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 ** Facilitate override of interface linkage and calling conventions. 47 ** Be aware that these macros may not be used within this particular 48 ** translation of the amalgamation and its associated header file. 49 ** 50 ** The SQLITE_EXTERN and SQLITE_API macros are used to instruct the 51 ** compiler that the target identifier should have external linkage. 52 ** 53 ** The SQLITE_CDECL macro is used to set the calling convention for 54 ** public functions that accept a variable number of arguments. 55 ** 56 ** The SQLITE_APICALL macro is used to set the calling convention for 57 ** public functions that accept a fixed number of arguments. 58 ** 59 ** The SQLITE_STDCALL macro is no longer used and is now deprecated. 60 ** 61 ** The SQLITE_CALLBACK macro is used to set the calling convention for 62 ** function pointers. 63 ** 64 ** The SQLITE_SYSAPI macro is used to set the calling convention for 65 ** functions provided by the operating system. 66 ** 67 ** Currently, the SQLITE_CDECL, SQLITE_APICALL, SQLITE_CALLBACK, and 68 ** SQLITE_SYSAPI macros are used only when building for environments 69 ** that require non-default calling conventions. 70 */ 71 #ifndef SQLITE_EXTERN 72 # define SQLITE_EXTERN extern 73 #endif 74 #ifndef SQLITE_API 75 # define SQLITE_API 76 #endif 77 #ifndef SQLITE_CDECL 78 # define SQLITE_CDECL 79 #endif 80 #ifndef SQLITE_APICALL 81 # define SQLITE_APICALL 82 #endif 83 #ifndef SQLITE_STDCALL 84 # define SQLITE_STDCALL SQLITE_APICALL 85 #endif 86 #ifndef SQLITE_CALLBACK 87 # define SQLITE_CALLBACK 88 #endif 89 #ifndef SQLITE_SYSAPI 90 # define SQLITE_SYSAPI 91 #endif 92 93 /* 94 ** These no-op macros are used in front of interfaces to mark those 95 ** interfaces as either deprecated or experimental. New applications 96 ** should not use deprecated interfaces - they are supported for backwards 97 ** compatibility only. Application writers should be aware that 98 ** experimental interfaces are subject to change in point releases. 99 ** 100 ** These macros used to resolve to various kinds of compiler magic that 101 ** would generate warning messages when they were used. But that 102 ** compiler magic ended up generating such a flurry of bug reports 103 ** that we have taken it all out and gone back to using simple 104 ** noop macros. 105 */ 106 #define SQLITE_DEPRECATED 107 #define SQLITE_EXPERIMENTAL 108 109 /* 110 ** Ensure these symbols were not defined by some previous header file. 111 */ 112 #ifdef SQLITE_VERSION 113 # undef SQLITE_VERSION 114 #endif 115 #ifdef SQLITE_VERSION_NUMBER 116 # undef SQLITE_VERSION_NUMBER 117 #endif 118 119 /* 120 ** CAPI3REF: Compile-Time Library Version Numbers 121 ** 122 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 123 ** evaluates to a string literal that is the SQLite version in the 124 ** format "X.Y.Z" where X is the major version number (always 3 for 125 ** SQLite3) and Y is the minor version number and Z is the release number.)^ 126 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 127 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 128 ** numbers used in [SQLITE_VERSION].)^ 129 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 130 ** be larger than the release from which it is derived. Either Y will 131 ** be held constant and Z will be incremented or else Y will be incremented 132 ** and Z will be reset to zero. 133 ** 134 ** Since [version 3.6.18] ([dateof:3.6.18]), 135 ** SQLite source code has been stored in the 136 ** <a href="http://www.fossil-scm.org/">Fossil configuration management 137 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 138 ** a string which identifies a particular check-in of SQLite 139 ** within its configuration management system. ^The SQLITE_SOURCE_ID 140 ** string contains the date and time of the check-in (UTC) and a SHA1 141 ** or SHA3-256 hash of the entire source tree. If the source code has 142 ** been edited in any way since it was last checked in, then the last 143 ** four hexadecimal digits of the hash may be modified. 144 ** 145 ** See also: [sqlite3_libversion()], 146 ** [sqlite3_libversion_number()], [sqlite3_sourceid()], 147 ** [sqlite_version()] and [sqlite_source_id()]. 148 */ 149 #define SQLITE_VERSION "3.45.0" 150 #define SQLITE_VERSION_NUMBER 3045000 151 #define SQLITE_SOURCE_ID "2024-01-15 17:01:13 1066602b2b1976fe58b5150777cced894af17c803e068f5918390d6915b46e1d" 152 153 /* 154 ** CAPI3REF: Run-Time Library Version Numbers 155 ** KEYWORDS: sqlite3_version sqlite3_sourceid 156 ** 157 ** These interfaces provide the same information as the [SQLITE_VERSION], 158 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 159 ** but are associated with the library instead of the header file. ^(Cautious 160 ** programmers might include assert() statements in their application to 161 ** verify that values returned by these interfaces match the macros in 162 ** the header, and thus ensure that the application is 163 ** compiled with matching library and header files. 164 ** 165 ** <blockquote><pre> 166 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 167 ** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 ); 168 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 169 ** </pre></blockquote>)^ 170 ** 171 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 172 ** macro. ^The sqlite3_libversion() function returns a pointer to the 173 ** to the sqlite3_version[] string constant. The sqlite3_libversion() 174 ** function is provided for use in DLLs since DLL users usually do not have 175 ** direct access to string constants within the DLL. ^The 176 ** sqlite3_libversion_number() function returns an integer equal to 177 ** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns 178 ** a pointer to a string constant whose value is the same as the 179 ** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built 180 ** using an edited copy of [the amalgamation], then the last four characters 181 ** of the hash might be different from [SQLITE_SOURCE_ID].)^ 182 ** 183 ** See also: [sqlite_version()] and [sqlite_source_id()]. 184 */ 185 SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 186 SQLITE_API const char *sqlite3_libversion(void); 187 SQLITE_API const char *sqlite3_sourceid(void); 188 SQLITE_API int sqlite3_libversion_number(void); 189 190 /* 191 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics 192 ** 193 ** ^The sqlite3_compileoption_used() function returns 0 or 1 194 ** indicating whether the specified option was defined at 195 ** compile time. ^The SQLITE_ prefix may be omitted from the 196 ** option name passed to sqlite3_compileoption_used(). 197 ** 198 ** ^The sqlite3_compileoption_get() function allows iterating 199 ** over the list of options that were defined at compile time by 200 ** returning the N-th compile time option string. ^If N is out of range, 201 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 202 ** prefix is omitted from any strings returned by 203 ** sqlite3_compileoption_get(). 204 ** 205 ** ^Support for the diagnostic functions sqlite3_compileoption_used() 206 ** and sqlite3_compileoption_get() may be omitted by specifying the 207 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 208 ** 209 ** See also: SQL functions [sqlite_compileoption_used()] and 210 ** [sqlite_compileoption_get()] and the [compile_options pragma]. 211 */ 212 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 213 SQLITE_API int sqlite3_compileoption_used(const char *zOptName); 214 SQLITE_API const char *sqlite3_compileoption_get(int N); 215 #else 216 # define sqlite3_compileoption_used(X) 0 217 # define sqlite3_compileoption_get(X) ((void*)0) 218 #endif 219 220 /* 221 ** CAPI3REF: Test To See If The Library Is Threadsafe 222 ** 223 ** ^The sqlite3_threadsafe() function returns zero if and only if 224 ** SQLite was compiled with mutexing code omitted due to the 225 ** [SQLITE_THREADSAFE] compile-time option being set to 0. 226 ** 227 ** SQLite can be compiled with or without mutexes. When 228 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 229 ** are enabled and SQLite is threadsafe. When the 230 ** [SQLITE_THREADSAFE] macro is 0, 231 ** the mutexes are omitted. Without the mutexes, it is not safe 232 ** to use SQLite concurrently from more than one thread. 233 ** 234 ** Enabling mutexes incurs a measurable performance penalty. 235 ** So if speed is of utmost importance, it makes sense to disable 236 ** the mutexes. But for maximum safety, mutexes should be enabled. 237 ** ^The default behavior is for mutexes to be enabled. 238 ** 239 ** This interface can be used by an application to make sure that the 240 ** version of SQLite that it is linking against was compiled with 241 ** the desired setting of the [SQLITE_THREADSAFE] macro. 242 ** 243 ** This interface only reports on the compile-time mutex setting 244 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 245 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 246 ** can be fully or partially disabled using a call to [sqlite3_config()] 247 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 248 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 249 ** sqlite3_threadsafe() function shows only the compile-time setting of 250 ** thread safety, not any run-time changes to that setting made by 251 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 252 ** is unchanged by calls to sqlite3_config().)^ 253 ** 254 ** See the [threading mode] documentation for additional information. 255 */ 256 SQLITE_API int sqlite3_threadsafe(void); 257 258 /* 259 ** CAPI3REF: Database Connection Handle 260 ** KEYWORDS: {database connection} {database connections} 261 ** 262 ** Each open SQLite database is represented by a pointer to an instance of 263 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 264 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 265 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 266 ** and [sqlite3_close_v2()] are its destructors. There are many other 267 ** interfaces (such as 268 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 269 ** [sqlite3_busy_timeout()] to name but three) that are methods on an 270 ** sqlite3 object. 271 */ 272 typedef struct sqlite3 sqlite3; 273 274 /* 275 ** CAPI3REF: 64-Bit Integer Types 276 ** KEYWORDS: sqlite_int64 sqlite_uint64 277 ** 278 ** Because there is no cross-platform way to specify 64-bit integer types 279 ** SQLite includes typedefs for 64-bit signed and unsigned integers. 280 ** 281 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 282 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards 283 ** compatibility only. 284 ** 285 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values 286 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 287 ** sqlite3_uint64 and sqlite_uint64 types can store integer values 288 ** between 0 and +18446744073709551615 inclusive. 289 */ 290 #ifdef SQLITE_INT64_TYPE 291 typedef SQLITE_INT64_TYPE sqlite_int64; 292 # ifdef SQLITE_UINT64_TYPE 293 typedef SQLITE_UINT64_TYPE sqlite_uint64; 294 # else 295 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 296 # endif 297 #elif defined(_MSC_VER) || defined(__BORLANDC__) 298 typedef __int64 sqlite_int64; 299 typedef unsigned __int64 sqlite_uint64; 300 #else 301 typedef long long int sqlite_int64; 302 typedef unsigned long long int sqlite_uint64; 303 #endif 304 typedef sqlite_int64 sqlite3_int64; 305 typedef sqlite_uint64 sqlite3_uint64; 306 307 /* 308 ** If compiling for a processor that lacks floating point support, 309 ** substitute integer for floating-point. 310 */ 311 #ifdef SQLITE_OMIT_FLOATING_POINT 312 # define double sqlite3_int64 313 #endif 314 315 /* 316 ** CAPI3REF: Closing A Database Connection 317 ** DESTRUCTOR: sqlite3 318 ** 319 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 320 ** for the [sqlite3] object. 321 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 322 ** the [sqlite3] object is successfully destroyed and all associated 323 ** resources are deallocated. 324 ** 325 ** Ideally, applications should [sqlite3_finalize | finalize] all 326 ** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and 327 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 328 ** with the [sqlite3] object prior to attempting to close the object. 329 ** ^If the database connection is associated with unfinalized prepared 330 ** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then 331 ** sqlite3_close() will leave the database connection open and return 332 ** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared 333 ** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups, 334 ** it returns [SQLITE_OK] regardless, but instead of deallocating the database 335 ** connection immediately, it marks the database connection as an unusable 336 ** "zombie" and makes arrangements to automatically deallocate the database 337 ** connection after all prepared statements are finalized, all BLOB handles 338 ** are closed, and all backups have finished. The sqlite3_close_v2() interface 339 ** is intended for use with host languages that are garbage collected, and 340 ** where the order in which destructors are called is arbitrary. 341 ** 342 ** ^If an [sqlite3] object is destroyed while a transaction is open, 343 ** the transaction is automatically rolled back. 344 ** 345 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 346 ** must be either a NULL 347 ** pointer or an [sqlite3] object pointer obtained 348 ** from [sqlite3_open()], [sqlite3_open16()], or 349 ** [sqlite3_open_v2()], and not previously closed. 350 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 351 ** argument is a harmless no-op. 352 */ 353 SQLITE_API int sqlite3_close(sqlite3*); 354 SQLITE_API int sqlite3_close_v2(sqlite3*); 355 356 /* 357 ** The type for a callback function. 358 ** This is legacy and deprecated. It is included for historical 359 ** compatibility and is not documented. 360 */ 361 typedef int (*sqlite3_callback)(void*,int,char**, char**); 362 363 /* 364 ** CAPI3REF: One-Step Query Execution Interface 365 ** METHOD: sqlite3 366 ** 367 ** The sqlite3_exec() interface is a convenience wrapper around 368 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 369 ** that allows an application to run multiple statements of SQL 370 ** without having to use a lot of C code. 371 ** 372 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 373 ** semicolon-separate SQL statements passed into its 2nd argument, 374 ** in the context of the [database connection] passed in as its 1st 375 ** argument. ^If the callback function of the 3rd argument to 376 ** sqlite3_exec() is not NULL, then it is invoked for each result row 377 ** coming out of the evaluated SQL statements. ^The 4th argument to 378 ** sqlite3_exec() is relayed through to the 1st argument of each 379 ** callback invocation. ^If the callback pointer to sqlite3_exec() 380 ** is NULL, then no callback is ever invoked and result rows are 381 ** ignored. 382 ** 383 ** ^If an error occurs while evaluating the SQL statements passed into 384 ** sqlite3_exec(), then execution of the current statement stops and 385 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 386 ** is not NULL then any error message is written into memory obtained 387 ** from [sqlite3_malloc()] and passed back through the 5th parameter. 388 ** To avoid memory leaks, the application should invoke [sqlite3_free()] 389 ** on error message strings returned through the 5th parameter of 390 ** sqlite3_exec() after the error message string is no longer needed. 391 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 392 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 393 ** NULL before returning. 394 ** 395 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 396 ** routine returns SQLITE_ABORT without invoking the callback again and 397 ** without running any subsequent SQL statements. 398 ** 399 ** ^The 2nd argument to the sqlite3_exec() callback function is the 400 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 401 ** callback is an array of pointers to strings obtained as if from 402 ** [sqlite3_column_text()], one for each column. ^If an element of a 403 ** result row is NULL then the corresponding string pointer for the 404 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 405 ** sqlite3_exec() callback is an array of pointers to strings where each 406 ** entry represents the name of corresponding result column as obtained 407 ** from [sqlite3_column_name()]. 408 ** 409 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 410 ** to an empty string, or a pointer that contains only whitespace and/or 411 ** SQL comments, then no SQL statements are evaluated and the database 412 ** is not changed. 413 ** 414 ** Restrictions: 415 ** 416 ** <ul> 417 ** <li> The application must ensure that the 1st parameter to sqlite3_exec() 418 ** is a valid and open [database connection]. 419 ** <li> The application must not close the [database connection] specified by 420 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 421 ** <li> The application must not modify the SQL statement text passed into 422 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 423 ** </ul> 424 */ 425 SQLITE_API int sqlite3_exec( 426 sqlite3*, /* An open database */ 427 const char *sql, /* SQL to be evaluated */ 428 int (*callback)(void*,int,char**,char**), /* Callback function */ 429 void *, /* 1st argument to callback */ 430 char **errmsg /* Error msg written here */ 431 ); 432 433 /* 434 ** CAPI3REF: Result Codes 435 ** KEYWORDS: {result code definitions} 436 ** 437 ** Many SQLite functions return an integer result code from the set shown 438 ** here in order to indicate success or failure. 439 ** 440 ** New error codes may be added in future versions of SQLite. 441 ** 442 ** See also: [extended result code definitions] 443 */ 444 #define SQLITE_OK 0 /* Successful result */ 445 /* beginning-of-error-codes */ 446 #define SQLITE_ERROR 1 /* Generic error */ 447 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 448 #define SQLITE_PERM 3 /* Access permission denied */ 449 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ 450 #define SQLITE_BUSY 5 /* The database file is locked */ 451 #define SQLITE_LOCKED 6 /* A table in the database is locked */ 452 #define SQLITE_NOMEM 7 /* A malloc() failed */ 453 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 454 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 455 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 456 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 457 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 458 #define SQLITE_FULL 13 /* Insertion failed because database is full */ 459 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 460 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 461 #define SQLITE_EMPTY 16 /* Internal use only */ 462 #define SQLITE_SCHEMA 17 /* The database schema changed */ 463 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 464 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 465 #define SQLITE_MISMATCH 20 /* Data type mismatch */ 466 #define SQLITE_MISUSE 21 /* Library used incorrectly */ 467 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 468 #define SQLITE_AUTH 23 /* Authorization denied */ 469 #define SQLITE_FORMAT 24 /* Not used */ 470 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 471 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ 472 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 473 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 474 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 475 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 476 /* end-of-error-codes */ 477 478 /* 479 ** CAPI3REF: Extended Result Codes 480 ** KEYWORDS: {extended result code definitions} 481 ** 482 ** In its default configuration, SQLite API routines return one of 30 integer 483 ** [result codes]. However, experience has shown that many of 484 ** these result codes are too coarse-grained. They do not provide as 485 ** much information about problems as programmers might like. In an effort to 486 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 487 ** and later) include 488 ** support for additional result codes that provide more detailed information 489 ** about errors. These [extended result codes] are enabled or disabled 490 ** on a per database connection basis using the 491 ** [sqlite3_extended_result_codes()] API. Or, the extended code for 492 ** the most recent error can be obtained using 493 ** [sqlite3_extended_errcode()]. 494 */ 495 #define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 496 #define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 497 #define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8)) 498 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 499 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 500 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 501 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 502 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 503 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 504 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 505 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 506 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 507 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 508 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 509 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 510 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 511 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 512 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 513 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 514 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 515 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 516 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 517 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 518 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 519 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 520 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 521 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 522 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 523 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 524 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 525 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 526 #define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 527 #define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 528 #define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 529 #define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8)) 530 #define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8)) 531 #define SQLITE_IOERR_IN_PAGE (SQLITE_IOERR | (34<<8)) 532 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 533 #define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 534 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 535 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 536 #define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8)) 537 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 538 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 539 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 540 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 541 #define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 542 #define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8)) 543 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 544 #define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 545 #define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8)) 546 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 547 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 548 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 549 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 550 #define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 551 #define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 552 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 553 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 554 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 555 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 556 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 557 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 558 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 559 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 560 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 561 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 562 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 563 #define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8)) 564 #define SQLITE_CONSTRAINT_DATATYPE (SQLITE_CONSTRAINT |(12<<8)) 565 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 566 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 567 #define SQLITE_NOTICE_RBU (SQLITE_NOTICE | (3<<8)) 568 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 569 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 570 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 571 #define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) /* internal use only */ 572 573 /* 574 ** CAPI3REF: Flags For File Open Operations 575 ** 576 ** These bit values are intended for use in the 577 ** 3rd parameter to the [sqlite3_open_v2()] interface and 578 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 579 ** 580 ** Only those flags marked as "Ok for sqlite3_open_v2()" may be 581 ** used as the third argument to the [sqlite3_open_v2()] interface. 582 ** The other flags have historically been ignored by sqlite3_open_v2(), 583 ** though future versions of SQLite might change so that an error is 584 ** raised if any of the disallowed bits are passed into sqlite3_open_v2(). 585 ** Applications should not depend on the historical behavior. 586 ** 587 ** Note in particular that passing the SQLITE_OPEN_EXCLUSIVE flag into 588 ** [sqlite3_open_v2()] does *not* cause the underlying database file 589 ** to be opened using O_EXCL. Passing SQLITE_OPEN_EXCLUSIVE into 590 ** [sqlite3_open_v2()] has historically be a no-op and might become an 591 ** error in future versions of SQLite. 592 */ 593 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 594 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 595 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 596 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 597 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 598 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 599 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 600 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 601 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 602 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 603 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 604 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 605 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 606 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 607 #define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */ 608 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 609 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 610 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 611 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 612 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 613 #define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */ 614 #define SQLITE_OPEN_EXRESCODE 0x02000000 /* Extended result codes */ 615 616 /* Reserved: 0x00F00000 */ 617 /* Legacy compatibility: */ 618 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 619 620 621 /* 622 ** CAPI3REF: Device Characteristics 623 ** 624 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 625 ** object returns an integer which is a vector of these 626 ** bit values expressing I/O characteristics of the mass storage 627 ** device that holds the file that the [sqlite3_io_methods] 628 ** refers to. 629 ** 630 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 631 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 632 ** mean that writes of blocks that are nnn bytes in size and 633 ** are aligned to an address which is an integer multiple of 634 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 635 ** that when data is appended to a file, the data is appended 636 ** first then the size of the file is extended, never the other 637 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 638 ** information is written to disk in the same order as calls 639 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 640 ** after reboot following a crash or power loss, the only bytes in a 641 ** file that were written at the application level might have changed 642 ** and that adjacent bytes, even bytes within the same sector are 643 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 644 ** flag indicates that a file cannot be deleted when open. The 645 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 646 ** read-only media and cannot be changed even by processes with 647 ** elevated privileges. 648 ** 649 ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 650 ** filesystem supports doing multiple write operations atomically when those 651 ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 652 ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 653 */ 654 #define SQLITE_IOCAP_ATOMIC 0x00000001 655 #define SQLITE_IOCAP_ATOMIC512 0x00000002 656 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 657 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 658 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 659 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 660 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 661 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 662 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 663 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 664 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 665 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 666 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 667 #define SQLITE_IOCAP_IMMUTABLE 0x00002000 668 #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 669 670 /* 671 ** CAPI3REF: File Locking Levels 672 ** 673 ** SQLite uses one of these integer values as the second 674 ** argument to calls it makes to the xLock() and xUnlock() methods 675 ** of an [sqlite3_io_methods] object. These values are ordered from 676 ** lest restrictive to most restrictive. 677 ** 678 ** The argument to xLock() is always SHARED or higher. The argument to 679 ** xUnlock is either SHARED or NONE. 680 */ 681 #define SQLITE_LOCK_NONE 0 /* xUnlock() only */ 682 #define SQLITE_LOCK_SHARED 1 /* xLock() or xUnlock() */ 683 #define SQLITE_LOCK_RESERVED 2 /* xLock() only */ 684 #define SQLITE_LOCK_PENDING 3 /* xLock() only */ 685 #define SQLITE_LOCK_EXCLUSIVE 4 /* xLock() only */ 686 687 /* 688 ** CAPI3REF: Synchronization Type Flags 689 ** 690 ** When SQLite invokes the xSync() method of an 691 ** [sqlite3_io_methods] object it uses a combination of 692 ** these integer values as the second argument. 693 ** 694 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 695 ** sync operation only needs to flush data to mass storage. Inode 696 ** information need not be flushed. If the lower four bits of the flag 697 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 698 ** If the lower four bits equal SQLITE_SYNC_FULL, that means 699 ** to use Mac OS X style fullsync instead of fsync(). 700 ** 701 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 702 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 703 ** settings. The [synchronous pragma] determines when calls to the 704 ** xSync VFS method occur and applies uniformly across all platforms. 705 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 706 ** energetic or rigorous or forceful the sync operations are and 707 ** only make a difference on Mac OSX for the default SQLite code. 708 ** (Third-party VFS implementations might also make the distinction 709 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 710 ** operating systems natively supported by SQLite, only Mac OSX 711 ** cares about the difference.) 712 */ 713 #define SQLITE_SYNC_NORMAL 0x00002 714 #define SQLITE_SYNC_FULL 0x00003 715 #define SQLITE_SYNC_DATAONLY 0x00010 716 717 /* 718 ** CAPI3REF: OS Interface Open File Handle 719 ** 720 ** An [sqlite3_file] object represents an open file in the 721 ** [sqlite3_vfs | OS interface layer]. Individual OS interface 722 ** implementations will 723 ** want to subclass this object by appending additional fields 724 ** for their own use. The pMethods entry is a pointer to an 725 ** [sqlite3_io_methods] object that defines methods for performing 726 ** I/O operations on the open file. 727 */ 728 typedef struct sqlite3_file sqlite3_file; 729 struct sqlite3_file { 730 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 731 }; 732 733 /* 734 ** CAPI3REF: OS Interface File Virtual Methods Object 735 ** 736 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 737 ** [sqlite3_file] object (or, more commonly, a subclass of the 738 ** [sqlite3_file] object) with a pointer to an instance of this object. 739 ** This object defines the methods used to perform various operations 740 ** against the open file represented by the [sqlite3_file] object. 741 ** 742 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 743 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 744 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 745 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 746 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 747 ** to NULL. 748 ** 749 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 750 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 751 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 752 ** flag may be ORed in to indicate that only the data of the file 753 ** and not its inode needs to be synced. 754 ** 755 ** The integer values to xLock() and xUnlock() are one of 756 ** <ul> 757 ** <li> [SQLITE_LOCK_NONE], 758 ** <li> [SQLITE_LOCK_SHARED], 759 ** <li> [SQLITE_LOCK_RESERVED], 760 ** <li> [SQLITE_LOCK_PENDING], or 761 ** <li> [SQLITE_LOCK_EXCLUSIVE]. 762 ** </ul> 763 ** xLock() upgrades the database file lock. In other words, xLock() moves the 764 ** database file lock in the direction NONE toward EXCLUSIVE. The argument to 765 ** xLock() is always on of SHARED, RESERVED, PENDING, or EXCLUSIVE, never 766 ** SQLITE_LOCK_NONE. If the database file lock is already at or above the 767 ** requested lock, then the call to xLock() is a no-op. 768 ** xUnlock() downgrades the database file lock to either SHARED or NONE. 769 * If the lock is already at or below the requested lock state, then the call 770 ** to xUnlock() is a no-op. 771 ** The xCheckReservedLock() method checks whether any database connection, 772 ** either in this process or in some other process, is holding a RESERVED, 773 ** PENDING, or EXCLUSIVE lock on the file. It returns true 774 ** if such a lock exists and false otherwise. 775 ** 776 ** The xFileControl() method is a generic interface that allows custom 777 ** VFS implementations to directly control an open file using the 778 ** [sqlite3_file_control()] interface. The second "op" argument is an 779 ** integer opcode. The third argument is a generic pointer intended to 780 ** point to a structure that may contain arguments or space in which to 781 ** write return values. Potential uses for xFileControl() might be 782 ** functions to enable blocking locks with timeouts, to change the 783 ** locking strategy (for example to use dot-file locks), to inquire 784 ** about the status of a lock, or to break stale locks. The SQLite 785 ** core reserves all opcodes less than 100 for its own use. 786 ** A [file control opcodes | list of opcodes] less than 100 is available. 787 ** Applications that define a custom xFileControl method should use opcodes 788 ** greater than 100 to avoid conflicts. VFS implementations should 789 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 790 ** recognize. 791 ** 792 ** The xSectorSize() method returns the sector size of the 793 ** device that underlies the file. The sector size is the 794 ** minimum write that can be performed without disturbing 795 ** other bytes in the file. The xDeviceCharacteristics() 796 ** method returns a bit vector describing behaviors of the 797 ** underlying device: 798 ** 799 ** <ul> 800 ** <li> [SQLITE_IOCAP_ATOMIC] 801 ** <li> [SQLITE_IOCAP_ATOMIC512] 802 ** <li> [SQLITE_IOCAP_ATOMIC1K] 803 ** <li> [SQLITE_IOCAP_ATOMIC2K] 804 ** <li> [SQLITE_IOCAP_ATOMIC4K] 805 ** <li> [SQLITE_IOCAP_ATOMIC8K] 806 ** <li> [SQLITE_IOCAP_ATOMIC16K] 807 ** <li> [SQLITE_IOCAP_ATOMIC32K] 808 ** <li> [SQLITE_IOCAP_ATOMIC64K] 809 ** <li> [SQLITE_IOCAP_SAFE_APPEND] 810 ** <li> [SQLITE_IOCAP_SEQUENTIAL] 811 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 812 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 813 ** <li> [SQLITE_IOCAP_IMMUTABLE] 814 ** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 815 ** </ul> 816 ** 817 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 818 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 819 ** mean that writes of blocks that are nnn bytes in size and 820 ** are aligned to an address which is an integer multiple of 821 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 822 ** that when data is appended to a file, the data is appended 823 ** first then the size of the file is extended, never the other 824 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 825 ** information is written to disk in the same order as calls 826 ** to xWrite(). 827 ** 828 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 829 ** in the unread portions of the buffer with zeros. A VFS that 830 ** fails to zero-fill short reads might seem to work. However, 831 ** failure to zero-fill short reads will eventually lead to 832 ** database corruption. 833 */ 834 typedef struct sqlite3_io_methods sqlite3_io_methods; 835 struct sqlite3_io_methods { 836 int iVersion; 837 int (*xClose)(sqlite3_file*); 838 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 839 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 840 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 841 int (*xSync)(sqlite3_file*, int flags); 842 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 843 int (*xLock)(sqlite3_file*, int); 844 int (*xUnlock)(sqlite3_file*, int); 845 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 846 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 847 int (*xSectorSize)(sqlite3_file*); 848 int (*xDeviceCharacteristics)(sqlite3_file*); 849 /* Methods above are valid for version 1 */ 850 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 851 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 852 void (*xShmBarrier)(sqlite3_file*); 853 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 854 /* Methods above are valid for version 2 */ 855 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 856 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 857 /* Methods above are valid for version 3 */ 858 /* Additional methods may be added in future releases */ 859 }; 860 861 /* 862 ** CAPI3REF: Standard File Control Opcodes 863 ** KEYWORDS: {file control opcodes} {file control opcode} 864 ** 865 ** These integer constants are opcodes for the xFileControl method 866 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 867 ** interface. 868 ** 869 ** <ul> 870 ** <li>[[SQLITE_FCNTL_LOCKSTATE]] 871 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 872 ** opcode causes the xFileControl method to write the current state of 873 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 874 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 875 ** into an integer that the pArg argument points to. 876 ** This capability is only available if SQLite is compiled with [SQLITE_DEBUG]. 877 ** 878 ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 879 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 880 ** layer a hint of how large the database file will grow to be during the 881 ** current transaction. This hint is not guaranteed to be accurate but it 882 ** is often close. The underlying VFS might choose to preallocate database 883 ** file space based on this hint in order to help writes to the database 884 ** file run faster. 885 ** 886 ** <li>[[SQLITE_FCNTL_SIZE_LIMIT]] 887 ** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that 888 ** implements [sqlite3_deserialize()] to set an upper bound on the size 889 ** of the in-memory database. The argument is a pointer to a [sqlite3_int64]. 890 ** If the integer pointed to is negative, then it is filled in with the 891 ** current limit. Otherwise the limit is set to the larger of the value 892 ** of the integer pointed to and the current database size. The integer 893 ** pointed to is set to the new limit. 894 ** 895 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 896 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 897 ** extends and truncates the database file in chunks of a size specified 898 ** by the user. The fourth argument to [sqlite3_file_control()] should 899 ** point to an integer (type int) containing the new chunk-size to use 900 ** for the nominated database. Allocating database file space in large 901 ** chunks (say 1MB at a time), may reduce file-system fragmentation and 902 ** improve performance on some systems. 903 ** 904 ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 905 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 906 ** to the [sqlite3_file] object associated with a particular database 907 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 908 ** 909 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 910 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 911 ** to the [sqlite3_file] object associated with the journal file (either 912 ** the [rollback journal] or the [write-ahead log]) for a particular database 913 ** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 914 ** 915 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 916 ** No longer in use. 917 ** 918 ** <li>[[SQLITE_FCNTL_SYNC]] 919 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 920 ** sent to the VFS immediately before the xSync method is invoked on a 921 ** database file descriptor. Or, if the xSync method is not invoked 922 ** because the user has configured SQLite with 923 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 924 ** of the xSync method. In most cases, the pointer argument passed with 925 ** this file-control is NULL. However, if the database file is being synced 926 ** as part of a multi-database commit, the argument points to a nul-terminated 927 ** string containing the transactions super-journal file name. VFSes that 928 ** do not need this signal should silently ignore this opcode. Applications 929 ** should not call [sqlite3_file_control()] with this opcode as doing so may 930 ** disrupt the operation of the specialized VFSes that do require it. 931 ** 932 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 933 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 934 ** and sent to the VFS after a transaction has been committed immediately 935 ** but before the database is unlocked. VFSes that do not need this signal 936 ** should silently ignore this opcode. Applications should not call 937 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 938 ** operation of the specialized VFSes that do require it. 939 ** 940 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 941 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 942 ** retry counts and intervals for certain disk I/O operations for the 943 ** windows [VFS] in order to provide robustness in the presence of 944 ** anti-virus programs. By default, the windows VFS will retry file read, 945 ** file write, and file delete operations up to 10 times, with a delay 946 ** of 25 milliseconds before the first retry and with the delay increasing 947 ** by an additional 25 milliseconds with each subsequent retry. This 948 ** opcode allows these two values (10 retries and 25 milliseconds of delay) 949 ** to be adjusted. The values are changed for all database connections 950 ** within the same process. The argument is a pointer to an array of two 951 ** integers where the first integer is the new retry count and the second 952 ** integer is the delay. If either integer is negative, then the setting 953 ** is not changed but instead the prior value of that setting is written 954 ** into the array entry, allowing the current retry settings to be 955 ** interrogated. The zDbName parameter is ignored. 