920 ** This API is only available if the library is built with pre-processor 8921 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 8922 */ 8923 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 8924 8925 /* 8926 ** CAPI3REF: Flush caches to disk mid-transaction 8927 ** 8928 ** ^If a write-transaction is open on [database connection] D when the 8929 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 8930 ** pages in the pager-cache that are not currently in use are written out 8931 ** to disk. A dirty page may be in use if a database cursor created by an 8932 ** active SQL statement is reading from it, or if it is page 1 of a database 8933 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 8934 ** interface flushes caches for all schemas - "main", "temp", and 8935 ** any [attached] databases. 8936 ** 8937 ** ^If this function needs to obtain extra database locks before dirty pages 8938 ** can be flushed to disk, it does so. ^If those locks cannot be obtained 8939 ** immediately and there is a busy-handler callback configured, it is invoked 8940 ** in the usual manner. ^If the required lock still cannot be obtained, then 8941 ** the database is skipped and an attempt made to flush any dirty pages 8942 ** belonging to the next (if any) database. ^If any databases are skipped 8943 ** because locks cannot be obtained, but no other error occurs, this 8944 ** function returns SQLITE_BUSY. 8945 ** 8946 ** ^If any other error occurs while flushing dirty pages to disk (for 8947 ** example an IO error or out-of-memory condition), then processing is 8948 ** abandoned and an SQLite [error code] is returned to the caller immediately. 8949 ** 8950 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 8951 ** 8952 ** ^This function does not set the database handle error code or message 8953 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 8954 */ 8955 SQLITE_API int sqlite3_db_cacheflush(sqlite3*); 8956 8957 /* 8958 ** CAPI3REF: The pre-update hook. 8959 ** 8960 ** ^These interfaces are only available if SQLite is compiled using the 8961 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 8962 ** 8963 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function 8964 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 8965 ** on a database table. 8966 ** ^At most one preupdate hook may be registered at a time on a single 8967 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 8968 ** the previous setting. 8969 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 8970 ** with a NULL pointer as the second parameter. 8971 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 8972 ** the first parameter to callbacks. 8973 ** 8974 ** ^The preupdate hook only fires for changes to real database tables; the 8975 ** preupdate hook is not invoked for changes to [virtual tables] or to 8976 ** system tables like sqlite_master or sqlite_stat1. 8977 ** 8978 ** ^The second parameter to the preupdate callback is a pointer to 8979 ** the [database connection] that registered the preupdate hook. 8980 ** ^The third parameter to the preupdate callback is one of the constants 8981 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 8982 ** kind of update operation that is about to occur. 8983 ** ^(The fourth parameter to the preupdate callback is the name of the 8984 ** database within the database connection that is being modified. This 8985 ** will be "main" for the main database or "temp" for TEMP tables or 8986 ** the name given after the AS keyword in the [ATTACH] statement for attached 8987 ** databases.)^ 8988 ** ^The fifth parameter to the preupdate callback is the name of the 8989 ** table that is being modified. 8990 ** 8991 ** For an UPDATE or DELETE operation on a [rowid table], the sixth 8992 ** parameter passed to the preupdate callback is the initial [rowid] of the 8993 ** row being modified or deleted. For an INSERT operation on a rowid table, 8994 ** or any operation on a WITHOUT ROWID table, the value of the sixth 8995 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the 8996 ** seventh parameter is the final rowid value of the row being inserted 8997 ** or updated. The value of the seventh parameter passed to the callback 8998 ** function is not defined for operations on WITHOUT ROWID tables, or for 8999 ** INSERT operations on rowid tables. 9000 ** 9001 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 9002 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 9003 ** provide additional information about a preupdate event. These routines 9004 ** may only be called from within a preupdate callback. Invoking any of 9005 ** these routines from outside of a preupdate callback or with a 9006 ** [database connection] pointer that is different from the one supplied 9007 ** to the preupdate callback results in undefined and probably undesirable 9008 ** behavior. 9009 ** 9010 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 9011 ** in the row that is being inserted, updated, or deleted. 9012 ** 9013 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 9014 ** a [protected sqlite3_value] that contains the value of the Nth column of 9015 ** the table row before it is updated. The N parameter must be between 0 9016 ** and one less than the number of columns or the behavior will be 9017 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 9018 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 9019 ** behavior is undefined. The [sqlite3_value] that P points to 9020 ** will be destroyed when the preupdate callback returns. 9021 ** 9022 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 9023 ** a [protected sqlite3_value] that contains the value of the Nth column of 9024 ** the table row after it is updated. The N parameter must be between 0 9025 ** and one less than the number of columns or the behavior will be 9026 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 9027 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 9028 ** behavior is undefined. The [sqlite3_value] that P points to 9029 ** will be destroyed when the preupdate callback returns. 9030 ** 9031 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 9032 ** callback was invoked as a result of a direct insert, update, or delete 9033 ** operation; or 1 for inserts, updates, or deletes invoked by top-level 9034 ** triggers; or 2 for changes resulting from triggers called by top-level 9035 ** triggers; and so forth. 9036 ** 9037 ** See also: [sqlite3_update_hook()] 9038 */ 9039 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 9040 SQLITE_API void *sqlite3_preupdate_hook( 9041 sqlite3 *db, 9042 void(*xPreUpdate)( 9043 void *pCtx, /* Copy of third arg to preupdate_hook() */ 9044 sqlite3 *db, /* Database handle */ 9045 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 9046 char const *zDb, /* Database name */ 9047 char const *zName, /* Table name */ 9048 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 9049 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 9050 ), 9051 void* 9052 ); 9053 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 9054 SQLITE_API int sqlite3_preupdate_count(sqlite3 *); 9055 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *); 9056 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 9057 #endif 9058 9059 /* 9060 ** CAPI3REF: Low-level system error code 9061 ** 9062 ** ^Attempt to return the underlying operating system error code or error 9063 ** number that caused the most recent I/O error or failure to open a file. 9064 ** The return value is OS-dependent. For example, on unix systems, after 9065 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 9066 ** called to get back the underlying "errno" that caused the problem, such 9067 ** as ENOSPC, EAUTH, EISDIR, and so forth. 9068 */ 9069 SQLITE_API int sqlite3_system_errno(sqlite3*); 9070 9071 /* 9072 ** CAPI3REF: Database Snapshot 9073 ** KEYWORDS: {snapshot} {sqlite3_snapshot} 9074 ** 9075 ** An instance of the snapshot object records the state of a [WAL mode] 9076 ** database for some specific point in history. 9077 ** 9078 ** In [WAL mode], multiple [database connections] that are open on the 9079 ** same database file can each be reading a different historical version 9080 ** of the database file. When a [database connection] begins a read 9081 ** transaction, that connection sees an unchanging copy of the database 9082 ** as it existed for the point in time when the transaction first started. 9083 ** Subsequent changes to the database from other connections are not seen 9084 ** by the reader until a new read transaction is started. 9085 ** 9086 ** The sqlite3_snapshot object records state information about an historical 9087 ** version of the database file so that it is possible to later open a new read 9088 ** transaction that sees that historical version of the database rather than 9089 ** the most recent version. 9090 */ 9091 typedef struct sqlite3_snapshot { 9092 unsigned char hidden[48]; 9093 } sqlite3_snapshot; 9094 9095 /* 9096 ** CAPI3REF: Record A Database Snapshot 9097 ** CONSTRUCTOR: sqlite3_snapshot 9098 ** 9099 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 9100 ** new [sqlite3_snapshot] object that records the current state of 9101 ** schema S in database connection D. ^On success, the 9102 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 9103 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 9104 ** If there is not already a read-transaction open on schema S when 9105 ** this function is called, one is opened automatically. 9106 ** 9107 ** The following must be true for this function to succeed. If any of 9108 ** the following statements are false when sqlite3_snapshot_get() is 9109 ** called, SQLITE_ERROR is returned. The final value of *P is undefined 9110 ** in this case. 9111 ** 9112 ** <ul> 9113 ** <li> The database handle must not be in [autocommit mode]. 9114 ** 9115 ** <li> Schema S of [database connection] D must be a [WAL mode] database. 9116 ** 9117 ** <li> There must not be a write transaction open on schema S of database 9118 ** connection D. 9119 ** 9120 ** <li> One or more transactions must have been written to the current wal 9121 ** file since it was created on disk (by any connection). This means 9122 ** that a snapshot cannot be taken on a wal mode database with no wal 9123 ** file immediately after it is first opened. At least one transaction 9124 ** must be written to it first. 9125 ** </ul> 9126 ** 9127 ** This function may also return SQLITE_NOMEM. If it is called with the 9128 ** database handle in autocommit mode but fails for some other reason, 9129 ** whether or not a read transaction is opened on schema S is undefined. 9130 ** 9131 ** The [sqlite3_snapshot] object returned from a successful call to 9132 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 9133 ** to avoid a memory leak. 9134 ** 9135 ** The [sqlite3_snapshot_get()] interface is only available when the 9136 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9137 */ 9138 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 9139 sqlite3 *db, 9140 const char *zSchema, 9141 sqlite3_snapshot **ppSnapshot 9142 ); 9143 9144 /* 9145 ** CAPI3REF: Start a read transaction on an historical snapshot 9146 ** METHOD: sqlite3_snapshot 9147 ** 9148 ** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 9149 ** transaction or upgrades an existing one for schema S of 9150 ** [database connection] D such that the read transaction refers to 9151 ** historical [snapshot] P, rather than the most recent change to the 9152 ** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 9153 ** on success or an appropriate [error code] if it fails. 9154 ** 9155 ** ^In order to succeed, the database connection must not be in 9156 ** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 9157 ** is already a read transaction open on schema S, then the database handle 9158 ** must have no active statements (SELECT statements that have been passed 9159 ** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 9160 ** SQLITE_ERROR is returned if either of these conditions is violated, or 9161 ** if schema S does not exist, or if the snapshot object is invalid. 9162 ** 9163 ** ^A call to sqlite3_snapshot_open() will fail to open if the specified 9164 ** snapshot has been overwritten by a [checkpoint]. In this case 9165 ** SQLITE_ERROR_SNAPSHOT is returned. 9166 ** 9167 ** If there is already a read transaction open when this function is 9168 ** invoked, then the same read transaction remains open (on the same 9169 ** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 9170 ** is returned. If another error code - for example SQLITE_PROTOCOL or an 9171 ** SQLITE_IOERR error code - is returned, then the final state of the 9172 ** read transaction is undefined. If SQLITE_OK is returned, then the 9173 ** read transaction is now open on database snapshot P. 9174 ** 9175 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 9176 ** database connection D does not know that the database file for 9177 ** schema S is in [WAL mode]. A database connection might not know 9178 ** that the database file is in [WAL mode] if there has been no prior 9179 ** I/O on that database connection, or if the database entered [WAL mode] 9180 ** after the most recent I/O on the database connection.)^ 9181 ** (Hint: Run "[PRAGMA application_id]" against a newly opened 9182 ** database connection in order to make it ready to use snapshots.) 9183 ** 9184 ** The [sqlite3_snapshot_open()] interface is only available when the 9185 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9186 */ 9187 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 9188 sqlite3 *db, 9189 const char *zSchema, 9190 sqlite3_snapshot *pSnapshot 9191 ); 9192 9193 /* 9194 ** CAPI3REF: Destroy a snapshot 9195 ** DESTRUCTOR: sqlite3_snapshot 9196 ** 9197 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 9198 ** The application must eventually free every [sqlite3_snapshot] object 9199 ** using this routine to avoid a memory leak. 9200 ** 9201 ** The [sqlite3_snapshot_free()] interface is only available when the 9202 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9203 */ 9204 SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 9205 9206 /* 9207 ** CAPI3REF: Compare the ages of two snapshot handles. 9208 ** METHOD: sqlite3_snapshot 9209 ** 9210 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 9211 ** of two valid snapshot handles. 9212 ** 9213 ** If the two snapshot handles are not associated with the same database 9214 ** file, the result of the comparison is undefined. 9215 ** 9216 ** Additionally, the result of the comparison is only valid if both of the 9217 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 9218 ** last time the wal file was deleted. The wal file is deleted when the 9219 ** database is changed back to rollback mode or when the number of database 9220 ** clients drops to zero. If either snapshot handle was obtained before the 9221 ** wal file was last deleted, the value returned by this function 9222 ** is undefined. 9223 ** 9224 ** Otherwise, this API returns a negative value if P1 refers to an older 9225 ** snapshot than P2, zero if the two handles refer to the same database 9226 ** snapshot, and a positive value if P1 is a newer snapshot than P2. 9227 ** 9228 ** This interface is only available if SQLite is compiled with the 9229 ** [SQLITE_ENABLE_SNAPSHOT] option. 9230 */ 9231 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 9232 sqlite3_snapshot *p1, 9233 sqlite3_snapshot *p2 9234 ); 9235 9236 /* 9237 ** CAPI3REF: Recover snapshots from a wal file 9238 ** METHOD: sqlite3_snapshot 9239 ** 9240 ** If a [WAL file] remains on disk after all database connections close 9241 ** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 9242 ** or because the last process to have the database opened exited without 9243 ** calling [sqlite3_close()]) and a new connection is subsequently opened 9244 ** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 9245 ** will only be able to open the last transaction added to the WAL file 9246 ** even though the WAL file contains other valid transactions. 9247 ** 9248 ** This function attempts to scan the WAL file associated with database zDb 9249 ** of database handle db and make all valid snapshots available to 9250 ** sqlite3_snapshot_open(). It is an error if there is already a read 9251 ** transaction open on the database, or if the database is not a WAL mode 9252 ** database. 9253 ** 9254 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 9255 ** 9256 ** This interface is only available if SQLite is compiled with the 9257 ** [SQLITE_ENABLE_SNAPSHOT] option. 