956 ** 957 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 958 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 959 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 960 ** write ahead log ([WAL file]) and shared memory 961 ** files used for transaction control 962 ** are automatically deleted when the latest connection to the database 963 ** closes. Setting persistent WAL mode causes those files to persist after 964 ** close. Persisting the files is useful when other processes that do not 965 ** have write permission on the directory containing the database file want 966 ** to read the database file, as the WAL and shared memory files must exist 967 ** in order for the database to be readable. The fourth parameter to 968 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 969 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 970 ** WAL mode. If the integer is -1, then it is overwritten with the current 971 ** WAL persistence setting. 972 ** 973 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 974 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 975 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 976 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 977 ** xDeviceCharacteristics methods. The fourth parameter to 978 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 979 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 980 ** mode. If the integer is -1, then it is overwritten with the current 981 ** zero-damage mode setting. 982 ** 983 ** <li>[[SQLITE_FCNTL_OVERWRITE]] 984 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 985 ** a write transaction to indicate that, unless it is rolled back for some 986 ** reason, the entire database file will be overwritten by the current 987 ** transaction. This is used by VACUUM operations. 988 ** 989 ** <li>[[SQLITE_FCNTL_VFSNAME]] 990 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 991 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the 992 ** final bottom-level VFS are written into memory obtained from 993 ** [sqlite3_malloc()] and the result is stored in the char* variable 994 ** that the fourth parameter of [sqlite3_file_control()] points to. 995 ** The caller is responsible for freeing the memory when done. As with 996 ** all file-control actions, there is no guarantee that this will actually 997 ** do anything. Callers should initialize the char* variable to a NULL 998 ** pointer in case this file-control is not implemented. This file-control 999 ** is intended for diagnostic use only. 1000 ** 1001 ** <li>[[SQLITE_FCNTL_VFS_POINTER]] 1002 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 1003 ** [VFSes] currently in use. ^(The argument X in 1004 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 1005 ** of type "[sqlite3_vfs] **". This opcodes will set *X 1006 ** to a pointer to the top-level VFS.)^ 1007 ** ^When there are multiple VFS shims in the stack, this opcode finds the 1008 ** upper-most shim only. 1009 ** 1010 ** <li>[[SQLITE_FCNTL_PRAGMA]] 1011 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 1012 ** file control is sent to the open [sqlite3_file] object corresponding 1013 ** to the database file to which the pragma statement refers. ^The argument 1014 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 1015 ** pointers to strings (char**) in which the second element of the array 1016 ** is the name of the pragma and the third element is the argument to the 1017 ** pragma or NULL if the pragma has no argument. ^The handler for an 1018 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 1019 ** of the char** argument point to a string obtained from [sqlite3_mprintf()] 1020 ** or the equivalent and that string will become the result of the pragma or 1021 ** the error message if the pragma fails. ^If the 1022 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 1023 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 1024 ** file control returns [SQLITE_OK], then the parser assumes that the 1025 ** VFS has handled the PRAGMA itself and the parser generates a no-op 1026 ** prepared statement if result string is NULL, or that returns a copy 1027 ** of the result string if the string is non-NULL. 1028 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 1029 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 1030 ** that the VFS encountered an error while handling the [PRAGMA] and the 1031 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 1032 ** file control occurs at the beginning of pragma statement analysis and so 1033 ** it is able to override built-in [PRAGMA] statements. 1034 ** 1035 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 1036 ** ^The [SQLITE_FCNTL_BUSYHANDLER] 1037 ** file-control may be invoked by SQLite on the database file handle 1038 ** shortly after it is opened in order to provide a custom VFS with access 1039 ** to the connection's busy-handler callback. The argument is of type (void**) 1040 ** - an array of two (void *) values. The first (void *) actually points 1041 ** to a function of type (int (*)(void *)). In order to invoke the connection's 1042 ** busy-handler, this function should be invoked with the second (void *) in 1043 ** the array as the only argument. If it returns non-zero, then the operation 1044 ** should be retried. If it returns zero, the custom VFS should abandon the 1045 ** current operation. 1046 ** 1047 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 1048 ** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 1049 ** to have SQLite generate a 1050 ** temporary filename using the same algorithm that is followed to generate 1051 ** temporary filenames for TEMP tables and other internal uses. The 1052 ** argument should be a char** which will be filled with the filename 1053 ** written into memory obtained from [sqlite3_malloc()]. The caller should 1054 ** invoke [sqlite3_free()] on the result to avoid a memory leak. 1055 ** 1056 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 1057 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 1058 ** maximum number of bytes that will be used for memory-mapped I/O. 1059 ** The argument is a pointer to a value of type sqlite3_int64 that 1060 ** is an advisory maximum number of bytes in the file to memory map. The 1061 ** pointer is overwritten with the old value. The limit is not changed if 1062 ** the value originally pointed to is negative, and so the current limit 1063 ** can be queried by passing in a pointer to a negative number. This 1064 ** file-control is used internally to implement [PRAGMA mmap_size]. 1065 ** 1066 ** <li>[[SQLITE_FCNTL_TRACE]] 1067 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information 1068 ** to the VFS about what the higher layers of the SQLite stack are doing. 1069 ** This file control is used by some VFS activity tracing [shims]. 1070 ** The argument is a zero-terminated string. Higher layers in the 1071 ** SQLite stack may generate instances of this file control if 1072 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1073 ** 1074 ** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1075 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1076 ** pointer to an integer and it writes a boolean into that integer depending 1077 ** on whether or not the file has been renamed, moved, or deleted since it 1078 ** was first opened. 1079 ** 1080 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1081 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1082 ** underlying native file handle associated with a file handle. This file 1083 ** control interprets its argument as a pointer to a native file handle and 1084 ** writes the resulting value there. 1085 ** 1086 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1087 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1088 ** opcode causes the xFileControl method to swap the file handle with the one 1089 ** pointed to by the pArg argument. This capability is used during testing 1090 ** and only needs to be supported when SQLITE_TEST is defined. 1091 ** 1092 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1093 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1094 ** be advantageous to block on the next WAL lock if the lock is not immediately 1095 ** available. The WAL subsystem issues this signal during rare 1096 ** circumstances in order to fix a problem with priority inversion. 1097 ** Applications should <em>not</em> use this file-control. 1098 ** 1099 ** <li>[[SQLITE_FCNTL_ZIPVFS]] 1100 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1101 ** VFS should return SQLITE_NOTFOUND for this opcode. 1102 ** 1103 ** <li>[[SQLITE_FCNTL_RBU]] 1104 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1105 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1106 ** this opcode. 1107 ** 1108 ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1109 ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1110 ** the file descriptor is placed in "batch write mode", which 1111 ** means all subsequent write operations will be deferred and done 1112 ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1113 ** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1114 ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1115 ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1116 ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1117 ** no VFS interface calls on the same [sqlite3_file] file descriptor 1118 ** except for calls to the xWrite method and the xFileControl method 1119 ** with [SQLITE_FCNTL_SIZE_HINT]. 1120 ** 1121 ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1122 ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1123 ** operations since the previous successful call to 1124 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1125 ** This file control returns [SQLITE_OK] if and only if the writes were 1126 ** all performed successfully and have been committed to persistent storage. 1127 ** ^Regardless of whether or not it is successful, this file control takes 1128 ** the file descriptor out of batch write mode so that all subsequent 1129 ** write operations are independent. 1130 ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1131 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1132 ** 1133 ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1134 ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1135 ** operations since the previous successful call to 1136 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1137 ** ^This file control takes the file descriptor out of batch write mode 1138 ** so that all subsequent write operations are independent. 1139 ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1140 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1141 ** 1142 ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1143 ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS 1144 ** to block for up to M milliseconds before failing when attempting to 1145 ** obtain a file lock using the xLock or xShmLock methods of the VFS. 1146 ** The parameter is a pointer to a 32-bit signed integer that contains 1147 ** the value that M is to be set to. Before returning, the 32-bit signed 1148 ** integer is overwritten with the previous value of M. 1149 ** 1150 ** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1151 ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1152 ** a database file. The argument is a pointer to a 32-bit unsigned integer. 1153 ** The "data version" for the pager is written into the pointer. The 1154 ** "data version" changes whenever any change occurs to the corresponding 1155 ** database file, either through SQL statements on the same database 1156 ** connection or through transactions committed by separate database 1157 ** connections possibly in other processes. The [sqlite3_total_changes()] 1158 ** interface can be used to find if any database on the connection has changed, 1159 ** but that interface responds to changes on TEMP as well as MAIN and does 1160 ** not provide a mechanism to detect changes to MAIN only. Also, the 1161 ** [sqlite3_total_changes()] interface responds to internal changes only and 1162 ** omits changes made by other database connections. The 1163 ** [PRAGMA data_version] command provides a mechanism to detect changes to 1164 ** a single attached database that occur due to other database connections, 1165 ** but omits changes implemented by the database connection on which it is 1166 ** called. This file control is the only mechanism to detect changes that 1167 ** happen either internally or externally and that are associated with 1168 ** a particular attached database. 1169 ** 1170 ** <li>[[SQLITE_FCNTL_CKPT_START]] 1171 ** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint 1172 ** in wal mode before the client starts to copy pages from the wal 1173 ** file to the database file. 1174 ** 1175 ** <li>[[SQLITE_FCNTL_CKPT_DONE]] 1176 ** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint 1177 ** in wal mode after the client has finished copying pages from the wal 1178 ** file to the database file, but before the *-shm file is updated to 1179 ** record the fact that the pages have been checkpointed. 1180 ** 1181 ** <li>[[SQLITE_FCNTL_EXTERNAL_READER]] 1182 ** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect 1183 ** whether or not there is a database client in another process with a wal-mode 1184 ** transaction open on the database or not. It is only available on unix.The 1185 ** (void*) argument passed with this file-control should be a pointer to a 1186 ** value of type (int). The integer value is set to 1 if the database is a wal 1187 ** mode database and there exists at least one client in another process that 1188 ** currently has an SQL transaction open on the database. It is set to 0 if 1189 ** the database is not a wal-mode db, or if there is no such connection in any 1190 ** other process. This opcode cannot be used to detect transactions opened 1191 ** by clients within the current process, only within other processes. 1192 ** 1193 ** <li>[[SQLITE_FCNTL_CKSM_FILE]] 1194 ** The [SQLITE_FCNTL_CKSM_FILE] opcode is for use internally by the 1195 ** [checksum VFS shim] only. 1196 ** 1197 ** <li>[[SQLITE_FCNTL_RESET_CACHE]] 1198 ** If there is currently no transaction open on the database, and the 1199 ** database is not a temp db, then the [SQLITE_FCNTL_RESET_CACHE] file-control 1200 ** purges the contents of the in-memory page cache. If there is an open 1201 ** transaction, or if the db is a temp-db, this opcode is a no-op, not an error. 1202 ** </ul> 1203 */ 1204 #define SQLITE_FCNTL_LOCKSTATE 1 1205 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1206 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1207 #define SQLITE_FCNTL_LAST_ERRNO 4 1208 #define SQLITE_FCNTL_SIZE_HINT 5 1209 #define SQLITE_FCNTL_CHUNK_SIZE 6 1210 #define SQLITE_FCNTL_FILE_POINTER 7 1211 #define SQLITE_FCNTL_SYNC_OMITTED 8 1212 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 1213 #define SQLITE_FCNTL_PERSIST_WAL 10 1214 #define SQLITE_FCNTL_OVERWRITE 11 1215 #define SQLITE_FCNTL_VFSNAME 12 1216 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1217 #define SQLITE_FCNTL_PRAGMA 14 1218 #define SQLITE_FCNTL_BUSYHANDLER 15 1219 #define SQLITE_FCNTL_TEMPFILENAME 16 1220 #define SQLITE_FCNTL_MMAP_SIZE 18 1221 #define SQLITE_FCNTL_TRACE 19 1222 #define SQLITE_FCNTL_HAS_MOVED 20 1223 #define SQLITE_FCNTL_SYNC 21 1224 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 1225 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1226 #define SQLITE_FCNTL_WAL_BLOCK 24 1227 #define SQLITE_FCNTL_ZIPVFS 25 1228 #define SQLITE_FCNTL_RBU 26 1229 #define SQLITE_FCNTL_VFS_POINTER 27 1230 #define SQLITE_FCNTL_JOURNAL_POINTER 28 1231 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1232 #define SQLITE_FCNTL_PDB 30 1233 #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1234 #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1235 #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1236 #define SQLITE_FCNTL_LOCK_TIMEOUT 34 1237 #define SQLITE_FCNTL_DATA_VERSION 35 1238 #define SQLITE_FCNTL_SIZE_LIMIT 36 1239 #define SQLITE_FCNTL_CKPT_DONE 37 1240 #define SQLITE_FCNTL_RESERVE_BYTES 38 1241 #define SQLITE_FCNTL_CKPT_START 39 1242 #define SQLITE_FCNTL_EXTERNAL_READER 40 1243 #define SQLITE_FCNTL_CKSM_FILE 41 1244 #define SQLITE_FCNTL_RESET_CACHE 42 1245 1246 /* deprecated names */ 1247 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1248 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1249 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1250 1251 1252 /* 1253 ** CAPI3REF: Mutex Handle 1254 ** 1255 ** The mutex module within SQLite defines [sqlite3_mutex] to be an 1256 ** abstract type for a mutex object. The SQLite core never looks 1257 ** at the internal representation of an [sqlite3_mutex]. It only 1258 ** deals with pointers to the [sqlite3_mutex] object. 1259 ** 1260 ** Mutexes are created using [sqlite3_mutex_alloc()]. 1261 */ 1262 typedef struct sqlite3_mutex sqlite3_mutex; 1263 1264 /* 1265 ** CAPI3REF: Loadable Extension Thunk 1266 ** 1267 ** A pointer to the opaque sqlite3_api_routines structure is passed as 1268 ** the third parameter to entry points of [loadable extensions]. This 1269 ** structure must be typedefed in order to work around compiler warnings 1270 ** on some platforms. 1271 */ 1272 typedef struct sqlite3_api_routines sqlite3_api_routines; 1273 1274 /* 1275 ** CAPI3REF: File Name 1276 ** 1277 ** Type [sqlite3_filename] is used by SQLite to pass filenames to the 1278 ** xOpen method of a [VFS]. It may be cast to (const char*) and treated 1279 ** as a normal, nul-terminated, UTF-8 buffer containing the filename, but 1280 ** may also be passed to special APIs such as: 1281 ** 1282 ** <ul> 1283 ** <li> sqlite3_filename_database() 1284 ** <li> sqlite3_filename_journal() 1285 ** <li> sqlite3_filename_wal() 1286 ** <li> sqlite3_uri_parameter() 1287 ** <li> sqlite3_uri_boolean() 1288 ** <li> sqlite3_uri_int64() 1289 ** <li> sqlite3_uri_key() 1290 ** </ul> 1291 */ 1292 typedef const char *sqlite3_filename; 1293 1294 /* 1295 ** CAPI3REF: OS Interface Object 1296 ** 1297 ** An instance of the sqlite3_vfs object defines the interface between 1298 ** the SQLite core and the underlying operating system. The "vfs" 1299 ** in the name of the object stands for "virtual file system". See 1300 ** the [VFS | VFS documentation] for further information. 1301 ** 1302 ** The VFS interface is sometimes extended by adding new methods onto 1303 ** the end. Each time such an extension occurs, the iVersion field 1304 ** is incremented. The iVersion value started out as 1 in 1305 ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1306 ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1307 ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1308 ** may be appended to the sqlite3_vfs object and the iVersion value 1309 ** may increase again in future versions of SQLite. 1310 ** Note that due to an oversight, the structure 1311 ** of the sqlite3_vfs object changed in the transition from 1312 ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1313 ** and yet the iVersion field was not increased. 1314 ** 1315 ** The szOsFile field is the size of the subclassed [sqlite3_file] 1316 ** structure used by this VFS. mxPathname is the maximum length of 1317 ** a pathname in this VFS. 1318 ** 1319 ** Registered sqlite3_vfs objects are kept on a linked list formed by 1320 ** the pNext pointer. The [sqlite3_vfs_register()] 1321 ** and [sqlite3_vfs_unregister()] interfaces manage this list 1322 ** in a thread-safe way. The [sqlite3_vfs_find()] interface 1323 ** searches the list. Neither the application code nor the VFS 1324 ** implementation should use the pNext pointer. 1325 ** 1326 ** The pNext field is the only field in the sqlite3_vfs 1327 ** structure that SQLite will ever modify. SQLite will only access 1328 ** or modify this field while holding a particular static mutex. 1329 ** The application should never modify anything within the sqlite3_vfs 1330 ** object once the object has been registered. 1331 ** 1332 ** The zName field holds the name of the VFS module. The name must 1333 ** be unique across all VFS modules. 1334 ** 1335 ** [[sqlite3_vfs.xOpen]] 1336 ** ^SQLite guarantees that the zFilename parameter to xOpen 1337 ** is either a NULL pointer or string obtained 1338 ** from xFullPathname() with an optional suffix added. 1339 ** ^If a suffix is added to the zFilename parameter, it will 1340 ** consist of a single "-" character followed by no more than 1341 ** 11 alphanumeric and/or "-" characters. 1342 ** ^SQLite further guarantees that 1343 ** the string will be valid and unchanged until xClose() is 1344 ** called. Because of the previous sentence, 1345 ** the [sqlite3_file] can safely store a pointer to the 1346 ** filename if it needs to remember the filename for some reason. 1347 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1348 ** must invent its own temporary name for the file. ^Whenever the 1349 ** xFilename parameter is NULL it will also be the case that the 1350 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1351 ** 1352 ** The flags argument to xOpen() includes all bits set in 1353 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1354 ** or [sqlite3_open16()] is used, then flags includes at least 1355 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1356 ** If xOpen() opens a file read-only then it sets *pOutFlags to 1357 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1358 ** 1359 ** ^(SQLite will also add one of the following flags to the xOpen() 1360 ** call, depending on the object being opened: 1361 ** 1362 ** <ul> 1363 ** <li> [SQLITE_OPEN_MAIN_DB] 1364 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1365 ** <li> [SQLITE_OPEN_TEMP_DB] 1366 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1367 ** <li> [SQLITE_OPEN_TRANSIENT_DB] 1368 ** <li> [SQLITE_OPEN_SUBJOURNAL] 1369 ** <li> [SQLITE_OPEN_SUPER_JOURNAL] 1370 ** <li> [SQLITE_OPEN_WAL] 1371 ** </ul>)^ 1372 ** 1373 ** The file I/O implementation can use the object type flags to 1374 ** change the way it deals with files. For example, an application 1375 ** that does not care about crash recovery or rollback might make 1376 ** the open of a journal file a no-op. Writes to this journal would 1377 ** also be no-ops, and any attempt to read the journal would return 1378 ** SQLITE_IOERR. Or the implementation might recognize that a database 1379 ** file will be doing page-aligned sector reads and writes in a random 1380 ** order and set up its I/O subsystem accordingly. 1381 ** 1382 ** SQLite might also add one of the following flags to the xOpen method: 1383 ** 1384 ** <ul> 1385 ** <li> [SQLITE_OPEN_DELETEONCLOSE] 1386 ** <li> [SQLITE_OPEN_EXCLUSIVE] 1387 ** </ul> 1388 ** 1389 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1390 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1391 ** will be set for TEMP databases and their journals, transient 1392 ** databases, and subjournals. 1393 ** 1394 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1395 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1396 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1397 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1398 ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1399 ** be created, and that it is an error if it already exists. 1400 ** It is <i>not</i> used to indicate the file should be opened 1401 ** for exclusive access. 1402 ** 1403 ** ^At least szOsFile bytes of memory are allocated by SQLite 1404 ** to hold the [sqlite3_file] structure passed as the third 1405 ** argument to xOpen. The xOpen method does not have to 1406 ** allocate the structure; it should just fill it in. Note that 1407 ** the xOpen method must set the sqlite3_file.pMethods to either 1408 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1409 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1410 ** element will be valid after xOpen returns regardless of the success 1411 ** or failure of the xOpen call. 1412 ** 1413 ** [[sqlite3_vfs.xAccess]] 1414 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1415 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1416 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1417 ** to test whether a file is at least readable. The SQLITE_ACCESS_READ 1418 ** flag is never actually used and is not implemented in the built-in 1419 ** VFSes of SQLite. The file is named by the second argument and can be a 1420 ** directory. The xAccess method returns [SQLITE_OK] on success or some 1421 ** non-zero error code if there is an I/O error or if the name of 1422 ** the file given in the second argument is illegal. If SQLITE_OK 1423 ** is returned, then non-zero or zero is written into *pResOut to indicate 1424 ** whether or not the file is accessible. 1425 ** 1426 ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1427 ** output buffer xFullPathname. The exact size of the output buffer 1428 ** is also passed as a parameter to both methods. If the output buffer 1429 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1430 ** handled as a fatal error by SQLite, vfs implementations should endeavor 1431 ** to prevent this by setting mxPathname to a sufficiently large value. 1432 ** 1433 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1434 ** interfaces are not strictly a part of the filesystem, but they are 1435 ** included in the VFS structure for completeness. 1436 ** The xRandomness() function attempts to return nBytes bytes 1437 ** of good-quality randomness into zOut. The return value is 1438 ** the actual number of bytes of randomness obtained. 1439 ** The xSleep() method causes the calling thread to sleep for at 1440 ** least the number of microseconds given. ^The xCurrentTime() 1441 ** method returns a Julian Day Number for the current date and time as 1442 ** a floating point value. 1443 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1444 ** Day Number multiplied by 86400000 (the number of milliseconds in 1445 ** a 24-hour day). 1446 ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1447 ** date and time if that method is available (if iVersion is 2 or 1448 ** greater and the function pointer is not NULL) and will fall back 1449 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1450 ** 1451 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1452 ** are not used by the SQLite core. These optional interfaces are provided 1453 ** by some VFSes to facilitate testing of the VFS code. By overriding 1454 ** system calls with functions under its control, a test program can 1455 ** simulate faults and error conditions that would otherwise be difficult 1456 ** or impossible to induce. The set of system calls that can be overridden 1457 ** varies from one VFS to another, and from one version of the same VFS to the 1458 ** next. Applications that use these interfaces must be prepared for any 1459 ** or all of these interfaces to be NULL or for their behavior to change 1460 ** from one release to the next. Applications must not attempt to access 1461 ** any of these methods if the iVersion of the VFS is less than 3. 1462 */ 1463 typedef struct sqlite3_vfs sqlite3_vfs; 1464 typedef void (*sqlite3_syscall_ptr)(void); 1465 struct sqlite3_vfs { 1466 int iVersion; /* Structure version number (currently 3) */ 1467 int szOsFile; /* Size of subclassed sqlite3_file */ 1468 int mxPathname; /* Maximum file pathname length */ 1469 sqlite3_vfs *pNext; /* Next registered VFS */ 1470 const char *zName; /* Name of this virtual file system */ 1471 void *pAppData; /* Pointer to application-specific data */ 1472 int (*xOpen)(sqlite3_vfs*, sqlite3_filename zName, sqlite3_file*, 1473 int flags, int *pOutFlags); 1474 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1475 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1476 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1477 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1478 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1479 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1480 void (*xDlClose)(sqlite3_vfs*, void*); 1481 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1482 int (*xSleep)(sqlite3_vfs*, int microseconds); 1483 int (*xCurrentTime)(sqlite3_vfs*, double*); 1484 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1485 /* 1486 ** The methods above are in version 1 of the sqlite_vfs object 1487 ** definition. Those that follow are added in version 2 or later 1488 */ 1489 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1490 /* 1491 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1492 ** Those below are for version 3 and greater. 1493 */ 1494 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1495 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1496 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1497 /* 1498 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1499 ** New fields may be appended in future versions. The iVersion 1500 ** value will increment whenever this happens. 1501 */ 1502 }; 1503 1504 /* 1505 ** CAPI3REF: Flags for the xAccess VFS method 1506 ** 1507 ** These integer constants can be used as the third parameter to 1508 ** the xAccess method of an [sqlite3_vfs] object. They determine 1509 ** what kind of permissions the xAccess method is looking for. 1510 ** With SQLITE_ACCESS_EXISTS, the xAccess method 1511 ** simply checks whether the file exists. 1512 ** With SQLITE_ACCESS_READWRITE, the xAccess method 1513 ** checks whether the named directory is both readable and writable 1514 ** (in other words, if files can be added, removed, and renamed within 1515 ** the directory). 1516 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1517 ** [temp_store_directory pragma], though this could change in a future 1518 ** release of SQLite. 1519 ** With SQLITE_ACCESS_READ, the xAccess method 1520 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1521 ** currently unused, though it might be used in a future release of 1522 ** SQLite. 1523 */ 1524 #define SQLITE_ACCESS_EXISTS 0 1525 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1526 #define SQLITE_ACCESS_READ 2 /* Unused */ 1527 1528 /* 1529 ** CAPI3REF: Flags for the xShmLock VFS method 1530 ** 1531 ** These integer constants define the various locking operations 1532 ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1533 ** following are the only legal combinations of flags to the 1534 ** xShmLock method: 1535 ** 1536 ** <ul> 1537 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1538 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1539 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1540 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1541 ** </ul> 1542 ** 1543 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1544 ** was given on the corresponding lock. 1545 ** 1546 ** The xShmLock method can transition between unlocked and SHARED or 1547 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1548 ** and EXCLUSIVE. 1549 */ 1550 #define SQLITE_SHM_UNLOCK 1 1551 #define SQLITE_SHM_LOCK 2 1552 #define SQLITE_SHM_SHARED 4 1553 #define SQLITE_SHM_EXCLUSIVE 8 1554 1555 /* 1556 ** CAPI3REF: Maximum xShmLock index 1557 ** 1558 ** The xShmLock method on [sqlite3_io_methods] may use values 1559 ** between 0 and this upper bound as its "offset" argument. 1560 ** The SQLite core will never attempt to acquire or release a 1561 ** lock outside of this range 1562 */ 1563 #define SQLITE_SHM_NLOCK 8 1564 1565 1566 /* 1567 ** CAPI3REF: Initialize The SQLite Library 1568 ** 1569 ** ^The sqlite3_initialize() routine initializes the 1570 ** SQLite library. ^The sqlite3_shutdown() routine 1571 ** deallocates any resources that were allocated by sqlite3_initialize(). 1572 ** These routines are designed to aid in process initialization and 1573 ** shutdown on embedded systems. Workstation applications using 1574 ** SQLite normally do not need to invoke either of these routines. 1575 ** 1576 ** A call to sqlite3_initialize() is an "effective" call if it is 1577 ** the first time sqlite3_initialize() is invoked during the lifetime of 1578 ** the process, or if it is the first time sqlite3_initialize() is invoked 1579 ** following a call to sqlite3_shutdown(). ^(Only an effective call 1580 ** of sqlite3_initialize() does any initialization. All other calls 1581 ** are harmless no-ops.)^ 1582 ** 1583 ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1584 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1585 ** an effective call to sqlite3_shutdown() does any deinitialization. 1586 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1587 ** 1588 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1589 ** is not. The sqlite3_shutdown() interface must only be called from a 1590 ** single thread. All open [database connections] must be closed and all 1591 ** other SQLite resources must be deallocated prior to invoking 1592 ** sqlite3_shutdown(). 1593 ** 1594 ** Among other things, ^sqlite3_initialize() will invoke 1595 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1596 ** will invoke sqlite3_os_end(). 1597 ** 1598 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1599 ** ^If for some reason, sqlite3_initialize() is unable to initialize 1600 ** the library (perhaps it is unable to allocate a needed resource such 1601 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1602 ** 1603 ** ^The sqlite3_initialize() routine is called internally by many other 1604 ** SQLite interfaces so that an application usually does not need to 1605 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1606 ** calls sqlite3_initialize() so the SQLite library will be automatically 1607 ** initialized when [sqlite3_open()] is called if it has not be initialized 1608 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1609 ** compile-time option, then the automatic calls to sqlite3_initialize() 1610 ** are omitted and the application must call sqlite3_initialize() directly 1611 ** prior to using any other SQLite interface. For maximum portability, 1612 ** it is recommended that applications always invoke sqlite3_initialize() 1613 ** directly prior to using any other SQLite interface. Future releases 1614 ** of SQLite may require this. In other words, the behavior exhibited 1615 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1616 ** default behavior in some future release of SQLite. 1617 ** 1618 ** The sqlite3_os_init() routine does operating-system specific 1619 ** initialization of the SQLite library. The sqlite3_os_end() 1620 ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1621 ** performed by these routines include allocation or deallocation 1622 ** of static resources, initialization of global variables, 1623 ** setting up a default [sqlite3_vfs] module, or setting up 1624 ** a default configuration using [sqlite3_config()]. 1625 ** 1626 ** The application should never invoke either sqlite3_os_init() 1627 ** or sqlite3_os_end() directly. The application should only invoke 1628 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1629 ** interface is called automatically by sqlite3_initialize() and 1630 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1631 ** implementations for sqlite3_os_init() and sqlite3_os_end() 1632 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1633 ** When [custom builds | built for other platforms] 1634 ** (using the [SQLITE_OS_OTHER=1] compile-time 1635 ** option) the application must supply a suitable implementation for 1636 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1637 ** implementation of sqlite3_os_init() or sqlite3_os_end() 1638 ** must return [SQLITE_OK] on success and some other [error code] upon 1639 ** failure. 1640 */ 1641 SQLITE_API int sqlite3_initialize(void); 1642 SQLITE_API int sqlite3_shutdown(void); 1643 SQLITE_API int sqlite3_os_init(void); 1644 SQLITE_API int sqlite3_os_end(void); 1645 1646 /* 1647 ** CAPI3REF: Configuring The SQLite Library 1648 ** 1649 ** The sqlite3_config() interface is used to make global configuration 1650 ** changes to SQLite in order to tune SQLite to the specific needs of 1651 ** the application. The default configuration is recommended for most 1652 ** applications and so this routine is usually not necessary. It is 1653 ** provided to support rare applications with unusual needs. 1654 ** 1655 ** <b>The sqlite3_config() interface is not threadsafe. The application 1656 ** must ensure that no other SQLite interfaces are invoked by other 1657 ** threads while sqlite3_config() is running.</b> 1658 ** 1659 ** The first argument to sqlite3_config() is an integer 1660 ** [configuration option] that determines 1661 ** what property of SQLite is to be configured. Subsequent arguments 1662 ** vary depending on the [configuration option] 1663 ** in the first argument. 1664 ** 1665 ** For most configuration options, the sqlite3_config() interface 1666 ** may only be invoked prior to library initialization using 1667 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1668 ** The exceptional configuration options that may be invoked at any time 1669 ** are called "anytime configuration options". 1670 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1671 ** [sqlite3_shutdown()] with a first argument that is not an anytime 1672 ** configuration option, then the sqlite3_config() call will return SQLITE_MISUSE. 1673 ** Note, however, that ^sqlite3_config() can be called as part of the 1674 ** implementation of an application-defined [sqlite3_os_init()]. 1675 ** 1676 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1677 ** ^If the option is unknown or SQLite is unable to set the option 1678 ** then this routine returns a non-zero [error code]. 1679 */ 1680 SQLITE_API int sqlite3_config(int, ...); 1681 1682 /* 1683 ** CAPI3REF: Configure database connections 1684 ** METHOD: sqlite3 1685 ** 1686 ** The sqlite3_db_config() interface is used to make configuration 1687 ** changes to a [database connection]. The interface is similar to 1688 ** [sqlite3_config()] except that the changes apply to a single 1689 ** [database connection] (specified in the first argument). 1690 ** 1691 ** The second argument to sqlite3_db_config(D,V,...) is the 1692 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1693 ** that indicates what aspect of the [database connection] is being configured. 1694 ** Subsequent arguments vary depending on the configuration verb. 1695 ** 1696 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1697 ** the call is considered successful. 1698 */ 1699 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1700 1701 /* 1702 ** CAPI3REF: Memory Allocation Routines 1703 ** 1704 ** An instance of this object defines the interface between SQLite 1705 ** and low-level memory allocation routines. 1706 ** 1707 ** This object is used in only one place in the SQLite interface. 1708 ** A pointer to an instance of this object is the argument to 1709 ** [sqlite3_config()] when the configuration option is 1710 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1711 ** By creating an instance of this object 1712 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1713 ** during configuration, an application can specify an alternative 1714 ** memory allocation subsystem for SQLite to use for all of its 1715 ** dynamic memory needs. 1716 ** 1717 ** Note that SQLite comes with several [built-in memory allocators] 1718 ** that are perfectly adequate for the overwhelming majority of applications 1719 ** and that this object is only useful to a tiny minority of applications 1720 ** with specialized memory allocation requirements. This object is 1721 ** also used during testing of SQLite in order to specify an alternative 1722 ** memory allocator that simulates memory out-of-memory conditions in 1723 ** order to verify that SQLite recovers gracefully from such 1724 ** conditions. 1725 ** 1726 ** The xMalloc, xRealloc, and xFree methods must work like the 1727 ** malloc(), realloc() and free() functions from the standard C library. 1728 ** ^SQLite guarantees that the second argument to 1729 ** xRealloc is always a value returned by a prior call to xRoundup. 1730 ** 1731 ** xSize should return the allocated size of a memory allocation 1732 ** previously obtained from xMalloc or xRealloc. The allocated size 1733 ** is always at least as big as the requested size but may be larger. 1734 ** 1735 ** The xRoundup method returns what would be the allocated size of 1736 ** a memory allocation given a particular requested size. Most memory 1737 ** allocators round up memory allocations at least to the next multiple 1738 ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1739 ** Every memory allocation request coming in through [sqlite3_malloc()] 1740 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1741 ** that causes the corresponding memory allocation to fail. 1742 ** 1743 ** The xInit method initializes the memory allocator. For example, 1744 ** it might allocate any required mutexes or initialize internal data 1745 ** structures. The xShutdown method is invoked (indirectly) by 1746 ** [sqlite3_shutdown()] and should deallocate any resources acquired 1747 ** by xInit. The pAppData pointer is used as the only parameter to 1748 ** xInit and xShutdown. 1749 ** 1750 ** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes 1751 ** the xInit method, so the xInit method need not be threadsafe. The 1752 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1753 ** not need to be threadsafe either. For all other methods, SQLite 1754 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1755 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1756 ** it is by default) and so the methods are automatically serialized. 1757 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1758 ** methods must be threadsafe or else make their own arrangements for 1759 ** serialization. 1760 ** 1761 ** SQLite will never invoke xInit() more than once without an intervening 1762 ** call to xShutdown(). 1763 */ 1764 typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1765 struct sqlite3_mem_methods { 1766 void *(*xMalloc)(int); /* Memory allocation function */ 1767 void (*xFree)(void*); /* Free a prior allocation */ 1768 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1769 int (*xSize)(void*); /* Return the size of an allocation */ 1770 int (*xRoundup)(int); /* Round up request size to allocation size */ 1771 int (*xInit)(void*); /* Initialize the memory allocator */ 1772 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1773 void *pAppData; /* Argument to xInit() and xShutdown() */ 1774 }; 1775 1776 /* 1777 ** CAPI3REF: Configuration Options 1778 ** KEYWORDS: {configuration option} 1779 ** 1780 ** These constants are the available integer configuration options that 1781 ** can be passed as the first argument to the [sqlite3_config()] interface. 1782 ** 1783 ** Most of the configuration options for sqlite3_config() 1784 ** will only work if invoked prior to [sqlite3_initialize()] or after 1785 ** [sqlite3_shutdown()]. The few exceptions to this rule are called 1786 ** "anytime configuration options". 1787 ** ^Calling [sqlite3_config()] with a first argument that is not an 1788 ** anytime configuration option in between calls to [sqlite3_initialize()] and 1789 ** [sqlite3_shutdown()] is a no-op that returns SQLITE_MISUSE. 1790 ** 1791 ** The set of anytime configuration options can change (by insertions 1792 ** and/or deletions) from one release of SQLite to the next. 1793 ** As of SQLite version 3.42.0, the complete set of anytime configuration 1794 ** options is: 1795 ** <ul> 1796 ** <li> SQLITE_CONFIG_LOG 1797 ** <li> SQLITE_CONFIG_PCACHE_HDRSZ 1798 ** </ul> 1799 ** 1800 ** New configuration options may be added in future releases of SQLite. 1801 ** Existing configuration options might be discontinued. Applications 1802 ** should check the return code from [sqlite3_config()] to make sure that 1803 ** the call worked. The [sqlite3_config()] interface will return a 1804 ** non-zero [error code] if a discontinued or unsupported configuration option 1805 ** is invoked. 1806 ** 1807 ** <dl> 1808 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1809 ** <dd>There are no arguments to this option. ^This option sets the 1810 ** [threading mode] to Single-thread. In other words, it disables 1811 ** all mutexing and puts SQLite into a mode where it can only be used 1812 ** by a single thread. ^If SQLite is compiled with 1813 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1814 ** it is not possible to change the [threading mode] from its default 1815 ** value of Single-thread and so [sqlite3_config()] will return 1816 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1817 ** configuration option.</dd> 1818 ** 1819 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1820 ** <dd>There are no arguments to this option. ^This option sets the 1821 ** [threading mode] to Multi-thread. In other words, it disables 1822 ** mutexing on [database connection] and [prepared statement] objects. 1823 ** The application is responsible for serializing access to 1824 ** [database connections] and [prepared statements]. But other mutexes 1825 ** are enabled so that SQLite will be safe to use in a multi-threaded 1826 ** environment as long as no two threads attempt to use the same 1827 ** [database connection] at the same time. ^If SQLite is compiled with 1828 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1829 ** it is not possible to set the Multi-thread [threading mode] and 1830 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1831 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1832 ** 1833 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1834 ** <dd>There are no arguments to this option. ^This option sets the 1835 ** [threading mode] to Serialized. In other words, this option enables 1836 ** all mutexes including the recursive 1837 ** mutexes on [database connection] and [prepared statement] objects. 1838 ** In this mode (which is the default when SQLite is compiled with 1839 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1840 ** to [database connections] and [prepared statements] so that the 1841 ** application is free to use the same [database connection] or the 1842 ** same [prepared statement] in different threads at the same time. 1843 ** ^If SQLite is compiled with 1844 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1845 ** it is not possible to set the Serialized [threading mode] and 1846 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1847 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1848 ** 1849 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1850 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1851 ** a pointer to an instance of the [sqlite3_mem_methods] structure. 1852 ** The argument specifies 1853 ** alternative low-level memory allocation routines to be used in place of 1854 ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1855 ** its own private copy of the content of the [sqlite3_mem_methods] structure 1856 ** before the [sqlite3_config()] call returns.</dd> 1857 ** 1858 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1859 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1860 ** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1861 ** The [sqlite3_mem_methods] 1862 ** structure is filled with the currently defined memory allocation routines.)^ 1863 ** This option can be used to overload the default memory allocation 1864 ** routines with a wrapper that simulations memory allocation failure or 1865 ** tracks memory usage, for example. </dd> 1866 ** 1867 ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1868 ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1869 ** type int, interpreted as a boolean, which if true provides a hint to 1870 ** SQLite that it should avoid large memory allocations if possible. 1871 ** SQLite will run faster if it is free to make large memory allocations, 1872 ** but some application might prefer to run slower in exchange for 1873 ** guarantees about memory fragmentation that are possible if large 1874 ** allocations are avoided. This hint is normally off. 1875 ** </dd> 1876 ** 1877 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1878 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1879 ** interpreted as a boolean, which enables or disables the collection of 1880 ** memory allocation statistics. ^(When memory allocation statistics are 1881 ** disabled, the following SQLite interfaces become non-operational: 1882 ** <ul> 1883 ** <li> [sqlite3_hard_heap_limit64()] 1884 ** <li> [sqlite3_memory_used()] 1885 ** <li> [sqlite3_memory_highwater()] 1886 ** <li> [sqlite3_soft_heap_limit64()] 1887 ** <li> [sqlite3_status64()] 1888 ** </ul>)^ 1889 ** ^Memory allocation statistics are enabled by default unless SQLite is 1890 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1891 ** allocation statistics are disabled by default. 1892 ** </dd> 1893 ** 1894 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1895 ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1896 ** </dd> 1897 ** 1898 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1899 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1900 ** that SQLite can use for the database page cache with the default page 1901 ** cache implementation. 1902 ** This configuration option is a no-op if an application-defined page 1903 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1904 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1905 ** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1906 ** and the number of cache lines (N). 1907 ** The sz argument should be the size of the largest database page 1908 ** (a power of two between 512 and 65536) plus some extra bytes for each 1909 ** page header. ^The number of extra bytes needed by the page header 1910 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1911 ** ^It is harmless, apart from the wasted memory, 1912 ** for the sz parameter to be larger than necessary. The pMem 1913 ** argument must be either a NULL pointer or a pointer to an 8-byte 1914 ** aligned block of memory of at least sz*N bytes, otherwise 1915 ** subsequent behavior is undefined. 1916 ** ^When pMem is not NULL, SQLite will strive to use the memory provided 1917 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1918 ** a page cache line is larger than sz bytes or if all of the pMem buffer 1919 ** is exhausted. 1920 ** ^If pMem is NULL and N is non-zero, then each database connection 1921 ** does an initial bulk allocation for page cache memory 1922 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1923 ** of -1024*N bytes if N is negative, . ^If additional 1924 ** page cache memory is needed beyond what is provided by the initial 1925 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1926 ** additional cache line. </dd> 1927 ** 1928 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1929 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1930 ** that SQLite will use for all of its dynamic memory allocation needs 1931 ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1932 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1933 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1934 ** [SQLITE_ERROR] if invoked otherwise. 1935 ** ^There are three arguments to SQLITE_CONFIG_HEAP: 1936 ** An 8-byte aligned pointer to the memory, 1937 ** the number of bytes in the memory buffer, and the minimum allocation size. 1938 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1939 ** to using its default memory allocator (the system malloc() implementation), 1940 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1941 ** memory pointer is not NULL then the alternative memory 1942 ** allocator is engaged to handle all of SQLites memory allocation needs. 1943 ** The first pointer (the memory pointer) must be aligned to an 8-byte 1944 ** boundary or subsequent behavior of SQLite will be undefined. 1945 ** The minimum allocation size is capped at 2**12. Reasonable values 1946 ** for the minimum allocation size are 2**5 through 2**8.</dd> 1947 ** 1948 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1949 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1950 ** pointer to an instance of the [sqlite3_mutex_methods] structure. 1951 ** The argument specifies alternative low-level mutex routines to be used 1952 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1953 ** the content of the [sqlite3_mutex_methods] structure before the call to 1954 ** [sqlite3_config()] returns. ^If SQLite is compiled with 1955 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1956 ** the entire mutexing subsystem is omitted from the build and hence calls to 1957 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1958 ** return [SQLITE_ERROR].</dd> 1959 ** 1960 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1961 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1962 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1963 ** [sqlite3_mutex_methods] 1964 ** structure is filled with the currently defined mutex routines.)^ 1965 ** This option can be used to overload the default mutex allocation 1966 ** routines with a wrapper used to track mutex usage for performance 1967 ** profiling or testing, for example. ^If SQLite is compiled with 1968 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1969 ** the entire mutexing subsystem is omitted from the build and hence calls to 1970 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1971 ** return [SQLITE_ERROR].</dd> 1972 ** 1973 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1974 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1975 ** the default size of lookaside memory on each [database connection]. 1976 ** The first argument is the 1977 ** size of each lookaside buffer slot and the second is the number of 1978 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1979 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1980 ** option to [sqlite3_db_config()] can be used to change the lookaside 1981 ** configuration on individual connections.)^ </dd> 1982 ** 1983 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1984 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1985 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1986 ** the interface to a custom page cache implementation.)^ 1987 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1988 ** 1989 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1990 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1991 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1992 ** the current page cache implementation into that object.)^ </dd> 1993 ** 1994 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1995 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1996 ** global [error log]. 1997 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1998 ** function with a call signature of void(*)(void*,int,const char*), 1999 ** and a pointer to void. ^If the function pointer is not NULL, it is 2000 ** invoked by [sqlite3_log()] to process each logging event. ^If the 2001 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 2002 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 2003 ** passed through as the first parameter to the application-defined logger 2004 ** function whenever that function is invoked. ^The second parameter to 2005 ** the logger function is a copy of the first parameter to the corresponding 2006 ** [sqlite3_log()] call and is intended to be a [result code] or an 2007 ** [extended result code]. ^The third parameter passed to the logger is 2008 ** log message after formatting via [sqlite3_snprintf()]. 2009 ** The SQLite logging interface is not reentrant; the logger function 2010 ** supplied by the application must not invoke any SQLite interface. 2011 ** In a multi-threaded application, the application-defined logger 2012 ** function must be threadsafe. </dd> 2013 ** 2014 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 2015 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 2016 ** If non-zero, then URI handling is globally enabled. If the parameter is zero, 2017 ** then URI handling is globally disabled.)^ ^If URI handling is globally 2018 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 2019 ** [sqlite3_open16()] or 2020 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 2021 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 2022 ** connection is opened. ^If it is globally disabled, filenames are 2023 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 2024 ** database connection is opened. ^(By default, URI handling is globally 2025 ** disabled. The default value may be changed by compiling with the 2026 ** [SQLITE_USE_URI] symbol defined.)^ 2027 ** 2028 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 2029 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 2030 ** argument which is interpreted as a boolean in order to enable or disable 2031 ** the use of covering indices for full table scans in the query optimizer. 2032 ** ^The default setting is determined 2033 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 2034 ** if that compile-time option is omitted. 2035 ** The ability to disable the use of covering indices for full table scans 2036 ** is because some incorrectly coded legacy applications might malfunction 2037 ** when the optimization is enabled. Providing the ability to 2038 ** disable the optimization allows the older, buggy application code to work 2039 ** without change even with newer versions of SQLite. 2040 ** 2041 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 2042 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 2043 ** <dd> These options are obsolete and should not be used by new code. 2044 ** They are retained for backwards compatibility but are now no-ops. 2045 ** </dd> 2046 ** 2047 ** [[SQLITE_CONFIG_SQLLOG]] 2048 ** <dt>SQLITE_CONFIG_SQLLOG 2049 ** <dd>This option is only available if sqlite is compiled with the 2050 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 2051 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 2052 ** The second should be of type (void*). The callback is invoked by the library 2053 ** in three separate circumstances, identified by the value passed as the 2054 ** fourth parameter. If the fourth parameter is 0, then the database connection 2055 ** passed as the second argument has just been opened. The third argument 2056 ** points to a buffer containing the name of the main database file. If the 2057 ** fourth parameter is 1, then the SQL statement that the third parameter 2058 ** points to has just been executed. Or, if the fourth parameter is 2, then 2059 ** the connection being passed as the second parameter is being closed. The 2060 ** third parameter is passed NULL In this case. An example of using this 2061 ** configuration option can be seen in the "test_sqllog.c" source file in 2062 ** the canonical SQLite source tree.</dd> 2063 ** 2064 ** [[SQLITE_CONFIG_MMAP_SIZE]] 2065 ** <dt>SQLITE_CONFIG_MMAP_SIZE 2066 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 2067 ** that are the default mmap size limit (the default setting for 2068 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 2069 ** ^The default setting can be overridden by each database connection using 2070 ** either the [PRAGMA mmap_size] command, or by using the 2071 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 2072 ** will be silently truncated if necessary so that it does not exceed the 2073 ** compile-time maximum mmap size set by the 2074 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 2075 ** ^If either argument to this option is negative, then that argument is 2076 ** changed to its compile-time default. 2077 ** 2078 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 2079 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 2080 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 2081 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 2082 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 2083 ** that specifies the maximum size of the created heap. 2084 ** 2085 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 2086 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 2087 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 2088 ** is a pointer to an integer and writes into that integer the number of extra 2089 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 2090 ** The amount of extra space required can change depending on the compiler, 2091 ** target platform, and SQLite version. 2092 ** 2093 ** [[SQLITE_CONFIG_PMASZ]] 2094 ** <dt>SQLITE_CONFIG_PMASZ 2095 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 2096 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 2097 ** sorter to that integer. The default minimum PMA Size is set by the 2098 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 2099 ** to help with sort operations when multithreaded sorting 2100 ** is enabled (using the [PRAGMA threads] command) and the amount of content 2101 ** to be sorted exceeds the page size times the minimum of the 2102 ** [PRAGMA cache_size] setting and this value. 2103 ** 2104 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 2105 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 2106 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 2107 ** becomes the [statement journal] spill-to-disk threshold. 2108 ** [Statement journals] are held in memory until their size (in bytes) 2109 ** exceeds this threshold, at which point they are written to disk. 2110 ** Or if the threshold is -1, statement journals are always held 2111 ** exclusively in memory. 2112 ** Since many statement journals never become large, setting the spill 2113 ** threshold to a value such as 64KiB can greatly reduce the amount of 2114 ** I/O required to support statement rollback. 2115 ** The default value for this setting is controlled by the 2116 ** [SQLITE_STMTJRNL_SPILL] compile-time option. 2117 ** 2118 ** [[SQLITE_CONFIG_SORTERREF_SIZE]] 2119 ** <dt>SQLITE_CONFIG_SORTERREF_SIZE 2120 ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 2121 ** of type (int) - the new value of the sorter-reference size threshold. 2122 ** Usually, when SQLite uses an external sort to order records according 2123 ** to an ORDER BY clause, all fields required by the caller are present in the 2124 ** sorted records. However, if SQLite determines based on the declared type 2125 ** of a table column that its values are likely to be very large - larger 2126 ** than the configured sorter-reference size threshold - then a reference 2127 ** is stored in each sorted record and the required column values loaded 2128 ** from the database as records are returned in sorted order. The default 2129 ** value for this option is to never use this optimization. Specifying a 2130 ** negative value for this option restores the default behavior. 2131 ** This option is only available if SQLite is compiled with the 2132 ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 2133 ** 2134 ** [[SQLITE_CONFIG_MEMDB_MAXSIZE]] 2135 ** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE 2136 ** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter 2137 ** [sqlite3_int64] parameter which is the default maximum size for an in-memory 2138 ** database created using [sqlite3_deserialize()]. This default maximum 2139 ** size can be adjusted up or down for individual databases using the 2140 ** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this 2141 ** configuration setting is never used, then the default maximum is determined 2142 ** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that 2143 ** compile-time option is not set, then the default maximum is 1073741824. 2144 ** </dl> 2145 */ 2146 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 2147 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 2148 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 2149 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 2150 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 2151 #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 2152 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 2153 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 2154 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 2155 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 2156 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 2157 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 2158 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 2159 #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 2160 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 2161 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 2162 #define SQLITE_CONFIG_URI 17 /* int */ 2163 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 2164 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 2165 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 2166 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 2167 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 2168 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 2169 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2170 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2171 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2172 #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2173 #define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2174 #define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */ 2175 2176 /* 2177 ** CAPI3REF: Database Connection Configuration Options 2178 ** 2179 ** These constants are the available integer configuration options that 2180 ** can be passed as the second argument to the [sqlite3_db_config()] interface. 2181 ** 2182 ** New configuration options may be added in future releases of SQLite. 2183 ** Existing configuration options might be discontinued. Applications 2184 ** should check the return code from [sqlite3_db_config()] to make sure that 2185 ** the call worked. ^The [sqlite3_db_config()] interface will return a 2186 ** non-zero [error code] if a discontinued or unsupported configuration option 2187 ** is invoked. 2188 ** 2189 ** <dl> 2190 ** [[SQLITE_DBCONFIG_LOOKASIDE]] 2191 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2192 ** <dd> ^This option takes three additional arguments that determine the 2193 ** [lookaside memory allocator] configuration for the [database connection]. 2194 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2195 ** pointer to a memory buffer to use for lookaside memory. 2196 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2197 ** may be NULL in which case SQLite will allocate the 2198 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2199 ** size of each lookaside buffer slot. ^The third argument is the number of 2200 ** slots. The size of the buffer in the first argument must be greater than 2201 ** or equal to the product of the second and third arguments. The buffer 2202 ** must be aligned to an 8-byte boundary. ^If the second argument to 2203 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2204 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2205 ** configuration for a database connection can only be changed when that 2206 ** connection is not currently using lookaside memory, or in other words 2207 ** when the "current value" returned by 2208 ** [sqlite3_db_status](D,[SQLITE_DBSTATUS_LOOKASIDE_USED],...) is zero. 2209 ** Any attempt to change the lookaside memory configuration when lookaside 2210 ** memory is in use leaves the configuration unchanged and returns 2211 ** [SQLITE_BUSY].)^</dd> 2212 ** 2213 ** [[SQLITE_DBCONFIG_ENABLE_FKEY]] 2214 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2215 ** <dd> ^This option is used to enable or disable the enforcement of 2216 ** [foreign key constraints]. There should be two additional arguments. 2217 ** The first argument is an integer which is 0 to disable FK enforcement, 2218 ** positive to enable FK enforcement or negative to leave FK enforcement 2219 ** unchanged. The second parameter is a pointer to an integer into which 2220 ** is written 0 or 1 to indicate whether FK enforcement is off or on 2221 ** following this call. The second parameter may be a NULL pointer, in 2222 ** which case the FK enforcement setting is not reported back. </dd> 2223 ** 2224 ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] 2225 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2226 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2227 ** There should be two additional arguments. 2228 ** The first argument is an integer which is 0 to disable triggers, 2229 ** positive to enable triggers or negative to leave the setting unchanged. 2230 ** The second parameter is a pointer to an integer into which 2231 ** is written 0 or 1 to indicate whether triggers are disabled or enabled 2232 ** following this call. The second parameter may be a NULL pointer, in 2233 ** which case the trigger setting is not reported back. 2234 ** 2235 ** <p>Originally this option disabled all triggers. ^(However, since 2236 ** SQLite version 3.35.0, TEMP triggers are still allowed even if 2237 ** this option is off. So, in other words, this option now only disables 2238 ** triggers in the main database schema or in the schemas of ATTACH-ed 2239 ** databases.)^ </dd> 2240 ** 2241 ** [[SQLITE_DBCONFIG_ENABLE_VIEW]] 2242 ** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt> 2243 ** <dd> ^This option is used to enable or disable [CREATE VIEW | views]. 2244 ** There should be two additional arguments. 2245 ** The first argument is an integer which is 0 to disable views, 2246 ** positive to enable views or negative to leave the setting unchanged. 2247 ** The second parameter is a pointer to an integer into which 2248 ** is written 0 or 1 to indicate whether views are disabled or enabled 2249 ** following this call. The second parameter may be a NULL pointer, in 2250 ** which case the view setting is not reported back. 2251 ** 2252 ** <p>Originally this option disabled all views. ^(However, since 2253 ** SQLite version 3.35.0, TEMP views are still allowed even if 2254 ** this option is off. So, in other words, this option now only disables 2255 ** views in the main database schema or in the schemas of ATTACH-ed 2256 ** databases.)^ </dd> 2257 ** 2258 ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] 2259 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2260 ** <dd> ^This option is used to enable or disable the 2261 ** [fts3_tokenizer()] function which is part of the 2262 ** [FTS3] full-text search engine extension. 2263 ** There should be two additional arguments. 2264 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2265 ** positive to enable fts3_tokenizer() or negative to leave the setting 2266 ** unchanged. 2267 ** The second parameter is a pointer to an integer into which 2268 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2269 ** following this call. The second parameter may be a NULL pointer, in 2270 ** which case the new setting is not reported back. </dd> 2271 ** 2272 ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] 2273 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2274 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2275 ** interface independently of the [load_extension()] SQL function. 2276 ** The [sqlite3_enable_load_extension()] API enables or disables both the 2277 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2278 ** There should be two additional arguments. 2279 ** When the first argument to this interface is 1, then only the C-API is 2280 ** enabled and the SQL function remains disabled. If the first argument to 2281 ** this interface is 0, then both the C-API and the SQL function are disabled. 2282 ** If the first argument is -1, then no changes are made to state of either the 2283 ** C-API or the SQL function. 2284 ** The second parameter is a pointer to an integer into which 2285 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2286 ** is disabled or enabled following this call. The second parameter may 2287 ** be a NULL pointer, in which case the new setting is not reported back. 2288 ** </dd> 2289 ** 2290 ** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2291 ** <dd> ^This option is used to change the name of the "main" database 2292 ** schema. ^The sole argument is a pointer to a constant UTF8 string 2293 ** which will become the new schema name in place of "main". ^SQLite 2294 ** does not make a copy of the new main schema name string, so the application 2295 ** must ensure that the argument passed into this DBCONFIG option is unchanged 2296 ** until after the database connection closes. 2297 ** </dd> 2298 ** 2299 ** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] 2300 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2301 ** <dd> Usually, when a database in wal mode is closed or detached from a 2302 ** database handle, SQLite checks if this will mean that there are now no 2303 ** connections at all to the database. If so, it performs a checkpoint 2304 ** operation before closing the connection. This option may be used to 2305 ** override this behavior. The first parameter passed to this operation 2306 ** is an integer - positive to disable checkpoints-on-close, or zero (the 2307 ** default) to enable them, and negative to leave the setting unchanged. 2308 ** The second parameter is a pointer to an integer 2309 ** into which is written 0 or 1 to indicate whether checkpoints-on-close 2310 ** have been disabled - 0 if they are not disabled, 1 if they are. 2311 ** </dd> 2312 ** 2313 ** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2314 ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2315 ** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2316 ** a single SQL query statement will always use the same algorithm regardless 2317 ** of values of [bound parameters].)^ The QPSG disables some query optimizations 2318 ** that look at the values of bound parameters, which can make some queries 2319 ** slower. But the QPSG has the advantage of more predictable behavior. With 2320 ** the QPSG active, SQLite will always use the same query plan in the field as 2321 ** was used during testing in the lab. 2322 ** The first argument to this setting is an integer which is 0 to disable 2323 ** the QPSG, positive to enable QPSG, or negative to leave the setting 2324 ** unchanged. The second parameter is a pointer to an integer into which 2325 ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2326 ** following this call. 2327 ** </dd> 2328 ** 2329 ** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2330 ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2331 ** include output for any operations performed by trigger programs. This 2332 ** option is used to set or clear (the default) a flag that governs this 2333 ** behavior. The first parameter passed to this operation is an integer - 2334 ** positive to enable output for trigger programs, or zero to disable it, 2335 ** or negative to leave the setting unchanged. 2336 ** The second parameter is a pointer to an integer into which is written 2337 ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2338 ** it is not disabled, 1 if it is. 2339 ** </dd> 2340 ** 2341 ** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2342 ** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2343 ** [VACUUM] in order to reset a database back to an empty database 2344 ** with no schema and no content. The following process works even for 2345 ** a badly corrupted database file: 2346 ** <ol> 2347 ** <li> If the database connection is newly opened, make sure it has read the 2348 ** database schema by preparing then discarding some query against the 2349 ** database, or calling sqlite3_table_column_metadata(), ignoring any 2350 ** errors. This step is only necessary if the application desires to keep 2351 ** the database in WAL mode after the reset if it was in WAL mode before 2352 ** the reset. 2353 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2354 ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2355 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2356 ** </ol> 2357 ** Because resetting a database is destructive and irreversible, the 2358 ** process requires the use of this obscure API and multiple steps to 2359 ** help ensure that it does not happen by accident. Because this 2360 ** feature must be capable of resetting corrupt databases, and 2361 ** shutting down virtual tables may require access to that corrupt 2362 ** storage, the library must abandon any installed virtual tables 2363 ** without calling their xDestroy() methods. 2364 ** 2365 ** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt> 2366 ** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the 2367 ** "defensive" flag for a database connection. When the defensive 2368 ** flag is enabled, language features that allow ordinary SQL to 2369 ** deliberately corrupt the database file are disabled. The disabled 2370 ** features include but are not limited to the following: 2371 ** <ul> 2372 ** <li> The [PRAGMA writable_schema=ON] statement. 2373 ** <li> The [PRAGMA journal_mode=OFF] statement. 2374 ** <li> The [PRAGMA schema_version=N] statement. 2375 ** <li> Writes to the [sqlite_dbpage] virtual table. 2376 ** <li> Direct writes to [shadow tables]. 2377 ** </ul> 2378 ** </dd> 2379 ** 2380 ** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt> 2381 ** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the 2382 ** "writable_schema" flag. This has the same effect and is logically equivalent 2383 ** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF]. 2384 ** The first argument to this setting is an integer which is 0 to disable 2385 ** the writable_schema, positive to enable writable_schema, or negative to 2386 ** leave the setting unchanged. The second parameter is a pointer to an 2387 ** integer into which is written 0 or 1 to indicate whether the writable_schema 2388 ** is enabled or disabled following this call. 2389 ** </dd> 2390 ** 2391 ** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]] 2392 ** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt> 2393 ** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates 2394 ** the legacy behavior of the [ALTER TABLE RENAME] command such it 2395 ** behaves as it did prior to [version 3.24.0] (2018-06-04). See the 2396 ** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for 2397 ** additional information. This feature can also be turned on and off 2398 ** using the [PRAGMA legacy_alter_table] statement. 2399 ** </dd> 2400 ** 2401 ** [[SQLITE_DBCONFIG_DQS_DML]] 2402 ** <dt>SQLITE_DBCONFIG_DQS_DML</dt> 2403 ** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates 2404 ** the legacy [double-quoted string literal] misfeature for DML statements 2405 ** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The 2406 ** default value of this setting is determined by the [-DSQLITE_DQS] 2407 ** compile-time option. 2408 ** </dd> 2409 ** 2410 ** [[SQLITE_DBCONFIG_DQS_DDL]] 2411 ** <dt>SQLITE_DBCONFIG_DQS_DDL</dt> 2412 ** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates 2413 ** the legacy [double-quoted string literal] misfeature for DDL statements, 2414 ** such as CREATE TABLE and CREATE INDEX. The 2415 ** default value of this setting is determined by the [-DSQLITE_DQS] 2416 ** compile-time option. 2417 ** </dd> 2418 ** 2419 ** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]] 2420 ** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</dt> 2421 ** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to 2422 ** assume that database schemas are untainted by malicious content. 2423 ** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite 2424 ** takes additional defensive steps to protect the application from harm 2425 ** including: 2426 ** <ul> 2427 ** <li> Prohibit the use of SQL functions inside triggers, views, 2428 ** CHECK constraints, DEFAULT clauses, expression indexes, 2429 ** partial indexes, or generated columns 2430 ** unless those functions are tagged with [SQLITE_INNOCUOUS]. 2431 ** <li> Prohibit the use of virtual tables inside of triggers or views 2432 ** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS]. 2433 ** </ul> 2434 ** This setting defaults to "on" for legacy compatibility, however 2435 ** all applications are advised to turn it off if possible. This setting 2436 ** can also be controlled using the [PRAGMA trusted_schema] statement. 2437 ** </dd> 2438 ** 2439 ** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]] 2440 ** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</dt> 2441 ** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates 2442 ** the legacy file format flag. When activated, this flag causes all newly 2443 ** created database file to have a schema format version number (the 4-byte 2444 ** integer found at offset 44 into the database header) of 1. This in turn 2445 ** means that the resulting database file will be readable and writable by 2446 ** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting, 2447 ** newly created databases are generally not understandable by SQLite versions 2448 ** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there 2449 ** is now scarcely any need to generate database files that are compatible 2450 ** all the way back to version 3.0.0, and so this setting is of little 2451 ** practical use, but is provided so that SQLite can continue to claim the 2452 ** ability to generate new database files that are compatible with version 2453 ** 3.0.0. 2454 ** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on, 2455 ** the [VACUUM] command will fail with an obscure error when attempting to 2456 ** process a table with generated columns and a descending index. This is 2457 ** not considered a bug since SQLite versions 3.3.0 and earlier do not support 2458 ** either generated columns or descending indexes. 2459 ** </dd> 2460 ** 2461 ** [[SQLITE_DBCONFIG_STMT_SCANSTATUS]] 2462 ** <dt>SQLITE_DBCONFIG_STMT_SCANSTATUS</dt> 2463 ** <dd>The SQLITE_DBCONFIG_STMT_SCANSTATUS option is only useful in 2464 ** SQLITE_ENABLE_STMT_SCANSTATUS builds. In this case, it sets or clears 2465 ** a flag that enables collection of the sqlite3_stmt_scanstatus_v2() 2466 ** statistics. For statistics to be collected, the flag must be set on 2467 ** the database handle both when the SQL statement is prepared and when it 2468 ** is stepped. The flag is set (collection of statistics is enabled) 2469 ** by default. This option takes two arguments: an integer and a pointer to 2470 ** an integer.. The first argument is 1, 0, or -1 to enable, disable, or 2471 ** leave unchanged the statement scanstatus option. If the second argument 2472 ** is not NULL, then the value of the statement scanstatus setting after 2473 ** processing the first argument is written into the integer that the second 2474 ** argument points to. 2475 ** </dd> 2476 ** 2477 ** [[SQLITE_DBCONFIG_REVERSE_SCANORDER]] 2478 ** <dt>SQLITE_DBCONFIG_REVERSE_SCANORDER</dt> 2479 ** <dd>The SQLITE_DBCONFIG_REVERSE_SCANORDER option changes the default order 2480 ** in which tables and indexes are scanned so that the scans start at the end 2481 ** and work toward the beginning rather than starting at the beginning and 2482 ** working toward the end. Setting SQLITE_DBCONFIG_REVERSE_SCANORDER is the 2483 ** same as setting [PRAGMA reverse_unordered_selects]. This option takes 2484 ** two arguments which are an integer and a pointer to an integer. The first 2485 ** argument is 1, 0, or -1 to enable, disable, or leave unchanged the 2486 ** reverse scan order flag, respectively. If the second argument is not NULL, 2487 ** then 0 or 1 is written into the integer that the second argument points to 2488 ** depending on if the reverse scan order flag is set after processing the 2489 ** first argument. 2490 ** </dd> 2491 ** 2492 ** </dl> 2493 */ 2494 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2495 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2496 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2497 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2498 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2499 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2500 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2501 #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2502 #define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2503 #define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2504 #define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ 2505 #define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */ 2506 #define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */ 2507 #define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */ 2508 #define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */ 2509 #define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */ 2510 #define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */ 2511 #define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */ 2512 #define SQLITE_DBCONFIG_STMT_SCANSTATUS 1018 /* int int* */ 2513 #define SQLITE_DBCONFIG_REVERSE_SCANORDER 1019 /* int int* */ 2514 #define SQLITE_DBCONFIG_MAX 1019 /* Largest DBCONFIG */ 2515 2516 /* 2517 ** CAPI3REF: Enable Or Disable Extended Result Codes 2518 ** METHOD: sqlite3 2519 ** 2520 ** ^The sqlite3_extended_result_codes() routine enables or disables the 2521 ** [extended result codes] feature of SQLite. ^The extended result 2522 ** codes are disabled by default for historical compatibility. 