9258 */ 9259 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 9260 9261 /* 9262 ** CAPI3REF: Serialize a database 9263 ** 9264 ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 9265 ** that is a serialization of the S database on [database connection] D. 9266 ** If P is not a NULL pointer, then the size of the database in bytes 9267 ** is written into *P. 9268 ** 9269 ** For an ordinary on-disk database file, the serialization is just a 9270 ** copy of the disk file. For an in-memory database or a "TEMP" database, 9271 ** the serialization is the same sequence of bytes which would be written 9272 ** to disk if that database where backed up to disk. 9273 ** 9274 ** The usual case is that sqlite3_serialize() copies the serialization of 9275 ** the database into memory obtained from [sqlite3_malloc64()] and returns 9276 ** a pointer to that memory. The caller is responsible for freeing the 9277 ** returned value to avoid a memory leak. However, if the F argument 9278 ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 9279 ** are made, and the sqlite3_serialize() function will return a pointer 9280 ** to the contiguous memory representation of the database that SQLite 9281 ** is currently using for that database, or NULL if the no such contiguous 9282 ** memory representation of the database exists. A contiguous memory 9283 ** representation of the database will usually only exist if there has 9284 ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 9285 ** values of D and S. 9286 ** The size of the database is written into *P even if the 9287 ** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 9288 ** of the database exists. 9289 ** 9290 ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 9291 ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 9292 ** allocation error occurs. 9293 ** 9294 ** This interface is only available if SQLite is compiled with the 9295 ** [SQLITE_ENABLE_DESERIALIZE] option. 9296 */ 9297 SQLITE_API unsigned char *sqlite3_serialize( 9298 sqlite3 *db, /* The database connection */ 9299 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 9300 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 9301 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 9302 ); 9303 9304 /* 9305 ** CAPI3REF: Flags for sqlite3_serialize 9306 ** 9307 ** Zero or more of the following constants can be OR-ed together for 9308 ** the F argument to [sqlite3_serialize(D,S,P,F)]. 9309 ** 9310 ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 9311 ** a pointer to contiguous in-memory database that it is currently using, 9312 ** without making a copy of the database. If SQLite is not currently using 9313 ** a contiguous in-memory database, then this option causes 9314 ** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 9315 ** using a contiguous in-memory database if it has been initialized by a 9316 ** prior call to [sqlite3_deserialize()]. 9317 */ 9318 #define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 9319 9320 /* 9321 ** CAPI3REF: Deserialize a database 9322 ** 9323 ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 9324 ** [database connection] D to disconnect from database S and then 9325 ** reopen S as an in-memory database based on the serialization contained 9326 ** in P. The serialized database P is N bytes in size. M is the size of 9327 ** the buffer P, which might be larger than N. If M is larger than N, and 9328 ** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 9329 ** permitted to add content to the in-memory database as long as the total 9330 ** size does not exceed M bytes. 9331 ** 9332 ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 9333 ** invoke sqlite3_free() on the serialization buffer when the database 9334 ** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 9335 ** SQLite will try to increase the buffer size using sqlite3_realloc64() 9336 ** if writes on the database cause it to grow larger than M bytes. 9337 ** 9338 ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 9339 ** database is currently in a read transaction or is involved in a backup 9340 ** operation. 9341 ** 9342 ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 9343 ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 9344 ** [sqlite3_free()] is invoked on argument P prior to returning. 9345 ** 9346 ** This interface is only available if SQLite is compiled with the 9347 ** [SQLITE_ENABLE_DESERIALIZE] option. 9348 */ 9349 SQLITE_API int sqlite3_deserialize( 9350 sqlite3 *db, /* The database connection */ 9351 const char *zSchema, /* Which DB to reopen with the deserialization */ 9352 unsigned char *pData, /* The serialized database content */ 9353 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 9354 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 9355 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 9356 ); 9357 9358 /* 9359 ** CAPI3REF: Flags for sqlite3_deserialize() 9360 ** 9361 ** The following are allowed values for 6th argument (the F argument) to 9362 ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 9363 ** 9364 ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 9365 ** in the P argument is held in memory obtained from [sqlite3_malloc64()] 9366 ** and that SQLite should take ownership of this memory and automatically 9367 ** free it when it has finished using it. Without this flag, the caller 9368 ** is responsible for freeing any dynamically allocated memory. 9369 ** 9370 ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 9371 ** grow the size of the database using calls to [sqlite3_realloc64()]. This 9372 ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 9373 ** Without this flag, the deserialized database cannot increase in size beyond 9374 ** the number of bytes specified by the M parameter. 9375 ** 9376 ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 9377 ** should be treated as read-only. 9378 */ 9379 #define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 9380 #define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 9381 #define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 9382 9383 /* 9384 ** Undo the hack that converts floating point types to integer for 9385 ** builds on processors without floating point support. 9386 */ 9387 #ifdef SQLITE_OMIT_FLOATING_POINT 9388 # undef double 9389 #endif 9390 9391 #ifdef __cplusplus 9392 } /* End of the 'extern "C"' block */ 9393 #endif 9394 #endif /* SQLITE3_H */ 9395 9396 /******** Begin file sqlite3rtree.h *********/ 9397 /* 9398 ** 2010 August 30 9399 ** 9400 ** The author disclaims copyright to this source code. In place of 9401 ** a legal notice, here is a blessing: 9402 ** 9403 ** May you do good and not evil. 9404 ** May you find forgiveness for yourself and forgive others. 9405 ** May you share freely, never taking more than you give. 9406 ** 9407 ************************************************************************* 9408 */ 9409 9410 #ifndef _SQLITE3RTREE_H_ 9411 #define _SQLITE3RTREE_H_ 9412 9413 9414 #ifdef __cplusplus 9415 extern "C" { 9416 #endif 9417 9418 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 9419 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 9420 9421 /* The double-precision datatype used by RTree depends on the 9422 ** SQLITE_RTREE_INT_ONLY compile-time option. 9423 */ 9424 #ifdef SQLITE_RTREE_INT_ONLY 9425 typedef sqlite3_int64 sqlite3_rtree_dbl; 9426 #else 9427 typedef double sqlite3_rtree_dbl; 9428 #endif 9429 9430 /* 9431 ** Register a geometry callback named zGeom that can be used as part of an 9432 ** R-Tree geometry query as follows: 9433 ** 9434 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 9435 */ 9436 SQLITE_API int sqlite3_rtree_geometry_callback( 9437 sqlite3 *db, 9438 const char *zGeom, 9439 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 9440 void *pContext 9441 ); 9442 9443 9444 /* 9445 ** A pointer to a structure of the following type is passed as the first 9446 ** argument to callbacks registered using rtree_geometry_callback(). 9447 */ 9448 struct sqlite3_rtree_geometry { 9449 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 9450 int nParam; /* Size of array aParam[] */ 9451 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 9452 void *pUser; /* Callback implementation user data */ 9453 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 9454 }; 9455 9456 /* 9457 ** Register a 2nd-generation geometry callback named zScore that can be 9458 ** used as part of an R-Tree geometry query as follows: 9459 ** 9460 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 9461 */ 9462 SQLITE_API int sqlite3_rtree_query_callback( 9463 sqlite3 *db, 9464 const char *zQueryFunc, 9465 int (*xQueryFunc)(sqlite3_rtree_query_info*), 9466 void *pContext, 9467 void (*xDestructor)(void*) 9468 ); 9469 9470 9471 /* 9472 ** A pointer to a structure of the following type is passed as the 9473 ** argument to scored geometry callback registered using 9474 ** sqlite3_rtree_query_callback(). 9475 ** 9476 ** Note that the first 5 fields of this structure are identical to 9477 ** sqlite3_rtree_geometry. This structure is a subclass of 9478 ** sqlite3_rtree_geometry. 9479 */ 9480 struct sqlite3_rtree_query_info { 9481 void *pContext; /* pContext from when function registered */ 9482 int nParam; /* Number of function parameters */ 9483 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 9484 void *pUser; /* callback can use this, if desired */ 9485 void (*xDelUser)(void*); /* function to free pUser */ 9486 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 9487 unsigned int *anQueue; /* Number of pending entries in the queue */ 9488 int nCoord; /* Number of coordinates */ 9489 int iLevel; /* Level of current node or entry */ 9490 int mxLevel; /* The largest iLevel value in the tree */ 9491 sqlite3_int64 iRowid; /* Rowid for current entry */ 9492 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 9493 int eParentWithin; /* Visibility of parent node */ 9494 int eWithin; /* OUT: Visibility */ 9495 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 9496 /* The following fields are only available in 3.8.11 and later */ 9497 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 9498 }; 9499 9500 /* 9501 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 9502 */ 9503 #define NOT_WITHIN 0 /* Object completely outside of query region */ 9504 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 9505 #define FULLY_WITHIN 2 /* Object fully contained within query region */ 9506 9507 9508 #ifdef __cplusplus 9509 } /* end of the 'extern "C"' block */ 9510 #endif 9511 9512 #endif /* ifndef _SQLITE3RTREE_H_ */ 9513 9514 /******** End of sqlite3rtree.h *********/ 9515 /******** Begin file sqlite3session.h *********/ 9516 9517 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 9518 #define __SQLITESESSION_H_ 1 9519 9520 /* 9521 ** Make sure we can call this stuff from C++. 9522 */ 9523 #ifdef __cplusplus 9524 extern "C" { 9525 #endif 9526 9527 9528 /* 9529 ** CAPI3REF: Session Object Handle 9530 ** 9531 ** An instance of this object is a [session] that can be used to 9532 ** record changes to a database. 9533 */ 9534 typedef struct sqlite3_session sqlite3_session; 9535 9536 /* 9537 ** CAPI3REF: Changeset Iterator Handle 9538 ** 9539 ** An instance of this object acts as a cursor for iterating 9540 ** over the elements of a [changeset] or [patchset]. 9541 */ 9542 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 9543 9544 /* 9545 ** CAPI3REF: Create A New Session Object 9546 ** CONSTRUCTOR: sqlite3_session 9547 ** 9548 ** Create a new session object attached to database handle db. If successful, 9549 ** a pointer to the new object is written to *ppSession and SQLITE_OK is 9550 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite 9551 ** error code (e.g. SQLITE_NOMEM) is returned. 9552 ** 9553 ** It is possible to create multiple session objects attached to a single 9554 ** database handle. 9555 ** 9556 ** Session objects created using this function should be deleted using the 9557 ** [sqlite3session_delete()] function before the database handle that they 9558 ** are attached to is itself closed. If the database handle is closed before 9559 ** the session object is deleted, then the results of calling any session 9560 ** module function, including [sqlite3session_delete()] on the session object 9561 ** are undefined. 9562 ** 9563 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it 9564 ** is not possible for an application to register a pre-update hook on a 9565 ** database handle that has one or more session objects attached. Nor is 9566 ** it possible to create a session object attached to a database handle for 9567 ** which a pre-update hook is already defined. The results of attempting 9568 ** either of these things are undefined. 9569 ** 9570 ** The session object will be used to create changesets for tables in 9571 ** database zDb, where zDb is either "main", or "temp", or the name of an 9572 ** attached database. It is not an error if database zDb is not attached 9573 ** to the database when the session object is created. 9574 */ 9575 SQLITE_API int sqlite3session_create( 9576 sqlite3 *db, /* Database handle */ 9577 const char *zDb, /* Name of db (e.g. "main") */ 9578 sqlite3_session **ppSession /* OUT: New session object */ 9579 ); 9580 9581 /* 9582 ** CAPI3REF: Delete A Session Object 9583 ** DESTRUCTOR: sqlite3_session 9584 ** 9585 ** Delete a session object previously allocated using 9586 ** [sqlite3session_create()]. Once a session object has been deleted, the 9587 ** results of attempting to use pSession with any other session module 9588 ** function are undefined. 9589 ** 9590 ** Session objects must be deleted before the database handle to which they 9591 ** are attached is closed. Refer to the documentation for 9592 ** [sqlite3session_create()] for details. 9593 */ 9594 SQLITE_API void sqlite3session_delete(sqlite3_session *pSession); 9595 9596 9597 /* 9598 ** CAPI3REF: Enable Or Disable A Session Object 9599 ** METHOD: sqlite3_session 9600 ** 9601 ** Enable or disable the recording of changes by a session object. When 9602 ** enabled, a session object records changes made to the database. When 9603 ** disabled - it does not. A newly created session object is enabled. 9604 ** Refer to the documentation for [sqlite3session_changeset()] for further 9605 ** details regarding how enabling and disabling a session object affects 9606 ** the eventual changesets. 9607 ** 9608 ** Passing zero to this function disables the session. Passing a value 9609 ** greater than zero enables it. Passing a value less than zero is a 9610 ** no-op, and may be used to query the current state of the session. 9611 ** 9612 ** The return value indicates the final state of the session object: 0 if 9613 ** the session is disabled, or 1 if it is enabled. 9614 */ 9615 SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 9616 9617 /* 9618 ** CAPI3REF: Set Or Clear the Indirect Change Flag 9619 ** METHOD: sqlite3_session 9620 ** 9621 ** Each change recorded by a session object is marked as either direct or 9622 ** indirect. A change is marked as indirect if either: 9623 ** 9624 ** <ul> 9625 ** <li> The session object "indirect" flag is set when the change is 9626 ** made, or 9627 ** <li> The change is made by an SQL trigger or foreign key action 9628 ** instead of directly as a result of a users SQL statement. 9629 ** </ul> 9630 ** 9631 ** If a single row is affected by more than one operation within a session, 9632 ** then the change is considered indirect if all operations meet the criteria 9633 ** for an indirect change above, or direct otherwise. 9634 ** 9635 ** This function is used to set, clear or query the session object indirect 9636 ** flag. If the second argument passed to this function is zero, then the 9637 ** indirect flag is cleared. If it is greater than zero, the indirect flag 9638 ** is set. Passing a value less than zero does not modify the current value 9639 ** of the indirect flag, and may be used to query the current state of the 9640 ** indirect flag for the specified session object. 9641 ** 9642 ** The return value indicates the final state of the indirect flag: 0 if 9643 ** it is clear, or 1 if it is set. 9644 */ 9645 SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 9646 9647 /* 9648 ** CAPI3REF: Attach A Table To A Session Object 9649 ** METHOD: sqlite3_session 9650 ** 9651 ** If argument zTab is not NULL, then it is the name of a table to attach 9652 ** to the session object passed as the first argument. All subsequent changes 9653 ** made to the table while the session object is enabled will be recorded. See 9654 ** documentation for [sqlite3session_changeset()] for further details. 