2523 */ 2524 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 2525 2526 /* 2527 ** CAPI3REF: Last Insert Rowid 2528 ** METHOD: sqlite3 2529 ** 2530 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2531 ** has a unique 64-bit signed 2532 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2533 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2534 ** names are not also used by explicitly declared columns. ^If 2535 ** the table has a column of type [INTEGER PRIMARY KEY] then that column 2536 ** is another alias for the rowid. 2537 ** 2538 ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2539 ** the most recent successful [INSERT] into a rowid table or [virtual table] 2540 ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2541 ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2542 ** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2543 ** zero. 2544 ** 2545 ** As well as being set automatically as rows are inserted into database 2546 ** tables, the value returned by this function may be set explicitly by 2547 ** [sqlite3_set_last_insert_rowid()] 2548 ** 2549 ** Some virtual table implementations may INSERT rows into rowid tables as 2550 ** part of committing a transaction (e.g. to flush data accumulated in memory 2551 ** to disk). In this case subsequent calls to this function return the rowid 2552 ** associated with these internal INSERT operations, which leads to 2553 ** unintuitive results. Virtual table implementations that do write to rowid 2554 ** tables in this way can avoid this problem by restoring the original 2555 ** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2556 ** control to the user. 2557 ** 2558 ** ^(If an [INSERT] occurs within a trigger then this routine will 2559 ** return the [rowid] of the inserted row as long as the trigger is 2560 ** running. Once the trigger program ends, the value returned 2561 ** by this routine reverts to what it was before the trigger was fired.)^ 2562 ** 2563 ** ^An [INSERT] that fails due to a constraint violation is not a 2564 ** successful [INSERT] and does not change the value returned by this 2565 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2566 ** and INSERT OR ABORT make no changes to the return value of this 2567 ** routine when their insertion fails. ^(When INSERT OR REPLACE 2568 ** encounters a constraint violation, it does not fail. The 2569 ** INSERT continues to completion after deleting rows that caused 2570 ** the constraint problem so INSERT OR REPLACE will always change 2571 ** the return value of this interface.)^ 2572 ** 2573 ** ^For the purposes of this routine, an [INSERT] is considered to 2574 ** be successful even if it is subsequently rolled back. 2575 ** 2576 ** This function is accessible to SQL statements via the 2577 ** [last_insert_rowid() SQL function]. 2578 ** 2579 ** If a separate thread performs a new [INSERT] on the same 2580 ** database connection while the [sqlite3_last_insert_rowid()] 2581 ** function is running and thus changes the last insert [rowid], 2582 ** then the value returned by [sqlite3_last_insert_rowid()] is 2583 ** unpredictable and might not equal either the old or the new 2584 ** last insert [rowid]. 2585 */ 2586 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2587 2588 /* 2589 ** CAPI3REF: Set the Last Insert Rowid value. 2590 ** METHOD: sqlite3 2591 ** 2592 ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2593 ** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2594 ** without inserting a row into the database. 2595 */ 2596 SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2597 2598 /* 2599 ** CAPI3REF: Count The Number Of Rows Modified 2600 ** METHOD: sqlite3 2601 ** 2602 ** ^These functions return the number of rows modified, inserted or 2603 ** deleted by the most recently completed INSERT, UPDATE or DELETE 2604 ** statement on the database connection specified by the only parameter. 2605 ** The two functions are identical except for the type of the return value 2606 ** and that if the number of rows modified by the most recent INSERT, UPDATE 2607 ** or DELETE is greater than the maximum value supported by type "int", then 2608 ** the return value of sqlite3_changes() is undefined. ^Executing any other 2609 ** type of SQL statement does not modify the value returned by these functions. 2610 ** 2611 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2612 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2613 ** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2614 ** 2615 ** Changes to a view that are intercepted by 2616 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2617 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2618 ** DELETE statement run on a view is always zero. Only changes made to real 2619 ** tables are counted. 2620 ** 2621 ** Things are more complicated if the sqlite3_changes() function is 2622 ** executed while a trigger program is running. This may happen if the 2623 ** program uses the [changes() SQL function], or if some other callback 2624 ** function invokes sqlite3_changes() directly. Essentially: 2625 ** 2626 ** <ul> 2627 ** <li> ^(Before entering a trigger program the value returned by 2628 ** sqlite3_changes() function is saved. After the trigger program 2629 ** has finished, the original value is restored.)^ 2630 ** 2631 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2632 ** statement sets the value returned by sqlite3_changes() 2633 ** upon completion as normal. Of course, this value will not include 2634 ** any changes performed by sub-triggers, as the sqlite3_changes() 2635 ** value will be saved and restored after each sub-trigger has run.)^ 2636 ** </ul> 2637 ** 2638 ** ^This means that if the changes() SQL function (or similar) is used 2639 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2640 ** returns the value as set when the calling statement began executing. 2641 ** ^If it is used by the second or subsequent such statement within a trigger 2642 ** program, the value returned reflects the number of rows modified by the 2643 ** previous INSERT, UPDATE or DELETE statement within the same trigger. 2644 ** 2645 ** If a separate thread makes changes on the same database connection 2646 ** while [sqlite3_changes()] is running then the value returned 2647 ** is unpredictable and not meaningful. 2648 ** 2649 ** See also: 2650 ** <ul> 2651 ** <li> the [sqlite3_total_changes()] interface 2652 ** <li> the [count_changes pragma] 2653 ** <li> the [changes() SQL function] 2654 ** <li> the [data_version pragma] 2655 ** </ul> 2656 */ 2657 SQLITE_API int sqlite3_changes(sqlite3*); 2658 SQLITE_API sqlite3_int64 sqlite3_changes64(sqlite3*); 2659 2660 /* 2661 ** CAPI3REF: Total Number Of Rows Modified 2662 ** METHOD: sqlite3 2663 ** 2664 ** ^These functions return the total number of rows inserted, modified or 2665 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2666 ** since the database connection was opened, including those executed as 2667 ** part of trigger programs. The two functions are identical except for the 2668 ** type of the return value and that if the number of rows modified by the 2669 ** connection exceeds the maximum value supported by type "int", then 2670 ** the return value of sqlite3_total_changes() is undefined. ^Executing 2671 ** any other type of SQL statement does not affect the value returned by 2672 ** sqlite3_total_changes(). 2673 ** 2674 ** ^Changes made as part of [foreign key actions] are included in the 2675 ** count, but those made as part of REPLACE constraint resolution are 2676 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2677 ** are not counted. 2678 ** 2679 ** The [sqlite3_total_changes(D)] interface only reports the number 2680 ** of rows that changed due to SQL statement run against database 2681 ** connection D. Any changes by other database connections are ignored. 2682 ** To detect changes against a database file from other database 2683 ** connections use the [PRAGMA data_version] command or the 2684 ** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2685 ** 2686 ** If a separate thread makes changes on the same database connection 2687 ** while [sqlite3_total_changes()] is running then the value 2688 ** returned is unpredictable and not meaningful. 2689 ** 2690 ** See also: 2691 ** <ul> 2692 ** <li> the [sqlite3_changes()] interface 2693 ** <li> the [count_changes pragma] 2694 ** <li> the [changes() SQL function] 2695 ** <li> the [data_version pragma] 2696 ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2697 ** </ul> 2698 */ 2699 SQLITE_API int sqlite3_total_changes(sqlite3*); 2700 SQLITE_API sqlite3_int64 sqlite3_total_changes64(sqlite3*); 2701 2702 /* 2703 ** CAPI3REF: Interrupt A Long-Running Query 2704 ** METHOD: sqlite3 2705 ** 2706 ** ^This function causes any pending database operation to abort and 2707 ** return at its earliest opportunity. This routine is typically 2708 ** called in response to a user action such as pressing "Cancel" 2709 ** or Ctrl-C where the user wants a long query operation to halt 2710 ** immediately. 2711 ** 2712 ** ^It is safe to call this routine from a thread different from the 2713 ** thread that is currently running the database operation. But it 2714 ** is not safe to call this routine with a [database connection] that 2715 ** is closed or might close before sqlite3_interrupt() returns. 2716 ** 2717 ** ^If an SQL operation is very nearly finished at the time when 2718 ** sqlite3_interrupt() is called, then it might not have an opportunity 2719 ** to be interrupted and might continue to completion. 2720 ** 2721 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2722 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2723 ** that is inside an explicit transaction, then the entire transaction 2724 ** will be rolled back automatically. 2725 ** 2726 ** ^The sqlite3_interrupt(D) call is in effect until all currently running 2727 ** SQL statements on [database connection] D complete. ^Any new SQL statements 2728 ** that are started after the sqlite3_interrupt() call and before the 2729 ** running statement count reaches zero are interrupted as if they had been 2730 ** running prior to the sqlite3_interrupt() call. ^New SQL statements 2731 ** that are started after the running statement count reaches zero are 2732 ** not effected by the sqlite3_interrupt(). 2733 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2734 ** SQL statements is a no-op and has no effect on SQL statements 2735 ** that are started after the sqlite3_interrupt() call returns. 2736 ** 2737 ** ^The [sqlite3_is_interrupted(D)] interface can be used to determine whether 2738 ** or not an interrupt is currently in effect for [database connection] D. 2739 ** It returns 1 if an interrupt is currently in effect, or 0 otherwise. 2740 */ 2741 SQLITE_API void sqlite3_interrupt(sqlite3*); 2742 SQLITE_API int sqlite3_is_interrupted(sqlite3*); 2743 2744 /* 2745 ** CAPI3REF: Determine If An SQL Statement Is Complete 2746 ** 2747 ** These routines are useful during command-line input to determine if the 2748 ** currently entered text seems to form a complete SQL statement or 2749 ** if additional input is needed before sending the text into 2750 ** SQLite for parsing. ^These routines return 1 if the input string 2751 ** appears to be a complete SQL statement. ^A statement is judged to be 2752 ** complete if it ends with a semicolon token and is not a prefix of a 2753 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2754 ** string literals or quoted identifier names or comments are not 2755 ** independent tokens (they are part of the token in which they are 2756 ** embedded) and thus do not count as a statement terminator. ^Whitespace 2757 ** and comments that follow the final semicolon are ignored. 2758 ** 2759 ** ^These routines return 0 if the statement is incomplete. ^If a 2760 ** memory allocation fails, then SQLITE_NOMEM is returned. 2761 ** 2762 ** ^These routines do not parse the SQL statements thus 2763 ** will not detect syntactically incorrect SQL. 2764 ** 2765 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2766 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2767 ** automatically by sqlite3_complete16(). If that initialization fails, 2768 ** then the return value from sqlite3_complete16() will be non-zero 2769 ** regardless of whether or not the input SQL is complete.)^ 2770 ** 2771 ** The input to [sqlite3_complete()] must be a zero-terminated 2772 ** UTF-8 string. 2773 ** 2774 ** The input to [sqlite3_complete16()] must be a zero-terminated 2775 ** UTF-16 string in native byte order. 2776 */ 2777 SQLITE_API int sqlite3_complete(const char *sql); 2778 SQLITE_API int sqlite3_complete16(const void *sql); 2779 2780 /* 2781 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2782 ** KEYWORDS: {busy-handler callback} {busy handler} 2783 ** METHOD: sqlite3 2784 ** 2785 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2786 ** that might be invoked with argument P whenever 2787 ** an attempt is made to access a database table associated with 2788 ** [database connection] D when another thread 2789 ** or process has the table locked. 2790 ** The sqlite3_busy_handler() interface is used to implement 2791 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2792 ** 2793 ** ^If the busy callback is NULL, then [SQLITE_BUSY] 2794 ** is returned immediately upon encountering the lock. ^If the busy callback 2795 ** is not NULL, then the callback might be invoked with two arguments. 2796 ** 2797 ** ^The first argument to the busy handler is a copy of the void* pointer which 2798 ** is the third argument to sqlite3_busy_handler(). ^The second argument to 2799 ** the busy handler callback is the number of times that the busy handler has 2800 ** been invoked previously for the same locking event. ^If the 2801 ** busy callback returns 0, then no additional attempts are made to 2802 ** access the database and [SQLITE_BUSY] is returned 2803 ** to the application. 2804 ** ^If the callback returns non-zero, then another attempt 2805 ** is made to access the database and the cycle repeats. 2806 ** 2807 ** The presence of a busy handler does not guarantee that it will be invoked 2808 ** when there is lock contention. ^If SQLite determines that invoking the busy 2809 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2810 ** to the application instead of invoking the 2811 ** busy handler. 2812 ** Consider a scenario where one process is holding a read lock that 2813 ** it is trying to promote to a reserved lock and 2814 ** a second process is holding a reserved lock that it is trying 2815 ** to promote to an exclusive lock. The first process cannot proceed 2816 ** because it is blocked by the second and the second process cannot 2817 ** proceed because it is blocked by the first. If both processes 2818 ** invoke the busy handlers, neither will make any progress. Therefore, 2819 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2820 ** will induce the first process to release its read lock and allow 2821 ** the second process to proceed. 2822 ** 2823 ** ^The default busy callback is NULL. 2824 ** 2825 ** ^(There can only be a single busy handler defined for each 2826 ** [database connection]. Setting a new busy handler clears any 2827 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2828 ** or evaluating [PRAGMA busy_timeout=N] will change the 2829 ** busy handler and thus clear any previously set busy handler. 2830 ** 2831 ** The busy callback should not take any actions which modify the 2832 ** database connection that invoked the busy handler. In other words, 2833 ** the busy handler is not reentrant. Any such actions 2834 ** result in undefined behavior. 2835 ** 2836 ** A busy handler must not close the database connection 2837 ** or [prepared statement] that invoked the busy handler. 2838 */ 2839 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2840 2841 /* 2842 ** CAPI3REF: Set A Busy Timeout 2843 ** METHOD: sqlite3 2844 ** 2845 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2846 ** for a specified amount of time when a table is locked. ^The handler 2847 ** will sleep multiple times until at least "ms" milliseconds of sleeping 2848 ** have accumulated. ^After at least "ms" milliseconds of sleeping, 2849 ** the handler returns 0 which causes [sqlite3_step()] to return 2850 ** [SQLITE_BUSY]. 2851 ** 2852 ** ^Calling this routine with an argument less than or equal to zero 2853 ** turns off all busy handlers. 2854 ** 2855 ** ^(There can only be a single busy handler for a particular 2856 ** [database connection] at any given moment. If another busy handler 2857 ** was defined (using [sqlite3_busy_handler()]) prior to calling 2858 ** this routine, that other busy handler is cleared.)^ 2859 ** 2860 ** See also: [PRAGMA busy_timeout] 2861 */ 2862 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2863 2864 /* 2865 ** CAPI3REF: Convenience Routines For Running Queries 2866 ** METHOD: sqlite3 2867 ** 2868 ** This is a legacy interface that is preserved for backwards compatibility. 2869 ** Use of this interface is not recommended. 2870 ** 2871 ** Definition: A <b>result table</b> is memory data structure created by the 2872 ** [sqlite3_get_table()] interface. A result table records the 2873 ** complete query results from one or more queries. 2874 ** 2875 ** The table conceptually has a number of rows and columns. But 2876 ** these numbers are not part of the result table itself. These 2877 ** numbers are obtained separately. Let N be the number of rows 2878 ** and M be the number of columns. 2879 ** 2880 ** A result table is an array of pointers to zero-terminated UTF-8 strings. 2881 ** There are (N+1)*M elements in the array. The first M pointers point 2882 ** to zero-terminated strings that contain the names of the columns. 2883 ** The remaining entries all point to query results. NULL values result 2884 ** in NULL pointers. All other values are in their UTF-8 zero-terminated 2885 ** string representation as returned by [sqlite3_column_text()]. 2886 ** 2887 ** A result table might consist of one or more memory allocations. 2888 ** It is not safe to pass a result table directly to [sqlite3_free()]. 2889 ** A result table should be deallocated using [sqlite3_free_table()]. 2890 ** 2891 ** ^(As an example of the result table format, suppose a query result 2892 ** is as follows: 2893 ** 2894 ** <blockquote><pre> 2895 ** Name | Age 2896 ** ----------------------- 2897 ** Alice | 43 2898 ** Bob | 28 2899 ** Cindy | 21 2900 ** </pre></blockquote> 2901 ** 2902 ** There are two columns (M==2) and three rows (N==3). Thus the 2903 ** result table has 8 entries. Suppose the result table is stored 2904 ** in an array named azResult. Then azResult holds this content: 2905 ** 2906 ** <blockquote><pre> 2907 ** azResult[0] = "Name"; 2908 ** azResult[1] = "Age"; 2909 ** azResult[2] = "Alice"; 2910 ** azResult[3] = "43"; 2911 ** azResult[4] = "Bob"; 2912 ** azResult[5] = "28"; 2913 ** azResult[6] = "Cindy"; 2914 ** azResult[7] = "21"; 2915 ** </pre></blockquote>)^ 2916 ** 2917 ** ^The sqlite3_get_table() function evaluates one or more 2918 ** semicolon-separated SQL statements in the zero-terminated UTF-8 2919 ** string of its 2nd parameter and returns a result table to the 2920 ** pointer given in its 3rd parameter. 2921 ** 2922 ** After the application has finished with the result from sqlite3_get_table(), 2923 ** it must pass the result table pointer to sqlite3_free_table() in order to 2924 ** release the memory that was malloced. Because of the way the 2925 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2926 ** function must not try to call [sqlite3_free()] directly. Only 2927 ** [sqlite3_free_table()] is able to release the memory properly and safely. 2928 ** 2929 ** The sqlite3_get_table() interface is implemented as a wrapper around 2930 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2931 ** to any internal data structures of SQLite. It uses only the public 2932 ** interface defined here. As a consequence, errors that occur in the 2933 ** wrapper layer outside of the internal [sqlite3_exec()] call are not 2934 ** reflected in subsequent calls to [sqlite3_errcode()] or 2935 ** [sqlite3_errmsg()]. 2936 */ 2937 SQLITE_API int sqlite3_get_table( 2938 sqlite3 *db, /* An open database */ 2939 const char *zSql, /* SQL to be evaluated */ 2940 char ***pazResult, /* Results of the query */ 2941 int *pnRow, /* Number of result rows written here */ 2942 int *pnColumn, /* Number of result columns written here */ 2943 char **pzErrmsg /* Error msg written here */ 2944 ); 2945 SQLITE_API void sqlite3_free_table(char **result); 2946 2947 /* 2948 ** CAPI3REF: Formatted String Printing Functions 2949 ** 2950 ** These routines are work-alikes of the "printf()" family of functions 2951 ** from the standard C library. 2952 ** These routines understand most of the common formatting options from 2953 ** the standard library printf() 2954 ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2955 ** See the [built-in printf()] documentation for details. 2956 ** 2957 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2958 ** results into memory obtained from [sqlite3_malloc64()]. 2959 ** The strings returned by these two routines should be 2960 ** released by [sqlite3_free()]. ^Both routines return a 2961 ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2962 ** memory to hold the resulting string. 2963 ** 2964 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2965 ** the standard C library. The result is written into the 2966 ** buffer supplied as the second parameter whose size is given by 2967 ** the first parameter. Note that the order of the 2968 ** first two parameters is reversed from snprintf().)^ This is an 2969 ** historical accident that cannot be fixed without breaking 2970 ** backwards compatibility. ^(Note also that sqlite3_snprintf() 2971 ** returns a pointer to its buffer instead of the number of 2972 ** characters actually written into the buffer.)^ We admit that 2973 ** the number of characters written would be a more useful return 2974 ** value but we cannot change the implementation of sqlite3_snprintf() 2975 ** now without breaking compatibility. 2976 ** 2977 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2978 ** guarantees that the buffer is always zero-terminated. ^The first 2979 ** parameter "n" is the total size of the buffer, including space for 2980 ** the zero terminator. So the longest string that can be completely 2981 ** written will be n-1 characters. 2982 ** 2983 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2984 ** 2985 ** See also: [built-in printf()], [printf() SQL function] 2986 */ 2987 SQLITE_API char *sqlite3_mprintf(const char*,...); 2988 SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2989 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2990 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2991 2992 /* 2993 ** CAPI3REF: Memory Allocation Subsystem 2994 ** 2995 ** The SQLite core uses these three routines for all of its own 2996 ** internal memory allocation needs. "Core" in the previous sentence 2997 ** does not include operating-system specific [VFS] implementation. The 2998 ** Windows VFS uses native malloc() and free() for some operations. 2999 ** 3000 ** ^The sqlite3_malloc() routine returns a pointer to a block 3001 ** of memory at least N bytes in length, where N is the parameter. 3002 ** ^If sqlite3_malloc() is unable to obtain sufficient free 3003 ** memory, it returns a NULL pointer. ^If the parameter N to 3004 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 3005 ** a NULL pointer. 3006 ** 3007 ** ^The sqlite3_malloc64(N) routine works just like 3008 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 3009 ** of a signed 32-bit integer. 3010 ** 3011 ** ^Calling sqlite3_free() with a pointer previously returned 3012 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 3013 ** that it might be reused. ^The sqlite3_free() routine is 3014 ** a no-op if is called with a NULL pointer. Passing a NULL pointer 3015 ** to sqlite3_free() is harmless. After being freed, memory 3016 ** should neither be read nor written. Even reading previously freed 3017 ** memory might result in a segmentation fault or other severe error. 3018 ** Memory corruption, a segmentation fault, or other severe error 3019 ** might result if sqlite3_free() is called with a non-NULL pointer that 3020 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 3021 ** 3022 ** ^The sqlite3_realloc(X,N) interface attempts to resize a 3023 ** prior memory allocation X to be at least N bytes. 3024 ** ^If the X parameter to sqlite3_realloc(X,N) 3025 ** is a NULL pointer then its behavior is identical to calling 3026 ** sqlite3_malloc(N). 3027 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or 3028 ** negative then the behavior is exactly the same as calling 3029 ** sqlite3_free(X). 3030 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 3031 ** of at least N bytes in size or NULL if insufficient memory is available. 3032 ** ^If M is the size of the prior allocation, then min(N,M) bytes 3033 ** of the prior allocation are copied into the beginning of buffer returned 3034 ** by sqlite3_realloc(X,N) and the prior allocation is freed. 3035 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 3036 ** prior allocation is not freed. 3037 ** 3038 ** ^The sqlite3_realloc64(X,N) interfaces works the same as 3039 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 3040 ** of a 32-bit signed integer. 3041 ** 3042 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 3043 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 3044 ** sqlite3_msize(X) returns the size of that memory allocation in bytes. 3045 ** ^The value returned by sqlite3_msize(X) might be larger than the number 3046 ** of bytes requested when X was allocated. ^If X is a NULL pointer then 3047 ** sqlite3_msize(X) returns zero. If X points to something that is not 3048 ** the beginning of memory allocation, or if it points to a formerly 3049 ** valid memory allocation that has now been freed, then the behavior 3050 ** of sqlite3_msize(X) is undefined and possibly harmful. 3051 ** 3052 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 3053 ** sqlite3_malloc64(), and sqlite3_realloc64() 3054 ** is always aligned to at least an 8 byte boundary, or to a 3055 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 3056 ** option is used. 3057 ** 3058 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 3059 ** must be either NULL or else pointers obtained from a prior 3060 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 3061 ** not yet been released. 3062 ** 3063 ** The application must not read or write any part of 3064 ** a block of memory after it has been released using 3065 ** [sqlite3_free()] or [sqlite3_realloc()]. 3066 */ 3067 SQLITE_API void *sqlite3_malloc(int); 3068 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 3069 SQLITE_API void *sqlite3_realloc(void*, int); 3070 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 3071 SQLITE_API void sqlite3_free(void*); 3072 SQLITE_API sqlite3_uint64 sqlite3_msize(void*); 3073 3074 /* 3075 ** CAPI3REF: Memory Allocator Statistics 3076 ** 3077 ** SQLite provides these two interfaces for reporting on the status 3078 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 3079 ** routines, which form the built-in memory allocation subsystem. 3080 ** 3081 ** ^The [sqlite3_memory_used()] routine returns the number of bytes 3082 ** of memory currently outstanding (malloced but not freed). 3083 ** ^The [sqlite3_memory_highwater()] routine returns the maximum 3084 ** value of [sqlite3_memory_used()] since the high-water mark 3085 ** was last reset. ^The values returned by [sqlite3_memory_used()] and 3086 ** [sqlite3_memory_highwater()] include any overhead 3087 ** added by SQLite in its implementation of [sqlite3_malloc()], 3088 ** but not overhead added by the any underlying system library 3089 ** routines that [sqlite3_malloc()] may call. 3090 ** 3091 ** ^The memory high-water mark is reset to the current value of 3092 ** [sqlite3_memory_used()] if and only if the parameter to 3093 ** [sqlite3_memory_highwater()] is true. ^The value returned 3094 ** by [sqlite3_memory_highwater(1)] is the high-water mark 3095 ** prior to the reset. 3096 */ 3097 SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 3098 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 3099 3100 /* 3101 ** CAPI3REF: Pseudo-Random Number Generator 3102 ** 3103 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 3104 ** select random [ROWID | ROWIDs] when inserting new records into a table that 3105 ** already uses the largest possible [ROWID]. The PRNG is also used for 3106 ** the built-in random() and randomblob() SQL functions. This interface allows 3107 ** applications to access the same PRNG for other purposes. 3108 ** 3109 ** ^A call to this routine stores N bytes of randomness into buffer P. 3110 ** ^The P parameter can be a NULL pointer. 3111 ** 3112 ** ^If this routine has not been previously called or if the previous 3113 ** call had N less than one or a NULL pointer for P, then the PRNG is 3114 ** seeded using randomness obtained from the xRandomness method of 3115 ** the default [sqlite3_vfs] object. 3116 ** ^If the previous call to this routine had an N of 1 or more and a 3117 ** non-NULL P then the pseudo-randomness is generated 3118 ** internally and without recourse to the [sqlite3_vfs] xRandomness 3119 ** method. 3120 */ 3121 SQLITE_API void sqlite3_randomness(int N, void *P); 3122 3123 /* 3124 ** CAPI3REF: Compile-Time Authorization Callbacks 3125 ** METHOD: sqlite3 3126 ** KEYWORDS: {authorizer callback} 3127 ** 3128 ** ^This routine registers an authorizer callback with a particular 3129 ** [database connection], supplied in the first argument. 3130 ** ^The authorizer callback is invoked as SQL statements are being compiled 3131 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 3132 ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 3133 ** and [sqlite3_prepare16_v3()]. ^At various 3134 ** points during the compilation process, as logic is being created 3135 ** to perform various actions, the authorizer callback is invoked to 3136 ** see if those actions are allowed. ^The authorizer callback should 3137 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 3138 ** specific action but allow the SQL statement to continue to be 3139 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 3140 ** rejected with an error. ^If the authorizer callback returns 3141 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 3142 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 3143 ** the authorizer will fail with an error message. 3144 ** 3145 ** When the callback returns [SQLITE_OK], that means the operation 3146 ** requested is ok. ^When the callback returns [SQLITE_DENY], the 3147 ** [sqlite3_prepare_v2()] or equivalent call that triggered the 3148 ** authorizer will fail with an error message explaining that 3149 ** access is denied. 3150 ** 3151 ** ^The first parameter to the authorizer callback is a copy of the third 3152 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 3153 ** to the callback is an integer [SQLITE_COPY | action code] that specifies 3154 ** the particular action to be authorized. ^The third through sixth parameters 3155 ** to the callback are either NULL pointers or zero-terminated strings 3156 ** that contain additional details about the action to be authorized. 3157 ** Applications must always be prepared to encounter a NULL pointer in any 3158 ** of the third through the sixth parameters of the authorization callback. 3159 ** 3160 ** ^If the action code is [SQLITE_READ] 3161 ** and the callback returns [SQLITE_IGNORE] then the 3162 ** [prepared statement] statement is constructed to substitute 3163 ** a NULL value in place of the table column that would have 3164 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 3165 ** return can be used to deny an untrusted user access to individual 3166 ** columns of a table. 3167 ** ^When a table is referenced by a [SELECT] but no column values are 3168 ** extracted from that table (for example in a query like 3169 ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 3170 ** is invoked once for that table with a column name that is an empty string. 3171 ** ^If the action code is [SQLITE_DELETE] and the callback returns 3172 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 3173 ** [truncate optimization] is disabled and all rows are deleted individually. 3174 ** 3175 ** An authorizer is used when [sqlite3_prepare | preparing] 3176 ** SQL statements from an untrusted source, to ensure that the SQL statements 3177 ** do not try to access data they are not allowed to see, or that they do not 3178 ** try to execute malicious statements that damage the database. For 3179 ** example, an application may allow a user to enter arbitrary 3180 ** SQL queries for evaluation by a database. But the application does 3181 ** not want the user to be able to make arbitrary changes to the 3182 ** database. An authorizer could then be put in place while the 3183 ** user-entered SQL is being [sqlite3_prepare | prepared] that 3184 ** disallows everything except [SELECT] statements. 3185 ** 3186 ** Applications that need to process SQL from untrusted sources 3187 ** might also consider lowering resource limits using [sqlite3_limit()] 3188 ** and limiting database size using the [max_page_count] [PRAGMA] 3189 ** in addition to using an authorizer. 3190 ** 3191 ** ^(Only a single authorizer can be in place on a database connection 3192 ** at a time. Each call to sqlite3_set_authorizer overrides the 3193 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 3194 ** The authorizer is disabled by default. 3195 ** 3196 ** The authorizer callback must not do anything that will modify 3197 ** the database connection that invoked the authorizer callback. 3198 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3199 ** database connections for the meaning of "modify" in this paragraph. 3200 ** 3201 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 3202 ** statement might be re-prepared during [sqlite3_step()] due to a 3203 ** schema change. Hence, the application should ensure that the 3204 ** correct authorizer callback remains in place during the [sqlite3_step()]. 3205 ** 3206 ** ^Note that the authorizer callback is invoked only during 3207 ** [sqlite3_prepare()] or its variants. Authorization is not 3208 ** performed during statement evaluation in [sqlite3_step()], unless 3209 ** as stated in the previous paragraph, sqlite3_step() invokes 3210 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 3211 */ 3212 SQLITE_API int sqlite3_set_authorizer( 3213 sqlite3*, 3214 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 3215 void *pUserData 3216 ); 3217 3218 /* 3219 ** CAPI3REF: Authorizer Return Codes 3220 ** 3221 ** The [sqlite3_set_authorizer | authorizer callback function] must 3222 ** return either [SQLITE_OK] or one of these two constants in order 3223 ** to signal SQLite whether or not the action is permitted. See the 3224 ** [sqlite3_set_authorizer | authorizer documentation] for additional 3225 ** information. 3226 ** 3227 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 3228 ** returned from the [sqlite3_vtab_on_conflict()] interface. 3229 */ 3230 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 3231 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 3232 3233 /* 3234 ** CAPI3REF: Authorizer Action Codes 3235 ** 3236 ** The [sqlite3_set_authorizer()] interface registers a callback function 3237 ** that is invoked to authorize certain SQL statement actions. The 3238 ** second parameter to the callback is an integer code that specifies 3239 ** what action is being authorized. These are the integer action codes that 3240 ** the authorizer callback may be passed. 3241 ** 3242 ** These action code values signify what kind of operation is to be 3243 ** authorized. The 3rd and 4th parameters to the authorization 3244 ** callback function will be parameters or NULL depending on which of these 3245 ** codes is used as the second parameter. ^(The 5th parameter to the 3246 ** authorizer callback is the name of the database ("main", "temp", 3247 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 3248 ** is the name of the inner-most trigger or view that is responsible for 3249 ** the access attempt or NULL if this access attempt is directly from 3250 ** top-level SQL code. 3251 */ 3252 /******************************************* 3rd ************ 4th ***********/ 3253 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 3254 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 3255 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 3256 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 3257 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 3258 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 3259 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 3260 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 3261 #define SQLITE_DELETE 9 /* Table Name NULL */ 3262 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 3263 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 3264 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 3265 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 3266 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 3267 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 3268 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 3269 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 3270 #define SQLITE_INSERT 18 /* Table Name NULL */ 3271 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 3272 #define SQLITE_READ 20 /* Table Name Column Name */ 3273 #define SQLITE_SELECT 21 /* NULL NULL */ 3274 #define SQLITE_TRANSACTION 22 /* Operation NULL */ 3275 #define SQLITE_UPDATE 23 /* Table Name Column Name */ 3276 #define SQLITE_ATTACH 24 /* Filename NULL */ 3277 #define SQLITE_DETACH 25 /* Database Name NULL */ 3278 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 3279 #define SQLITE_REINDEX 27 /* Index Name NULL */ 3280 #define SQLITE_ANALYZE 28 /* Table Name NULL */ 3281 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 3282 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 3283 #define SQLITE_FUNCTION 31 /* NULL Function Name */ 3284 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 3285 #define SQLITE_COPY 0 /* No longer used */ 3286 #define SQLITE_RECURSIVE 33 /* NULL NULL */ 3287 3288 /* 3289 ** CAPI3REF: Tracing And Profiling Functions 3290 ** METHOD: sqlite3 3291 ** 3292 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 3293 ** instead of the routines described here. 3294 ** 3295 ** These routines register callback functions that can be used for 3296 ** tracing and profiling the execution of SQL statements. 3297 ** 3298 ** ^The callback function registered by sqlite3_trace() is invoked at 3299 ** various times when an SQL statement is being run by [sqlite3_step()]. 3300 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 3301 ** SQL statement text as the statement first begins executing. 3302 ** ^(Additional sqlite3_trace() callbacks might occur 3303 ** as each triggered subprogram is entered. The callbacks for triggers 3304 ** contain a UTF-8 SQL comment that identifies the trigger.)^ 3305 ** 3306 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 3307 ** the length of [bound parameter] expansion in the output of sqlite3_trace(). 3308 ** 3309 ** ^The callback function registered by sqlite3_profile() is invoked 3310 ** as each SQL statement finishes. ^The profile callback contains 3311 ** the original statement text and an estimate of wall-clock time 3312 ** of how long that statement took to run. ^The profile callback 3313 ** time is in units of nanoseconds, however the current implementation 3314 ** is only capable of millisecond resolution so the six least significant 3315 ** digits in the time are meaningless. Future versions of SQLite 3316 ** might provide greater resolution on the profiler callback. Invoking 3317 ** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the 3318 ** profile callback. 3319 */ 3320 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 3321 void(*xTrace)(void*,const char*), void*); 3322 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 3323 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 3324 3325 /* 3326 ** CAPI3REF: SQL Trace Event Codes 3327 ** KEYWORDS: SQLITE_TRACE 3328 ** 3329 ** These constants identify classes of events that can be monitored 3330 ** using the [sqlite3_trace_v2()] tracing logic. The M argument 3331 ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 3332 ** the following constants. ^The first argument to the trace callback 3333 ** is one of the following constants. 3334 ** 3335 ** New tracing constants may be added in future releases. 3336 ** 3337 ** ^A trace callback has four arguments: xCallback(T,C,P,X). 3338 ** ^The T argument is one of the integer type codes above. 3339 ** ^The C argument is a copy of the context pointer passed in as the 3340 ** fourth argument to [sqlite3_trace_v2()]. 3341 ** The P and X arguments are pointers whose meanings depend on T. 3342 ** 3343 ** <dl> 3344 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3345 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3346 ** first begins running and possibly at other times during the 3347 ** execution of the prepared statement, such as at the start of each 3348 ** trigger subprogram. ^The P argument is a pointer to the 3349 ** [prepared statement]. ^The X argument is a pointer to a string which 3350 ** is the unexpanded SQL text of the prepared statement or an SQL comment 3351 ** that indicates the invocation of a trigger. ^The callback can compute 3352 ** the same text that would have been returned by the legacy [sqlite3_trace()] 3353 ** interface by using the X argument when X begins with "--" and invoking 3354 ** [sqlite3_expanded_sql(P)] otherwise. 3355 ** 3356 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3357 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3358 ** information as is provided by the [sqlite3_profile()] callback. 3359 ** ^The P argument is a pointer to the [prepared statement] and the 3360 ** X argument points to a 64-bit integer which is approximately 3361 ** the number of nanoseconds that the prepared statement took to run. 3362 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3363 ** 3364 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3365 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3366 ** statement generates a single row of result. 3367 ** ^The P argument is a pointer to the [prepared statement] and the 3368 ** X argument is unused. 3369 ** 3370 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3371 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3372 ** connection closes. 3373 ** ^The P argument is a pointer to the [database connection] object 3374 ** and the X argument is unused. 3375 ** </dl> 3376 */ 3377 #define SQLITE_TRACE_STMT 0x01 3378 #define SQLITE_TRACE_PROFILE 0x02 3379 #define SQLITE_TRACE_ROW 0x04 3380 #define SQLITE_TRACE_CLOSE 0x08 3381 3382 /* 3383 ** CAPI3REF: SQL Trace Hook 3384 ** METHOD: sqlite3 3385 ** 3386 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3387 ** function X against [database connection] D, using property mask M 3388 ** and context pointer P. ^If the X callback is 3389 ** NULL or if the M mask is zero, then tracing is disabled. The 3390 ** M argument should be the bitwise OR-ed combination of 3391 ** zero or more [SQLITE_TRACE] constants. 3392 ** 3393 ** ^Each call to either sqlite3_trace(D,X,P) or sqlite3_trace_v2(D,M,X,P) 3394 ** overrides (cancels) all prior calls to sqlite3_trace(D,X,P) or 3395 ** sqlite3_trace_v2(D,M,X,P) for the [database connection] D. Each 3396 ** database connection may have at most one trace callback. 3397 ** 3398 ** ^The X callback is invoked whenever any of the events identified by 3399 ** mask M occur. ^The integer return value from the callback is currently 3400 ** ignored, though this may change in future releases. Callback 3401 ** implementations should return zero to ensure future compatibility. 3402 ** 3403 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3404 ** ^The T argument is one of the [SQLITE_TRACE] 3405 ** constants to indicate why the callback was invoked. 3406 ** ^The C argument is a copy of the context pointer. 3407 ** The P and X arguments are pointers whose meanings depend on T. 3408 ** 3409 ** The sqlite3_trace_v2() interface is intended to replace the legacy 3410 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3411 ** are deprecated. 3412 */ 3413 SQLITE_API int sqlite3_trace_v2( 3414 sqlite3*, 3415 unsigned uMask, 3416 int(*xCallback)(unsigned,void*,void*,void*), 3417 void *pCtx 3418 ); 3419 3420 /* 3421 ** CAPI3REF: Query Progress Callbacks 3422 ** METHOD: sqlite3 3423 ** 3424 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3425 ** function X to be invoked periodically during long running calls to 3426 ** [sqlite3_step()] and [sqlite3_prepare()] and similar for 3427 ** database connection D. An example use for this 3428 ** interface is to keep a GUI updated during a large query. 3429 ** 3430 ** ^The parameter P is passed through as the only parameter to the 3431 ** callback function X. ^The parameter N is the approximate number of 3432 ** [virtual machine instructions] that are evaluated between successive 3433 ** invocations of the callback X. ^If N is less than one then the progress 3434 ** handler is disabled. 3435 ** 3436 ** ^Only a single progress handler may be defined at one time per 3437 ** [database connection]; setting a new progress handler cancels the 3438 ** old one. ^Setting parameter X to NULL disables the progress handler. 3439 ** ^The progress handler is also disabled by setting N to a value less 3440 ** than 1. 3441 ** 3442 ** ^If the progress callback returns non-zero, the operation is 3443 ** interrupted. This feature can be used to implement a 3444 ** "Cancel" button on a GUI progress dialog box. 3445 ** 3446 ** The progress handler callback must not do anything that will modify 3447 ** the database connection that invoked the progress handler. 3448 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3449 ** database connections for the meaning of "modify" in this paragraph. 3450 ** 3451 ** The progress handler callback would originally only be invoked from the 3452 ** bytecode engine. It still might be invoked during [sqlite3_prepare()] 3453 ** and similar because those routines might force a reparse of the schema 3454 ** which involves running the bytecode engine. However, beginning with 3455 ** SQLite version 3.41.0, the progress handler callback might also be 3456 ** invoked directly from [sqlite3_prepare()] while analyzing and generating 3457 ** code for complex queries. 3458 */ 3459 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3460 3461 /* 3462 ** CAPI3REF: Opening A New Database Connection 3463 ** CONSTRUCTOR: sqlite3 3464 ** 3465 ** ^These routines open an SQLite database file as specified by the 3466 ** filename argument. ^The filename argument is interpreted as UTF-8 for 3467 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3468 ** order for sqlite3_open16(). ^(A [database connection] handle is usually 3469 ** returned in *ppDb, even if an error occurs. The only exception is that 3470 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3471 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3472 ** object.)^ ^(If the database is opened (and/or created) successfully, then 3473 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3474 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3475 ** an English language description of the error following a failure of any 3476 ** of the sqlite3_open() routines. 3477 ** 3478 ** ^The default encoding will be UTF-8 for databases created using 3479 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3480 ** created using sqlite3_open16() will be UTF-16 in the native byte order. 3481 ** 3482 ** Whether or not an error occurs when it is opened, resources 3483 ** associated with the [database connection] handle should be released by 3484 ** passing it to [sqlite3_close()] when it is no longer required. 3485 ** 3486 ** The sqlite3_open_v2() interface works like sqlite3_open() 3487 ** except that it accepts two additional parameters for additional control 3488 ** over the new database connection. ^(The flags parameter to 3489 ** sqlite3_open_v2() must include, at a minimum, one of the following 3490 ** three flag combinations:)^ 3491 ** 3492 ** <dl> 3493 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3494 ** <dd>The database is opened in read-only mode. If the database does 3495 ** not already exist, an error is returned.</dd>)^ 3496 ** 3497 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3498 ** <dd>The database is opened for reading and writing if possible, or 3499 ** reading only if the file is write protected by the operating 3500 ** system. In either case the database must already exist, otherwise 3501 ** an error is returned. For historical reasons, if opening in 3502 ** read-write mode fails due to OS-level permissions, an attempt is 3503 ** made to open it in read-only mode. [sqlite3_db_readonly()] can be 3504 ** used to determine whether the database is actually 3505 ** read-write.</dd>)^ 3506 ** 3507 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3508 ** <dd>The database is opened for reading and writing, and is created if 3509 ** it does not already exist. This is the behavior that is always used for 3510 ** sqlite3_open() and sqlite3_open16().</dd>)^ 3511 ** </dl> 3512 ** 3513 ** In addition to the required flags, the following optional flags are 3514 ** also supported: 3515 ** 3516 ** <dl> 3517 ** ^(<dt>[SQLITE_OPEN_URI]</dt> 3518 ** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^ 3519 ** 3520 ** ^(<dt>[SQLITE_OPEN_MEMORY]</dt> 3521 ** <dd>The database will be opened as an in-memory database. The database 3522 ** is named by the "filename" argument for the purposes of cache-sharing, 3523 ** if shared cache mode is enabled, but the "filename" is otherwise ignored. 3524 ** </dd>)^ 3525 ** 3526 ** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt> 3527 ** <dd>The new database connection will use the "multi-thread" 3528 ** [threading mode].)^ This means that separate threads are allowed 3529 ** to use SQLite at the same time, as long as each thread is using 3530 ** a different [database connection]. 3531 ** 3532 ** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt> 3533 ** <dd>The new database connection will use the "serialized" 3534 ** [threading mode].)^ This means the multiple threads can safely 3535 ** attempt to use the same database connection at the same time. 3536 ** (Mutexes will block any actual concurrency, but in this mode 3537 ** there is no harm in trying.) 3538 ** 3539 ** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt> 3540 ** <dd>The database is opened [shared cache] enabled, overriding 3541 ** the default shared cache setting provided by 3542 ** [sqlite3_enable_shared_cache()].)^ 3543 ** The [use of shared cache mode is discouraged] and hence shared cache 3544 ** capabilities may be omitted from many builds of SQLite. In such cases, 3545 ** this option is a no-op. 3546 ** 3547 ** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt> 3548 ** <dd>The database is opened [shared cache] disabled, overriding 3549 ** the default shared cache setting provided by 3550 ** [sqlite3_enable_shared_cache()].)^ 3551 ** 3552 ** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt> 3553 ** <dd>The database connection comes up in "extended result code mode". 3554 ** In other words, the database behaves has if 3555 ** [sqlite3_extended_result_codes(db,1)] where called on the database 3556 ** connection as soon as the connection is created. In addition to setting 3557 ** the extended result code mode, this flag also causes [sqlite3_open_v2()] 3558 ** to return an extended result code.</dd> 3559 ** 3560 ** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt> 3561 ** <dd>The database filename is not allowed to contain a symbolic link</dd> 3562 ** </dl>)^ 3563 ** 3564 ** If the 3rd parameter to sqlite3_open_v2() is not one of the 3565 ** required combinations shown above optionally combined with other 3566 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3567 ** then the behavior is undefined. Historic versions of SQLite 3568 ** have silently ignored surplus bits in the flags parameter to 3569 ** sqlite3_open_v2(), however that behavior might not be carried through 3570 ** into future versions of SQLite and so applications should not rely 3571 ** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op 3572 ** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause 3573 ** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE 3574 ** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not 3575 ** by sqlite3_open_v2(). 3576 ** 3577 ** ^The fourth parameter to sqlite3_open_v2() is the name of the 3578 ** [sqlite3_vfs] object that defines the operating system interface that 3579 ** the new database connection should use. ^If the fourth parameter is 3580 ** a NULL pointer then the default [sqlite3_vfs] object is used. 3581 ** 3582 ** ^If the filename is ":memory:", then a private, temporary in-memory database 3583 ** is created for the connection. ^This in-memory database will vanish when 3584 ** the database connection is closed. Future versions of SQLite might 3585 ** make use of additional special filenames that begin with the ":" character. 3586 ** It is recommended that when a database filename actually does begin with 3587 ** a ":" character you should prefix the filename with a pathname such as 3588 ** "./" to avoid ambiguity. 3589 ** 3590 ** ^If the filename is an empty string, then a private, temporary 3591 ** on-disk database will be created. ^This private database will be 3592 ** automatically deleted as soon as the database connection is closed. 3593 ** 3594 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3595 ** 3596 ** ^If [URI filename] interpretation is enabled, and the filename argument 3597 ** begins with "file:", then the filename is interpreted as a URI. ^URI 3598 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3599 ** set in the third argument to sqlite3_open_v2(), or if it has 3600 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3601 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3602 ** URI filename interpretation is turned off 3603 ** by default, but future releases of SQLite might enable URI filename 3604 ** interpretation by default. See "[URI filenames]" for additional 3605 ** information. 3606 ** 3607 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3608 ** authority, then it must be either an empty string or the string 3609 ** "localhost". ^If the authority is not an empty string or "localhost", an 3610 ** error is returned to the caller. ^The fragment component of a URI, if 3611 ** present, is ignored. 3612 ** 3613 ** ^SQLite uses the path component of the URI as the name of the disk file 3614 ** which contains the database. ^If the path begins with a '/' character, 3615 ** then it is interpreted as an absolute path. ^If the path does not begin 3616 ** with a '/' (meaning that the authority section is omitted from the URI) 3617 ** then the path is interpreted as a relative path. 3618 ** ^(On windows, the first component of an absolute path 3619 ** is a drive specification (e.g. "C:").)^ 3620 ** 3621 ** [[core URI query parameters]] 3622 ** The query component of a URI may contain parameters that are interpreted 3623 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3624 ** SQLite and its built-in [VFSes] interpret the 3625 ** following query parameters: 3626 ** 3627 ** <ul> 3628 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3629 ** a VFS object that provides the operating system interface that should 3630 ** be used to access the database file on disk. ^If this option is set to 3631 ** an empty string the default VFS object is used. ^Specifying an unknown 3632 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3633 ** present, then the VFS specified by the option takes precedence over 3634 ** the value passed as the fourth parameter to sqlite3_open_v2(). 3635 ** 3636 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3637 ** "rwc", or "memory". Attempting to set it to any other value is 3638 ** an error)^. 3639 ** ^If "ro" is specified, then the database is opened for read-only 3640 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3641 ** third argument to sqlite3_open_v2(). ^If the mode option is set to 3642 ** "rw", then the database is opened for read-write (but not create) 3643 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3644 ** been set. ^Value "rwc" is equivalent to setting both 3645 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3646 ** set to "memory" then a pure [in-memory database] that never reads 3647 ** or writes from disk is used. ^It is an error to specify a value for 3648 ** the mode parameter that is less restrictive than that specified by 3649 ** the flags passed in the third parameter to sqlite3_open_v2(). 3650 ** 3651 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3652 ** "private". ^Setting it to "shared" is equivalent to setting the 3653 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3654 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3655 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3656 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3657 ** a URI filename, its value overrides any behavior requested by setting 3658 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3659 ** 3660 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3661 ** [powersafe overwrite] property does or does not apply to the 3662 ** storage media on which the database file resides. 3663 ** 3664 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3665 ** which if set disables file locking in rollback journal modes. This 3666 ** is useful for accessing a database on a filesystem that does not 3667 ** support locking. Caution: Database corruption might result if two 3668 ** or more processes write to the same database and any one of those 3669 ** processes uses nolock=1. 3670 ** 3671 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3672 ** parameter that indicates that the database file is stored on 3673 ** read-only media. ^When immutable is set, SQLite assumes that the 3674 ** database file cannot be changed, even by a process with higher 3675 ** privilege, and so the database is opened read-only and all locking 3676 ** and change detection is disabled. Caution: Setting the immutable 3677 ** property on a database file that does in fact change can result 3678 ** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3679 ** See also: [SQLITE_IOCAP_IMMUTABLE]. 3680 ** 3681 ** </ul> 3682 ** 3683 ** ^Specifying an unknown parameter in the query component of a URI is not an 3684 ** error. Future versions of SQLite might understand additional query 3685 ** parameters. See "[query parameters with special meaning to SQLite]" for 3686 ** additional information. 3687 ** 3688 ** [[URI filename examples]] <h3>URI filename examples</h3> 3689 ** 3690 ** <table border="1" align=center cellpadding=5> 3691 ** <tr><th> URI filenames <th> Results 3692 ** <tr><td> file:data.db <td> 3693 ** Open the file "data.db" in the current directory. 3694 ** <tr><td> file:/home/fred/data.db<br> 3695 ** file:///home/fred/data.db <br> 3696 ** file://localhost/home/fred/data.db <br> <td> 3697 ** Open the database file "/home/fred/data.db". 3698 ** <tr><td> file://darkstar/home/fred/data.db <td> 3699 ** An error. "darkstar" is not a recognized authority. 3700 ** <tr><td style="white-space:nowrap"> 3701 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3702 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3703 ** C:. Note that the %20 escaping in this example is not strictly 3704 ** necessary - space characters can be used literally 3705 ** in URI filenames. 3706 ** <tr><td> file:data.db?mode=ro&cache=private <td> 3707 ** Open file "data.db" in the current directory for read-only access. 3708 ** Regardless of whether or not shared-cache mode is enabled by 3709 ** default, use a private cache. 3710 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3711 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3712 ** that uses dot-files in place of posix advisory locking. 3713 ** <tr><td> file:data.db?mode=readonly <td> 3714 ** An error. "readonly" is not a valid option for the "mode" parameter. 3715 ** Use "ro" instead: "file:data.db?mode=ro". 3716 ** </table> 3717 ** 3718 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3719 ** query components of a URI. A hexadecimal escape sequence consists of a 3720 ** percent sign - "%" - followed by exactly two hexadecimal digits 3721 ** specifying an octet value. ^Before the path or query components of a 3722 ** URI filename are interpreted, they are encoded using UTF-8 and all 3723 ** hexadecimal escape sequences replaced by a single byte containing the 3724 ** corresponding octet. If this process generates an invalid UTF-8 encoding, 3725 ** the results are undefined. 3726 ** 3727 ** <b>Note to Windows users:</b> The encoding used for the filename argument 3728 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3729 ** codepage is currently defined. Filenames containing international 3730 ** characters must be converted to UTF-8 prior to passing them into 3731 ** sqlite3_open() or sqlite3_open_v2(). 3732 ** 3733 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3734 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3735 ** features that require the use of temporary files may fail. 3736 ** 3737 ** See also: [sqlite3_temp_directory] 3738 */ 3739 SQLITE_API int sqlite3_open( 3740 const char *filename, /* Database filename (UTF-8) */ 3741 sqlite3 **ppDb /* OUT: SQLite db handle */ 3742 ); 3743 SQLITE_API int sqlite3_open16( 3744 const void *filename, /* Database filename (UTF-16) */ 3745 sqlite3 **ppDb /* OUT: SQLite db handle */ 3746 ); 3747 SQLITE_API int sqlite3_open_v2( 3748 const char *filename, /* Database filename (UTF-8) */ 3749 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3750 int flags, /* Flags */ 3751 const char *zVfs /* Name of VFS module to use */ 3752 ); 3753 3754 /* 3755 ** CAPI3REF: Obtain Values For URI Parameters 3756 ** 3757 ** These are utility routines, useful to [VFS|custom VFS implementations], 3758 ** that check if a database file was a URI that contained a specific query 3759 ** parameter, and if so obtains the value of that query parameter. 3760 ** 3761 ** The first parameter to these interfaces (hereafter referred to 3762 ** as F) must be one of: 3763 ** <ul> 3764 ** <li> A database filename pointer created by the SQLite core and 3765 ** passed into the xOpen() method of a VFS implementation, or 3766 ** <li> A filename obtained from [sqlite3_db_filename()], or 3767 ** <li> A new filename constructed using [sqlite3_create_filename()]. 3768 ** </ul> 3769 ** If the F parameter is not one of the above, then the behavior is 3770 ** undefined and probably undesirable. Older versions of SQLite were 3771 ** more tolerant of invalid F parameters than newer versions. 3772 ** 3773 ** If F is a suitable filename (as described in the previous paragraph) 3774 ** and if P is the name of the query parameter, then 3775 ** sqlite3_uri_parameter(F,P) returns the value of the P 3776 ** parameter if it exists or a NULL pointer if P does not appear as a 3777 ** query parameter on F. If P is a query parameter of F and it 3778 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3779 ** a pointer to an empty string. 3780 ** 3781 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3782 ** parameter and returns true (1) or false (0) according to the value 3783 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3784 ** value of query parameter P is one of "yes", "true", or "on" in any 3785 ** case or if the value begins with a non-zero number. The 3786 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3787 ** query parameter P is one of "no", "false", or "off" in any case or 3788 ** if the value begins with a numeric zero. If P is not a query 3789 ** parameter on F or if the value of P does not match any of the 3790 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3791 ** 3792 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3793 ** 64-bit signed integer and returns that integer, or D if P does not 3794 ** exist. If the value of P is something other than an integer, then 3795 ** zero is returned. 3796 ** 3797 ** The sqlite3_uri_key(F,N) returns a pointer to the name (not 3798 ** the value) of the N-th query parameter for filename F, or a NULL 3799 ** pointer if N is less than zero or greater than the number of query 3800 ** parameters minus 1. The N value is zero-based so N should be 0 to obtain 3801 ** the name of the first query parameter, 1 for the second parameter, and 3802 ** so forth. 3803 ** 3804 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3805 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3806 ** is not a database file pathname pointer that the SQLite core passed 3807 ** into the xOpen VFS method, then the behavior of this routine is undefined 3808 ** and probably undesirable. 3809 ** 3810 ** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F 3811 ** parameter can also be the name of a rollback journal file or WAL file 3812 ** in addition to the main database file. Prior to version 3.31.0, these 3813 ** routines would only work if F was the name of the main database file. 3814 ** When the F parameter is the name of the rollback journal or WAL file, 3815 ** it has access to all the same query parameters as were found on the 3816 ** main database file. 3817 ** 3818 ** See the [URI filename] documentation for additional information. 3819 */ 3820 SQLITE_API const char *sqlite3_uri_parameter(sqlite3_filename z, const char *zParam); 3821 SQLITE_API int sqlite3_uri_boolean(sqlite3_filename z, const char *zParam, int bDefault); 3822 SQLITE_API sqlite3_int64 sqlite3_uri_int64(sqlite3_filename, const char*, sqlite3_int64); 3823 SQLITE_API const char *sqlite3_uri_key(sqlite3_filename z, int N); 3824 3825 /* 3826 ** CAPI3REF: Translate filenames 3827 ** 3828 ** These routines are available to [VFS|custom VFS implementations] for 3829 ** translating filenames between the main database file, the journal file, 3830 ** and the WAL file. 3831 ** 3832 ** If F is the name of an sqlite database file, journal file, or WAL file 3833 ** passed by the SQLite core into the VFS, then sqlite3_filename_database(F) 3834 ** returns the name of the corresponding database file. 3835 ** 3836 ** If F is the name of an sqlite database file, journal file, or WAL file 3837 ** passed by the SQLite core into the VFS, or if F is a database filename 3838 ** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F) 3839 ** returns the name of the corresponding rollback journal file. 3840 ** 3841 ** If F is the name of an sqlite database file, journal file, or WAL file 3842 ** that was passed by the SQLite core into the VFS, or if F is a database 3843 ** filename obtained from [sqlite3_db_filename()], then 3844 ** sqlite3_filename_wal(F) returns the name of the corresponding 3845 ** WAL file. 3846 ** 3847 ** In all of the above, if F is not the name of a database, journal or WAL 3848 ** filename passed into the VFS from the SQLite core and F is not the 3849 ** return value from [sqlite3_db_filename()], then the result is 3850 ** undefined and is likely a memory access violation. 3851 */ 3852 SQLITE_API const char *sqlite3_filename_database(sqlite3_filename); 3853 SQLITE_API const char *sqlite3_filename_journal(sqlite3_filename); 3854 SQLITE_API const char *sqlite3_filename_wal(sqlite3_filename); 3855 3856 /* 3857 ** CAPI3REF: Database File Corresponding To A Journal 3858 ** 3859 ** ^If X is the name of a rollback or WAL-mode journal file that is 3860 ** passed into the xOpen method of [sqlite3_vfs], then 3861 ** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file] 3862 ** object that represents the main database file. 3863 ** 3864 ** This routine is intended for use in custom [VFS] implementations 3865 ** only. It is not a general-purpose interface. 3866 ** The argument sqlite3_file_object(X) must be a filename pointer that 3867 ** has been passed into [sqlite3_vfs].xOpen method where the 3868 ** flags parameter to xOpen contains one of the bits 3869 ** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use 3870 ** of this routine results in undefined and probably undesirable 3871 ** behavior. 3872 */ 3873 SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*); 3874 3875 /* 3876 ** CAPI3REF: Create and Destroy VFS Filenames 3877 ** 3878 ** These interfaces are provided for use by [VFS shim] implementations and 3879 ** are not useful outside of that context. 3880 ** 3881 ** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of 3882 ** database filename D with corresponding journal file J and WAL file W and 3883 ** with N URI parameters key/values pairs in the array P. The result from 3884 ** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that 3885 ** is safe to pass to routines like: 3886 ** <ul> 3887 ** <li> [sqlite3_uri_parameter()], 3888 ** <li> [sqlite3_uri_boolean()], 3889 ** <li> [sqlite3_uri_int64()], 3890 ** <li> [sqlite3_uri_key()], 3891 ** <li> [sqlite3_filename_database()], 3892 ** <li> [sqlite3_filename_journal()], or 3893 ** <li> [sqlite3_filename_wal()]. 3894 ** </ul> 3895 ** If a memory allocation error occurs, sqlite3_create_filename() might 3896 ** return a NULL pointer. The memory obtained from sqlite3_create_filename(X) 3897 ** must be released by a corresponding call to sqlite3_free_filename(Y). 3898 ** 3899 ** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array 3900 ** of 2*N pointers to strings. Each pair of pointers in this array corresponds 3901 ** to a key and value for a query parameter. The P parameter may be a NULL 3902 ** pointer if N is zero. None of the 2*N pointers in the P array may be 3903 ** NULL pointers and key pointers should not be empty strings. 3904 ** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may 3905 ** be NULL pointers, though they can be empty strings. 3906 ** 3907 ** The sqlite3_free_filename(Y) routine releases a memory allocation 3908 ** previously obtained from sqlite3_create_filename(). Invoking 3909 ** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op. 3910 ** 3911 ** If the Y parameter to sqlite3_free_filename(Y) is anything other 3912 ** than a NULL pointer or a pointer previously acquired from 3913 ** sqlite3_create_filename(), then bad things such as heap 3914 ** corruption or segfaults may occur. The value Y should not be 3915 ** used again after sqlite3_free_filename(Y) has been called. This means 3916 ** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y, 3917 ** then the corresponding [sqlite3_module.xClose() method should also be 3918 ** invoked prior to calling sqlite3_free_filename(Y). 3919 */ 3920 SQLITE_API sqlite3_filename sqlite3_create_filename( 3921 const char *zDatabase, 3922 const char *zJournal, 3923 const char *zWal, 3924 int nParam, 3925 const char **azParam 3926 ); 3927 SQLITE_API void sqlite3_free_filename(sqlite3_filename); 3928 3929 /* 3930 ** CAPI3REF: Error Codes And Messages 3931 ** METHOD: sqlite3 3932 ** 3933 ** ^If the most recent sqlite3_* API call associated with 3934 ** [database connection] D failed, then the sqlite3_errcode(D) interface 3935 ** returns the numeric [result code] or [extended result code] for that 3936 ** API call. 3937 ** ^The sqlite3_extended_errcode() 3938 ** interface is the same except that it always returns the 3939 ** [extended result code] even when extended result codes are 3940 ** disabled. 3941 ** 3942 ** The values returned by sqlite3_errcode() and/or 3943 ** sqlite3_extended_errcode() might change with each API call. 3944 ** Except, there are some interfaces that are guaranteed to never 3945 ** change the value of the error code. The error-code preserving 3946 ** interfaces include the following: 3947 ** 3948 ** <ul> 3949 ** <li> sqlite3_errcode() 3950 ** <li> sqlite3_extended_errcode() 3951 ** <li> sqlite3_errmsg() 3952 ** <li> sqlite3_errmsg16() 3953 ** <li> sqlite3_error_offset() 3954 ** </ul> 3955 ** 3956 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3957 ** text that describes the error, as either UTF-8 or UTF-16 respectively, 3958 ** or NULL if no error message is available. 3959 ** (See how SQLite handles [invalid UTF] for exceptions to this rule.) 3960 ** ^(Memory to hold the error message string is managed internally. 3961 ** The application does not need to worry about freeing the result. 3962 ** However, the error string might be overwritten or deallocated by 3963 ** subsequent calls to other SQLite interface functions.)^ 3964 ** 3965 ** ^The sqlite3_errstr(E) interface returns the English-language text 3966 ** that describes the [result code] E, as UTF-8, or NULL if E is not an 3967 ** result code for which a text error message is available. 3968 ** ^(Memory to hold the error message string is managed internally 3969 ** and must not be freed by the application)^. 3970 ** 3971 ** ^If the most recent error references a specific token in the input 3972 ** SQL, the sqlite3_error_offset() interface returns the byte offset 3973 ** of the start of that token. ^The byte offset returned by 3974 ** sqlite3_error_offset() assumes that the input SQL is UTF8. 3975 ** ^If the most recent error does not reference a specific token in the input 3976 ** SQL, then the sqlite3_error_offset() function returns -1. 3977 ** 3978 ** When the serialized [threading mode] is in use, it might be the 3979 ** case that a second error occurs on a separate thread in between 3980 ** the time of the first error and the call to these interfaces. 3981 ** When that happens, the second error will be reported since these 3982 ** interfaces always report the most recent result. To avoid 3983 ** this, each thread can obtain exclusive use of the [database connection] D 3984 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3985 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3986 ** all calls to the interfaces listed here are completed. 3987 ** 3988 ** If an interface fails with SQLITE_MISUSE, that means the interface 3989 ** was invoked incorrectly by the application. In that case, the 3990 ** error code and message may or may not be set. 3991 */ 3992 SQLITE_API int sqlite3_errcode(sqlite3 *db); 3993 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 3994 SQLITE_API const char *sqlite3_errmsg(sqlite3*); 3995 SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 3996 SQLITE_API const char *sqlite3_errstr(int); 3997 SQLITE_API int sqlite3_error_offset(sqlite3 *db); 3998 3999 /* 4000 ** CAPI3REF: Prepared Statement Object 4001 ** KEYWORDS: {prepared statement} {prepared statements} 4002 ** 4003 ** An instance of this object represents a single SQL statement that 4004 ** has been compiled into binary form and is ready to be evaluated. 4005 ** 4006 ** Think of each SQL statement as a separate computer program. The 4007 ** original SQL text is source code. A prepared statement object 4008 ** is the compiled object code. All SQL must be converted into a 4009 ** prepared statement before it can be run. 4010 ** 4011 ** The life-cycle of a prepared statement object usually goes like this: 4012 ** 4013 ** <ol> 4014 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 4015 ** <li> Bind values to [parameters] using the sqlite3_bind_*() 4016 ** interfaces. 4017 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 4018 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back 4019 ** to step 2. Do this zero or more times. 4020 ** <li> Destroy the object using [sqlite3_finalize()]. 4021 ** </ol> 4022 */ 4023 typedef struct sqlite3_stmt sqlite3_stmt; 4024 4025 /* 4026 ** CAPI3REF: Run-time Limits 4027 ** METHOD: sqlite3 4028 ** 4029 ** ^(This interface allows the size of various constructs to be limited 4030 ** on a connection by connection basis. The first parameter is the 4031 ** [database connection] whose limit is to be set or queried. The 4032 ** second parameter is one of the [limit categories] that define a 4033 ** class of constructs to be size limited. The third parameter is the 4034 ** new limit for that construct.)^ 4035 ** 4036 ** ^If the new limit is a negative number, the limit is unchanged. 4037 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 4038 ** [limits | hard upper bound] 4039 ** set at compile-time by a C preprocessor macro called 4040 ** [limits | SQLITE_MAX_<i>NAME</i>]. 4041 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 4042 ** ^Attempts to increase a limit above its hard upper bound are 4043 ** silently truncated to the hard upper bound. 4044 ** 4045 ** ^Regardless of whether or not the limit was changed, the 4046 ** [sqlite3_limit()] interface returns the prior value of the limit. 4047 ** ^Hence, to find the current value of a limit without changing it, 4048 ** simply invoke this interface with the third parameter set to -1. 4049 ** 4050 ** Run-time limits are intended for use in applications that manage 4051 ** both their own internal database and also databases that are controlled 4052 ** by untrusted external sources. An example application might be a 4053 ** web browser that has its own databases for storing history and 4054 ** separate databases controlled by JavaScript applications downloaded 4055 ** off the Internet. The internal databases can be given the 4056 ** large, default limits. Databases managed by external sources can 4057 ** be given much smaller limits designed to prevent a denial of service 4058 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 4059 ** interface to further control untrusted SQL. The size of the database 4060 ** created by an untrusted script can be contained using the 4061 ** [max_page_count] [PRAGMA]. 4062 ** 4063 ** New run-time limit categories may be added in future releases. 4064 */ 4065 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 4066 4067 /* 4068 ** CAPI3REF: Run-Time Limit Categories 4069 ** KEYWORDS: {limit category} {*limit categories} 4070 ** 4071 ** These constants define various performance limits 4072 ** that can be lowered at run-time using [sqlite3_limit()]. 4073 ** The synopsis of the meanings of the various limits is shown below. 4074 ** Additional information is available at [limits | Limits in SQLite]. 4075 ** 4076 ** <dl> 4077 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 4078 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 4079 ** 4080 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 4081 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 4082 ** 4083 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 4084 ** <dd>The maximum number of columns in a table definition or in the 4085 ** result set of a [SELECT] or the maximum number of columns in an index 4086 ** or in an ORDER BY or GROUP BY clause.</dd>)^ 4087 ** 4088 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 4089 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 4090 ** 4091 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 4092 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 4093 ** 4094 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 4095 ** <dd>The maximum number of instructions in a virtual machine program 4096 ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 4097 ** the equivalent tries to allocate space for more than this many opcodes 4098 ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 4099 ** 4100 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 4101 ** <dd>The maximum number of arguments on a function.</dd>)^ 4102 ** 4103 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 4104 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 4105 ** 4106 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 4107 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 4108 ** <dd>The maximum length of the pattern argument to the [LIKE] or 4109 ** [GLOB] operators.</dd>)^ 4110 ** 4111 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 4112 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 4113 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 4114 ** 4115 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 4116 ** <dd>The maximum depth of recursion for triggers.</dd>)^ 4117 ** 4118 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 4119 ** <dd>The maximum number of auxiliary worker threads that a single 4120 ** [prepared statement] may start.</dd>)^ 4121 ** </dl> 4122 */ 4123 #define SQLITE_LIMIT_LENGTH 0 4124 #define SQLITE_LIMIT_SQL_LENGTH 1 4125 #define SQLITE_LIMIT_COLUMN 2 4126 #define SQLITE_LIMIT_EXPR_DEPTH 3 4127 #define SQLITE_LIMIT_COMPOUND_SELECT 4 4128 #define SQLITE_LIMIT_VDBE_OP 5 4129 #define SQLITE_LIMIT_FUNCTION_ARG 6 4130 #define SQLITE_LIMIT_ATTACHED 7 4131 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 4132 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 4133 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 4134 #define SQLITE_LIMIT_WORKER_THREADS 11 4135 4136 /* 4137 ** CAPI3REF: Prepare Flags 4138 ** 4139 ** These constants define various flags that can be passed into 4140 ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 4141 ** [sqlite3_prepare16_v3()] interfaces. 4142 ** 4143 ** New flags may be added in future releases of SQLite. 4144 ** 4145 ** <dl> 4146 ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 4147 ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 4148 ** that the prepared statement will be retained for a long time and 4149 ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 4150 ** and [sqlite3_prepare16_v3()] assume that the prepared statement will 4151 ** be used just once or at most a few times and then destroyed using 4152 ** [sqlite3_finalize()] relatively soon. The current implementation acts 4153 ** on this hint by avoiding the use of [lookaside memory] so as not to 4154 ** deplete the limited store of lookaside memory. Future versions of 4155 ** SQLite may act on this hint differently. 4156 ** 4157 ** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt> 4158 ** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used 4159 ** to be required for any prepared statement that wanted to use the 4160 ** [sqlite3_normalized_sql()] interface. However, the 4161 ** [sqlite3_normalized_sql()] interface is now available to all 4162 ** prepared statements, regardless of whether or not they use this 4163 ** flag. 4164 ** 4165 ** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt> 4166 ** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler 4167 ** to return an error (error code SQLITE_ERROR) if the statement uses 4168 ** any virtual tables. 4169 ** </dl> 4170 */ 4171 #define SQLITE_PREPARE_PERSISTENT 0x01 4172 #define SQLITE_PREPARE_NORMALIZE 0x02 4173 #define SQLITE_PREPARE_NO_VTAB 0x04 4174 4175 /* 4176 ** CAPI3REF: Compiling An SQL Statement 4177 ** KEYWORDS: {SQL statement compiler} 4178 ** METHOD: sqlite3 4179 ** CONSTRUCTOR: sqlite3_stmt 4180 ** 4181 ** To execute an SQL statement, it must first be compiled into a byte-code 4182 ** program using one of these routines. Or, in other words, these routines 4183 ** are constructors for the [prepared statement] object. 4184 ** 4185 ** The preferred routine to use is [sqlite3_prepare_v2()]. The 4186 ** [sqlite3_prepare()] interface is legacy and should be avoided. 4187 ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 4188 ** for special purposes. 4189 ** 4190 ** The use of the UTF-8 interfaces is preferred, as SQLite currently 4191 ** does all parsing using UTF-8. The UTF-16 interfaces are provided 4192 ** as a convenience. The UTF-16 interfaces work by converting the 4193 ** input text into UTF-8, then invoking the corresponding UTF-8 interface. 4194 ** 4195 ** The first argument, "db", is a [database connection] obtained from a 4196 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 4197 ** [sqlite3_open16()]. The database connection must not have been closed. 4198 ** 4199 ** The second argument, "zSql", is the statement to be compiled, encoded 4200 ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 4201 ** and sqlite3_prepare_v3() 4202 ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 4203 ** and sqlite3_prepare16_v3() use UTF-16. 4204 ** 4205 ** ^If the nByte argument is negative, then zSql is read up to the 4206 ** first zero terminator. ^If nByte is positive, then it is the 4207 ** number of bytes read from zSql. ^If nByte is zero, then no prepared 4208 ** statement is generated. 4209 ** If the caller knows that the supplied string is nul-terminated, then 4210 ** there is a small performance advantage to passing an nByte parameter that 4211 ** is the number of bytes in the input string <i>including</i> 4212 ** the nul-terminator. 4213 ** 4214 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 4215 ** past the end of the first SQL statement in zSql. These routines only 4216 ** compile the first statement in zSql, so *pzTail is left pointing to 4217 ** what remains uncompiled. 4218 ** 4219 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 4220 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 4221 ** to NULL. ^If the input text contains no SQL (if the input is an empty 4222 ** string or a comment) then *ppStmt is set to NULL. 4223 ** The calling procedure is responsible for deleting the compiled 4224 ** SQL statement using [sqlite3_finalize()] after it has finished with it. 4225 ** ppStmt may not be NULL. 4226 ** 4227 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 4228 ** otherwise an [error code] is returned. 4229 ** 4230 ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 4231 ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 4232 ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 4233 ** are retained for backwards compatibility, but their use is discouraged. 4234 ** ^In the "vX" interfaces, the prepared statement 4235 ** that is returned (the [sqlite3_stmt] object) contains a copy of the 4236 ** original SQL text. This causes the [sqlite3_step()] interface to 4237 ** behave differently in three ways: 4238 ** 4239 ** <ol> 4240 ** <li> 4241 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 4242 ** always used to do, [sqlite3_step()] will automatically recompile the SQL 4243 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 4244 ** retries will occur before sqlite3_step() gives up and returns an error. 