9655 ** 9656 ** Or, if argument zTab is NULL, then changes are recorded for all tables 9657 ** in the database. If additional tables are added to the database (by 9658 ** executing "CREATE TABLE" statements) after this call is made, changes for 9659 ** the new tables are also recorded. 9660 ** 9661 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 9662 ** defined as part of their CREATE TABLE statement. It does not matter if the 9663 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 9664 ** KEY may consist of a single column, or may be a composite key. 9665 ** 9666 ** It is not an error if the named table does not exist in the database. Nor 9667 ** is it an error if the named table does not have a PRIMARY KEY. However, 9668 ** no changes will be recorded in either of these scenarios. 9669 ** 9670 ** Changes are not recorded for individual rows that have NULL values stored 9671 ** in one or more of their PRIMARY KEY columns. 9672 ** 9673 ** SQLITE_OK is returned if the call completes without error. Or, if an error 9674 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 9675 ** 9676 ** <h3>Special sqlite_stat1 Handling</h3> 9677 ** 9678 ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to 9679 ** some of the rules above. In SQLite, the schema of sqlite_stat1 is: 9680 ** <pre> 9681 ** CREATE TABLE sqlite_stat1(tbl,idx,stat) 9682 ** </pre> 9683 ** 9684 ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are 9685 ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes 9686 ** are recorded for rows for which (idx IS NULL) is true. However, for such 9687 ** rows a zero-length blob (SQL value X'') is stored in the changeset or 9688 ** patchset instead of a NULL value. This allows such changesets to be 9689 ** manipulated by legacy implementations of sqlite3changeset_invert(), 9690 ** concat() and similar. 9691 ** 9692 ** The sqlite3changeset_apply() function automatically converts the 9693 ** zero-length blob back to a NULL value when updating the sqlite_stat1 9694 ** table. However, if the application calls sqlite3changeset_new(), 9695 ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset 9696 ** iterator directly (including on a changeset iterator passed to a 9697 ** conflict-handler callback) then the X'' value is returned. The application 9698 ** must translate X'' to NULL itself if required. 9699 ** 9700 ** Legacy (older than 3.22.0) versions of the sessions module cannot capture 9701 ** changes made to the sqlite_stat1 table. Legacy versions of the 9702 ** sqlite3changeset_apply() function silently ignore any modifications to the 9703 ** sqlite_stat1 table that are part of a changeset or patchset. 9704 */ 9705 SQLITE_API int sqlite3session_attach( 9706 sqlite3_session *pSession, /* Session object */ 9707 const char *zTab /* Table name */ 9708 ); 9709 9710 /* 9711 ** CAPI3REF: Set a table filter on a Session Object. 9712 ** METHOD: sqlite3_session 9713 ** 9714 ** The second argument (xFilter) is the "filter callback". For changes to rows 9715 ** in tables that are not attached to the Session object, the filter is called 9716 ** to determine whether changes to the table's rows should be tracked or not. 9717 ** If xFilter returns 0, changes is not tracked. Note that once a table is 9718 ** attached, xFilter will not be called again. 9719 */ 9720 SQLITE_API void sqlite3session_table_filter( 9721 sqlite3_session *pSession, /* Session object */ 9722 int(*xFilter)( 9723 void *pCtx, /* Copy of third arg to _filter_table() */ 9724 const char *zTab /* Table name */ 9725 ), 9726 void *pCtx /* First argument passed to xFilter */ 9727 ); 9728 9729 /* 9730 ** CAPI3REF: Generate A Changeset From A Session Object 9731 ** METHOD: sqlite3_session 9732 ** 9733 ** Obtain a changeset containing changes to the tables attached to the 9734 ** session object passed as the first argument. If successful, 9735 ** set *ppChangeset to point to a buffer containing the changeset 9736 ** and *pnChangeset to the size of the changeset in bytes before returning 9737 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 9738 ** zero and return an SQLite error code. 9739 ** 9740 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 9741 ** each representing a change to a single row of an attached table. An INSERT 9742 ** change contains the values of each field of a new database row. A DELETE 9743 ** contains the original values of each field of a deleted database row. An 9744 ** UPDATE change contains the original values of each field of an updated 9745 ** database row along with the updated values for each updated non-primary-key 9746 ** column. It is not possible for an UPDATE change to represent a change that 9747 ** modifies the values of primary key columns. If such a change is made, it 9748 ** is represented in a changeset as a DELETE followed by an INSERT. 9749 ** 9750 ** Changes are not recorded for rows that have NULL values stored in one or 9751 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 9752 ** no corresponding change is present in the changesets returned by this 9753 ** function. If an existing row with one or more NULL values stored in 9754 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 9755 ** only an INSERT is appears in the changeset. Similarly, if an existing row 9756 ** with non-NULL PRIMARY KEY values is updated so that one or more of its 9757 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 9758 ** DELETE change only. 9759 ** 9760 ** The contents of a changeset may be traversed using an iterator created 9761 ** using the [sqlite3changeset_start()] API. A changeset may be applied to 9762 ** a database with a compatible schema using the [sqlite3changeset_apply()] 9763 ** API. 9764 ** 9765 ** Within a changeset generated by this function, all changes related to a 9766 ** single table are grouped together. In other words, when iterating through 9767 ** a changeset or when applying a changeset to a database, all changes related 9768 ** to a single table are processed before moving on to the next table. Tables 9769 ** are sorted in the same order in which they were attached (or auto-attached) 9770 ** to the sqlite3_session object. The order in which the changes related to 9771 ** a single table are stored is undefined. 9772 ** 9773 ** Following a successful call to this function, it is the responsibility of 9774 ** the caller to eventually free the buffer that *ppChangeset points to using 9775 ** [sqlite3_free()]. 9776 ** 9777 ** <h3>Changeset Generation</h3> 9778 ** 9779 ** Once a table has been attached to a session object, the session object 9780 ** records the primary key values of all new rows inserted into the table. 9781 ** It also records the original primary key and other column values of any 9782 ** deleted or updated rows. For each unique primary key value, data is only 9783 ** recorded once - the first time a row with said primary key is inserted, 9784 ** updated or deleted in the lifetime of the session. 9785 ** 9786 ** There is one exception to the previous paragraph: when a row is inserted, 9787 ** updated or deleted, if one or more of its primary key columns contain a 9788 ** NULL value, no record of the change is made. 9789 ** 9790 ** The session object therefore accumulates two types of records - those 9791 ** that consist of primary key values only (created when the user inserts 9792 ** a new record) and those that consist of the primary key values and the 9793 ** original values of other table columns (created when the users deletes 9794 ** or updates a record). 9795 ** 9796 ** When this function is called, the requested changeset is created using 9797 ** both the accumulated records and the current contents of the database 9798 ** file. Specifically: 9799 ** 9800 ** <ul> 9801 ** <li> For each record generated by an insert, the database is queried 9802 ** for a row with a matching primary key. If one is found, an INSERT 9803 ** change is added to the changeset. If no such row is found, no change 9804 ** is added to the changeset. 9805 ** 9806 ** <li> For each record generated by an update or delete, the database is 9807 ** queried for a row with a matching primary key. If such a row is 9808 ** found and one or more of the non-primary key fields have been 9809 ** modified from their original values, an UPDATE change is added to 9810 ** the changeset. Or, if no such row is found in the table, a DELETE 9811 ** change is added to the changeset. If there is a row with a matching 9812 ** primary key in the database, but all fields contain their original 9813 ** values, no change is added to the changeset. 9814 ** </ul> 9815 ** 9816 ** This means, amongst other things, that if a row is inserted and then later 9817 ** deleted while a session object is active, neither the insert nor the delete 9818 ** will be present in the changeset. Or if a row is deleted and then later a 9819 ** row with the same primary key values inserted while a session object is 9820 ** active, the resulting changeset will contain an UPDATE change instead of 9821 ** a DELETE and an INSERT. 9822 ** 9823 ** When a session object is disabled (see the [sqlite3session_enable()] API), 9824 ** it does not accumulate records when rows are inserted, updated or deleted. 9825 ** This may appear to have some counter-intuitive effects if a single row 9826 ** is written to more than once during a session. For example, if a row 9827 ** is inserted while a session object is enabled, then later deleted while 9828 ** the same session object is disabled, no INSERT record will appear in the 9829 ** changeset, even though the delete took place while the session was disabled. 9830 ** Or, if one field of a row is updated while a session is disabled, and 9831 ** another field of the same row is updated while the session is enabled, the 9832 ** resulting changeset will contain an UPDATE change that updates both fields. 9833 */ 9834 SQLITE_API int sqlite3session_changeset( 9835 sqlite3_session *pSession, /* Session object */ 9836 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 9837 void **ppChangeset /* OUT: Buffer containing changeset */ 9838 ); 9839 9840 /* 9841 ** CAPI3REF: Load The Difference Between Tables Into A Session 9842 ** METHOD: sqlite3_session 9843 ** 9844 ** If it is not already attached to the session object passed as the first 9845 ** argument, this function attaches table zTbl in the same manner as the 9846 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it 9847 ** does not have a primary key, this function is a no-op (but does not return 9848 ** an error). 9849 ** 9850 ** Argument zFromDb must be the name of a database ("main", "temp" etc.) 9851 ** attached to the same database handle as the session object that contains 9852 ** a table compatible with the table attached to the session by this function. 9853 ** A table is considered compatible if it: 9854 ** 9855 ** <ul> 9856 ** <li> Has the same name, 9857 ** <li> Has the same set of columns declared in the same order, and 9858 ** <li> Has the same PRIMARY KEY definition. 9859 ** </ul> 9860 ** 9861 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 9862 ** are compatible but do not have any PRIMARY KEY columns, it is not an error 9863 ** but no changes are added to the session object. As with other session 9864 ** APIs, tables without PRIMARY KEYs are simply ignored. 9865 ** 9866 ** This function adds a set of changes to the session object that could be 9867 ** used to update the table in database zFrom (call this the "from-table") 9868 ** so that its content is the same as the table attached to the session 9869 ** object (call this the "to-table"). Specifically: 9870 ** 9871 ** <ul> 9872 ** <li> For each row (primary key) that exists in the to-table but not in 9873 ** the from-table, an INSERT record is added to the session object. 9874 ** 9875 ** <li> For each row (primary key) that exists in the to-table but not in 9876 ** the from-table, a DELETE record is added to the session object. 9877 ** 9878 ** <li> For each row (primary key) that exists in both tables, but features 9879 ** different non-PK values in each, an UPDATE record is added to the 9880 ** session. 9881 ** </ul> 9882 ** 9883 ** To clarify, if this function is called and then a changeset constructed 9884 ** using [sqlite3session_changeset()], then after applying that changeset to 9885 ** database zFrom the contents of the two compatible tables would be 9886 ** identical. 9887 ** 9888 ** It an error if database zFrom does not exist or does not contain the 9889 ** required compatible table. 9890 ** 9891 ** If the operation successful, SQLITE_OK is returned. Otherwise, an SQLite 9892 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 9893 ** may be set to point to a buffer containing an English language error 9894 ** message. It is the responsibility of the caller to free this buffer using 9895 ** sqlite3_free(). 9896 */ 9897 SQLITE_API int sqlite3session_diff( 9898 sqlite3_session *pSession, 9899 const char *zFromDb, 9900 const char *zTbl, 9901 char **pzErrMsg 9902 ); 9903 9904 9905 /* 9906 ** CAPI3REF: Generate A Patchset From A Session Object 9907 ** METHOD: sqlite3_session 9908 ** 9909 ** The differences between a patchset and a changeset are that: 9910 ** 9911 ** <ul> 9912 ** <li> DELETE records consist of the primary key fields only. The 9913 ** original values of other fields are omitted. 9914 ** <li> The original values of any modified fields are omitted from 9915 ** UPDATE records. 9916 ** </ul> 9917 ** 9918 ** A patchset blob may be used with up to date versions of all 9919 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 9920 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 9921 ** attempting to use a patchset blob with old versions of the 9922 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 9923 ** 9924 ** Because the non-primary key "old.*" fields are omitted, no 9925 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 9926 ** is passed to the sqlite3changeset_apply() API. Other conflict types work 9927 ** in the same way as for changesets. 9928 ** 9929 ** Changes within a patchset are ordered in the same way as for changesets 9930 ** generated by the sqlite3session_changeset() function (i.e. all changes for 9931 ** a single table are grouped together, tables appear in the order in which 9932 ** they were attached to the session object). 9933 */ 9934 SQLITE_API int sqlite3session_patchset( 9935 sqlite3_session *pSession, /* Session object */ 9936 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */ 9937 void **ppPatchset /* OUT: Buffer containing patchset */ 9938 ); 9939 9940 /* 9941 ** CAPI3REF: Test if a changeset has recorded any changes. 9942 ** 9943 ** Return non-zero if no changes to attached tables have been recorded by 9944 ** the session object passed as the first argument. Otherwise, if one or 9945 ** more changes have been recorded, return zero. 9946 ** 9947 ** Even if this function returns zero, it is possible that calling 9948 ** [sqlite3session_changeset()] on the session handle may still return a 9949 ** changeset that contains no changes. This can happen when a row in 9950 ** an attached table is modified and then later on the original values 9951 ** are restored. However, if this function returns non-zero, then it is 9952 ** guaranteed that a call to sqlite3session_changeset() will return a 9953 ** changeset containing zero changes. 9954 */ 9955 SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession); 9956 9957 /* 9958 ** CAPI3REF: Create An Iterator To Traverse A Changeset 9959 ** CONSTRUCTOR: sqlite3_changeset_iter 9960 ** 9961 ** Create an iterator used to iterate through the contents of a changeset. 9962 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK 9963 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an 9964 ** SQLite error code is returned. 9965 ** 9966 ** The following functions can be used to advance and query a changeset 9967 ** iterator created by this function: 9968 ** 9969 ** <ul> 9970 ** <li> [sqlite3changeset_next()] 9971 ** <li> [sqlite3changeset_op()] 9972 ** <li> [sqlite3changeset_new()] 9973 ** <li> [sqlite3changeset_old()] 9974 ** </ul> 9975 ** 9976 ** It is the responsibility of the caller to eventually destroy the iterator 9977 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 9978 ** changeset (pChangeset) must remain valid until after the iterator is 9979 ** destroyed. 