4245 ** </li> 4246 ** 4247 ** <li> 4248 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 4249 ** [error codes] or [extended error codes]. ^The legacy behavior was that 4250 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 4251 ** and the application would have to make a second call to [sqlite3_reset()] 4252 ** in order to find the underlying cause of the problem. With the "v2" prepare 4253 ** interfaces, the underlying reason for the error is returned immediately. 4254 ** </li> 4255 ** 4256 ** <li> 4257 ** ^If the specific value bound to a [parameter | host parameter] in the 4258 ** WHERE clause might influence the choice of query plan for a statement, 4259 ** then the statement will be automatically recompiled, as if there had been 4260 ** a schema change, on the first [sqlite3_step()] call following any change 4261 ** to the [sqlite3_bind_text | bindings] of that [parameter]. 4262 ** ^The specific value of a WHERE-clause [parameter] might influence the 4263 ** choice of query plan if the parameter is the left-hand side of a [LIKE] 4264 ** or [GLOB] operator or if the parameter is compared to an indexed column 4265 ** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled. 4266 ** </li> 4267 ** </ol> 4268 ** 4269 ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 4270 ** the extra prepFlags parameter, which is a bit array consisting of zero or 4271 ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 4272 ** sqlite3_prepare_v2() interface works exactly the same as 4273 ** sqlite3_prepare_v3() with a zero prepFlags parameter. 4274 */ 4275 SQLITE_API int sqlite3_prepare( 4276 sqlite3 *db, /* Database handle */ 4277 const char *zSql, /* SQL statement, UTF-8 encoded */ 4278 int nByte, /* Maximum length of zSql in bytes. */ 4279 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4280 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4281 ); 4282 SQLITE_API int sqlite3_prepare_v2( 4283 sqlite3 *db, /* Database handle */ 4284 const char *zSql, /* SQL statement, UTF-8 encoded */ 4285 int nByte, /* Maximum length of zSql in bytes. */ 4286 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4287 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4288 ); 4289 SQLITE_API int sqlite3_prepare_v3( 4290 sqlite3 *db, /* Database handle */ 4291 const char *zSql, /* SQL statement, UTF-8 encoded */ 4292 int nByte, /* Maximum length of zSql in bytes. */ 4293 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4294 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4295 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4296 ); 4297 SQLITE_API int sqlite3_prepare16( 4298 sqlite3 *db, /* Database handle */ 4299 const void *zSql, /* SQL statement, UTF-16 encoded */ 4300 int nByte, /* Maximum length of zSql in bytes. */ 4301 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4302 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4303 ); 4304 SQLITE_API int sqlite3_prepare16_v2( 4305 sqlite3 *db, /* Database handle */ 4306 const void *zSql, /* SQL statement, UTF-16 encoded */ 4307 int nByte, /* Maximum length of zSql in bytes. */ 4308 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4309 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4310 ); 4311 SQLITE_API int sqlite3_prepare16_v3( 4312 sqlite3 *db, /* Database handle */ 4313 const void *zSql, /* SQL statement, UTF-16 encoded */ 4314 int nByte, /* Maximum length of zSql in bytes. */ 4315 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4316 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4317 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4318 ); 4319 4320 /* 4321 ** CAPI3REF: Retrieving Statement SQL 4322 ** METHOD: sqlite3_stmt 4323 ** 4324 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 4325 ** SQL text used to create [prepared statement] P if P was 4326 ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 4327 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4328 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 4329 ** string containing the SQL text of prepared statement P with 4330 ** [bound parameters] expanded. 4331 ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 4332 ** string containing the normalized SQL text of prepared statement P. The 4333 ** semantics used to normalize a SQL statement are unspecified and subject 4334 ** to change. At a minimum, literal values will be replaced with suitable 4335 ** placeholders. 4336 ** 4337 ** ^(For example, if a prepared statement is created using the SQL 4338 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 4339 ** and parameter :xyz is unbound, then sqlite3_sql() will return 4340 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 4341 ** will return "SELECT 2345,NULL".)^ 4342 ** 4343 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 4344 ** is available to hold the result, or if the result would exceed the 4345 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 4346 ** 4347 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 4348 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 4349 ** option causes sqlite3_expanded_sql() to always return NULL. 4350 ** 4351 ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) 4352 ** are managed by SQLite and are automatically freed when the prepared 4353 ** statement is finalized. 4354 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 4355 ** is obtained from [sqlite3_malloc()] and must be freed by the application 4356 ** by passing it to [sqlite3_free()]. 4357 ** 4358 ** ^The sqlite3_normalized_sql() interface is only available if 4359 ** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined. 4360 */ 4361 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 4362 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 4363 #ifdef SQLITE_ENABLE_NORMALIZE 4364 SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); 4365 #endif 4366 4367 /* 4368 ** CAPI3REF: Determine If An SQL Statement Writes The Database 4369 ** METHOD: sqlite3_stmt 4370 ** 4371 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 4372 ** and only if the [prepared statement] X makes no direct changes to 4373 ** the content of the database file. 4374 ** 4375 ** Note that [application-defined SQL functions] or 4376 ** [virtual tables] might change the database indirectly as a side effect. 4377 ** ^(For example, if an application defines a function "eval()" that 4378 ** calls [sqlite3_exec()], then the following SQL statement would 4379 ** change the database file through side-effects: 4380 ** 4381 ** <blockquote><pre> 4382 ** SELECT eval('DELETE FROM t1') FROM t2; 4383 ** </pre></blockquote> 4384 ** 4385 ** But because the [SELECT] statement does not change the database file 4386 ** directly, sqlite3_stmt_readonly() would still return true.)^ 4387 ** 4388 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 4389 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 4390 ** since the statements themselves do not actually modify the database but 4391 ** rather they control the timing of when other statements modify the 4392 ** database. ^The [ATTACH] and [DETACH] statements also cause 4393 ** sqlite3_stmt_readonly() to return true since, while those statements 4394 ** change the configuration of a database connection, they do not make 4395 ** changes to the content of the database files on disk. 4396 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 4397 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 4398 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 4399 ** sqlite3_stmt_readonly() returns false for those commands. 4400 ** 4401 ** ^This routine returns false if there is any possibility that the 4402 ** statement might change the database file. ^A false return does 4403 ** not guarantee that the statement will change the database file. 4404 ** ^For example, an UPDATE statement might have a WHERE clause that 4405 ** makes it a no-op, but the sqlite3_stmt_readonly() result would still 4406 ** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a 4407 ** read-only no-op if the table already exists, but 4408 ** sqlite3_stmt_readonly() still returns false for such a statement. 4409 ** 4410 ** ^If prepared statement X is an [EXPLAIN] or [EXPLAIN QUERY PLAN] 4411 ** statement, then sqlite3_stmt_readonly(X) returns the same value as 4412 ** if the EXPLAIN or EXPLAIN QUERY PLAN prefix were omitted. 4413 */ 4414 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 4415 4416 /* 4417 ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement 4418 ** METHOD: sqlite3_stmt 4419 ** 4420 ** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the 4421 ** prepared statement S is an EXPLAIN statement, or 2 if the 4422 ** statement S is an EXPLAIN QUERY PLAN. 4423 ** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is 4424 ** an ordinary statement or a NULL pointer. 4425 */ 4426 SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt); 4427 4428 /* 4429 ** CAPI3REF: Change The EXPLAIN Setting For A Prepared Statement 4430 ** METHOD: sqlite3_stmt 4431 ** 4432 ** The sqlite3_stmt_explain(S,E) interface changes the EXPLAIN 4433 ** setting for [prepared statement] S. If E is zero, then S becomes 4434 ** a normal prepared statement. If E is 1, then S behaves as if 4435 ** its SQL text began with "[EXPLAIN]". If E is 2, then S behaves as if 4436 ** its SQL text began with "[EXPLAIN QUERY PLAN]". 4437 ** 4438 ** Calling sqlite3_stmt_explain(S,E) might cause S to be reprepared. 4439 ** SQLite tries to avoid a reprepare, but a reprepare might be necessary 4440 ** on the first transition into EXPLAIN or EXPLAIN QUERY PLAN mode. 4441 ** 4442 ** Because of the potential need to reprepare, a call to 4443 ** sqlite3_stmt_explain(S,E) will fail with SQLITE_ERROR if S cannot be 4444 ** reprepared because it was created using [sqlite3_prepare()] instead of 4445 ** the newer [sqlite3_prepare_v2()] or [sqlite3_prepare_v3()] interfaces and 4446 ** hence has no saved SQL text with which to reprepare. 4447 ** 4448 ** Changing the explain setting for a prepared statement does not change 4449 ** the original SQL text for the statement. Hence, if the SQL text originally 4450 ** began with EXPLAIN or EXPLAIN QUERY PLAN, but sqlite3_stmt_explain(S,0) 4451 ** is called to convert the statement into an ordinary statement, the EXPLAIN 4452 ** or EXPLAIN QUERY PLAN keywords will still appear in the sqlite3_sql(S) 4453 ** output, even though the statement now acts like a normal SQL statement. 4454 ** 4455 ** This routine returns SQLITE_OK if the explain mode is successfully 4456 ** changed, or an error code if the explain mode could not be changed. 4457 ** The explain mode cannot be changed while a statement is active. 4458 ** Hence, it is good practice to call [sqlite3_reset(S)] 4459 ** immediately prior to calling sqlite3_stmt_explain(S,E). 4460 */ 4461 SQLITE_API int sqlite3_stmt_explain(sqlite3_stmt *pStmt, int eMode); 4462 4463 /* 4464 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 4465 ** METHOD: sqlite3_stmt 4466 ** 4467 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 4468 ** [prepared statement] S has been stepped at least once using 4469 ** [sqlite3_step(S)] but has neither run to completion (returned 4470 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor 4471 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 4472 ** interface returns false if S is a NULL pointer. If S is not a 4473 ** NULL pointer and is not a pointer to a valid [prepared statement] 4474 ** object, then the behavior is undefined and probably undesirable. 4475 ** 4476 ** This interface can be used in combination [sqlite3_next_stmt()] 4477 ** to locate all prepared statements associated with a database 4478 ** connection that are in need of being reset. This can be used, 4479 ** for example, in diagnostic routines to search for prepared 4480 ** statements that are holding a transaction open. 4481 */ 4482 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 4483 4484 /* 4485 ** CAPI3REF: Dynamically Typed Value Object 4486 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 4487 ** 4488 ** SQLite uses the sqlite3_value object to represent all values 4489 ** that can be stored in a database table. SQLite uses dynamic typing 4490 ** for the values it stores. ^Values stored in sqlite3_value objects 4491 ** can be integers, floating point values, strings, BLOBs, or NULL. 4492 ** 4493 ** An sqlite3_value object may be either "protected" or "unprotected". 4494 ** Some interfaces require a protected sqlite3_value. Other interfaces 4495 ** will accept either a protected or an unprotected sqlite3_value. 4496 ** Every interface that accepts sqlite3_value arguments specifies 4497 ** whether or not it requires a protected sqlite3_value. The 4498 ** [sqlite3_value_dup()] interface can be used to construct a new 4499 ** protected sqlite3_value from an unprotected sqlite3_value. 4500 ** 4501 ** The terms "protected" and "unprotected" refer to whether or not 4502 ** a mutex is held. An internal mutex is held for a protected 4503 ** sqlite3_value object but no mutex is held for an unprotected 4504 ** sqlite3_value object. If SQLite is compiled to be single-threaded 4505 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 4506 ** or if SQLite is run in one of reduced mutex modes 4507 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 4508 ** then there is no distinction between protected and unprotected 4509 ** sqlite3_value objects and they can be used interchangeably. However, 4510 ** for maximum code portability it is recommended that applications 4511 ** still make the distinction between protected and unprotected 4512 ** sqlite3_value objects even when not strictly required. 4513 ** 4514 ** ^The sqlite3_value objects that are passed as parameters into the 4515 ** implementation of [application-defined SQL functions] are protected. 4516 ** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()] 4517 ** are protected. 4518 ** ^The sqlite3_value object returned by 4519 ** [sqlite3_column_value()] is unprotected. 4520 ** Unprotected sqlite3_value objects may only be used as arguments 4521 ** to [sqlite3_result_value()], [sqlite3_bind_value()], and 4522 ** [sqlite3_value_dup()]. 4523 ** The [sqlite3_value_blob | sqlite3_value_type()] family of 4524 ** interfaces require protected sqlite3_value objects. 4525 */ 4526 typedef struct sqlite3_value sqlite3_value; 4527 4528 /* 4529 ** CAPI3REF: SQL Function Context Object 4530 ** 4531 ** The context in which an SQL function executes is stored in an 4532 ** sqlite3_context object. ^A pointer to an sqlite3_context object 4533 ** is always first parameter to [application-defined SQL functions]. 4534 ** The application-defined SQL function implementation will pass this 4535 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 4536 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 4537 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 4538 ** and/or [sqlite3_set_auxdata()]. 4539 */ 4540 typedef struct sqlite3_context sqlite3_context; 4541 4542 /* 4543 ** CAPI3REF: Binding Values To Prepared Statements 4544 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 4545 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 4546 ** METHOD: sqlite3_stmt 4547 ** 4548 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 4549 ** literals may be replaced by a [parameter] that matches one of following 4550 ** templates: 4551 ** 4552 ** <ul> 4553 ** <li> ? 4554 ** <li> ?NNN 4555 ** <li> :VVV 4556 ** <li> @VVV 4557 ** <li> $VVV 4558 ** </ul> 4559 ** 4560 ** In the templates above, NNN represents an integer literal, 4561 ** and VVV represents an alphanumeric identifier.)^ ^The values of these 4562 ** parameters (also called "host parameter names" or "SQL parameters") 4563 ** can be set using the sqlite3_bind_*() routines defined here. 4564 ** 4565 ** ^The first argument to the sqlite3_bind_*() routines is always 4566 ** a pointer to the [sqlite3_stmt] object returned from 4567 ** [sqlite3_prepare_v2()] or its variants. 4568 ** 4569 ** ^The second argument is the index of the SQL parameter to be set. 4570 ** ^The leftmost SQL parameter has an index of 1. ^When the same named 4571 ** SQL parameter is used more than once, second and subsequent 4572 ** occurrences have the same index as the first occurrence. 4573 ** ^The index for named parameters can be looked up using the 4574 ** [sqlite3_bind_parameter_index()] API if desired. ^The index 4575 ** for "?NNN" parameters is the value of NNN. 4576 ** ^The NNN value must be between 1 and the [sqlite3_limit()] 4577 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766). 4578 ** 4579 ** ^The third argument is the value to bind to the parameter. 4580 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4581 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 4582 ** is ignored and the end result is the same as sqlite3_bind_null(). 4583 ** ^If the third parameter to sqlite3_bind_text() is not NULL, then 4584 ** it should be a pointer to well-formed UTF8 text. 4585 ** ^If the third parameter to sqlite3_bind_text16() is not NULL, then 4586 ** it should be a pointer to well-formed UTF16 text. 4587 ** ^If the third parameter to sqlite3_bind_text64() is not NULL, then 4588 ** it should be a pointer to a well-formed unicode string that is 4589 ** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16 4590 ** otherwise. 4591 ** 4592 ** [[byte-order determination rules]] ^The byte-order of 4593 ** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF) 4594 ** found in first character, which is removed, or in the absence of a BOM 4595 ** the byte order is the native byte order of the host 4596 ** machine for sqlite3_bind_text16() or the byte order specified in 4597 ** the 6th parameter for sqlite3_bind_text64().)^ 4598 ** ^If UTF16 input text contains invalid unicode 4599 ** characters, then SQLite might change those invalid characters 4600 ** into the unicode replacement character: U+FFFD. 4601 ** 4602 ** ^(In those routines that have a fourth argument, its value is the 4603 ** number of bytes in the parameter. To be clear: the value is the 4604 ** number of <u>bytes</u> in the value, not the number of characters.)^ 4605 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4606 ** is negative, then the length of the string is 4607 ** the number of bytes up to the first zero terminator. 4608 ** If the fourth parameter to sqlite3_bind_blob() is negative, then 4609 ** the behavior is undefined. 4610 ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 4611 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then 4612 ** that parameter must be the byte offset 4613 ** where the NUL terminator would occur assuming the string were NUL 4614 ** terminated. If any NUL characters occurs at byte offsets less than 4615 ** the value of the fourth parameter then the resulting string value will 4616 ** contain embedded NULs. The result of expressions involving strings 4617 ** with embedded NULs is undefined. 4618 ** 4619 ** ^The fifth argument to the BLOB and string binding interfaces controls 4620 ** or indicates the lifetime of the object referenced by the third parameter. 4621 ** These three options exist: 4622 ** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished 4623 ** with it may be passed. ^It is called to dispose of the BLOB or string even 4624 ** if the call to the bind API fails, except the destructor is not called if 4625 ** the third parameter is a NULL pointer or the fourth parameter is negative. 4626 ** ^ (2) The special constant, [SQLITE_STATIC], may be passed to indicate that 4627 ** the application remains responsible for disposing of the object. ^In this 4628 ** case, the object and the provided pointer to it must remain valid until 4629 ** either the prepared statement is finalized or the same SQL parameter is 4630 ** bound to something else, whichever occurs sooner. 4631 ** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the 4632 ** object is to be copied prior to the return from sqlite3_bind_*(). ^The 4633 ** object and pointer to it must remain valid until then. ^SQLite will then 4634 ** manage the lifetime of its private copy. 4635 ** 4636 ** ^The sixth argument to sqlite3_bind_text64() must be one of 4637 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 4638 ** to specify the encoding of the text in the third parameter. If 4639 ** the sixth argument to sqlite3_bind_text64() is not one of the 4640 ** allowed values shown above, or if the text encoding is different 4641 ** from the encoding specified by the sixth parameter, then the behavior 4642 ** is undefined. 4643 ** 4644 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 4645 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 4646 ** (just an integer to hold its size) while it is being processed. 4647 ** Zeroblobs are intended to serve as placeholders for BLOBs whose 4648 ** content is later written using 4649 ** [sqlite3_blob_open | incremental BLOB I/O] routines. 4650 ** ^A negative value for the zeroblob results in a zero-length BLOB. 4651 ** 4652 ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 4653 ** [prepared statement] S to have an SQL value of NULL, but to also be 4654 ** associated with the pointer P of type T. ^D is either a NULL pointer or 4655 ** a pointer to a destructor function for P. ^SQLite will invoke the 4656 ** destructor D with a single argument of P when it is finished using 4657 ** P. The T parameter should be a static string, preferably a string 4658 ** literal. The sqlite3_bind_pointer() routine is part of the 4659 ** [pointer passing interface] added for SQLite 3.20.0. 4660 ** 4661 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4662 ** for the [prepared statement] or with a prepared statement for which 4663 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4664 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4665 ** routine is passed a [prepared statement] that has been finalized, the 4666 ** result is undefined and probably harmful. 4667 ** 4668 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4669 ** ^Unbound parameters are interpreted as NULL. 4670 ** 4671 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4672 ** [error code] if anything goes wrong. 4673 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4674 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4675 ** [SQLITE_MAX_LENGTH]. 4676 ** ^[SQLITE_RANGE] is returned if the parameter 4677 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4678 ** 4679 ** See also: [sqlite3_bind_parameter_count()], 4680 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4681 */ 4682 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4683 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4684 void(*)(void*)); 4685 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 4686 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 4687 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4688 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 4689 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4690 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4691 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4692 void(*)(void*), unsigned char encoding); 4693 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4694 SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4695 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4696 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4697 4698 /* 4699 ** CAPI3REF: Number Of SQL Parameters 4700 ** METHOD: sqlite3_stmt 4701 ** 4702 ** ^This routine can be used to find the number of [SQL parameters] 4703 ** in a [prepared statement]. SQL parameters are tokens of the 4704 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4705 ** placeholders for values that are [sqlite3_bind_blob | bound] 4706 ** to the parameters at a later time. 4707 ** 4708 ** ^(This routine actually returns the index of the largest (rightmost) 4709 ** parameter. For all forms except ?NNN, this will correspond to the 4710 ** number of unique parameters. If parameters of the ?NNN form are used, 4711 ** there may be gaps in the list.)^ 4712 ** 4713 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4714 ** [sqlite3_bind_parameter_name()], and 4715 ** [sqlite3_bind_parameter_index()]. 4716 */ 4717 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 4718 4719 /* 4720 ** CAPI3REF: Name Of A Host Parameter 4721 ** METHOD: sqlite3_stmt 4722 ** 4723 ** ^The sqlite3_bind_parameter_name(P,N) interface returns 4724 ** the name of the N-th [SQL parameter] in the [prepared statement] P. 4725 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4726 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4727 ** respectively. 4728 ** In other words, the initial ":" or "$" or "@" or "?" 4729 ** is included as part of the name.)^ 4730 ** ^Parameters of the form "?" without a following integer have no name 4731 ** and are referred to as "nameless" or "anonymous parameters". 4732 ** 4733 ** ^The first host parameter has an index of 1, not 0. 4734 ** 4735 ** ^If the value N is out of range or if the N-th parameter is 4736 ** nameless, then NULL is returned. ^The returned string is 4737 ** always in UTF-8 encoding even if the named parameter was 4738 ** originally specified as UTF-16 in [sqlite3_prepare16()], 4739 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4740 ** 4741 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4742 ** [sqlite3_bind_parameter_count()], and 4743 ** [sqlite3_bind_parameter_index()]. 4744 */ 4745 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4746 4747 /* 4748 ** CAPI3REF: Index Of A Parameter With A Given Name 4749 ** METHOD: sqlite3_stmt 4750 ** 4751 ** ^Return the index of an SQL parameter given its name. ^The 4752 ** index value returned is suitable for use as the second 4753 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4754 ** is returned if no matching parameter is found. ^The parameter 4755 ** name must be given in UTF-8 even if the original statement 4756 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4757 ** [sqlite3_prepare16_v3()]. 4758 ** 4759 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4760 ** [sqlite3_bind_parameter_count()], and 4761 ** [sqlite3_bind_parameter_name()]. 4762 */ 4763 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4764 4765 /* 4766 ** CAPI3REF: Reset All Bindings On A Prepared Statement 4767 ** METHOD: sqlite3_stmt 4768 ** 4769 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4770 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4771 ** ^Use this routine to reset all host parameters to NULL. 4772 */ 4773 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 4774 4775 /* 4776 ** CAPI3REF: Number Of Columns In A Result Set 4777 ** METHOD: sqlite3_stmt 4778 ** 4779 ** ^Return the number of columns in the result set returned by the 4780 ** [prepared statement]. ^If this routine returns 0, that means the 4781 ** [prepared statement] returns no data (for example an [UPDATE]). 4782 ** ^However, just because this routine returns a positive number does not 4783 ** mean that one or more rows of data will be returned. ^A SELECT statement 4784 ** will always have a positive sqlite3_column_count() but depending on the 4785 ** WHERE clause constraints and the table content, it might return no rows. 4786 ** 4787 ** See also: [sqlite3_data_count()] 4788 */ 4789 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 4790 4791 /* 4792 ** CAPI3REF: Column Names In A Result Set 4793 ** METHOD: sqlite3_stmt 4794 ** 4795 ** ^These routines return the name assigned to a particular column 4796 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4797 ** interface returns a pointer to a zero-terminated UTF-8 string 4798 ** and sqlite3_column_name16() returns a pointer to a zero-terminated 4799 ** UTF-16 string. ^The first parameter is the [prepared statement] 4800 ** that implements the [SELECT] statement. ^The second parameter is the 4801 ** column number. ^The leftmost column is number 0. 4802 ** 4803 ** ^The returned string pointer is valid until either the [prepared statement] 4804 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4805 ** reprepared by the first call to [sqlite3_step()] for a particular run 4806 ** or until the next call to 4807 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4808 ** 4809 ** ^If sqlite3_malloc() fails during the processing of either routine 4810 ** (for example during a conversion from UTF-8 to UTF-16) then a 4811 ** NULL pointer is returned. 4812 ** 4813 ** ^The name of a result column is the value of the "AS" clause for 4814 ** that column, if there is an AS clause. If there is no AS clause 4815 ** then the name of the column is unspecified and may change from 4816 ** one release of SQLite to the next. 4817 */ 4818 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 4819 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4820 4821 /* 4822 ** CAPI3REF: Source Of Data In A Query Result 4823 ** METHOD: sqlite3_stmt 4824 ** 4825 ** ^These routines provide a means to determine the database, table, and 4826 ** table column that is the origin of a particular result column in 4827 ** [SELECT] statement. 4828 ** ^The name of the database or table or column can be returned as 4829 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4830 ** the database name, the _table_ routines return the table name, and 4831 ** the origin_ routines return the column name. 4832 ** ^The returned string is valid until the [prepared statement] is destroyed 4833 ** using [sqlite3_finalize()] or until the statement is automatically 4834 ** reprepared by the first call to [sqlite3_step()] for a particular run 4835 ** or until the same information is requested 4836 ** again in a different encoding. 4837 ** 4838 ** ^The names returned are the original un-aliased names of the 4839 ** database, table, and column. 4840 ** 4841 ** ^The first argument to these interfaces is a [prepared statement]. 4842 ** ^These functions return information about the Nth result column returned by 4843 ** the statement, where N is the second function argument. 4844 ** ^The left-most column is column 0 for these routines. 4845 ** 4846 ** ^If the Nth column returned by the statement is an expression or 4847 ** subquery and is not a column value, then all of these functions return 4848 ** NULL. ^These routines might also return NULL if a memory allocation error 4849 ** occurs. ^Otherwise, they return the name of the attached database, table, 4850 ** or column that query result column was extracted from. 4851 ** 4852 ** ^As with all other SQLite APIs, those whose names end with "16" return 4853 ** UTF-16 encoded strings and the other functions return UTF-8. 4854 ** 4855 ** ^These APIs are only available if the library was compiled with the 4856 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4857 ** 4858 ** If two or more threads call one or more 4859 ** [sqlite3_column_database_name | column metadata interfaces] 4860 ** for the same [prepared statement] and result column 4861 ** at the same time then the results are undefined. 4862 */ 4863 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4864 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4865 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4866 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4867 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4868 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4869 4870 /* 4871 ** CAPI3REF: Declared Datatype Of A Query Result 4872 ** METHOD: sqlite3_stmt 4873 ** 4874 ** ^(The first parameter is a [prepared statement]. 4875 ** If this statement is a [SELECT] statement and the Nth column of the 4876 ** returned result set of that [SELECT] is a table column (not an 4877 ** expression or subquery) then the declared type of the table 4878 ** column is returned.)^ ^If the Nth column of the result set is an 4879 ** expression or subquery, then a NULL pointer is returned. 4880 ** ^The returned string is always UTF-8 encoded. 4881 ** 4882 ** ^(For example, given the database schema: 4883 ** 4884 ** CREATE TABLE t1(c1 VARIANT); 4885 ** 4886 ** and the following statement to be compiled: 4887 ** 4888 ** SELECT c1 + 1, c1 FROM t1; 4889 ** 4890 ** this routine would return the string "VARIANT" for the second result 4891 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4892 ** 4893 ** ^SQLite uses dynamic run-time typing. ^So just because a column 4894 ** is declared to contain a particular type does not mean that the 4895 ** data stored in that column is of the declared type. SQLite is 4896 ** strongly typed, but the typing is dynamic not static. ^Type 4897 ** is associated with individual values, not with the containers 4898 ** used to hold those values. 4899 */ 4900 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4901 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4902 4903 /* 4904 ** CAPI3REF: Evaluate An SQL Statement 4905 ** METHOD: sqlite3_stmt 4906 ** 4907 ** After a [prepared statement] has been prepared using any of 4908 ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4909 ** or [sqlite3_prepare16_v3()] or one of the legacy 4910 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4911 ** must be called one or more times to evaluate the statement. 4912 ** 4913 ** The details of the behavior of the sqlite3_step() interface depend 4914 ** on whether the statement was prepared using the newer "vX" interfaces 4915 ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4916 ** [sqlite3_prepare16_v2()] or the older legacy 4917 ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4918 ** new "vX" interface is recommended for new applications but the legacy 4919 ** interface will continue to be supported. 4920 ** 4921 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4922 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4923 ** ^With the "v2" interface, any of the other [result codes] or 4924 ** [extended result codes] might be returned as well. 4925 ** 4926 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4927 ** database locks it needs to do its job. ^If the statement is a [COMMIT] 4928 ** or occurs outside of an explicit transaction, then you can retry the 4929 ** statement. If the statement is not a [COMMIT] and occurs within an 4930 ** explicit transaction then you should rollback the transaction before 4931 ** continuing. 4932 ** 4933 ** ^[SQLITE_DONE] means that the statement has finished executing 4934 ** successfully. sqlite3_step() should not be called again on this virtual 4935 ** machine without first calling [sqlite3_reset()] to reset the virtual 4936 ** machine back to its initial state. 4937 ** 4938 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4939 ** is returned each time a new row of data is ready for processing by the 4940 ** caller. The values may be accessed using the [column access functions]. 4941 ** sqlite3_step() is called again to retrieve the next row of data. 4942 ** 4943 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4944 ** violation) has occurred. sqlite3_step() should not be called again on 4945 ** the VM. More information may be found by calling [sqlite3_errmsg()]. 4946 ** ^With the legacy interface, a more specific error code (for example, 4947 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4948 ** can be obtained by calling [sqlite3_reset()] on the 4949 ** [prepared statement]. ^In the "v2" interface, 4950 ** the more specific error code is returned directly by sqlite3_step(). 4951 ** 4952 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4953 ** Perhaps it was called on a [prepared statement] that has 4954 ** already been [sqlite3_finalize | finalized] or on one that had 4955 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4956 ** be the case that the same database connection is being used by two or 4957 ** more threads at the same moment in time. 4958 ** 4959 ** For all versions of SQLite up to and including 3.6.23.1, a call to 4960 ** [sqlite3_reset()] was required after sqlite3_step() returned anything 4961 ** other than [SQLITE_ROW] before any subsequent invocation of 4962 ** sqlite3_step(). Failure to reset the prepared statement using 4963 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4964 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4965 ** sqlite3_step() began 4966 ** calling [sqlite3_reset()] automatically in this circumstance rather 4967 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4968 ** break because any application that ever receives an SQLITE_MISUSE error 4969 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4970 ** can be used to restore the legacy behavior. 4971 ** 4972 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4973 ** API always returns a generic error code, [SQLITE_ERROR], following any 4974 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4975 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4976 ** specific [error codes] that better describes the error. 4977 ** We admit that this is a goofy design. The problem has been fixed 4978 ** with the "v2" interface. If you prepare all of your SQL statements 4979 ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4980 ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4981 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4982 ** then the more specific [error codes] are returned directly 4983 ** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4984 */ 4985 SQLITE_API int sqlite3_step(sqlite3_stmt*); 4986 4987 /* 4988 ** CAPI3REF: Number of columns in a result set 4989 ** METHOD: sqlite3_stmt 4990 ** 4991 ** ^The sqlite3_data_count(P) interface returns the number of columns in the 4992 ** current row of the result set of [prepared statement] P. 4993 ** ^If prepared statement P does not have results ready to return 4994 ** (via calls to the [sqlite3_column_int | sqlite3_column()] family of 4995 ** interfaces) then sqlite3_data_count(P) returns 0. 4996 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4997 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4998 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4999 ** will return non-zero if previous call to [sqlite3_step](P) returned 5000 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 5001 ** where it always returns zero since each step of that multi-step 5002 ** pragma returns 0 columns of data. 5003 ** 5004 ** See also: [sqlite3_column_count()] 5005 */ 5006 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 5007 5008 /* 5009 ** CAPI3REF: Fundamental Datatypes 5010 ** KEYWORDS: SQLITE_TEXT 5011 ** 5012 ** ^(Every value in SQLite has one of five fundamental datatypes: 5013 ** 5014 ** <ul> 5015 ** <li> 64-bit signed integer 5016 ** <li> 64-bit IEEE floating point number 5017 ** <li> string 5018 ** <li> BLOB 5019 ** <li> NULL 5020 ** </ul>)^ 5021 ** 5022 ** These constants are codes for each of those types. 5023 ** 5024 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 5025 ** for a completely different meaning. Software that links against both 5026 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 5027 ** SQLITE_TEXT. 5028 */ 5029 #define SQLITE_INTEGER 1 5030 #define SQLITE_FLOAT 2 5031 #define SQLITE_BLOB 4 5032 #define SQLITE_NULL 5 5033 #ifdef SQLITE_TEXT 5034 # undef SQLITE_TEXT 5035 #else 5036 # define SQLITE_TEXT 3 5037 #endif 5038 #define SQLITE3_TEXT 3 5039 5040 /* 5041 ** CAPI3REF: Result Values From A Query 5042 ** KEYWORDS: {column access functions} 5043 ** METHOD: sqlite3_stmt 5044 ** 5045 ** <b>Summary:</b> 5046 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5047 ** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 5048 ** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 5049 ** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 5050 ** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 5051 ** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 5052 ** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 5053 ** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 5054 ** [sqlite3_value|unprotected sqlite3_value] object. 5055 ** <tr><td> <td> <td> 5056 ** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 5057 ** or a UTF-8 TEXT result in bytes 5058 ** <tr><td><b>sqlite3_column_bytes16 </b> 5059 ** <td>→ <td>Size of UTF-16 5060 ** TEXT in bytes 5061 ** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 5062 ** datatype of the result 5063 ** </table></blockquote> 5064 ** 5065 ** <b>Details:</b> 5066 ** 5067 ** ^These routines return information about a single column of the current 5068 ** result row of a query. ^In every case the first argument is a pointer 5069 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 5070 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 5071 ** and the second argument is the index of the column for which information 5072 ** should be returned. ^The leftmost column of the result set has the index 0. 5073 ** ^The number of columns in the result can be determined using 5074 ** [sqlite3_column_count()]. 5075 ** 5076 ** If the SQL statement does not currently point to a valid row, or if the 5077 ** column index is out of range, the result is undefined. 5078 ** These routines may only be called when the most recent call to 5079 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 5080 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 5081 ** If any of these routines are called after [sqlite3_reset()] or 5082 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 5083 ** something other than [SQLITE_ROW], the results are undefined. 5084 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 5085 ** are called from a different thread while any of these routines 5086 ** are pending, then the results are undefined. 5087 ** 5088 ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 5089 ** each return the value of a result column in a specific data format. If 5090 ** the result column is not initially in the requested format (for example, 5091 ** if the query returns an integer but the sqlite3_column_text() interface 5092 ** is used to extract the value) then an automatic type conversion is performed. 5093 ** 5094 ** ^The sqlite3_column_type() routine returns the 5095 ** [SQLITE_INTEGER | datatype code] for the initial data type 5096 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 5097 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 5098 ** The return value of sqlite3_column_type() can be used to decide which 5099 ** of the first six interface should be used to extract the column value. 5100 ** The value returned by sqlite3_column_type() is only meaningful if no 5101 ** automatic type conversions have occurred for the value in question. 5102 ** After a type conversion, the result of calling sqlite3_column_type() 5103 ** is undefined, though harmless. Future 5104 ** versions of SQLite may change the behavior of sqlite3_column_type() 5105 ** following a type conversion. 5106 ** 5107 ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 5108 ** or sqlite3_column_bytes16() interfaces can be used to determine the size 5109 ** of that BLOB or string. 5110 ** 5111 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 5112 ** routine returns the number of bytes in that BLOB or string. 5113 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 5114 ** the string to UTF-8 and then returns the number of bytes. 5115 ** ^If the result is a numeric value then sqlite3_column_bytes() uses 5116 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 5117 ** the number of bytes in that string. 5118 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 5119 ** 5120 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 5121 ** routine returns the number of bytes in that BLOB or string. 