9980 ** 9981 ** Assuming the changeset blob was created by one of the 9982 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 9983 ** [sqlite3changeset_invert()] functions, all changes within the changeset 9984 ** that apply to a single table are grouped together. This means that when 9985 ** an application iterates through a changeset using an iterator created by 9986 ** this function, all changes that relate to a single table are visited 9987 ** consecutively. There is no chance that the iterator will visit a change 9988 ** the applies to table X, then one for table Y, and then later on visit 9989 ** another change for table X. 9990 ** 9991 ** The behavior of sqlite3changeset_start_v2() and its streaming equivalent 9992 ** may be modified by passing a combination of 9993 ** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter. 9994 ** 9995 ** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b> 9996 ** and therefore subject to change. 9997 */ 9998 SQLITE_API int sqlite3changeset_start( 9999 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 10000 int nChangeset, /* Size of changeset blob in bytes */ 10001 void *pChangeset /* Pointer to blob containing changeset */ 10002 ); 10003 SQLITE_API int sqlite3changeset_start_v2( 10004 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 10005 int nChangeset, /* Size of changeset blob in bytes */ 10006 void *pChangeset, /* Pointer to blob containing changeset */ 10007 int flags /* SESSION_CHANGESETSTART_* flags */ 10008 ); 10009 10010 /* 10011 ** CAPI3REF: Flags for sqlite3changeset_start_v2 10012 ** 10013 ** The following flags may passed via the 4th parameter to 10014 ** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]: 10015 ** 10016 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 10017 ** Invert the changeset while iterating through it. This is equivalent to 10018 ** inverting a changeset using sqlite3changeset_invert() before applying it. 10019 ** It is an error to specify this flag with a patchset. 10020 */ 10021 #define SQLITE_CHANGESETSTART_INVERT 0x0002 10022 10023 10024 /* 10025 ** CAPI3REF: Advance A Changeset Iterator 10026 ** METHOD: sqlite3_changeset_iter 10027 ** 10028 ** This function may only be used with iterators created by function 10029 ** [sqlite3changeset_start()]. If it is called on an iterator passed to 10030 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 10031 ** is returned and the call has no effect. 10032 ** 10033 ** Immediately after an iterator is created by sqlite3changeset_start(), it 10034 ** does not point to any change in the changeset. Assuming the changeset 10035 ** is not empty, the first call to this function advances the iterator to 10036 ** point to the first change in the changeset. Each subsequent call advances 10037 ** the iterator to point to the next change in the changeset (if any). If 10038 ** no error occurs and the iterator points to a valid change after a call 10039 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 10040 ** Otherwise, if all changes in the changeset have already been visited, 10041 ** SQLITE_DONE is returned. 10042 ** 10043 ** If an error occurs, an SQLite error code is returned. Possible error 10044 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 10045 ** SQLITE_NOMEM. 10046 */ 10047 SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 10048 10049 /* 10050 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 10051 ** METHOD: sqlite3_changeset_iter 10052 ** 10053 ** The pIter argument passed to this function may either be an iterator 10054 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10055 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 10056 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 10057 ** is not the case, this function returns [SQLITE_MISUSE]. 10058 ** 10059 ** If argument pzTab is not NULL, then *pzTab is set to point to a 10060 ** nul-terminated utf-8 encoded string containing the name of the table 10061 ** affected by the current change. The buffer remains valid until either 10062 ** sqlite3changeset_next() is called on the iterator or until the 10063 ** conflict-handler function returns. If pnCol is not NULL, then *pnCol is 10064 ** set to the number of columns in the table affected by the change. If 10065 ** pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change 10066 ** is an indirect change, or false (0) otherwise. See the documentation for 10067 ** [sqlite3session_indirect()] for a description of direct and indirect 10068 ** changes. Finally, if pOp is not NULL, then *pOp is set to one of 10069 ** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the 10070 ** type of change that the iterator currently points to. 10071 ** 10072 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an 10073 ** SQLite error code is returned. The values of the output variables may not 10074 ** be trusted in this case. 10075 */ 10076 SQLITE_API int sqlite3changeset_op( 10077 sqlite3_changeset_iter *pIter, /* Iterator object */ 10078 const char **pzTab, /* OUT: Pointer to table name */ 10079 int *pnCol, /* OUT: Number of columns in table */ 10080 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 10081 int *pbIndirect /* OUT: True for an 'indirect' change */ 10082 ); 10083 10084 /* 10085 ** CAPI3REF: Obtain The Primary Key Definition Of A Table 10086 ** METHOD: sqlite3_changeset_iter 10087 ** 10088 ** For each modified table, a changeset includes the following: 10089 ** 10090 ** <ul> 10091 ** <li> The number of columns in the table, and 10092 ** <li> Which of those columns make up the tables PRIMARY KEY. 10093 ** </ul> 10094 ** 10095 ** This function is used to find which columns comprise the PRIMARY KEY of 10096 ** the table modified by the change that iterator pIter currently points to. 10097 ** If successful, *pabPK is set to point to an array of nCol entries, where 10098 ** nCol is the number of columns in the table. Elements of *pabPK are set to 10099 ** 0x01 if the corresponding column is part of the tables primary key, or 10100 ** 0x00 if it is not. 10101 ** 10102 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns 10103 ** in the table. 10104 ** 10105 ** If this function is called when the iterator does not point to a valid 10106 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 10107 ** SQLITE_OK is returned and the output variables populated as described 10108 ** above. 10109 */ 10110 SQLITE_API int sqlite3changeset_pk( 10111 sqlite3_changeset_iter *pIter, /* Iterator object */ 10112 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 10113 int *pnCol /* OUT: Number of entries in output array */ 10114 ); 10115 10116 /* 10117 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator 10118 ** METHOD: sqlite3_changeset_iter 10119 ** 10120 ** The pIter argument passed to this function may either be an iterator 10121 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10122 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 10123 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 10124 ** Furthermore, it may only be called if the type of change that the iterator 10125 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 10126 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 10127 ** 10128 ** Argument iVal must be greater than or equal to 0, and less than the number 10129 ** of columns in the table affected by the current change. Otherwise, 10130 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10131 ** 10132 ** If successful, this function sets *ppValue to point to a protected 10133 ** sqlite3_value object containing the iVal'th value from the vector of 10134 ** original row values stored as part of the UPDATE or DELETE change and 10135 ** returns SQLITE_OK. The name of the function comes from the fact that this 10136 ** is similar to the "old.*" columns available to update or delete triggers. 10137 ** 10138 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 10139 ** is returned and *ppValue is set to NULL. 10140 */ 10141 SQLITE_API int sqlite3changeset_old( 10142 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10143 int iVal, /* Column number */ 10144 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 10145 ); 10146 10147 /* 10148 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator 10149 ** METHOD: sqlite3_changeset_iter 10150 ** 10151 ** The pIter argument passed to this function may either be an iterator 10152 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10153 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 10154 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 10155 ** Furthermore, it may only be called if the type of change that the iterator 10156 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 10157 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 10158 ** 10159 ** Argument iVal must be greater than or equal to 0, and less than the number 10160 ** of columns in the table affected by the current change. Otherwise, 10161 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10162 ** 10163 ** If successful, this function sets *ppValue to point to a protected 10164 ** sqlite3_value object containing the iVal'th value from the vector of 10165 ** new row values stored as part of the UPDATE or INSERT change and 10166 ** returns SQLITE_OK. If the change is an UPDATE and does not include 10167 ** a new value for the requested column, *ppValue is set to NULL and 10168 ** SQLITE_OK returned. The name of the function comes from the fact that 10169 ** this is similar to the "new.*" columns available to update or delete 10170 ** triggers. 10171 ** 10172 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 10173 ** is returned and *ppValue is set to NULL. 10174 */ 10175 SQLITE_API int sqlite3changeset_new( 10176 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10177 int iVal, /* Column number */ 10178 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 10179 ); 10180 10181 /* 10182 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 10183 ** METHOD: sqlite3_changeset_iter 10184 ** 10185 ** This function should only be used with iterator objects passed to a 10186 ** conflict-handler callback by [sqlite3changeset_apply()] with either 10187 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 10188 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 10189 ** is set to NULL. 10190 ** 10191 ** Argument iVal must be greater than or equal to 0, and less than the number 10192 ** of columns in the table affected by the current change. Otherwise, 10193 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10194 ** 10195 ** If successful, this function sets *ppValue to point to a protected 10196 ** sqlite3_value object containing the iVal'th value from the 10197 ** "conflicting row" associated with the current conflict-handler callback 10198 ** and returns SQLITE_OK. 10199 ** 10200 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 10201 ** is returned and *ppValue is set to NULL. 10202 */ 10203 SQLITE_API int sqlite3changeset_conflict( 10204 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10205 int iVal, /* Column number */ 10206 sqlite3_value **ppValue /* OUT: Value from conflicting row */ 10207 ); 10208 10209 /* 10210 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 10211 ** METHOD: sqlite3_changeset_iter 10212 ** 10213 ** This function may only be called with an iterator passed to an 10214 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 10215 ** it sets the output variable to the total number of known foreign key 10216 ** violations in the destination database and returns SQLITE_OK. 10217 ** 10218 ** In all other cases this function returns SQLITE_MISUSE. 10219 */ 10220 SQLITE_API int sqlite3changeset_fk_conflicts( 10221 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10222 int *pnOut /* OUT: Number of FK violations */ 10223 ); 10224 10225 10226 /* 10227 ** CAPI3REF: Finalize A Changeset Iterator 10228 ** METHOD: sqlite3_changeset_iter 10229 ** 10230 ** This function is used to finalize an iterator allocated with 10231 ** [sqlite3changeset_start()]. 10232 ** 10233 ** This function should only be called on iterators created using the 10234 ** [sqlite3changeset_start()] function. If an application calls this 10235 ** function with an iterator passed to a conflict-handler by 10236 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 10237 ** call has no effect. 10238 ** 10239 ** If an error was encountered within a call to an sqlite3changeset_xxx() 10240 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 10241 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 10242 ** to that error is returned by this function. Otherwise, SQLITE_OK is 10243 ** returned. This is to allow the following pattern (pseudo-code): 10244 ** 10245 ** <pre> 10246 ** sqlite3changeset_start(); 10247 ** while( SQLITE_ROW==sqlite3changeset_next() ){ 10248 ** // Do something with change. 10249 ** } 10250 ** rc = sqlite3changeset_finalize(); 10251 ** if( rc!=SQLITE_OK ){ 10252 ** // An error has occurred 10253 ** } 10254 ** </pre> 10255 */ 10256 SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 10257 10258 /* 10259 ** CAPI3REF: Invert A Changeset 10260 ** 10261 ** This function is used to "invert" a changeset object. Applying an inverted 10262 ** changeset to a database reverses the effects of applying the uninverted 10263 ** changeset. Specifically: 10264 ** 10265 ** <ul> 10266 ** <li> Each DELETE change is changed to an INSERT, and 10267 ** <li> Each INSERT change is changed to a DELETE, and 10268 ** <li> For each UPDATE change, the old.* and new.* values are exchanged. 10269 ** </ul> 10270 ** 10271 ** This function does not change the order in which changes appear within 10272 ** the changeset. It merely reverses the sense of each individual change. 10273 ** 10274 ** If successful, a pointer to a buffer containing the inverted changeset 10275 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 10276 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 10277 ** zeroed and an SQLite error code returned. 10278 ** 10279 ** It is the responsibility of the caller to eventually call sqlite3_free() 10280 ** on the *ppOut pointer to free the buffer allocation following a successful 10281 ** call to this function. 10282 ** 10283 ** WARNING/TODO: This function currently assumes that the input is a valid 10284 ** changeset. If it is not, the results are undefined. 10285 */ 10286 SQLITE_API int sqlite3changeset_invert( 10287 int nIn, const void *pIn, /* Input changeset */ 10288 int *pnOut, void **ppOut /* OUT: Inverse of input */ 10289 ); 10290 10291 /* 10292 ** CAPI3REF: Concatenate Two Changeset Objects 10293 ** 10294 ** This function is used to concatenate two changesets, A and B, into a 10295 ** single changeset. The result is a changeset equivalent to applying 10296 ** changeset A followed by changeset B. 10297 ** 10298 ** This function combines the two input changesets using an 10299 ** sqlite3_changegroup object. Calling it produces similar results as the 10300 ** following code fragment: 10301 ** 10302 ** <pre> 10303 ** sqlite3_changegroup *pGrp; 10304 ** rc = sqlite3_changegroup_new(&pGrp); 10305 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 10306 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 10307 ** if( rc==SQLITE_OK ){ 10308 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 10309 ** }else{ 10310 ** *ppOut = 0; 10311 ** *pnOut = 0; 10312 ** } 10313 ** </pre> 10314 ** 10315 ** Refer to the sqlite3_changegroup documentation below for details. 10316 */ 10317 SQLITE_API int sqlite3changeset_concat( 10318 int nA, /* Number of bytes in buffer pA */ 10319 void *pA, /* Pointer to buffer containing changeset A */ 10320 int nB, /* Number of bytes in buffer pB */ 10321 void *pB, /* Pointer to buffer containing changeset B */ 10322 int *pnOut, /* OUT: Number of bytes in output changeset */ 10323 void **ppOut /* OUT: Buffer containing output changeset */ 10324 ); 10325 10326 10327 /* 10328 ** CAPI3REF: Changegroup Handle 10329 ** 10330 ** A changegroup is an object used to combine two or more 10331 ** [changesets] or [patchsets] 10332 */ 10333 typedef struct sqlite3_changegroup sqlite3_changegroup; 10334 10335 /* 10336 ** CAPI3REF: Create A New Changegroup Object 10337 ** CONSTRUCTOR: sqlite3_changegroup 10338 ** 10339 ** An sqlite3_changegroup object is used to combine two or more changesets 10340 ** (or patchsets) into a single changeset (or patchset). A single changegroup 10341 ** object may combine changesets or patchsets, but not both. The output is 10342 ** always in the same format as the input. 10343 ** 10344 ** If successful, this function returns SQLITE_OK and populates (*pp) with 10345 ** a pointer to a new sqlite3_changegroup object before returning. The caller 10346 ** should eventually free the returned object using a call to 10347 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 10348 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 10349 ** 10350 ** The usual usage pattern for an sqlite3_changegroup object is as follows: 10351 ** 10352 ** <ul> 10353 ** <li> It is created using a call to sqlite3changegroup_new(). 10354 ** 10355 ** <li> Zero or more changesets (or patchsets) are added to the object 10356 ** by calling sqlite3changegroup_add(). 10357 ** 10358 ** <li> The result of combining all input changesets together is obtained 10359 ** by the application via a call to sqlite3changegroup_output(). 10360 ** 10361 ** <li> The object is deleted using a call to sqlite3changegroup_delete(). 10362 ** </ul> 10363 ** 10364 ** Any number of calls to add() and output() may be made between the calls to 10365 ** new() and delete(), and in any order. 10366 ** 10367 ** As well as the regular sqlite3changegroup_add() and 10368 ** sqlite3changegroup_output() functions, also available are the streaming 10369 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 10370 */ 10371 SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp); 10372 10373 /* 10374 ** CAPI3REF: Add A Changeset To A Changegroup 10375 ** METHOD: sqlite3_changegroup 10376 ** 10377 ** Add all changes within the changeset (or patchset) in buffer pData (size 10378 ** nData bytes) to the changegroup. 10379 ** 10380 ** If the buffer contains a patchset, then all prior calls to this function 10381 ** on the same changegroup object must also have specified patchsets. Or, if 10382 ** the buffer contains a changeset, so must have the earlier calls to this 10383 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added 10384 ** to the changegroup. 10385 ** 10386 ** Rows within the changeset and changegroup are identified by the values in 10387 ** their PRIMARY KEY columns. A change in the changeset is considered to 10388 ** apply to the same row as a change already present in the changegroup if 10389 ** the two rows have the same primary key. 10390 ** 10391 ** Changes to rows that do not already appear in the changegroup are 10392 ** simply copied into it. Or, if both the new changeset and the changegroup 10393 ** contain changes that apply to a single row, the final contents of the 10394 ** changegroup depends on the type of each change, as follows: 10395 ** 10396 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 10397 ** <tr><th style="white-space:pre">Existing Change </th> 10398 ** <th style="white-space:pre">New Change </th> 10399 ** <th>Output Change 10400 ** <tr><td>INSERT <td>INSERT <td> 10401 ** The new change is ignored. This case does not occur if the new 10402 ** changeset was recorded immediately after the changesets already 10403 ** added to the changegroup. 10404 ** <tr><td>INSERT <td>UPDATE <td> 10405 ** The INSERT change remains in the changegroup. The values in the 10406 ** INSERT change are modified as if the row was inserted by the 10407 ** existing change and then updated according to the new change. 10408 ** <tr><td>INSERT <td>DELETE <td> 10409 ** The existing INSERT is removed from the changegroup. The DELETE is 10410 ** not added. 10411 ** <tr><td>UPDATE <td>INSERT <td> 10412 ** The new change is ignored. This case does not occur if the new 10413 ** changeset was recorded immediately after the changesets already 10414 ** added to the changegroup. 10415 ** <tr><td>UPDATE <td>UPDATE <td> 10416 ** The existing UPDATE remains within the changegroup. It is amended 10417 ** so that the accompanying values are as if the row was updated once 10418 ** by the existing change and then again by the new change. 10419 ** <tr><td>UPDATE <td>DELETE <td> 10420 ** The existing UPDATE is replaced by the new DELETE within the 10421 ** changegroup. 10422 ** <tr><td>DELETE <td>INSERT <td> 10423 ** If one or more of the column values in the row inserted by the 10424 ** new change differ from those in the row deleted by the existing 10425 ** change, the existing DELETE is replaced by an UPDATE within the 10426 ** changegroup. Otherwise, if the inserted row is exactly the same 10427 ** as the deleted row, the existing DELETE is simply discarded. 10428 ** <tr><td>DELETE <td>UPDATE <td> 10429 ** The new change is ignored. This case does not occur if the new 10430 ** changeset was recorded immediately after the changesets already 10431 ** added to the changegroup. 10432 ** <tr><td>DELETE <td>DELETE <td> 10433 ** The new change is ignored. This case does not occur if the new 10434 ** changeset was recorded immediately after the changesets already 10435 ** added to the changegroup. 10436 ** </table> 10437 ** 10438 ** If the new changeset contains changes to a table that is already present 10439 ** in the changegroup, then the number of columns and the position of the 10440 ** primary key columns for the table must be consistent. If this is not the 10441 ** case, this function fails with SQLITE_SCHEMA. If the input changeset 10442 ** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is 10443 ** returned. Or, if an out-of-memory condition occurs during processing, this 10444 ** function returns SQLITE_NOMEM. In all cases, if an error occurs the 10445 ** final contents of the changegroup is undefined. 10446 ** 10447 ** If no error occurs, SQLITE_OK is returned. 10448 */ 10449 SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 10450 10451 /* 10452 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup 10453 ** METHOD: sqlite3_changegroup 10454 ** 10455 ** Obtain a buffer containing a changeset (or patchset) representing the 10456 ** current contents of the changegroup. If the inputs to the changegroup 10457 ** were themselves changesets, the output is a changeset. Or, if the 10458 ** inputs were patchsets, the output is also a patchset. 10459 ** 10460 ** As with the output of the sqlite3session_changeset() and 10461 ** sqlite3session_patchset() functions, all changes related to a single 10462 ** table are grouped together in the output of this function. Tables appear 10463 ** in the same order as for the very first changeset added to the changegroup. 10464 ** If the second or subsequent changesets added to the changegroup contain 10465 ** changes for tables that do not appear in the first changeset, they are 10466 ** appended onto the end of the output changeset, again in the order in 10467 ** which they are first encountered. 10468 ** 10469 ** If an error occurs, an SQLite error code is returned and the output 10470 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 10471 ** is returned and the output variables are set to the size of and a 10472 ** pointer to the output buffer, respectively. In this case it is the 10473 ** responsibility of the caller to eventually free the buffer using a 10474 ** call to sqlite3_free(). 10475 */ 10476 SQLITE_API int sqlite3changegroup_output( 10477 sqlite3_changegroup*, 10478 int *pnData, /* OUT: Size of output buffer in bytes */ 10479 void **ppData /* OUT: Pointer to output buffer */ 10480 ); 10481 10482 /* 10483 ** CAPI3REF: Delete A Changegroup Object 10484 ** DESTRUCTOR: sqlite3_changegroup 10485 */ 10486 SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*); 10487 10488 /* 10489 ** CAPI3REF: Apply A Changeset To A Database 10490 ** 10491 ** Apply a changeset or patchset to a database. These functions attempt to 10492 ** update the "main" database attached to handle db with the changes found in 10493 ** the changeset passed via the second and third arguments. 10494 ** 10495 ** The fourth argument (xFilter) passed to these functions is the "filter 10496 ** callback". If it is not NULL, then for each table affected by at least one 10497 ** change in the changeset, the filter callback is invoked with 10498 ** the table name as the second argument, and a copy of the context pointer 10499 ** passed as the sixth argument as the first. If the "filter callback" 10500 ** returns zero, then no attempt is made to apply any changes to the table. 10501 ** Otherwise, if the return value is non-zero or the xFilter argument to 10502 ** is NULL, all changes related to the table are attempted. 10503 ** 10504 ** For each table that is not excluded by the filter callback, this function 10505 ** tests that the target database contains a compatible table. A table is 10506 ** considered compatible if all of the following are true: 10507 ** 10508 ** <ul> 10509 ** <li> The table has the same name as the name recorded in the 10510 ** changeset, and 10511 ** <li> The table has at least as many columns as recorded in the 10512 ** changeset, and 10513 ** <li> The table has primary key columns in the same position as 10514 ** recorded in the changeset. 10515 ** </ul> 10516 ** 10517 ** If there is no compatible table, it is not an error, but none of the 10518 ** changes associated with the table are applied. A warning message is issued 10519 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 10520 ** one such warning is issued for each table in the changeset. 10521 ** 10522 ** For each change for which there is a compatible table, an attempt is made 10523 ** to modify the table contents according to the UPDATE, INSERT or DELETE 10524 ** change. If a change cannot be applied cleanly, the conflict handler 10525 ** function passed as the fifth argument to sqlite3changeset_apply() may be 10526 ** invoked. A description of exactly when the conflict handler is invoked for 10527 ** each type of change is below. 10528 ** 10529 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results 10530 ** of passing anything other than a valid function pointer as the xConflict 10531 ** argument are undefined. 10532 ** 10533 ** Each time the conflict handler function is invoked, it must return one 10534 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 10535 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 10536 ** if the second argument passed to the conflict handler is either 10537 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 10538 ** returns an illegal value, any changes already made are rolled back and 10539 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 10540 ** actions are taken by sqlite3changeset_apply() depending on the value 10541 ** returned by each invocation of the conflict-handler function. Refer to 10542 ** the documentation for the three 10543 ** [SQLITE_CHANGESET_OMIT|available return values] for details. 10544 ** 10545 ** <dl> 10546 ** <dt>DELETE Changes<dd> 10547 ** For each DELETE change, the function checks if the target database 10548 ** contains a row with the same primary key value (or values) as the 10549 ** original row values stored in the changeset. If it does, and the values 10550 ** stored in all non-primary key columns also match the values stored in 10551 ** the changeset the row is deleted from the target database. 10552 ** 10553 ** If a row with matching primary key values is found, but one or more of 10554 ** the non-primary key fields contains a value different from the original 10555 ** row value stored in the changeset, the conflict-handler function is 10556 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the 10557 ** database table has more columns than are recorded in the changeset, 10558 ** only the values of those non-primary key fields are compared against 10559 ** the current database contents - any trailing database table columns 10560 ** are ignored. 10561 ** 10562 ** If no row with matching primary key values is found in the database, 10563 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 10564 ** passed as the second argument. 10565 ** 10566 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 10567 ** (which can only happen if a foreign key constraint is violated), the 10568 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 10569 ** passed as the second argument. This includes the case where the DELETE 10570 ** operation is attempted because an earlier call to the conflict handler 10571 ** function returned [SQLITE_CHANGESET_REPLACE]. 10572 ** 10573 ** <dt>INSERT Changes<dd> 10574 ** For each INSERT change, an attempt is made to insert the new row into 10575 ** the database. If the changeset row contains fewer fields than the 10576 ** database table, the trailing fields are populated with their default 10577 ** values. 10578 ** 10579 ** If the attempt to insert the row fails because the database already 10580 ** contains a row with the same primary key values, the conflict handler 10581 ** function is invoked with the second argument set to 10582 ** [SQLITE_CHANGESET_CONFLICT]. 10583 ** 10584 ** If the attempt to insert the row fails because of some other constraint 10585 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 10586 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 10587 ** This includes the case where the INSERT operation is re-attempted because 10588 ** an earlier call to the conflict handler function returned 10589 ** [SQLITE_CHANGESET_REPLACE]. 10590 ** 10591 ** <dt>UPDATE Changes<dd> 10592 ** For each UPDATE change, the function checks if the target database 10593 ** contains a row with the same primary key value (or values) as the 10594 ** original row values stored in the changeset. If it does, and the values 10595 ** stored in all modified non-primary key columns also match the values 10596 ** stored in the changeset the row is updated within the target database. 10597 ** 10598 ** If a row with matching primary key values is found, but one or more of 10599 ** the modified non-primary key fields contains a value different from an 10600 ** original row value stored in the changeset, the conflict-handler function 10601 ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 10602 ** UPDATE changes only contain values for non-primary key fields that are 10603 ** to be modified, only those fields need to match the original values to 10604 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 10605 ** 10606 ** If no row with matching primary key values is found in the database, 10607 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 10608 ** passed as the second argument. 10609 ** 10610 ** If the UPDATE operation is attempted, but SQLite returns 10611 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 10612 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 10613 ** This includes the case where the UPDATE operation is attempted after 10614 ** an earlier call to the conflict handler function returned 10615 ** [SQLITE_CHANGESET_REPLACE]. 10616 ** </dl> 10617 ** 10618 ** It is safe to execute SQL statements, including those that write to the 10619 ** table that the callback related to, from within the xConflict callback. 10620 ** This can be used to further customize the applications conflict 10621 ** resolution strategy. 10622 ** 10623 ** All changes made by these functions are enclosed in a savepoint transaction. 10624 ** If any other error (aside from a constraint failure when attempting to 10625 ** write to the target database) occurs, then the savepoint transaction is 10626 ** rolled back, restoring the target database to its original state, and an 10627 ** SQLite error code returned. 10628 ** 10629 ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and 10630 ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2() 10631 ** may set (*ppRebase) to point to a "rebase" that may be used with the 10632 ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase) 10633 ** is set to the size of the buffer in bytes. It is the responsibility of the 10634 ** caller to eventually free any such buffer using sqlite3_free(). The buffer 10635 ** is only allocated and populated if one or more conflicts were encountered 10636 ** while applying the patchset. See comments surrounding the sqlite3_rebaser 10637 ** APIs for further details. 10638 ** 10639 ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent 10640 ** may be modified by passing a combination of 10641 ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter. 10642 ** 10643 ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b> 10644 ** and therefore subject to change. 