5122 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 5123 ** the string to UTF-16 and then returns the number of bytes. 5124 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 5125 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 5126 ** the number of bytes in that string. 5127 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 5128 ** 5129 ** ^The values returned by [sqlite3_column_bytes()] and 5130 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 5131 ** of the string. ^For clarity: the values returned by 5132 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 5133 ** bytes in the string, not the number of characters. 5134 ** 5135 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 5136 ** even empty strings, are always zero-terminated. ^The return 5137 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 5138 ** 5139 ** ^Strings returned by sqlite3_column_text16() always have the endianness 5140 ** which is native to the platform, regardless of the text encoding set 5141 ** for the database. 5142 ** 5143 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 5144 ** [unprotected sqlite3_value] object. In a multithreaded environment, 5145 ** an unprotected sqlite3_value object may only be used safely with 5146 ** [sqlite3_bind_value()] and [sqlite3_result_value()]. 5147 ** If the [unprotected sqlite3_value] object returned by 5148 ** [sqlite3_column_value()] is used in any other way, including calls 5149 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 5150 ** or [sqlite3_value_bytes()], the behavior is not threadsafe. 5151 ** Hence, the sqlite3_column_value() interface 5152 ** is normally only useful within the implementation of 5153 ** [application-defined SQL functions] or [virtual tables], not within 5154 ** top-level application code. 5155 ** 5156 ** These routines may attempt to convert the datatype of the result. 5157 ** ^For example, if the internal representation is FLOAT and a text result 5158 ** is requested, [sqlite3_snprintf()] is used internally to perform the 5159 ** conversion automatically. ^(The following table details the conversions 5160 ** that are applied: 5161 ** 5162 ** <blockquote> 5163 ** <table border="1"> 5164 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 5165 ** 5166 ** <tr><td> NULL <td> INTEGER <td> Result is 0 5167 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 5168 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 5169 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 5170 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 5171 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 5172 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 5173 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 5174 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 5175 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 5176 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 5177 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 5178 ** <tr><td> TEXT <td> BLOB <td> No change 5179 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 5180 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 5181 ** <tr><td> BLOB <td> TEXT <td> [CAST] to TEXT, ensure zero terminator 5182 ** </table> 5183 ** </blockquote>)^ 5184 ** 5185 ** Note that when type conversions occur, pointers returned by prior 5186 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 5187 ** sqlite3_column_text16() may be invalidated. 5188 ** Type conversions and pointer invalidations might occur 5189 ** in the following cases: 5190 ** 5191 ** <ul> 5192 ** <li> The initial content is a BLOB and sqlite3_column_text() or 5193 ** sqlite3_column_text16() is called. A zero-terminator might 5194 ** need to be added to the string.</li> 5195 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 5196 ** sqlite3_column_text16() is called. The content must be converted 5197 ** to UTF-16.</li> 5198 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 5199 ** sqlite3_column_text() is called. The content must be converted 5200 ** to UTF-8.</li> 5201 ** </ul> 5202 ** 5203 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 5204 ** not invalidate a prior pointer, though of course the content of the buffer 5205 ** that the prior pointer references will have been modified. Other kinds 5206 ** of conversion are done in place when it is possible, but sometimes they 5207 ** are not possible and in those cases prior pointers are invalidated. 5208 ** 5209 ** The safest policy is to invoke these routines 5210 ** in one of the following ways: 5211 ** 5212 ** <ul> 5213 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 5214 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 5215 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 5216 ** </ul> 5217 ** 5218 ** In other words, you should call sqlite3_column_text(), 5219 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 5220 ** into the desired format, then invoke sqlite3_column_bytes() or 5221 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 5222 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 5223 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 5224 ** with calls to sqlite3_column_bytes(). 5225 ** 5226 ** ^The pointers returned are valid until a type conversion occurs as 5227 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 5228 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 5229 ** and BLOBs is freed automatically. Do not pass the pointers returned 5230 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 5231 ** [sqlite3_free()]. 5232 ** 5233 ** As long as the input parameters are correct, these routines will only 5234 ** fail if an out-of-memory error occurs during a format conversion. 5235 ** Only the following subset of interfaces are subject to out-of-memory 5236 ** errors: 5237 ** 5238 ** <ul> 5239 ** <li> sqlite3_column_blob() 5240 ** <li> sqlite3_column_text() 5241 ** <li> sqlite3_column_text16() 5242 ** <li> sqlite3_column_bytes() 5243 ** <li> sqlite3_column_bytes16() 5244 ** </ul> 5245 ** 5246 ** If an out-of-memory error occurs, then the return value from these 5247 ** routines is the same as if the column had contained an SQL NULL value. 5248 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 5249 ** by invoking the [sqlite3_errcode()] immediately after the suspect 5250 ** return value is obtained and before any 5251 ** other SQLite interface is called on the same [database connection]. 5252 */ 5253 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 5254 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 5255 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 5256 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 5257 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 5258 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 5259 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 5260 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 5261 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 5262 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 5263 5264 /* 5265 ** CAPI3REF: Destroy A Prepared Statement Object 5266 ** DESTRUCTOR: sqlite3_stmt 5267 ** 5268 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 5269 ** ^If the most recent evaluation of the statement encountered no errors 5270 ** or if the statement is never been evaluated, then sqlite3_finalize() returns 5271 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 5272 ** sqlite3_finalize(S) returns the appropriate [error code] or 5273 ** [extended error code]. 5274 ** 5275 ** ^The sqlite3_finalize(S) routine can be called at any point during 5276 ** the life cycle of [prepared statement] S: 5277 ** before statement S is ever evaluated, after 5278 ** one or more calls to [sqlite3_reset()], or after any call 5279 ** to [sqlite3_step()] regardless of whether or not the statement has 5280 ** completed execution. 5281 ** 5282 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 5283 ** 5284 ** The application must finalize every [prepared statement] in order to avoid 5285 ** resource leaks. It is a grievous error for the application to try to use 5286 ** a prepared statement after it has been finalized. Any use of a prepared 5287 ** statement after it has been finalized can result in undefined and 5288 ** undesirable behavior such as segfaults and heap corruption. 5289 */ 5290 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 5291 5292 /* 5293 ** CAPI3REF: Reset A Prepared Statement Object 5294 ** METHOD: sqlite3_stmt 5295 ** 5296 ** The sqlite3_reset() function is called to reset a [prepared statement] 5297 ** object back to its initial state, ready to be re-executed. 5298 ** ^Any SQL statement variables that had values bound to them using 5299 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 5300 ** Use [sqlite3_clear_bindings()] to reset the bindings. 5301 ** 5302 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 5303 ** back to the beginning of its program. 5304 ** 5305 ** ^The return code from [sqlite3_reset(S)] indicates whether or not 5306 ** the previous evaluation of prepared statement S completed successfully. 5307 ** ^If [sqlite3_step(S)] has never before been called on S or if 5308 ** [sqlite3_step(S)] has not been called since the previous call 5309 ** to [sqlite3_reset(S)], then [sqlite3_reset(S)] will return 5310 ** [SQLITE_OK]. 5311 ** 5312 ** ^If the most recent call to [sqlite3_step(S)] for the 5313 ** [prepared statement] S indicated an error, then 5314 ** [sqlite3_reset(S)] returns an appropriate [error code]. 5315 ** ^The [sqlite3_reset(S)] interface might also return an [error code] 5316 ** if there were no prior errors but the process of resetting 5317 ** the prepared statement caused a new error. ^For example, if an 5318 ** [INSERT] statement with a [RETURNING] clause is only stepped one time, 5319 ** that one call to [sqlite3_step(S)] might return SQLITE_ROW but 5320 ** the overall statement might still fail and the [sqlite3_reset(S)] call 5321 ** might return SQLITE_BUSY if locking constraints prevent the 5322 ** database change from committing. Therefore, it is important that 5323 ** applications check the return code from [sqlite3_reset(S)] even if 5324 ** no prior call to [sqlite3_step(S)] indicated a problem. 5325 ** 5326 ** ^The [sqlite3_reset(S)] interface does not change the values 5327 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 5328 */ 5329 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 5330 5331 5332 /* 5333 ** CAPI3REF: Create Or Redefine SQL Functions 5334 ** KEYWORDS: {function creation routines} 5335 ** METHOD: sqlite3 5336 ** 5337 ** ^These functions (collectively known as "function creation routines") 5338 ** are used to add SQL functions or aggregates or to redefine the behavior 5339 ** of existing SQL functions or aggregates. The only differences between 5340 ** the three "sqlite3_create_function*" routines are the text encoding 5341 ** expected for the second parameter (the name of the function being 5342 ** created) and the presence or absence of a destructor callback for 5343 ** the application data pointer. Function sqlite3_create_window_function() 5344 ** is similar, but allows the user to supply the extra callback functions 5345 ** needed by [aggregate window functions]. 5346 ** 5347 ** ^The first parameter is the [database connection] to which the SQL 5348 ** function is to be added. ^If an application uses more than one database 5349 ** connection then application-defined SQL functions must be added 5350 ** to each database connection separately. 5351 ** 5352 ** ^The second parameter is the name of the SQL function to be created or 5353 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 5354 ** representation, exclusive of the zero-terminator. ^Note that the name 5355 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 5356 ** ^Any attempt to create a function with a longer name 5357 ** will result in [SQLITE_MISUSE] being returned. 5358 ** 5359 ** ^The third parameter (nArg) 5360 ** is the number of arguments that the SQL function or 5361 ** aggregate takes. ^If this parameter is -1, then the SQL function or 5362 ** aggregate may take any number of arguments between 0 and the limit 5363 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 5364 ** parameter is less than -1 or greater than 127 then the behavior is 5365 ** undefined. 5366 ** 5367 ** ^The fourth parameter, eTextRep, specifies what 5368 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 5369 ** its parameters. The application should set this parameter to 5370 ** [SQLITE_UTF16LE] if the function implementation invokes 5371 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 5372 ** implementation invokes [sqlite3_value_text16be()] on an input, or 5373 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 5374 ** otherwise. ^The same SQL function may be registered multiple times using 5375 ** different preferred text encodings, with different implementations for 5376 ** each encoding. 5377 ** ^When multiple implementations of the same function are available, SQLite 5378 ** will pick the one that involves the least amount of data conversion. 5379 ** 5380 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 5381 ** to signal that the function will always return the same result given 5382 ** the same inputs within a single SQL statement. Most SQL functions are 5383 ** deterministic. The built-in [random()] SQL function is an example of a 5384 ** function that is not deterministic. The SQLite query planner is able to 5385 ** perform additional optimizations on deterministic functions, so use 5386 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 5387 ** 5388 ** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY] 5389 ** flag, which if present prevents the function from being invoked from 5390 ** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions, 5391 ** index expressions, or the WHERE clause of partial indexes. 5392 ** 5393 ** For best security, the [SQLITE_DIRECTONLY] flag is recommended for 5394 ** all application-defined SQL functions that do not need to be 5395 ** used inside of triggers, view, CHECK constraints, or other elements of 5396 ** the database schema. This flags is especially recommended for SQL 5397 ** functions that have side effects or reveal internal application state. 5398 ** Without this flag, an attacker might be able to modify the schema of 5399 ** a database file to include invocations of the function with parameters 5400 ** chosen by the attacker, which the application will then execute when 5401 ** the database file is opened and read. 5402 ** 5403 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 5404 ** function can gain access to this pointer using [sqlite3_user_data()].)^ 5405 ** 5406 ** ^The sixth, seventh and eighth parameters passed to the three 5407 ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 5408 ** pointers to C-language functions that implement the SQL function or 5409 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 5410 ** callback only; NULL pointers must be passed as the xStep and xFinal 5411 ** parameters. ^An aggregate SQL function requires an implementation of xStep 5412 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 5413 ** SQL function or aggregate, pass NULL pointers for all three function 5414 ** callbacks. 5415 ** 5416 ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 5417 ** and xInverse) passed to sqlite3_create_window_function are pointers to 5418 ** C-language callbacks that implement the new function. xStep and xFinal 5419 ** must both be non-NULL. xValue and xInverse may either both be NULL, in 5420 ** which case a regular aggregate function is created, or must both be 5421 ** non-NULL, in which case the new function may be used as either an aggregate 5422 ** or aggregate window function. More details regarding the implementation 5423 ** of aggregate window functions are 5424 ** [user-defined window functions|available here]. 5425 ** 5426 ** ^(If the final parameter to sqlite3_create_function_v2() or 5427 ** sqlite3_create_window_function() is not NULL, then it is destructor for 5428 ** the application data pointer. The destructor is invoked when the function 5429 ** is deleted, either by being overloaded or when the database connection 5430 ** closes.)^ ^The destructor is also invoked if the call to 5431 ** sqlite3_create_function_v2() fails. ^When the destructor callback is 5432 ** invoked, it is passed a single argument which is a copy of the application 5433 ** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 5434 ** 5435 ** ^It is permitted to register multiple implementations of the same 5436 ** functions with the same name but with either differing numbers of 5437 ** arguments or differing preferred text encodings. ^SQLite will use 5438 ** the implementation that most closely matches the way in which the 5439 ** SQL function is used. ^A function implementation with a non-negative 5440 ** nArg parameter is a better match than a function implementation with 5441 ** a negative nArg. ^A function where the preferred text encoding 5442 ** matches the database encoding is a better 5443 ** match than a function where the encoding is different. 5444 ** ^A function where the encoding difference is between UTF16le and UTF16be 5445 ** is a closer match than a function where the encoding difference is 5446 ** between UTF8 and UTF16. 5447 ** 5448 ** ^Built-in functions may be overloaded by new application-defined functions. 5449 ** 5450 ** ^An application-defined function is permitted to call other 5451 ** SQLite interfaces. However, such calls must not 5452 ** close the database connection nor finalize or reset the prepared 5453 ** statement in which the function is running. 5454 */ 5455 SQLITE_API int sqlite3_create_function( 5456 sqlite3 *db, 5457 const char *zFunctionName, 5458 int nArg, 5459 int eTextRep, 5460 void *pApp, 5461 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5462 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5463 void (*xFinal)(sqlite3_context*) 5464 ); 5465 SQLITE_API int sqlite3_create_function16( 5466 sqlite3 *db, 5467 const void *zFunctionName, 5468 int nArg, 5469 int eTextRep, 5470 void *pApp, 5471 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5472 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5473 void (*xFinal)(sqlite3_context*) 5474 ); 5475 SQLITE_API int sqlite3_create_function_v2( 5476 sqlite3 *db, 5477 const char *zFunctionName, 5478 int nArg, 5479 int eTextRep, 5480 void *pApp, 5481 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5482 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5483 void (*xFinal)(sqlite3_context*), 5484 void(*xDestroy)(void*) 5485 ); 5486 SQLITE_API int sqlite3_create_window_function( 5487 sqlite3 *db, 5488 const char *zFunctionName, 5489 int nArg, 5490 int eTextRep, 5491 void *pApp, 5492 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5493 void (*xFinal)(sqlite3_context*), 5494 void (*xValue)(sqlite3_context*), 5495 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 5496 void(*xDestroy)(void*) 5497 ); 5498 5499 /* 5500 ** CAPI3REF: Text Encodings 5501 ** 5502 ** These constant define integer codes that represent the various 5503 ** text encodings supported by SQLite. 5504 */ 5505 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 5506 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 5507 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 5508 #define SQLITE_UTF16 4 /* Use native byte order */ 5509 #define SQLITE_ANY 5 /* Deprecated */ 5510 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 5511 5512 /* 5513 ** CAPI3REF: Function Flags 5514 ** 5515 ** These constants may be ORed together with the 5516 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 5517 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 5518 ** [sqlite3_create_function_v2()]. 5519 ** 5520 ** <dl> 5521 ** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd> 5522 ** The SQLITE_DETERMINISTIC flag means that the new function always gives 5523 ** the same output when the input parameters are the same. 5524 ** The [abs|abs() function] is deterministic, for example, but 5525 ** [randomblob|randomblob()] is not. Functions must 5526 ** be deterministic in order to be used in certain contexts such as 5527 ** with the WHERE clause of [partial indexes] or in [generated columns]. 5528 ** SQLite might also optimize deterministic functions by factoring them 5529 ** out of inner loops. 5530 ** </dd> 5531 ** 5532 ** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd> 5533 ** The SQLITE_DIRECTONLY flag means that the function may only be invoked 5534 ** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in 5535 ** schema structures such as [CHECK constraints], [DEFAULT clauses], 5536 ** [expression indexes], [partial indexes], or [generated columns]. 5537 ** <p> 5538 ** The SQLITE_DIRECTONLY flag is recommended for any 5539 ** [application-defined SQL function] 5540 ** that has side-effects or that could potentially leak sensitive information. 5541 ** This will prevent attacks in which an application is tricked 5542 ** into using a database file that has had its schema surreptitiously 5543 ** modified to invoke the application-defined function in ways that are 5544 ** harmful. 5545 ** <p> 5546 ** Some people say it is good practice to set SQLITE_DIRECTONLY on all 5547 ** [application-defined SQL functions], regardless of whether or not they 5548 ** are security sensitive, as doing so prevents those functions from being used 5549 ** inside of the database schema, and thus ensures that the database 5550 ** can be inspected and modified using generic tools (such as the [CLI]) 5551 ** that do not have access to the application-defined functions. 5552 ** </dd> 5553 ** 5554 ** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd> 5555 ** The SQLITE_INNOCUOUS flag means that the function is unlikely 5556 ** to cause problems even if misused. An innocuous function should have 5557 ** no side effects and should not depend on any values other than its 5558 ** input parameters. The [abs|abs() function] is an example of an 5559 ** innocuous function. 5560 ** The [load_extension() SQL function] is not innocuous because of its 5561 ** side effects. 5562 ** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not 5563 ** exactly the same. The [random|random() function] is an example of a 5564 ** function that is innocuous but not deterministic. 5565 ** <p>Some heightened security settings 5566 ** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF]) 5567 ** disable the use of SQL functions inside views and triggers and in 5568 ** schema structures such as [CHECK constraints], [DEFAULT clauses], 5569 ** [expression indexes], [partial indexes], and [generated columns] unless 5570 ** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions 5571 ** are innocuous. Developers are advised to avoid using the 5572 ** SQLITE_INNOCUOUS flag for application-defined functions unless the 5573 ** function has been carefully audited and found to be free of potentially 5574 ** security-adverse side-effects and information-leaks. 5575 ** </dd> 5576 ** 5577 ** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd> 5578 ** The SQLITE_SUBTYPE flag indicates to SQLite that a function might call 5579 ** [sqlite3_value_subtype()] to inspect the sub-types of its arguments. 5580 ** This flag instructs SQLite to omit some corner-case optimizations that 5581 ** might disrupt the operation of the [sqlite3_value_subtype()] function, 5582 ** causing it to return zero rather than the correct subtype(). 5583 ** SQL functions that invokes [sqlite3_value_subtype()] should have this 5584 ** property. If the SQLITE_SUBTYPE property is omitted, then the return 5585 ** value from [sqlite3_value_subtype()] might sometimes be zero even though 5586 ** a non-zero subtype was specified by the function argument expression. 5587 ** 5588 ** [[SQLITE_RESULT_SUBTYPE]] <dt>SQLITE_RESULT_SUBTYPE</dt><dd> 5589 ** The SQLITE_RESULT_SUBTYPE flag indicates to SQLite that a function might call 5590 ** [sqlite3_result_subtype()] to cause a sub-type to be associated with its 5591 ** result. 5592 ** Every function that invokes [sqlite3_result_subtype()] should have this 5593 ** property. If it does not, then the call to [sqlite3_result_subtype()] 5594 ** might become a no-op if the function is used as term in an 5595 ** [expression index]. On the other hand, SQL functions that never invoke 5596 ** [sqlite3_result_subtype()] should avoid setting this property, as the 5597 ** purpose of this property is to disable certain optimizations that are 5598 ** incompatible with subtypes. 5599 ** </dd> 5600 ** </dl> 5601 */ 5602 #define SQLITE_DETERMINISTIC 0x000000800 5603 #define SQLITE_DIRECTONLY 0x000080000 5604 #define SQLITE_SUBTYPE 0x000100000 5605 #define SQLITE_INNOCUOUS 0x000200000 5606 #define SQLITE_RESULT_SUBTYPE 0x001000000 5607 5608 /* 5609 ** CAPI3REF: Deprecated Functions 5610 ** DEPRECATED 5611 ** 5612 ** These functions are [deprecated]. In order to maintain 5613 ** backwards compatibility with older code, these functions continue 5614 ** to be supported. However, new applications should avoid 5615 ** the use of these functions. To encourage programmers to avoid 5616 ** these functions, we will not explain what they do. 5617 */ 5618 #ifndef SQLITE_OMIT_DEPRECATED 5619 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 5620 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 5621 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 5622 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 5623 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 5624 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 5625 void*,sqlite3_int64); 5626 #endif 5627 5628 /* 5629 ** CAPI3REF: Obtaining SQL Values 5630 ** METHOD: sqlite3_value 5631 ** 5632 ** <b>Summary:</b> 5633 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5634 ** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 5635 ** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 5636 ** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 5637 ** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 5638 ** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 5639 ** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 5640 ** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 5641 ** the native byteorder 5642 ** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 5643 ** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 5644 ** <tr><td> <td> <td> 5645 ** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 5646 ** or a UTF-8 TEXT in bytes 5647 ** <tr><td><b>sqlite3_value_bytes16 </b> 5648 ** <td>→ <td>Size of UTF-16 5649 ** TEXT in bytes 5650 ** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 5651 ** datatype of the value 5652 ** <tr><td><b>sqlite3_value_numeric_type </b> 5653 ** <td>→ <td>Best numeric datatype of the value 5654 ** <tr><td><b>sqlite3_value_nochange </b> 5655 ** <td>→ <td>True if the column is unchanged in an UPDATE 5656 ** against a virtual table. 5657 ** <tr><td><b>sqlite3_value_frombind </b> 5658 ** <td>→ <td>True if value originated from a [bound parameter] 5659 ** </table></blockquote> 5660 ** 5661 ** <b>Details:</b> 5662 ** 5663 ** These routines extract type, size, and content information from 5664 ** [protected sqlite3_value] objects. Protected sqlite3_value objects 5665 ** are used to pass parameter information into the functions that 5666 ** implement [application-defined SQL functions] and [virtual tables]. 5667 ** 5668 ** These routines work only with [protected sqlite3_value] objects. 5669 ** Any attempt to use these routines on an [unprotected sqlite3_value] 5670 ** is not threadsafe. 5671 ** 5672 ** ^These routines work just like the corresponding [column access functions] 5673 ** except that these routines take a single [protected sqlite3_value] object 5674 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 5675 ** 5676 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 5677 ** in the native byte-order of the host machine. ^The 5678 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 5679 ** extract UTF-16 strings as big-endian and little-endian respectively. 5680 ** 5681 ** ^If [sqlite3_value] object V was initialized 5682 ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 5683 ** and if X and Y are strings that compare equal according to strcmp(X,Y), 5684 ** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 5685 ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 5686 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5687 ** 5688 ** ^(The sqlite3_value_type(V) interface returns the 5689 ** [SQLITE_INTEGER | datatype code] for the initial datatype of the 5690 ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 5691 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 5692 ** Other interfaces might change the datatype for an sqlite3_value object. 5693 ** For example, if the datatype is initially SQLITE_INTEGER and 5694 ** sqlite3_value_text(V) is called to extract a text value for that 5695 ** integer, then subsequent calls to sqlite3_value_type(V) might return 5696 ** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 5697 ** occurs is undefined and may change from one release of SQLite to the next. 5698 ** 5699 ** ^(The sqlite3_value_numeric_type() interface attempts to apply 5700 ** numeric affinity to the value. This means that an attempt is 5701 ** made to convert the value to an integer or floating point. If 5702 ** such a conversion is possible without loss of information (in other 5703 ** words, if the value is a string that looks like a number) 5704 ** then the conversion is performed. Otherwise no conversion occurs. 5705 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 5706 ** 5707 ** ^Within the [xUpdate] method of a [virtual table], the 5708 ** sqlite3_value_nochange(X) interface returns true if and only if 5709 ** the column corresponding to X is unchanged by the UPDATE operation 5710 ** that the xUpdate method call was invoked to implement and if 5711 ** and the prior [xColumn] method call that was invoked to extracted 5712 ** the value for that column returned without setting a result (probably 5713 ** because it queried [sqlite3_vtab_nochange()] and found that the column 5714 ** was unchanging). ^Within an [xUpdate] method, any value for which 5715 ** sqlite3_value_nochange(X) is true will in all other respects appear 5716 ** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 5717 ** than within an [xUpdate] method call for an UPDATE statement, then 5718 ** the return value is arbitrary and meaningless. 5719 ** 5720 ** ^The sqlite3_value_frombind(X) interface returns non-zero if the 5721 ** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()] 5722 ** interfaces. ^If X comes from an SQL literal value, or a table column, 5723 ** or an expression, then sqlite3_value_frombind(X) returns zero. 5724 ** 5725 ** Please pay particular attention to the fact that the pointer returned 5726 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 5727 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 5728 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 5729 ** or [sqlite3_value_text16()]. 5730 ** 5731 ** These routines must be called from the same thread as 5732 ** the SQL function that supplied the [sqlite3_value*] parameters. 5733 ** 5734 ** As long as the input parameter is correct, these routines can only 5735 ** fail if an out-of-memory error occurs during a format conversion. 5736 ** Only the following subset of interfaces are subject to out-of-memory 5737 ** errors: 5738 ** 5739 ** <ul> 5740 ** <li> sqlite3_value_blob() 5741 ** <li> sqlite3_value_text() 5742 ** <li> sqlite3_value_text16() 5743 ** <li> sqlite3_value_text16le() 5744 ** <li> sqlite3_value_text16be() 5745 ** <li> sqlite3_value_bytes() 5746 ** <li> sqlite3_value_bytes16() 5747 ** </ul> 5748 ** 5749 ** If an out-of-memory error occurs, then the return value from these 5750 ** routines is the same as if the column had contained an SQL NULL value. 5751 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 5752 ** by invoking the [sqlite3_errcode()] immediately after the suspect 5753 ** return value is obtained and before any 5754 ** other SQLite interface is called on the same [database connection]. 5755 */ 5756 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 5757 SQLITE_API double sqlite3_value_double(sqlite3_value*); 5758 SQLITE_API int sqlite3_value_int(sqlite3_value*); 5759 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 5760 SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*); 5761 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 5762 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 5763 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 5764 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 5765 SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 5766 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 5767 SQLITE_API int sqlite3_value_type(sqlite3_value*); 5768 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 5769 SQLITE_API int sqlite3_value_nochange(sqlite3_value*); 5770 SQLITE_API int sqlite3_value_frombind(sqlite3_value*); 5771 5772 /* 5773 ** CAPI3REF: Report the internal text encoding state of an sqlite3_value object 5774 ** METHOD: sqlite3_value 5775 ** 5776 ** ^(The sqlite3_value_encoding(X) interface returns one of [SQLITE_UTF8], 5777 ** [SQLITE_UTF16BE], or [SQLITE_UTF16LE] according to the current text encoding 5778 ** of the value X, assuming that X has type TEXT.)^ If sqlite3_value_type(X) 5779 ** returns something other than SQLITE_TEXT, then the return value from 5780 ** sqlite3_value_encoding(X) is meaningless. ^Calls to 5781 ** [sqlite3_value_text(X)], [sqlite3_value_text16(X)], [sqlite3_value_text16be(X)], 5782 ** [sqlite3_value_text16le(X)], [sqlite3_value_bytes(X)], or 5783 ** [sqlite3_value_bytes16(X)] might change the encoding of the value X and 5784 ** thus change the return from subsequent calls to sqlite3_value_encoding(X). 5785 ** 5786 ** This routine is intended for used by applications that test and validate 5787 ** the SQLite implementation. This routine is inquiring about the opaque 5788 ** internal state of an [sqlite3_value] object. Ordinary applications should 5789 ** not need to know what the internal state of an sqlite3_value object is and 5790 ** hence should not need to use this interface. 5791 */ 5792 SQLITE_API int sqlite3_value_encoding(sqlite3_value*); 5793 5794 /* 5795 ** CAPI3REF: Finding The Subtype Of SQL Values 5796 ** METHOD: sqlite3_value 5797 ** 5798 ** The sqlite3_value_subtype(V) function returns the subtype for 5799 ** an [application-defined SQL function] argument V. The subtype 5800 ** information can be used to pass a limited amount of context from 5801 ** one SQL function to another. Use the [sqlite3_result_subtype()] 5802 ** routine to set the subtype for the return value of an SQL function. 5803 ** 5804 ** Every [application-defined SQL function] that invoke this interface 5805 ** should include the [SQLITE_SUBTYPE] property in the text 5806 ** encoding argument when the function is [sqlite3_create_function|registered]. 5807 ** If the [SQLITE_SUBTYPE] property is omitted, then sqlite3_value_subtype() 5808 ** might return zero instead of the upstream subtype in some corner cases. 5809 */ 5810 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); 5811 5812 /* 5813 ** CAPI3REF: Copy And Free SQL Values 5814 ** METHOD: sqlite3_value 5815 ** 5816 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 5817 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 5818 ** is a [protected sqlite3_value] object even if the input is not. 5819 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 5820 ** memory allocation fails. ^If V is a [pointer value], then the result 5821 ** of sqlite3_value_dup(V) is a NULL value. 5822 ** 5823 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 5824 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 5825 ** then sqlite3_value_free(V) is a harmless no-op. 5826 */ 5827 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 5828 SQLITE_API void sqlite3_value_free(sqlite3_value*); 5829 5830 /* 5831 ** CAPI3REF: Obtain Aggregate Function Context 5832 ** METHOD: sqlite3_context 5833 ** 5834 ** Implementations of aggregate SQL functions use this 5835 ** routine to allocate memory for storing their state. 5836 ** 5837 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 5838 ** for a particular aggregate function, SQLite allocates 5839 ** N bytes of memory, zeroes out that memory, and returns a pointer 5840 ** to the new memory. ^On second and subsequent calls to 5841 ** sqlite3_aggregate_context() for the same aggregate function instance, 5842 ** the same buffer is returned. Sqlite3_aggregate_context() is normally 5843 ** called once for each invocation of the xStep callback and then one 5844 ** last time when the xFinal callback is invoked. ^(When no rows match 5845 ** an aggregate query, the xStep() callback of the aggregate function 5846 ** implementation is never called and xFinal() is called exactly once. 5847 ** In those cases, sqlite3_aggregate_context() might be called for the 5848 ** first time from within xFinal().)^ 5849 ** 5850 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5851 ** when first called if N is less than or equal to zero or if a memory 5852 ** allocation error occurs. 5853 ** 5854 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 5855 ** determined by the N parameter on first successful call. Changing the 5856 ** value of N in any subsequent call to sqlite3_aggregate_context() within 5857 ** the same aggregate function instance will not resize the memory 5858 ** allocation.)^ Within the xFinal callback, it is customary to set 5859 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5860 ** pointless memory allocations occur. 5861 ** 5862 ** ^SQLite automatically frees the memory allocated by 5863 ** sqlite3_aggregate_context() when the aggregate query concludes. 5864 ** 5865 ** The first parameter must be a copy of the 5866 ** [sqlite3_context | SQL function context] that is the first parameter 5867 ** to the xStep or xFinal callback routine that implements the aggregate 5868 ** function. 5869 ** 5870 ** This routine must be called from the same thread in which 5871 ** the aggregate SQL function is running. 5872 */ 5873 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 5874 5875 /* 5876 ** CAPI3REF: User Data For Functions 5877 ** METHOD: sqlite3_context 5878 ** 5879 ** ^The sqlite3_user_data() interface returns a copy of 5880 ** the pointer that was the pUserData parameter (the 5th parameter) 5881 ** of the [sqlite3_create_function()] 5882 ** and [sqlite3_create_function16()] routines that originally 5883 ** registered the application defined function. 5884 ** 5885 ** This routine must be called from the same thread in which 5886 ** the application-defined function is running. 5887 */ 5888 SQLITE_API void *sqlite3_user_data(sqlite3_context*); 5889 5890 /* 5891 ** CAPI3REF: Database Connection For Functions 5892 ** METHOD: sqlite3_context 5893 ** 5894 ** ^The sqlite3_context_db_handle() interface returns a copy of 5895 ** the pointer to the [database connection] (the 1st parameter) 5896 ** of the [sqlite3_create_function()] 5897 ** and [sqlite3_create_function16()] routines that originally 5898 ** registered the application defined function. 5899 */ 5900 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5901 5902 /* 5903 ** CAPI3REF: Function Auxiliary Data 5904 ** METHOD: sqlite3_context 5905 ** 5906 ** These functions may be used by (non-aggregate) SQL functions to 5907 ** associate auxiliary data with argument values. If the same argument 5908 ** value is passed to multiple invocations of the same SQL function during 5909 ** query execution, under some circumstances the associated auxiliary data 5910 ** might be preserved. An example of where this might be useful is in a 5911 ** regular-expression matching function. The compiled version of the regular 5912 ** expression can be stored as auxiliary data associated with the pattern string. 5913 ** Then as long as the pattern string remains the same, 5914 ** the compiled regular expression can be reused on multiple 5915 ** invocations of the same function. 5916 ** 5917 ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the auxiliary data 5918 ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5919 ** value to the application-defined function. ^N is zero for the left-most 5920 ** function argument. ^If there is no auxiliary data 5921 ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5922 ** returns a NULL pointer. 5923 ** 5924 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as auxiliary data for the 5925 ** N-th argument of the application-defined function. ^Subsequent 5926 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5927 ** sqlite3_set_auxdata(C,N,P,X) call if the auxiliary data is still valid or 5928 ** NULL if the auxiliary data has been discarded. 5929 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5930 ** SQLite will invoke the destructor function X with parameter P exactly 5931 ** once, when the auxiliary data is discarded. 5932 ** SQLite is free to discard the auxiliary data at any time, including: <ul> 5933 ** <li> ^(when the corresponding function parameter changes)^, or 5934 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5935 ** SQL statement)^, or 5936 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5937 ** parameter)^, or 5938 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5939 ** allocation error occurs.)^ 5940 ** <li> ^(during the original sqlite3_set_auxdata() call if the function 5941 ** is evaluated during query planning instead of during query execution, 5942 ** as sometimes happens with [SQLITE_ENABLE_STAT4].)^ </ul> 5943 ** 5944 ** Note the last two bullets in particular. The destructor X in 5945 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5946 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5947 ** should be called near the end of the function implementation and the 5948 ** function implementation should not make any use of P after 5949 ** sqlite3_set_auxdata() has been called. Furthermore, a call to 5950 ** sqlite3_get_auxdata() that occurs immediately after a corresponding call 5951 ** to sqlite3_set_auxdata() might still return NULL if an out-of-memory 5952 ** condition occurred during the sqlite3_set_auxdata() call or if the 5953 ** function is being evaluated during query planning rather than during 5954 ** query execution. 5955 ** 5956 ** ^(In practice, auxiliary data is preserved between function calls for 5957 ** function parameters that are compile-time constants, including literal 5958 ** values and [parameters] and expressions composed from the same.)^ 5959 ** 5960 ** The value of the N parameter to these interfaces should be non-negative. 5961 ** Future enhancements may make use of negative N values to define new 5962 ** kinds of function caching behavior. 5963 ** 5964 ** These routines must be called from the same thread in which 5965 ** the SQL function is running. 5966 ** 5967 ** See also: [sqlite3_get_clientdata()] and [sqlite3_set_clientdata()]. 5968 */ 5969 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 5970 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5971 5972 /* 5973 ** CAPI3REF: Database Connection Client Data 5974 ** METHOD: sqlite3 5975 ** 5976 ** These functions are used to associate one or more named pointers 5977 ** with a [database connection]. 