10645 */ 10646 SQLITE_API int sqlite3changeset_apply( 10647 sqlite3 *db, /* Apply change to "main" db of this handle */ 10648 int nChangeset, /* Size of changeset in bytes */ 10649 void *pChangeset, /* Changeset blob */ 10650 int(*xFilter)( 10651 void *pCtx, /* Copy of sixth arg to _apply() */ 10652 const char *zTab /* Table name */ 10653 ), 10654 int(*xConflict)( 10655 void *pCtx, /* Copy of sixth arg to _apply() */ 10656 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 10657 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 10658 ), 10659 void *pCtx /* First argument passed to xConflict */ 10660 ); 10661 SQLITE_API int sqlite3changeset_apply_v2( 10662 sqlite3 *db, /* Apply change to "main" db of this handle */ 10663 int nChangeset, /* Size of changeset in bytes */ 10664 void *pChangeset, /* Changeset blob */ 10665 int(*xFilter)( 10666 void *pCtx, /* Copy of sixth arg to _apply() */ 10667 const char *zTab /* Table name */ 10668 ), 10669 int(*xConflict)( 10670 void *pCtx, /* Copy of sixth arg to _apply() */ 10671 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 10672 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 10673 ), 10674 void *pCtx, /* First argument passed to xConflict */ 10675 void **ppRebase, int *pnRebase, /* OUT: Rebase data */ 10676 int flags /* SESSION_CHANGESETAPPLY_* flags */ 10677 ); 10678 10679 /* 10680 ** CAPI3REF: Flags for sqlite3changeset_apply_v2 10681 ** 10682 ** The following flags may passed via the 9th parameter to 10683 ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]: 10684 ** 10685 ** <dl> 10686 ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd> 10687 ** Usually, the sessions module encloses all operations performed by 10688 ** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The 10689 ** SAVEPOINT is committed if the changeset or patchset is successfully 10690 ** applied, or rolled back if an error occurs. Specifying this flag 10691 ** causes the sessions module to omit this savepoint. In this case, if the 10692 ** caller has an open transaction or savepoint when apply_v2() is called, 10693 ** it may revert the partially applied changeset by rolling it back. 10694 ** 10695 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 10696 ** Invert the changeset before applying it. This is equivalent to inverting 10697 ** a changeset using sqlite3changeset_invert() before applying it. It is 10698 ** an error to specify this flag with a patchset. 10699 */ 10700 #define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001 10701 #define SQLITE_CHANGESETAPPLY_INVERT 0x0002 10702 10703 /* 10704 ** CAPI3REF: Constants Passed To The Conflict Handler 10705 ** 10706 ** Values that may be passed as the second argument to a conflict-handler. 10707 ** 10708 ** <dl> 10709 ** <dt>SQLITE_CHANGESET_DATA<dd> 10710 ** The conflict handler is invoked with CHANGESET_DATA as the second argument 10711 ** when processing a DELETE or UPDATE change if a row with the required 10712 ** PRIMARY KEY fields is present in the database, but one or more other 10713 ** (non primary-key) fields modified by the update do not contain the 10714 ** expected "before" values. 10715 ** 10716 ** The conflicting row, in this case, is the database row with the matching 10717 ** primary key. 10718 ** 10719 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 10720 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 10721 ** argument when processing a DELETE or UPDATE change if a row with the 10722 ** required PRIMARY KEY fields is not present in the database. 10723 ** 10724 ** There is no conflicting row in this case. The results of invoking the 10725 ** sqlite3changeset_conflict() API are undefined. 10726 ** 10727 ** <dt>SQLITE_CHANGESET_CONFLICT<dd> 10728 ** CHANGESET_CONFLICT is passed as the second argument to the conflict 10729 ** handler while processing an INSERT change if the operation would result 10730 ** in duplicate primary key values. 10731 ** 10732 ** The conflicting row in this case is the database row with the matching 10733 ** primary key. 10734 ** 10735 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 10736 ** If foreign key handling is enabled, and applying a changeset leaves the 10737 ** database in a state containing foreign key violations, the conflict 10738 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 10739 ** exactly once before the changeset is committed. If the conflict handler 10740 ** returns CHANGESET_OMIT, the changes, including those that caused the 10741 ** foreign key constraint violation, are committed. Or, if it returns 10742 ** CHANGESET_ABORT, the changeset is rolled back. 10743 ** 10744 ** No current or conflicting row information is provided. The only function 10745 ** it is possible to call on the supplied sqlite3_changeset_iter handle 10746 ** is sqlite3changeset_fk_conflicts(). 10747 ** 10748 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 10749 ** If any other constraint violation occurs while applying a change (i.e. 10750 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 10751 ** invoked with CHANGESET_CONSTRAINT as the second argument. 10752 ** 10753 ** There is no conflicting row in this case. The results of invoking the 10754 ** sqlite3changeset_conflict() API are undefined. 10755 ** 10756 ** </dl> 10757 */ 10758 #define SQLITE_CHANGESET_DATA 1 10759 #define SQLITE_CHANGESET_NOTFOUND 2 10760 #define SQLITE_CHANGESET_CONFLICT 3 10761 #define SQLITE_CHANGESET_CONSTRAINT 4 10762 #define SQLITE_CHANGESET_FOREIGN_KEY 5 10763 10764 /* 10765 ** CAPI3REF: Constants Returned By The Conflict Handler 10766 ** 10767 ** A conflict handler callback must return one of the following three values. 10768 ** 10769 ** <dl> 10770 ** <dt>SQLITE_CHANGESET_OMIT<dd> 10771 ** If a conflict handler returns this value no special action is taken. The 10772 ** change that caused the conflict is not applied. The session module 10773 ** continues to the next change in the changeset. 10774 ** 10775 ** <dt>SQLITE_CHANGESET_REPLACE<dd> 10776 ** This value may only be returned if the second argument to the conflict 10777 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 10778 ** is not the case, any changes applied so far are rolled back and the 10779 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 10780 ** 10781 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 10782 ** handler, then the conflicting row is either updated or deleted, depending 10783 ** on the type of change. 10784 ** 10785 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 10786 ** handler, then the conflicting row is removed from the database and a 10787 ** second attempt to apply the change is made. If this second attempt fails, 10788 ** the original row is restored to the database before continuing. 10789 ** 10790 ** <dt>SQLITE_CHANGESET_ABORT<dd> 10791 ** If this value is returned, any changes applied so far are rolled back 10792 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 10793 ** </dl> 10794 */ 10795 #define SQLITE_CHANGESET_OMIT 0 10796 #define SQLITE_CHANGESET_REPLACE 1 10797 #define SQLITE_CHANGESET_ABORT 2 10798 10799 /* 10800 ** CAPI3REF: Rebasing changesets 10801 ** EXPERIMENTAL 10802 ** 10803 ** Suppose there is a site hosting a database in state S0. And that 10804 ** modifications are made that move that database to state S1 and a 10805 ** changeset recorded (the "local" changeset). Then, a changeset based 10806 ** on S0 is received from another site (the "remote" changeset) and 10807 ** applied to the database. The database is then in state 10808 ** (S1+"remote"), where the exact state depends on any conflict 10809 ** resolution decisions (OMIT or REPLACE) made while applying "remote". 10810 ** Rebasing a changeset is to update it to take those conflict 10811 ** resolution decisions into account, so that the same conflicts 10812 ** do not have to be resolved elsewhere in the network. 10813 ** 10814 ** For example, if both the local and remote changesets contain an 10815 ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)": 10816 ** 10817 ** local: INSERT INTO t1 VALUES(1, 'v1'); 10818 ** remote: INSERT INTO t1 VALUES(1, 'v2'); 10819 ** 10820 ** and the conflict resolution is REPLACE, then the INSERT change is 10821 ** removed from the local changeset (it was overridden). Or, if the 10822 ** conflict resolution was "OMIT", then the local changeset is modified 10823 ** to instead contain: 10824 ** 10825 ** UPDATE t1 SET b = 'v2' WHERE a=1; 10826 ** 10827 ** Changes within the local changeset are rebased as follows: 10828 ** 10829 ** <dl> 10830 ** <dt>Local INSERT<dd> 10831 ** This may only conflict with a remote INSERT. If the conflict 10832 ** resolution was OMIT, then add an UPDATE change to the rebased 10833 ** changeset. Or, if the conflict resolution was REPLACE, add 10834 ** nothing to the rebased changeset. 10835 ** 10836 ** <dt>Local DELETE<dd> 10837 ** This may conflict with a remote UPDATE or DELETE. In both cases the 10838 ** only possible resolution is OMIT. If the remote operation was a 10839 ** DELETE, then add no change to the rebased changeset. If the remote 10840 ** operation was an UPDATE, then the old.* fields of change are updated 10841 ** to reflect the new.* values in the UPDATE. 10842 ** 10843 ** <dt>Local UPDATE<dd> 10844 ** This may conflict with a remote UPDATE or DELETE. If it conflicts 10845 ** with a DELETE, and the conflict resolution was OMIT, then the update 10846 ** is changed into an INSERT. Any undefined values in the new.* record 10847 ** from the update change are filled in using the old.* values from 10848 ** the conflicting DELETE. Or, if the conflict resolution was REPLACE, 10849 ** the UPDATE change is simply omitted from the rebased changeset. 10850 ** 10851 ** If conflict is with a remote UPDATE and the resolution is OMIT, then 10852 ** the old.* values are rebased using the new.* values in the remote 10853 ** change. Or, if the resolution is REPLACE, then the change is copied 10854 ** into the rebased changeset with updates to columns also updated by 10855 ** the conflicting remote UPDATE removed. If this means no columns would 10856 ** be updated, the change is omitted. 10857 ** </dl> 10858 ** 10859 ** A local change may be rebased against multiple remote changes 10860 ** simultaneously. If a single key is modified by multiple remote 10861 ** changesets, they are combined as follows before the local changeset 10862 ** is rebased: 10863 ** 10864 ** <ul> 10865 ** <li> If there has been one or more REPLACE resolutions on a 10866 ** key, it is rebased according to a REPLACE. 10867 ** 10868 ** <li> If there have been no REPLACE resolutions on a key, then 10869 ** the local changeset is rebased according to the most recent 10870 ** of the OMIT resolutions. 10871 ** </ul> 10872 ** 10873 ** Note that conflict resolutions from multiple remote changesets are 10874 ** combined on a per-field basis, not per-row. This means that in the 10875 ** case of multiple remote UPDATE operations, some fields of a single 10876 ** local change may be rebased for REPLACE while others are rebased for 10877 ** OMIT. 10878 ** 10879 ** In order to rebase a local changeset, the remote changeset must first 10880 ** be applied to the local database using sqlite3changeset_apply_v2() and 10881 ** the buffer of rebase information captured. Then: 10882 ** 10883 ** <ol> 10884 ** <li> An sqlite3_rebaser object is created by calling 10885 ** sqlite3rebaser_create(). 10886 ** <li> The new object is configured with the rebase buffer obtained from 10887 ** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure(). 10888 ** If the local changeset is to be rebased against multiple remote 10889 ** changesets, then sqlite3rebaser_configure() should be called 10890 ** multiple times, in the same order that the multiple 10891 ** sqlite3changeset_apply_v2() calls were made. 10892 ** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase(). 10893 ** <li> The sqlite3_rebaser object is deleted by calling 10894 ** sqlite3rebaser_delete(). 10895 ** </ol> 10896 */ 10897 typedef struct sqlite3_rebaser sqlite3_rebaser; 10898 10899 /* 10900 ** CAPI3REF: Create a changeset rebaser object. 10901 ** EXPERIMENTAL 10902 ** 10903 ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to 10904 ** point to the new object and return SQLITE_OK. Otherwise, if an error 10905 ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew) 10906 ** to NULL. 10907 */ 10908 SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew); 10909 10910 /* 10911 ** CAPI3REF: Configure a changeset rebaser object. 10912 ** EXPERIMENTAL 10913 ** 10914 ** Configure the changeset rebaser object to rebase changesets according 10915 ** to the conflict resolutions described by buffer pRebase (size nRebase 10916 ** bytes), which must have been obtained from a previous call to 10917 ** sqlite3changeset_apply_v2(). 10918 */ 10919 SQLITE_API int sqlite3rebaser_configure( 10920 sqlite3_rebaser*, 10921 int nRebase, const void *pRebase 10922 ); 10923 10924 /* 10925 ** CAPI3REF: Rebase a changeset 10926 ** EXPERIMENTAL 10927 ** 10928 ** Argument pIn must point to a buffer containing a changeset nIn bytes 10929 ** in size. This function allocates and populates a buffer with a copy 10930 ** of the changeset rebased rebased according to the configuration of the 10931 ** rebaser object passed as the first argument. If successful, (*ppOut) 10932 ** is set to point to the new buffer containing the rebased changeset and 10933 ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the 10934 ** responsibility of the caller to eventually free the new buffer using 10935 ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut) 10936 ** are set to zero and an SQLite error code returned. 10937 */ 10938 SQLITE_API int sqlite3rebaser_rebase( 10939 sqlite3_rebaser*, 10940 int nIn, const void *pIn, 10941 int *pnOut, void **ppOut 10942 ); 10943 10944 /* 10945 ** CAPI3REF: Delete a changeset rebaser object. 10946 ** EXPERIMENTAL 10947 ** 10948 ** Delete the changeset rebaser object and all associated resources. There 10949 ** should be one call to this function for each successful invocation 10950 ** of sqlite3rebaser_create(). 10951 */ 10952 SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p); 10953 10954 /* 10955 ** CAPI3REF: Streaming Versions of API functions. 10956 ** 10957 ** The six streaming API xxx_strm() functions serve similar purposes to the 10958 ** corresponding non-streaming API functions: 10959 ** 10960 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 10961 ** <tr><th>Streaming function<th>Non-streaming equivalent</th> 10962 ** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply] 10963 ** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2] 10964 ** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat] 10965 ** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert] 10966 ** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start] 10967 ** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset] 10968 ** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset] 10969 ** </table> 10970 ** 10971 ** Non-streaming functions that accept changesets (or patchsets) as input 10972 ** require that the entire changeset be stored in a single buffer in memory. 10973 ** Similarly, those that return a changeset or patchset do so by returning 10974 ** a pointer to a single large buffer allocated using sqlite3_malloc(). 10975 ** Normally this is convenient. However, if an application running in a 10976 ** low-memory environment is required to handle very large changesets, the 10977 ** large contiguous memory allocations required can become onerous. 10978 ** 10979 ** In order to avoid this problem, instead of a single large buffer, input 10980 ** is passed to a streaming API functions by way of a callback function that 10981 ** the sessions module invokes to incrementally request input data as it is 10982 ** required. In all cases, a pair of API function parameters such as 10983 ** 10984 ** <pre> 10985 ** int nChangeset, 10986 ** void *pChangeset, 10987 ** </pre> 10988 ** 10989 ** Is replaced by: 10990 ** 10991 ** <pre> 10992 ** int (*xInput)(void *pIn, void *pData, int *pnData), 10993 ** void *pIn, 10994 ** </pre> 10995 ** 10996 ** Each time the xInput callback is invoked by the sessions module, the first 10997 ** argument passed is a copy of the supplied pIn context pointer. The second 10998 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 10999 ** error occurs the xInput method should copy up to (*pnData) bytes of data 11000 ** into the buffer and set (*pnData) to the actual number of bytes copied 11001 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 11002 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite 11003 ** error code should be returned. In all cases, if an xInput callback returns 11004 ** an error, all processing is abandoned and the streaming API function 11005 ** returns a copy of the error code to the caller. 11006 ** 11007 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be 11008 ** invoked by the sessions module at any point during the lifetime of the 11009 ** iterator. If such an xInput callback returns an error, the iterator enters 11010 ** an error state, whereby all subsequent calls to iterator functions 11011 ** immediately fail with the same error code as returned by xInput. 11012 ** 11013 ** Similarly, streaming API functions that return changesets (or patchsets) 11014 ** return them in chunks by way of a callback function instead of via a 11015 ** pointer to a single large buffer. In this case, a pair of parameters such 11016 ** as: 11017 ** 11018 ** <pre> 11019 ** int *pnChangeset, 11020 ** void **ppChangeset, 11021 ** </pre> 11022 ** 11023 ** Is replaced by: 11024 ** 11025 ** <pre> 11026 ** int (*xOutput)(void *pOut, const void *pData, int nData), 11027 ** void *pOut 11028 ** </pre> 11029 ** 11030 ** The xOutput callback is invoked zero or more times to return data to 11031 ** the application. The first parameter passed to each call is a copy of the 11032 ** pOut pointer supplied by the application. The second parameter, pData, 11033 ** points to a buffer nData bytes in size containing the chunk of output 11034 ** data being returned. If the xOutput callback successfully processes the 11035 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 11036 ** it should return some other SQLite error code. In this case processing 11037 ** is immediately abandoned and the streaming API function returns a copy 11038 ** of the xOutput error code to the application. 11039 ** 11040 ** The sessions module never invokes an xOutput callback with the third 11041 ** parameter set to a value less than or equal to zero. Other than this, 11042 ** no guarantees are made as to the size of the chunks of data returned. 11043 */ 11044 SQLITE_API int sqlite3changeset_apply_strm( 11045 sqlite3 *db, /* Apply change to "main" db of this handle */ 11046 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 11047 void *pIn, /* First arg for xInput */ 11048 int(*xFilter)( 11049 void *pCtx, /* Copy of sixth arg to _apply() */ 11050 const char *zTab /* Table name */ 11051 ), 11052 int(*xConflict)( 11053 void *pCtx, /* Copy of sixth arg to _apply() */ 11054 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11055 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11056 ), 11057 void *pCtx /* First argument passed to xConflict */ 11058 ); 11059 SQLITE_API int sqlite3changeset_apply_v2_strm( 11060 sqlite3 *db, /* Apply change to "main" db of this handle */ 11061 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 11062 void *pIn, /* First arg for xInput */ 11063 int(*xFilter)( 11064 void *pCtx, /* Copy of sixth arg to _apply() */ 11065 const char *zTab /* Table name */ 11066 ), 11067 int(*xConflict)( 11068 void *pCtx, /* Copy of sixth arg to _apply() */ 11069 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11070 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11071 ), 11072 void *pCtx, /* First argument passed to xConflict */ 11073 void **ppRebase, int *pnRebase, 11074 int flags 11075 ); 11076 SQLITE_API int sqlite3changeset_concat_strm( 11077 int (*xInputA)(void *pIn, void *pData, int *pnData), 11078 void *pInA, 11079 int (*xInputB)(void *pIn, void *pData, int *pnData), 11080 void *pInB, 11081 int (*xOutput)(void *pOut, const void *pData, int nData), 11082 void *pOut 11083 ); 11084 SQLITE_API int sqlite3changeset_invert_strm( 11085 int (*xInput)(void *pIn, void *pData, int *pnData), 11086 void *pIn, 11087 int (*xOutput)(void *pOut, const void *pData, int nData), 11088 void *pOut 11089 ); 11090 SQLITE_API int sqlite3changeset_start_strm( 11091 sqlite3_changeset_iter **pp, 11092 int (*xInput)(void *pIn, void *pData, int *pnData), 11093 void *pIn 11094 ); 11095 SQLITE_API int sqlite3changeset_start_v2_strm( 11096 sqlite3_changeset_iter **pp, 11097 int (*xInput)(void *pIn, void *pData, int *pnData), 11098 void *pIn, 11099 int flags 11100 ); 11101 SQLITE_API int sqlite3session_changeset_strm( 11102 sqlite3_session *pSession, 11103 int (*xOutput)(void *pOut, const void *pData, int nData), 11104 void *pOut 11105 ); 11106 SQLITE_API int sqlite3session_patchset_strm( 11107 sqlite3_session *pSession, 11108 int (*xOutput)(void *pOut, const void *pData, int nData), 11109 void *pOut 11110 ); 11111 SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*, 11112 int (*xInput)(void *pIn, void *pData, int *pnData), 11113 void *pIn 11114 ); 11115 SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*, 11116 int (*xOutput)(void *pOut, const void *pData, int nData), 11117 void *pOut 11118 ); 11119 SQLITE_API int sqlite3rebaser_rebase_strm( 11120 sqlite3_rebaser *pRebaser, 11121 int (*xInput)(void *pIn, void *pData, int *pnData), 11122 void *pIn, 11123 int (*xOutput)(void *pOut, const void *pData, int nData), 11124 void *pOut 11125 ); 11126 11127 /* 11128 ** CAPI3REF: Configure global parameters 11129 ** 11130 ** The sqlite3session_config() interface is used to make global configuration 11131 ** changes to the sessions module in order to tune it to the specific needs 11132 ** of the application. 11133 ** 11134 ** The sqlite3session_config() interface is not threadsafe. If it is invoked 11135 ** while any other thread is inside any other sessions method then the 11136 ** results are undefined. Furthermore, if it is invoked after any sessions 11137 ** related objects have been created, the results are also undefined. 11138 ** 11139 ** The first argument to the sqlite3session_config() function must be one 11140 ** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The 11141 ** interpretation of the (void*) value passed as the second parameter and 11142 ** the effect of calling this function depends on the value of the first 11143 ** parameter. 11144 ** 11145 ** <dl> 11146 ** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd> 11147 ** By default, the sessions module streaming interfaces attempt to input 11148 ** and output data in approximately 1 KiB chunks. This operand may be used 11149 ** to set and query the value of this configuration setting. The pointer 11150 ** passed as the second argument must point to a value of type (int). 11151 ** If this value is greater than 0, it is used as the new streaming data 11152 ** chunk size for both input and output. Before returning, the (int) value 11153 ** pointed to by pArg is set to the final value of the streaming interface 11154 ** chunk size. 11155 ** </dl> 11156 ** 11157 ** This function returns SQLITE_OK if successful, or an SQLite error code 11158 ** otherwise. 11159 */ 11160 SQLITE_API int sqlite3session_config(int op, void *pArg); 11161 11162 /* 11163 ** CAPI3REF: Values for sqlite3session_config(). 11164 */ 11165 #define SQLITE_SESSION_CONFIG_STRMSIZE 1 11166 11167 /* 11168 ** Make sure we can call this stuff from C++. 11169 */ 11170 #ifdef __cplusplus 11171 } 11172 #endif 11173 11174 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 11175 11176 /******** End of sqlite3session.h *********/ 11177 /******** Begin file fts5.h *********/ 11178 /* 11179 ** 2014 May 31 11180 ** 11181 ** The author disclaims copyright to this source code. In place of 11182 ** a legal notice, here is a blessing: 11183 ** 11184 ** May you do good and not evil. 11185 ** May you find forgiveness for yourself and forgive others. 11186 ** May you share freely, never taking more than you give. 11187 ** 11188 ****************************************************************************** 11189 ** 11190 ** Interfaces to extend FTS5. Using the interfaces defined in this file, 11191 ** FTS5 may be extended with: 11192 ** 11193 ** * custom tokenizers, and 11194 ** * custom auxiliary functions. 11195 */ 11196 11197 11198 #ifndef _FTS5_H 11199 #define _FTS5_H 11200 11201 11202 #ifdef __cplusplus 11203 extern "C" { 11204 #endif 11205 11206 /************************************************************************* 11207 ** CUSTOM AUXILIARY FUNCTIONS 11208 ** 11209 ** Virtual table implementations may overload SQL functions by implementing 11210 ** the sqlite3_module.xFindFunction() method. 11211 */ 11212 11213 typedef struct Fts5ExtensionApi Fts5ExtensionApi; 11214 typedef struct Fts5Context Fts5Context; 11215 typedef struct Fts5PhraseIter Fts5PhraseIter; 11216 11217 typedef void (*fts5_extension_function)( 11218 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 11219 Fts5Context *pFts, /* First arg to pass to pApi functions */ 11220 sqlite3_context *pCtx, /* Context for returning result/error */ 11221 int nVal, /* Number of values in apVal[] array */ 11222 sqlite3_value **apVal /* Array of trailing arguments */ 11223 ); 11224 11225 struct Fts5PhraseIter { 11226 const unsigned char *a; 11227 const unsigned char *b; 11228 }; 11229 11230 /* 11231 ** EXTENSION API FUNCTIONS 11232 ** 11233 ** xUserData(pFts): 11234 ** Return a copy of the context pointer the extension function was 11235 ** registered with. 11236 ** 11237 ** xColumnTotalSize(pFts, iCol, pnToken): 11238 ** If parameter iCol is less than zero, set output variable *pnToken 11239 ** to the total number of tokens in the FTS5 table. Or, if iCol is 11240 ** non-negative but less than the number of columns in the table, return 11241 ** the total number of tokens in column iCol, considering all rows in 11242 ** the FTS5 table. 11243 ** 11244 ** If parameter iCol is greater than or equal to the number of columns 11245 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 11246 ** an OOM condition or IO error), an appropriate SQLite error code is 11247 ** returned. 11248 ** 11249 ** xColumnCount(pFts): 11250 ** Return the number of columns in the table. 11251 ** 11252 ** xColumnSize(pFts, iCol, pnToken): 11253 ** If parameter iCol is less than zero, set output variable *pnToken 11254 ** to the total number of tokens in the current row. Or, if iCol is 11255 ** non-negative but less than the number of columns in the table, set 11256 ** *pnToken to the number of tokens in column iCol of the current row. 11257 ** 11258 ** If parameter iCol is greater than or equal to the number of columns 11259 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 11260 ** an OOM condition or IO error), an appropriate SQLite error code is 11261 ** returned. 11262 ** 11263 ** This function may be quite inefficient if used with an FTS5 table 11264 ** created with the "columnsize=0" option. 11265 ** 11266 ** xColumnText: 11267 ** This function attempts to retrieve the text of column iCol of the 11268 ** current document. If successful, (*pz) is set to point to a buffer 11269 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 11270 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 11271 ** if an error occurs, an SQLite error code is returned and the final values 11272 ** of (*pz) and (*pn) are undefined. 11273 ** 11274 ** xPhraseCount: 11275 ** Returns the number of phrases in the current query expression. 11276 ** 11277 ** xPhraseSize: 11278 ** Returns the number of tokens in phrase iPhrase of the query. Phrases 11279 ** are numbered starting from zero. 11280 ** 11281 ** xInstCount: 11282 ** Set *pnInst to the total number of occurrences of all phrases within 11283 ** the query within the current row. Return SQLITE_OK if successful, or 11284 ** an error code (i.e. SQLITE_NOMEM) if an error occurs. 11285 ** 11286 ** This API can be quite slow if used with an FTS5 table created with the 11287 ** "detail=none" or "detail=column" option. If the FTS5 table is created 11288 ** with either "detail=none" or "detail=column" and "content=" option 11289 ** (i.e. if it is a contentless table), then this API always returns 0. 11290 ** 11291 ** xInst: 11292 ** Query for the details of phrase match iIdx within the current row. 11293 ** Phrase matches are numbered starting from zero, so the iIdx argument 11294 ** should be greater than or equal to zero and smaller than the value 11295 ** output by xInstCount(). 11296 ** 11297 ** Usually, output parameter *piPhrase is set to the phrase number, *piCol 11298 ** to the column in which it occurs and *piOff the token offset of the 11299 ** first token of the phrase. Returns SQLITE_OK if successful, or an error 11300 ** code (i.e. SQLITE_NOMEM) if an error occurs. 11301 ** 11302 ** This API can be quite slow if used with an FTS5 table created with the 11303 ** "detail=none" or "detail=column" option. 11304 ** 11305 ** xRowid: 11306 ** Returns the rowid of the current row. 11307 ** 11308 ** xTokenize: 11309 ** Tokenize text using the tokenizer belonging to the FTS5 table. 11310 ** 11311 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 11312 ** This API function is used to query the FTS table for phrase iPhrase 11313 ** of the current query. Specifically, a query equivalent to: 11314 ** 11315 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 11316 ** 11317 ** with $p set to a phrase equivalent to the phrase iPhrase of the 11318 ** current query is executed. Any column filter that applies to 11319 ** phrase iPhrase of the current query is included in $p. For each 11320 ** row visited, the callback function passed as the fourth argument 11321 ** is invoked. The context and API objects passed to the callback 11322 ** function may be used to access the properties of each matched row. 11323 ** Invoking Api.xUserData() returns a copy of the pointer passed as 11324 ** the third argument to pUserData. 11325 ** 11326 ** If the callback function returns any value other than SQLITE_OK, the 11327 ** query is abandoned and the xQueryPhrase function returns immediately. 11328 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 11329 ** Otherwise, the error code is propagated upwards. 11330 ** 11331 ** If the query runs to completion without incident, SQLITE_OK is returned. 11332 ** Or, if some error occurs before the query completes or is aborted by 11333 ** the callback, an SQLite error code is returned. 11334 ** 11335 ** 11336 ** xSetAuxdata(pFts5, pAux, xDelete) 11337 ** 11338 ** Save the pointer passed as the second argument as the extension functions 11339 ** "auxiliary data". The pointer may then be retrieved by the current or any 11340 ** future invocation of the same fts5 extension function made as part of 11341 ** the same MATCH query using the xGetAuxdata() API. 11342 ** 11343 ** Each extension function is allocated a single auxiliary data slot for 11344 ** each FTS query (MATCH expression). If the extension function is invoked 11345 ** more than once for a single FTS query, then all invocations share a 11346 ** single auxiliary data context. 11347 ** 11348 ** If there is already an auxiliary data pointer when this function is 11349 ** invoked, then it is replaced by the new pointer. If an xDelete callback 11350 ** was specified along with the original pointer, it is invoked at this 11351 ** point. 11352 ** 11353 ** The xDelete callback, if one is specified, is also invoked on the 11354 ** auxiliary data pointer after the FTS5 query has finished. 11355 ** 11356 ** If an error (e.g. an OOM condition) occurs within this function, 11357 ** the auxiliary data is set to NULL and an error code returned. If the 11358 ** xDelete parameter was not NULL, it is invoked on the auxiliary data 11359 ** pointer before returning. 11360 ** 11361 ** 11362 ** xGetAuxdata(pFts5, bClear) 11363 ** 11364 ** Returns the current auxiliary data pointer for the fts5 extension 11365 ** function. See the xSetAuxdata() method for details. 11366 ** 11367 ** If the bClear argument is non-zero, then the auxiliary data is cleared 11368 ** (set to NULL) before this function returns. In this case the xDelete, 11369 ** if any, is not invoked. 11370 ** 11371 ** 11372 ** xRowCount(pFts5, pnRow) 11373 ** 11374 ** This function is used to retrieve the total number of rows in the table. 11375 ** In other words, the same value that would be returned by: 11376 ** 11377 ** SELECT count(*) FROM ftstable; 11378 ** 11379 ** xPhraseFirst() 11380 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext 11381 ** method, to iterate through all instances of a single query phrase within 11382 ** the current row. This is the same information as is accessible via the 11383 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 11384 ** to use, this API may be faster under some circumstances. To iterate 11385 ** through instances of phrase iPhrase, use the following code: 11386 ** 11387 ** Fts5PhraseIter iter; 11388 ** int iCol, iOff; 11389 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 11390 ** iCol>=0; 11391 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 11392 ** ){ 11393 ** // An instance of phrase iPhrase at offset iOff of column iCol 11394 ** } 11395 ** 11396 ** The Fts5PhraseIter structure is defined above. Applications should not 11397 ** modify this structure directly - it should only be used as shown above 11398 ** with the xPhraseFirst() and xPhraseNext() API methods (and by 11399 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 11400 ** 11401 ** This API can be quite slow if used with an FTS5 table created with the 11402 ** "detail=none" or "detail=column" option. If the FTS5 table is created 11403 ** with either "detail=none" or "detail=column" and "content=" option 11404 ** (i.e. if it is a contentless table), then this API always iterates 11405 ** through an empty set (all calls to xPhraseFirst() set iCol to -1). 11406 ** 11407 ** xPhraseNext() 11408 ** See xPhraseFirst above. 11409 ** 11410 ** xPhraseFirstColumn() 11411 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 11412 ** and xPhraseNext() APIs described above. The difference is that instead 11413 ** of iterating through all instances of a phrase in the current row, these 11414 ** APIs are used to iterate through the set of columns in the current row 11415 ** that contain one or more instances of a specified phrase. For example: 11416 ** 11417 ** Fts5PhraseIter iter; 11418 ** int iCol; 11419 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 11420 ** iCol>=0; 11421 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 11422 ** ){ 11423 ** // Column iCol contains at least one instance of phrase iPhrase 11424 ** } 11425 ** 11426 ** This API can be quite slow if used with an FTS5 table created with the 11427 ** "detail=none" option. If the FTS5 table is created with either 11428 ** "detail=none" "content=" option (i.e. if it is a contentless table), 11429 ** then this API always iterates through an empty set (all calls to 11430 ** xPhraseFirstColumn() set iCol to -1). 11431 ** 11432 ** The information accessed using this API and its companion 11433 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 11434 ** (or xInst/xInstCount). The chief advantage of this API is that it is 11435 ** significantly more efficient than those alternatives when used with 11436 ** "detail=column" tables. 11437 ** 11438 ** xPhraseNextColumn() 11439 ** See xPhraseFirstColumn above. 11440 */ 11441 struct Fts5ExtensionApi { 11442 int iVersion; /* Currently always set to 3 */ 11443 11444 void *(*xUserData)(Fts5Context*); 11445 11446 int (*xColumnCount)(Fts5Context*); 11447 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 11448 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 11449 11450 int (*xTokenize)(Fts5Context*, 11451 const char *pText, int nText, /* Text to tokenize */ 11452 void *pCtx, /* Context passed to xToken() */ 11453 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 11454 ); 11455 11456 int (*xPhraseCount)(Fts5Context*); 11457 int (*xPhraseSize)(Fts5Context*, int iPhrase); 11458 11459 int (*xInstCount)(Fts5Context*, int *pnInst); 11460 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 11461 11462 sqlite3_int64 (*xRowid)(Fts5Context*); 11463 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 11464 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 11465 11466 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 11467 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 11468 ); 11469 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 11470 void *(*xGetAuxdata)(Fts5Context*, int bClear); 11471 11472 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 11473 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 11474 11475 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 11476 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 11477 }; 11478 11479 /* 11480 ** CUSTOM AUXILIARY FUNCTIONS 11481 *************************************************************************/ 11482 11483 /************************************************************************* 11484 ** CUSTOM TOKENIZERS 11485 ** 11486 ** Applications may also register custom tokenizer types. A tokenizer 11487 ** is registered by providing fts5 with a populated instance of the 11488 ** following structure. All structure methods must be defined, setting 11489 ** any member of the fts5_tokenizer struct to NULL leads to undefined 11490 ** behaviour. The structure methods are expected to function as follows: 11491 ** 11492 ** xCreate: 11493 ** This function is used to allocate and initialize a tokenizer instance. 11494 ** A tokenizer instance is required to actually tokenize text. 11495 ** 11496 ** The first argument passed to this function is a copy of the (void*) 11497 ** pointer provided by the application when the fts5_tokenizer object 11498 ** was registered with FTS5 (the third argument to xCreateTokenizer()). 11499 ** The second and third arguments are an array of nul-terminated strings 11500 ** containing the tokenizer arguments, if any, specified following the 11501 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 11502 ** to create the FTS5 table. 11503 ** 11504 ** The final argument is an output variable. If successful, (*ppOut) 11505 ** should be set to point to the new tokenizer handle and SQLITE_OK 11506 ** returned. If an error occurs, some value other than SQLITE_OK should 11507 ** be returned. In this case, fts5 assumes that the final value of *ppOut 11508 ** is undefined. 11509 ** 11510 ** xDelete: 11511 ** This function is invoked to delete a tokenizer handle previously 11512 ** allocated using xCreate(). Fts5 guarantees that this function will 11513 ** be invoked exactly once for each successful call to xCreate(). 11514 ** 11515 ** xTokenize: 11516 ** This function is expected to tokenize the nText byte string indicated 11517 ** by argument pText. pText may or may not be nul-terminated. The first 11518 ** argument passed to this function is a pointer to an Fts5Tokenizer object 11519 ** returned by an earlier call to xCreate(). 11520 ** 11521 ** The second argument indicates the reason that FTS5 is requesting 11522 ** tokenization of the supplied text. This is always one of the following 11523 ** four values: 11524 ** 11525 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 11526 ** or removed from the FTS table. The tokenizer is being invoked to 11527 ** determine the set of tokens to add to (or delete from) the 11528 ** FTS index. 11529 ** 11530 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 11531 ** against the FTS index. The tokenizer is being called to tokenize 11532 ** a bareword or quoted string specified as part of the query. 11533 ** 11534 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 11535 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 11536 ** followed by a "*" character, indicating that the last token 11537 ** returned by the tokenizer will be treated as a token prefix. 11538 ** 11539 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 11540 ** satisfy an fts5_api.xTokenize() request made by an auxiliary 11541 ** function. Or an fts5_api.xColumnSize() request made by the same 11542 ** on a columnsize=0 database. 11543 ** </ul> 11544 ** 11545 ** For each token in the input string, the supplied callback xToken() must 11546 ** be invoked. The first argument to it should be a copy of the pointer 11547 ** passed as the second argument to xTokenize(). The third and fourth 11548 ** arguments are a pointer to a buffer containing the token text, and the 11549 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets 11550 ** of the first byte of and first byte immediately following the text from 11551 ** which the token is derived within the input. 11552 ** 11553 ** The second argument passed to the xToken() callback ("tflags") should 11554 ** normally be set to 0. The exception is if the tokenizer supports 11555 ** synonyms. In this case see the discussion below for details. 11556 ** 11557 ** FTS5 assumes the xToken() callback is invoked for each token in the 11558 ** order that they occur within the input text. 11559 ** 11560 ** If an xToken() callback returns any value other than SQLITE_OK, then 11561 ** the tokenization should be abandoned and the xTokenize() method should 11562 ** immediately return a copy of the xToken() return value. Or, if the 11563 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 11564 ** if an error occurs with the xTokenize() implementation itself, it 11565 ** may abandon the tokenization and return any error code other than 11566 ** SQLITE_OK or SQLITE_DONE. 11567 ** 11568 ** SYNONYM SUPPORT 11569 ** 11570 ** Custom tokenizers may also support synonyms. Consider a case in which a 11571 ** user wishes to query for a phrase such as "first place". Using the 11572 ** built-in tokenizers, the FTS5 query 'first + place' will match instances 11573 ** of "first place" within the document set, but not alternative forms 11574 ** such as "1st place". In some applications, it would be better to match 11575 ** all instances of "first place" or "1st place" regardless of which form 11576 ** the user specified in the MATCH query text. 11577 ** 11578 ** There are several ways to approach this in FTS5: 11579 ** 11580 ** <ol><li> By mapping all synonyms to a single token. In this case, the 11581 ** In the above example, this means that the tokenizer returns the 11582 ** same token for inputs "first" and "1st". Say that token is in 11583 ** fact "first", so that when the user inserts the document "I won 11584 ** 1st place" entries are added to the index for tokens "i", "won", 11585 ** "first" and "place". If the user then queries for '1st + place', 11586 ** the tokenizer substitutes "first" for "1st" and the query works 11587 ** as expected. 11588 ** 11589 ** <li> By querying the index for all synonyms of each query term 11590 ** separately. In this case, when tokenizing query text, the 11591 ** tokenizer may provide multiple synonyms for a single term 11592 ** within the document. FTS5 then queries the index for each 11593 ** synonym individually. For example, faced with the query: 11594 ** 11595 ** <codeblock> 11596 ** ... MATCH 'first place'</codeblock> 11597 ** 11598 ** the tokenizer offers both "1st" and "first" as synonyms for the 11599 ** first token in the MATCH query and FTS5 effectively runs a query 11600 ** similar to: 11601 ** 11602 ** <codeblock> 11603 ** ... MATCH '(first OR 1st) place'</codeblock> 11604 ** 11605 ** except that, for the purposes of auxiliary functions, the query 11606 ** still appears to contain just two phrases - "(first OR 1st)" 11607 ** being treated as a single phrase. 11608 ** 11609 ** <li> By adding multiple synonyms for a single term to the FTS index. 11610 ** Using this method, when tokenizing document text, the tokenizer 11611 ** provides multiple synonyms for each token. So that when a 11612 ** document such as "I won first place" is tokenized, entries are 11613 ** added to the FTS index for "i", "won", "first", "1st" and 11614 ** "place". 11615 ** 11616 ** This way, even if the tokenizer does not provide synonyms 11617 ** when tokenizing query text (it should not - to do so would be 11618 ** inefficient), it doesn't matter if the user queries for 11619 ** 'first + place' or '1st + place', as there are entries in the 11620 ** FTS index corresponding to both forms of the first token. 11621 ** </ol> 11622 ** 11623 ** Whether it is parsing document or query text, any call to xToken that 11624 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 11625 ** is considered to supply a synonym for the previous token. For example, 11626 ** when parsing the document "I won first place", a tokenizer that supports 11627 ** synonyms would call xToken() 5 times, as follows: 11628 ** 11629 ** <codeblock> 11630 ** xToken(pCtx, 0, "i", 1, 0, 1); 11631 ** xToken(pCtx, 0, "won", 3, 2, 5); 11632 ** xToken(pCtx, 0, "first", 5, 6, 11); 11633 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 11634 ** xToken(pCtx, 0, "place", 5, 12, 17); 11635 **</codeblock> 11636 ** 11637 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 11638 ** xToken() is called. Multiple synonyms may be specified for a single token 11639 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 11640 ** There is no limit to the number of synonyms that may be provided for a 11641 ** single token. 11642 ** 11643 ** In many cases, method (1) above is the best approach. It does not add 11644 ** extra data to the FTS index or require FTS5 to query for multiple terms, 11645 ** so it is efficient in terms of disk space and query speed. However, it 11646 ** does not support prefix queries very well. If, as suggested above, the 11647 ** token "first" is substituted for "1st" by the tokenizer, then the query: 11648 ** 11649 ** <codeblock> 11650 ** ... MATCH '1s*'</codeblock> 11651 ** 11652 ** will not match documents that contain the token "1st" (as the tokenizer 11653 ** will probably not map "1s" to any prefix of "first"). 11654 ** 11655 ** For full prefix support, method (3) may be preferred. In this case, 11656 ** because the index contains entries for both "first" and "1st", prefix 11657 ** queries such as 'fi*' or '1s*' will match correctly. However, because 11658 ** extra entries are added to the FTS index, this method uses more space 11659 ** within the database. 11660 ** 11661 ** Method (2) offers a midpoint between (1) and (3). Using this method, 11662 ** a query such as '1s*' will match documents that contain the literal 11663 ** token "1st", but not "first" (assuming the tokenizer is not able to 11664 ** provide synonyms for prefixes). However, a non-prefix query like '1st' 11665 ** will match against "1st" and "first". This method does not require 11666 ** extra disk space, as no extra entries are added to the FTS index. 11667 ** On the other hand, it may require more CPU cycles to run MATCH queries, 11668 ** as separate queries of the FTS index are required for each synonym. 11669 ** 11670 ** When using methods (2) or (3), it is important that the tokenizer only 11671 ** provide synonyms when tokenizing document text (method (2)) or query 11672 ** text (method (3)), not both. Doing so will not cause any errors, but is 11673 ** inefficient. 11674 */ 11675 typedef struct Fts5Tokenizer Fts5Tokenizer; 11676 typedef struct fts5_tokenizer fts5_tokenizer; 11677 struct fts5_tokenizer { 11678 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 11679 void (*xDelete)(Fts5Tokenizer*); 11680 int (*xTokenize)(Fts5Tokenizer*, 11681 void *pCtx, 11682 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 11683 const char *pText, int nText, 11684 int (*xToken)( 11685 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 11686 int tflags, /* Mask of FTS5_TOKEN_* flags */ 11687 const char *pToken, /* Pointer to buffer containing token */ 11688 int nToken, /* Size of token in bytes */ 11689 int iStart, /* Byte offset of token within input text */ 11690 int iEnd /* Byte offset of end of token within input text */ 11691 ) 11692 ); 11693 }; 11694 11695 /* Flags that may be passed as the third argument to xTokenize() */ 11696 #define FTS5_TOKENIZE_QUERY 0x0001 11697 #define FTS5_TOKENIZE_PREFIX 0x0002 11698 #define FTS5_TOKENIZE_DOCUMENT 0x0004 11699 #define FTS5_TOKENIZE_AUX 0x0008 11700 11701 /* Flags that may be passed by the tokenizer implementation back to FTS5 11702 ** as the third argument to the supplied xToken callback. */ 11703 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 11704 11705 /* 11706 ** END OF CUSTOM TOKENIZERS 11707 *************************************************************************/ 11708 11709 /************************************************************************* 11710 ** FTS5 EXTENSION REGISTRATION API 11711 */ 11712 typedef struct fts5_api fts5_api; 11713 struct fts5_api { 11714 int iVersion; /* Currently always set to 2 */ 11715 11716 /* Create a new tokenizer */ 11717 int (*xCreateTokenizer)( 11718 fts5_api *pApi, 11719 const char *zName, 11720 void *pContext, 11721 fts5_tokenizer *pTokenizer, 11722 void (*xDestroy)(void*) 11723 ); 11724 11725 /* Find an existing tokenizer */ 11726 int (*xFindTokenizer)( 11727 fts5_api *pApi, 11728 const char *zName, 11729 void **ppContext, 11730 fts5_tokenizer *pTokenizer 11731 ); 11732 11733 /* Create a new auxiliary function */ 11734 int (*xCreateFunction)( 11735 fts5_api *pApi, 11736 const char *zName, 11737 void *pContext, 11738 fts5_extension_function xFunction, 11739 void (*xDestroy)(void*) 11740 ); 11741 }; 11742 11743 /* 11744 ** END OF REGISTRATION API 11745 *************************************************************************/ 11746 11747 #ifdef __cplusplus 11748 } /* end of the 'extern "C"' block */ 11749 #endif 11750 11751 #endif /* _FTS5_H */ 11752 11753 /******** End of fts5.h *********/ 11754