5978 ** A call to sqlite3_set_clientdata(D,N,P,X) causes the pointer P 5979 ** to be attached to [database connection] D using name N. Subsequent 5980 ** calls to sqlite3_get_clientdata(D,N) will return a copy of pointer P 5981 ** or a NULL pointer if there were no prior calls to 5982 ** sqlite3_set_clientdata() with the same values of D and N. 5983 ** Names are compared using strcmp() and are thus case sensitive. 5984 ** 5985 ** If P and X are both non-NULL, then the destructor X is invoked with 5986 ** argument P on the first of the following occurrences: 5987 ** <ul> 5988 ** <li> An out-of-memory error occurs during the call to 5989 ** sqlite3_set_clientdata() which attempts to register pointer P. 5990 ** <li> A subsequent call to sqlite3_set_clientdata(D,N,P,X) is made 5991 ** with the same D and N parameters. 5992 ** <li> The database connection closes. SQLite does not make any guarantees 5993 ** about the order in which destructors are called, only that all 5994 ** destructors will be called exactly once at some point during the 5995 ** database connection closing process. 5996 ** </ul> 5997 ** 5998 ** SQLite does not do anything with client data other than invoke 5999 ** destructors on the client data at the appropriate time. The intended 6000 ** use for client data is to provide a mechanism for wrapper libraries 6001 ** to store additional information about an SQLite database connection. 6002 ** 6003 ** There is no limit (other than available memory) on the number of different 6004 ** client data pointers (with different names) that can be attached to a 6005 ** single database connection. However, the implementation is optimized 6006 ** for the case of having only one or two different client data names. 6007 ** Applications and wrapper libraries are discouraged from using more than 6008 ** one client data name each. 6009 ** 6010 ** There is no way to enumerate the client data pointers 6011 ** associated with a database connection. The N parameter can be thought 6012 ** of as a secret key such that only code that knows the secret key is able 6013 ** to access the associated data. 6014 ** 6015 ** Security Warning: These interfaces should not be exposed in scripting 6016 ** languages or in other circumstances where it might be possible for an 6017 ** an attacker to invoke them. Any agent that can invoke these interfaces 6018 ** can probably also take control of the process. 6019 ** 6020 ** Database connection client data is only available for SQLite 6021 ** version 3.44.0 ([dateof:3.44.0]) and later. 6022 ** 6023 ** See also: [sqlite3_set_auxdata()] and [sqlite3_get_auxdata()]. 6024 */ 6025 SQLITE_API void *sqlite3_get_clientdata(sqlite3*,const char*); 6026 SQLITE_API int sqlite3_set_clientdata(sqlite3*, const char*, void*, void(*)(void*)); 6027 6028 /* 6029 ** CAPI3REF: Constants Defining Special Destructor Behavior 6030 ** 6031 ** These are special values for the destructor that is passed in as the 6032 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 6033 ** argument is SQLITE_STATIC, it means that the content pointer is constant 6034 ** and will never change. It does not need to be destroyed. ^The 6035 ** SQLITE_TRANSIENT value means that the content will likely change in 6036 ** the near future and that SQLite should make its own private copy of 6037 ** the content before returning. 6038 ** 6039 ** The typedef is necessary to work around problems in certain 6040 ** C++ compilers. 6041 */ 6042 typedef void (*sqlite3_destructor_type)(void*); 6043 #define SQLITE_STATIC ((sqlite3_destructor_type)0) 6044 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 6045 6046 /* 6047 ** CAPI3REF: Setting The Result Of An SQL Function 6048 ** METHOD: sqlite3_context 6049 ** 6050 ** These routines are used by the xFunc or xFinal callbacks that 6051 ** implement SQL functions and aggregates. See 6052 ** [sqlite3_create_function()] and [sqlite3_create_function16()] 6053 ** for additional information. 6054 ** 6055 ** These functions work very much like the [parameter binding] family of 6056 ** functions used to bind values to host parameters in prepared statements. 6057 ** Refer to the [SQL parameter] documentation for additional information. 6058 ** 6059 ** ^The sqlite3_result_blob() interface sets the result from 6060 ** an application-defined function to be the BLOB whose content is pointed 6061 ** to by the second parameter and which is N bytes long where N is the 6062 ** third parameter. 6063 ** 6064 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 6065 ** interfaces set the result of the application-defined function to be 6066 ** a BLOB containing all zero bytes and N bytes in size. 6067 ** 6068 ** ^The sqlite3_result_double() interface sets the result from 6069 ** an application-defined function to be a floating point value specified 6070 ** by its 2nd argument. 6071 ** 6072 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 6073 ** cause the implemented SQL function to throw an exception. 6074 ** ^SQLite uses the string pointed to by the 6075 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 6076 ** as the text of an error message. ^SQLite interprets the error 6077 ** message string from sqlite3_result_error() as UTF-8. ^SQLite 6078 ** interprets the string from sqlite3_result_error16() as UTF-16 using 6079 ** the same [byte-order determination rules] as [sqlite3_bind_text16()]. 6080 ** ^If the third parameter to sqlite3_result_error() 6081 ** or sqlite3_result_error16() is negative then SQLite takes as the error 6082 ** message all text up through the first zero character. 6083 ** ^If the third parameter to sqlite3_result_error() or 6084 ** sqlite3_result_error16() is non-negative then SQLite takes that many 6085 ** bytes (not characters) from the 2nd parameter as the error message. 6086 ** ^The sqlite3_result_error() and sqlite3_result_error16() 6087 ** routines make a private copy of the error message text before 6088 ** they return. Hence, the calling function can deallocate or 6089 ** modify the text after they return without harm. 6090 ** ^The sqlite3_result_error_code() function changes the error code 6091 ** returned by SQLite as a result of an error in a function. ^By default, 6092 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 6093 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 6094 ** 6095 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 6096 ** error indicating that a string or BLOB is too long to represent. 6097 ** 6098 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 6099 ** error indicating that a memory allocation failed. 6100 ** 6101 ** ^The sqlite3_result_int() interface sets the return value 6102 ** of the application-defined function to be the 32-bit signed integer 6103 ** value given in the 2nd argument. 6104 ** ^The sqlite3_result_int64() interface sets the return value 6105 ** of the application-defined function to be the 64-bit signed integer 6106 ** value given in the 2nd argument. 6107 ** 6108 ** ^The sqlite3_result_null() interface sets the return value 6109 ** of the application-defined function to be NULL. 6110 ** 6111 ** ^The sqlite3_result_text(), sqlite3_result_text16(), 6112 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 6113 ** set the return value of the application-defined function to be 6114 ** a text string which is represented as UTF-8, UTF-16 native byte order, 6115 ** UTF-16 little endian, or UTF-16 big endian, respectively. 6116 ** ^The sqlite3_result_text64() interface sets the return value of an 6117 ** application-defined function to be a text string in an encoding 6118 ** specified by the fifth (and last) parameter, which must be one 6119 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 6120 ** ^SQLite takes the text result from the application from 6121 ** the 2nd parameter of the sqlite3_result_text* interfaces. 6122 ** ^If the 3rd parameter to any of the sqlite3_result_text* interfaces 6123 ** other than sqlite3_result_text64() is negative, then SQLite computes 6124 ** the string length itself by searching the 2nd parameter for the first 6125 ** zero character. 6126 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 6127 ** is non-negative, then as many bytes (not characters) of the text 6128 ** pointed to by the 2nd parameter are taken as the application-defined 6129 ** function result. If the 3rd parameter is non-negative, then it 6130 ** must be the byte offset into the string where the NUL terminator would 6131 ** appear if the string where NUL terminated. If any NUL characters occur 6132 ** in the string at a byte offset that is less than the value of the 3rd 6133 ** parameter, then the resulting string will contain embedded NULs and the 6134 ** result of expressions operating on strings with embedded NULs is undefined. 6135 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 6136 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 6137 ** function as the destructor on the text or BLOB result when it has 6138 ** finished using that result. 6139 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 6140 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 6141 ** assumes that the text or BLOB result is in constant space and does not 6142 ** copy the content of the parameter nor call a destructor on the content 6143 ** when it has finished using that result. 6144 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 6145 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 6146 ** then SQLite makes a copy of the result into space obtained 6147 ** from [sqlite3_malloc()] before it returns. 6148 ** 6149 ** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and 6150 ** sqlite3_result_text16be() routines, and for sqlite3_result_text64() 6151 ** when the encoding is not UTF8, if the input UTF16 begins with a 6152 ** byte-order mark (BOM, U+FEFF) then the BOM is removed from the 6153 ** string and the rest of the string is interpreted according to the 6154 ** byte-order specified by the BOM. ^The byte-order specified by 6155 ** the BOM at the beginning of the text overrides the byte-order 6156 ** specified by the interface procedure. ^So, for example, if 6157 ** sqlite3_result_text16le() is invoked with text that begins 6158 ** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the 6159 ** first two bytes of input are skipped and the remaining input 6160 ** is interpreted as UTF16BE text. 6161 ** 6162 ** ^For UTF16 input text to the sqlite3_result_text16(), 6163 ** sqlite3_result_text16be(), sqlite3_result_text16le(), and 6164 ** sqlite3_result_text64() routines, if the text contains invalid 6165 ** UTF16 characters, the invalid characters might be converted 6166 ** into the unicode replacement character, U+FFFD. 6167 ** 6168 ** ^The sqlite3_result_value() interface sets the result of 6169 ** the application-defined function to be a copy of the 6170 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 6171 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 6172 ** so that the [sqlite3_value] specified in the parameter may change or 6173 ** be deallocated after sqlite3_result_value() returns without harm. 6174 ** ^A [protected sqlite3_value] object may always be used where an 6175 ** [unprotected sqlite3_value] object is required, so either 6176 ** kind of [sqlite3_value] object can be used with this interface. 6177 ** 6178 ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 6179 ** SQL NULL value, just like [sqlite3_result_null(C)], except that it 6180 ** also associates the host-language pointer P or type T with that 6181 ** NULL value such that the pointer can be retrieved within an 6182 ** [application-defined SQL function] using [sqlite3_value_pointer()]. 6183 ** ^If the D parameter is not NULL, then it is a pointer to a destructor 6184 ** for the P parameter. ^SQLite invokes D with P as its only argument 6185 ** when SQLite is finished with P. The T parameter should be a static 6186 ** string and preferably a string literal. The sqlite3_result_pointer() 6187 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 6188 ** 6189 ** If these routines are called from within the different thread 6190 ** than the one containing the application-defined function that received 6191 ** the [sqlite3_context] pointer, the results are undefined. 6192 */ 6193 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 6194 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 6195 sqlite3_uint64,void(*)(void*)); 6196 SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 6197 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 6198 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 6199 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 6200 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 6201 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 6202 SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 6203 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 6204 SQLITE_API void sqlite3_result_null(sqlite3_context*); 6205 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 6206 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 6207 void(*)(void*), unsigned char encoding); 6208 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 6209 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 6210 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 6211 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 6212 SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 6213 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 6214 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 6215 6216 6217 /* 6218 ** CAPI3REF: Setting The Subtype Of An SQL Function 6219 ** METHOD: sqlite3_context 6220 ** 6221 ** The sqlite3_result_subtype(C,T) function causes the subtype of 6222 ** the result from the [application-defined SQL function] with 6223 ** [sqlite3_context] C to be the value T. Only the lower 8 bits 6224 ** of the subtype T are preserved in current versions of SQLite; 6225 ** higher order bits are discarded. 6226 ** The number of subtype bytes preserved by SQLite might increase 6227 ** in future releases of SQLite. 6228 ** 6229 ** Every [application-defined SQL function] that invokes this interface 6230 ** should include the [SQLITE_RESULT_SUBTYPE] property in its 6231 ** text encoding argument when the SQL function is 6232 ** [sqlite3_create_function|registered]. If the [SQLITE_RESULT_SUBTYPE] 6233 ** property is omitted from the function that invokes sqlite3_result_subtype(), 6234 ** then in some cases the sqlite3_result_subtype() might fail to set 6235 ** the result subtype. 6236 ** 6237 ** If SQLite is compiled with -DSQLITE_STRICT_SUBTYPE=1, then any 6238 ** SQL function that invokes the sqlite3_result_subtype() interface 6239 ** and that does not have the SQLITE_RESULT_SUBTYPE property will raise 6240 ** an error. Future versions of SQLite might enable -DSQLITE_STRICT_SUBTYPE=1 6241 ** by default. 6242 */ 6243 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); 6244 6245 /* 6246 ** CAPI3REF: Define New Collating Sequences 6247 ** METHOD: sqlite3 6248 ** 6249 ** ^These functions add, remove, or modify a [collation] associated 6250 ** with the [database connection] specified as the first argument. 6251 ** 6252 ** ^The name of the collation is a UTF-8 string 6253 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 6254 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 6255 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 6256 ** considered to be the same name. 6257 ** 6258 ** ^(The third argument (eTextRep) must be one of the constants: 6259 ** <ul> 6260 ** <li> [SQLITE_UTF8], 6261 ** <li> [SQLITE_UTF16LE], 6262 ** <li> [SQLITE_UTF16BE], 6263 ** <li> [SQLITE_UTF16], or 6264 ** <li> [SQLITE_UTF16_ALIGNED]. 6265 ** </ul>)^ 6266 ** ^The eTextRep argument determines the encoding of strings passed 6267 ** to the collating function callback, xCompare. 6268 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 6269 ** force strings to be UTF16 with native byte order. 6270 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 6271 ** on an even byte address. 6272 ** 6273 ** ^The fourth argument, pArg, is an application data pointer that is passed 6274 ** through as the first argument to the collating function callback. 6275 ** 6276 ** ^The fifth argument, xCompare, is a pointer to the collating function. 6277 ** ^Multiple collating functions can be registered using the same name but 6278 ** with different eTextRep parameters and SQLite will use whichever 6279 ** function requires the least amount of data transformation. 6280 ** ^If the xCompare argument is NULL then the collating function is 6281 ** deleted. ^When all collating functions having the same name are deleted, 6282 ** that collation is no longer usable. 6283 ** 6284 ** ^The collating function callback is invoked with a copy of the pArg 6285 ** application data pointer and with two strings in the encoding specified 6286 ** by the eTextRep argument. The two integer parameters to the collating 6287 ** function callback are the length of the two strings, in bytes. The collating 6288 ** function must return an integer that is negative, zero, or positive 6289 ** if the first string is less than, equal to, or greater than the second, 6290 ** respectively. A collating function must always return the same answer 6291 ** given the same inputs. If two or more collating functions are registered 6292 ** to the same collation name (using different eTextRep values) then all 6293 ** must give an equivalent answer when invoked with equivalent strings. 6294 ** The collating function must obey the following properties for all 6295 ** strings A, B, and C: 6296 ** 6297 ** <ol> 6298 ** <li> If A==B then B==A. 6299 ** <li> If A==B and B==C then A==C. 6300 ** <li> If A<B THEN B>A. 6301 ** <li> If A<B and B<C then A<C. 6302 ** </ol> 6303 ** 6304 ** If a collating function fails any of the above constraints and that 6305 ** collating function is registered and used, then the behavior of SQLite 6306 ** is undefined. 6307 ** 6308 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 6309 ** with the addition that the xDestroy callback is invoked on pArg when 6310 ** the collating function is deleted. 6311 ** ^Collating functions are deleted when they are overridden by later 6312 ** calls to the collation creation functions or when the 6313 ** [database connection] is closed using [sqlite3_close()]. 6314 ** 6315 ** ^The xDestroy callback is <u>not</u> called if the 6316 ** sqlite3_create_collation_v2() function fails. Applications that invoke 6317 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 6318 ** check the return code and dispose of the application data pointer 6319 ** themselves rather than expecting SQLite to deal with it for them. 6320 ** This is different from every other SQLite interface. The inconsistency 6321 ** is unfortunate but cannot be changed without breaking backwards 6322 ** compatibility. 6323 ** 6324 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 6325 */ 6326 SQLITE_API int sqlite3_create_collation( 6327 sqlite3*, 6328 const char *zName, 6329 int eTextRep, 6330 void *pArg, 6331 int(*xCompare)(void*,int,const void*,int,const void*) 6332 ); 6333 SQLITE_API int sqlite3_create_collation_v2( 6334 sqlite3*, 6335 const char *zName, 6336 int eTextRep, 6337 void *pArg, 6338 int(*xCompare)(void*,int,const void*,int,const void*), 6339 void(*xDestroy)(void*) 6340 ); 6341 SQLITE_API int sqlite3_create_collation16( 6342 sqlite3*, 6343 const void *zName, 6344 int eTextRep, 6345 void *pArg, 6346 int(*xCompare)(void*,int,const void*,int,const void*) 6347 ); 6348 6349 /* 6350 ** CAPI3REF: Collation Needed Callbacks 6351 ** METHOD: sqlite3 6352 ** 6353 ** ^To avoid having to register all collation sequences before a database 6354 ** can be used, a single callback function may be registered with the 6355 ** [database connection] to be invoked whenever an undefined collation 6356 ** sequence is required. 6357 ** 6358 ** ^If the function is registered using the sqlite3_collation_needed() API, 6359 ** then it is passed the names of undefined collation sequences as strings 6360 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 6361 ** the names are passed as UTF-16 in machine native byte order. 6362 ** ^A call to either function replaces the existing collation-needed callback. 6363 ** 6364 ** ^(When the callback is invoked, the first argument passed is a copy 6365 ** of the second argument to sqlite3_collation_needed() or 6366 ** sqlite3_collation_needed16(). The second argument is the database 6367 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 6368 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 6369 ** sequence function required. The fourth parameter is the name of the 6370 ** required collation sequence.)^ 6371 ** 6372 ** The callback function should register the desired collation using 6373 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 6374 ** [sqlite3_create_collation_v2()]. 6375 */ 6376 SQLITE_API int sqlite3_collation_needed( 6377 sqlite3*, 6378 void*, 6379 void(*)(void*,sqlite3*,int eTextRep,const char*) 6380 ); 6381 SQLITE_API int sqlite3_collation_needed16( 6382 sqlite3*, 6383 void*, 6384 void(*)(void*,sqlite3*,int eTextRep,const void*) 6385 ); 6386 6387 #ifdef SQLITE_ENABLE_CEROD 6388 /* 6389 ** Specify the activation key for a CEROD database. Unless 6390 ** activated, none of the CEROD routines will work. 6391 */ 6392 SQLITE_API void sqlite3_activate_cerod( 6393 const char *zPassPhrase /* Activation phrase */ 6394 ); 6395 #endif 6396 6397 /* 6398 ** CAPI3REF: Suspend Execution For A Short Time 6399 ** 6400 ** The sqlite3_sleep() function causes the current thread to suspend execution 6401 ** for at least a number of milliseconds specified in its parameter. 6402 ** 6403 ** If the operating system does not support sleep requests with 6404 ** millisecond time resolution, then the time will be rounded up to 6405 ** the nearest second. The number of milliseconds of sleep actually 6406 ** requested from the operating system is returned. 6407 ** 6408 ** ^SQLite implements this interface by calling the xSleep() 6409 ** method of the default [sqlite3_vfs] object. If the xSleep() method 6410 ** of the default VFS is not implemented correctly, or not implemented at 6411 ** all, then the behavior of sqlite3_sleep() may deviate from the description 6412 ** in the previous paragraphs. 6413 ** 6414 ** If a negative argument is passed to sqlite3_sleep() the results vary by 6415 ** VFS and operating system. Some system treat a negative argument as an 6416 ** instruction to sleep forever. Others understand it to mean do not sleep 6417 ** at all. ^In SQLite version 3.42.0 and later, a negative 6418 ** argument passed into sqlite3_sleep() is changed to zero before it is relayed 6419 ** down into the xSleep method of the VFS. 6420 */ 6421 SQLITE_API int sqlite3_sleep(int); 6422 6423 /* 6424 ** CAPI3REF: Name Of The Folder Holding Temporary Files 6425 ** 6426 ** ^(If this global variable is made to point to a string which is 6427 ** the name of a folder (a.k.a. directory), then all temporary files 6428 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 6429 ** will be placed in that directory.)^ ^If this variable 6430 ** is a NULL pointer, then SQLite performs a search for an appropriate 6431 ** temporary file directory. 6432 ** 6433 ** Applications are strongly discouraged from using this global variable. 6434 ** It is required to set a temporary folder on Windows Runtime (WinRT). 6435 ** But for all other platforms, it is highly recommended that applications 6436 ** neither read nor write this variable. This global variable is a relic 6437 ** that exists for backwards compatibility of legacy applications and should 6438 ** be avoided in new projects. 6439 ** 6440 ** It is not safe to read or modify this variable in more than one 6441 ** thread at a time. It is not safe to read or modify this variable 6442 ** if a [database connection] is being used at the same time in a separate 6443 ** thread. 6444 ** It is intended that this variable be set once 6445 ** as part of process initialization and before any SQLite interface 6446 ** routines have been called and that this variable remain unchanged 6447 ** thereafter. 6448 ** 6449 ** ^The [temp_store_directory pragma] may modify this variable and cause 6450 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6451 ** the [temp_store_directory pragma] always assumes that any string 6452 ** that this variable points to is held in memory obtained from 6453 ** [sqlite3_malloc] and the pragma may attempt to free that memory 6454 ** using [sqlite3_free]. 6455 ** Hence, if this variable is modified directly, either it should be 6456 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 6457 ** or else the use of the [temp_store_directory pragma] should be avoided. 6458 ** Except when requested by the [temp_store_directory pragma], SQLite 6459 ** does not free the memory that sqlite3_temp_directory points to. If 6460 ** the application wants that memory to be freed, it must do 6461 ** so itself, taking care to only do so after all [database connection] 6462 ** objects have been destroyed. 6463 ** 6464 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 6465 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 6466 ** features that require the use of temporary files may fail. Here is an 6467 ** example of how to do this using C++ with the Windows Runtime: 6468 ** 6469 ** <blockquote><pre> 6470 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 6471 ** TemporaryFolder->Path->Data(); 6472 ** char zPathBuf[MAX_PATH + 1]; 6473 ** memset(zPathBuf, 0, sizeof(zPathBuf)); 6474 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 6475 ** NULL, NULL); 6476 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 6477 ** </pre></blockquote> 6478 */ 6479 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 6480 6481 /* 6482 ** CAPI3REF: Name Of The Folder Holding Database Files 6483 ** 6484 ** ^(If this global variable is made to point to a string which is 6485 ** the name of a folder (a.k.a. directory), then all database files 6486 ** specified with a relative pathname and created or accessed by 6487 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 6488 ** to be relative to that directory.)^ ^If this variable is a NULL 6489 ** pointer, then SQLite assumes that all database files specified 6490 ** with a relative pathname are relative to the current directory 6491 ** for the process. Only the windows VFS makes use of this global 6492 ** variable; it is ignored by the unix VFS. 6493 ** 6494 ** Changing the value of this variable while a database connection is 6495 ** open can result in a corrupt database. 6496 ** 6497 ** It is not safe to read or modify this variable in more than one 6498 ** thread at a time. It is not safe to read or modify this variable 6499 ** if a [database connection] is being used at the same time in a separate 6500 ** thread. 6501 ** It is intended that this variable be set once 6502 ** as part of process initialization and before any SQLite interface 6503 ** routines have been called and that this variable remain unchanged 6504 ** thereafter. 6505 ** 6506 ** ^The [data_store_directory pragma] may modify this variable and cause 6507 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6508 ** the [data_store_directory pragma] always assumes that any string 6509 ** that this variable points to is held in memory obtained from 6510 ** [sqlite3_malloc] and the pragma may attempt to free that memory 6511 ** using [sqlite3_free]. 6512 ** Hence, if this variable is modified directly, either it should be 6513 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 6514 ** or else the use of the [data_store_directory pragma] should be avoided. 6515 */ 6516 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 6517 6518 /* 6519 ** CAPI3REF: Win32 Specific Interface 6520 ** 6521 ** These interfaces are available only on Windows. The 6522 ** [sqlite3_win32_set_directory] interface is used to set the value associated 6523 ** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 6524 ** zValue, depending on the value of the type parameter. The zValue parameter 6525 ** should be NULL to cause the previous value to be freed via [sqlite3_free]; 6526 ** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 6527 ** prior to being used. The [sqlite3_win32_set_directory] interface returns 6528 ** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 6529 ** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 6530 ** [sqlite3_data_directory] variable is intended to act as a replacement for 6531 ** the current directory on the sub-platforms of Win32 where that concept is 6532 ** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 6533 ** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 6534 ** sqlite3_win32_set_directory interface except the string parameter must be 6535 ** UTF-8 or UTF-16, respectively. 6536 */ 6537 SQLITE_API int sqlite3_win32_set_directory( 6538 unsigned long type, /* Identifier for directory being set or reset */ 6539 void *zValue /* New value for directory being set or reset */ 6540 ); 6541 SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 6542 SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 6543 6544 /* 6545 ** CAPI3REF: Win32 Directory Types 6546 ** 6547 ** These macros are only available on Windows. They define the allowed values 6548 ** for the type argument to the [sqlite3_win32_set_directory] interface. 6549 */ 6550 #define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 6551 #define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 6552 6553 /* 6554 ** CAPI3REF: Test For Auto-Commit Mode 6555 ** KEYWORDS: {autocommit mode} 6556 ** METHOD: sqlite3 6557 ** 6558 ** ^The sqlite3_get_autocommit() interface returns non-zero or 6559 ** zero if the given database connection is or is not in autocommit mode, 6560 ** respectively. ^Autocommit mode is on by default. 6561 ** ^Autocommit mode is disabled by a [BEGIN] statement. 6562 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 6563 ** 6564 ** If certain kinds of errors occur on a statement within a multi-statement 6565 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 6566 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 6567 ** transaction might be rolled back automatically. The only way to 6568 ** find out whether SQLite automatically rolled back the transaction after 6569 ** an error is to use this function. 6570 ** 6571 ** If another thread changes the autocommit status of the database 6572 ** connection while this routine is running, then the return value 6573 ** is undefined. 6574 */ 6575 SQLITE_API int sqlite3_get_autocommit(sqlite3*); 6576 6577 /* 6578 ** CAPI3REF: Find The Database Handle Of A Prepared Statement 6579 ** METHOD: sqlite3_stmt 6580 ** 6581 ** ^The sqlite3_db_handle interface returns the [database connection] handle 6582 ** to which a [prepared statement] belongs. ^The [database connection] 6583 ** returned by sqlite3_db_handle is the same [database connection] 6584 ** that was the first argument 6585 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 6586 ** create the statement in the first place. 6587 */ 6588 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 6589 6590 /* 6591 ** CAPI3REF: Return The Schema Name For A Database Connection 6592 ** METHOD: sqlite3 6593 ** 6594 ** ^The sqlite3_db_name(D,N) interface returns a pointer to the schema name 6595 ** for the N-th database on database connection D, or a NULL pointer of N is 6596 ** out of range. An N value of 0 means the main database file. An N of 1 is 6597 ** the "temp" schema. Larger values of N correspond to various ATTACH-ed 6598 ** databases. 6599 ** 6600 ** Space to hold the string that is returned by sqlite3_db_name() is managed 6601 ** by SQLite itself. The string might be deallocated by any operation that 6602 ** changes the schema, including [ATTACH] or [DETACH] or calls to 6603 ** [sqlite3_serialize()] or [sqlite3_deserialize()], even operations that 6604 ** occur on a different thread. Applications that need to 6605 ** remember the string long-term should make their own copy. Applications that 6606 ** are accessing the same database connection simultaneously on multiple 6607 ** threads should mutex-protect calls to this API and should make their own 6608 ** private copy of the result prior to releasing the mutex. 6609 */ 6610 SQLITE_API const char *sqlite3_db_name(sqlite3 *db, int N); 6611 6612 /* 6613 ** CAPI3REF: Return The Filename For A Database Connection 6614 ** METHOD: sqlite3 6615 ** 6616 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename 6617 ** associated with database N of connection D. 6618 ** ^If there is no attached database N on the database 6619 ** connection D, or if database N is a temporary or in-memory database, then 6620 ** this function will return either a NULL pointer or an empty string. 6621 ** 6622 ** ^The string value returned by this routine is owned and managed by 6623 ** the database connection. ^The value will be valid until the database N 6624 ** is [DETACH]-ed or until the database connection closes. 6625 ** 6626 ** ^The filename returned by this function is the output of the 6627 ** xFullPathname method of the [VFS]. ^In other words, the filename 6628 ** will be an absolute pathname, even if the filename used 6629 ** to open the database originally was a URI or relative pathname. 6630 ** 6631 ** If the filename pointer returned by this routine is not NULL, then it 6632 ** can be used as the filename input parameter to these routines: 6633 ** <ul> 6634 ** <li> [sqlite3_uri_parameter()] 6635 ** <li> [sqlite3_uri_boolean()] 6636 ** <li> [sqlite3_uri_int64()] 6637 ** <li> [sqlite3_filename_database()] 6638 ** <li> [sqlite3_filename_journal()] 6639 ** <li> [sqlite3_filename_wal()] 6640 ** </ul> 6641 */ 6642 SQLITE_API sqlite3_filename sqlite3_db_filename(sqlite3 *db, const char *zDbName); 6643 6644 /* 6645 ** CAPI3REF: Determine if a database is read-only 6646 ** METHOD: sqlite3 6647 ** 6648 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 6649 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not 6650 ** the name of a database on connection D. 6651 */ 6652 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 6653 6654 /* 6655 ** CAPI3REF: Determine the transaction state of a database 6656 ** METHOD: sqlite3 6657 ** 6658 ** ^The sqlite3_txn_state(D,S) interface returns the current 6659 ** [transaction state] of schema S in database connection D. ^If S is NULL, 6660 ** then the highest transaction state of any schema on database connection D 6661 ** is returned. Transaction states are (in order of lowest to highest): 6662 ** <ol> 6663 ** <li value="0"> SQLITE_TXN_NONE 6664 ** <li value="1"> SQLITE_TXN_READ 6665 ** <li value="2"> SQLITE_TXN_WRITE 6666 ** </ol> 6667 ** ^If the S argument to sqlite3_txn_state(D,S) is not the name of 6668 ** a valid schema, then -1 is returned. 6669 */ 6670 SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema); 6671 6672 /* 6673 ** CAPI3REF: Allowed return values from sqlite3_txn_state() 6674 ** KEYWORDS: {transaction state} 6675 ** 6676 ** These constants define the current transaction state of a database file. 6677 ** ^The [sqlite3_txn_state(D,S)] interface returns one of these 6678 ** constants in order to describe the transaction state of schema S 6679 ** in [database connection] D. 6680 ** 6681 ** <dl> 6682 ** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt> 6683 ** <dd>The SQLITE_TXN_NONE state means that no transaction is currently 6684 ** pending.</dd> 6685 ** 6686 ** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt> 6687 ** <dd>The SQLITE_TXN_READ state means that the database is currently 6688 ** in a read transaction. Content has been read from the database file 6689 ** but nothing in the database file has changed. The transaction state 6690 ** will advanced to SQLITE_TXN_WRITE if any changes occur and there are 6691 ** no other conflicting concurrent write transactions. The transaction 6692 ** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or 6693 ** [COMMIT].</dd> 6694 ** 6695 ** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt> 6696 ** <dd>The SQLITE_TXN_WRITE state means that the database is currently 6697 ** in a write transaction. Content has been written to the database file 6698 ** but has not yet committed. The transaction state will change to 6699 ** to SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd> 6700 */ 6701 #define SQLITE_TXN_NONE 0 6702 #define SQLITE_TXN_READ 1 6703 #define SQLITE_TXN_WRITE 2 6704 6705 /* 6706 ** CAPI3REF: Find the next prepared statement 6707 ** METHOD: sqlite3 6708 ** 6709 ** ^This interface returns a pointer to the next [prepared statement] after 6710 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 6711 ** then this interface returns a pointer to the first prepared statement 6712 ** associated with the database connection pDb. ^If no prepared statement 6713 ** satisfies the conditions of this routine, it returns NULL. 6714 ** 6715 ** The [database connection] pointer D in a call to 6716 ** [sqlite3_next_stmt(D,S)] must refer to an open database 6717 ** connection and in particular must not be a NULL pointer. 6718 */ 6719 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 6720 6721 /* 6722 ** CAPI3REF: Commit And Rollback Notification Callbacks 6723 ** METHOD: sqlite3 6724 ** 6725 ** ^The sqlite3_commit_hook() interface registers a callback 6726 ** function to be invoked whenever a transaction is [COMMIT | committed]. 6727 ** ^Any callback set by a previous call to sqlite3_commit_hook() 6728 ** for the same database connection is overridden. 6729 ** ^The sqlite3_rollback_hook() interface registers a callback 6730 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 6731 ** ^Any callback set by a previous call to sqlite3_rollback_hook() 6732 ** for the same database connection is overridden. 6733 ** ^The pArg argument is passed through to the callback. 6734 ** ^If the callback on a commit hook function returns non-zero, 6735 ** then the commit is converted into a rollback. 6736 ** 6737 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 6738 ** return the P argument from the previous call of the same function 6739 ** on the same [database connection] D, or NULL for 6740 ** the first call for each function on D. 6741 ** 6742 ** The commit and rollback hook callbacks are not reentrant. 6743 ** The callback implementation must not do anything that will modify 6744 ** the database connection that invoked the callback. Any actions 6745 ** to modify the database connection must be deferred until after the 6746 ** completion of the [sqlite3_step()] call that triggered the commit 6747 ** or rollback hook in the first place. 6748 ** Note that running any other SQL statements, including SELECT statements, 6749 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 6750 ** the database connections for the meaning of "modify" in this paragraph. 6751 ** 6752 ** ^Registering a NULL function disables the callback. 6753 ** 6754 ** ^When the commit hook callback routine returns zero, the [COMMIT] 6755 ** operation is allowed to continue normally. ^If the commit hook 6756 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 6757 ** ^The rollback hook is invoked on a rollback that results from a commit 6758 ** hook returning non-zero, just as it would be with any other rollback. 6759 ** 6760 ** ^For the purposes of this API, a transaction is said to have been 6761 ** rolled back if an explicit "ROLLBACK" statement is executed, or 6762 ** an error or constraint causes an implicit rollback to occur. 6763 ** ^The rollback callback is not invoked if a transaction is 6764 ** automatically rolled back because the database connection is closed. 6765 ** 6766 ** See also the [sqlite3_update_hook()] interface. 6767 */ 6768 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 6769 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 6770 6771 /* 6772 ** CAPI3REF: Autovacuum Compaction Amount Callback 6773 ** METHOD: sqlite3 6774 ** 6775 ** ^The sqlite3_autovacuum_pages(D,C,P,X) interface registers a callback 6776 ** function C that is invoked prior to each autovacuum of the database 6777 ** file. ^The callback is passed a copy of the generic data pointer (P), 6778 ** the schema-name of the attached database that is being autovacuumed, 6779 ** the size of the database file in pages, the number of free pages, 6780 ** and the number of bytes per page, respectively. The callback should 6781 ** return the number of free pages that should be removed by the 6782 ** autovacuum. ^If the callback returns zero, then no autovacuum happens. 6783 ** ^If the value returned is greater than or equal to the number of 6784 ** free pages, then a complete autovacuum happens. 6785 ** 6786 ** <p>^If there are multiple ATTACH-ed database files that are being 6787 ** modified as part of a transaction commit, then the autovacuum pages 6788 ** callback is invoked separately for each file. 6789 ** 6790 ** <p><b>The callback is not reentrant.</b> The callback function should 6791 ** not attempt to invoke any other SQLite interface. If it does, bad 6792 ** things may happen, including segmentation faults and corrupt database 6793 ** files. The callback function should be a simple function that 6794 ** does some arithmetic on its input parameters and returns a result. 6795 ** 6796 ** ^The X parameter to sqlite3_autovacuum_pages(D,C,P,X) is an optional 6797 ** destructor for the P parameter. ^If X is not NULL, then X(P) is 6798 ** invoked whenever the database connection closes or when the callback 6799 ** is overwritten by another invocation of sqlite3_autovacuum_pages(). 6800 ** 6801 ** <p>^There is only one autovacuum pages callback per database connection. 6802 ** ^Each call to the sqlite3_autovacuum_pages() interface overrides all 6803 ** previous invocations for that database connection. ^If the callback 6804 ** argument (C) to sqlite3_autovacuum_pages(D,C,P,X) is a NULL pointer, 6805 ** then the autovacuum steps callback is canceled. The return value 6806 ** from sqlite3_autovacuum_pages() is normally SQLITE_OK, but might 6807 ** be some other error code if something goes wrong. The current 6808 ** implementation will only return SQLITE_OK or SQLITE_MISUSE, but other 6809 ** return codes might be added in future releases. 6810 ** 6811 ** <p>If no autovacuum pages callback is specified (the usual case) or 6812 ** a NULL pointer is provided for the callback, 6813 ** then the default behavior is to vacuum all free pages. So, in other 6814 ** words, the default behavior is the same as if the callback function 6815 ** were something like this: 6816 ** 6817 ** <blockquote><pre> 6818 ** unsigned int demonstration_autovac_pages_callback( 6819 ** void *pClientData, 6820 ** const char *zSchema, 6821 ** unsigned int nDbPage, 6822 ** unsigned int nFreePage, 6823 ** unsigned int nBytePerPage 6824 ** ){ 6825 ** return nFreePage; 6826 ** } 6827 ** </pre></blockquote> 6828 */ 6829 SQLITE_API int sqlite3_autovacuum_pages( 6830 sqlite3 *db, 6831 unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int), 6832 void*, 6833 void(*)(void*) 6834 ); 6835 6836 6837 /* 6838 ** CAPI3REF: Data Change Notification Callbacks 6839 ** METHOD: sqlite3 6840 ** 6841 ** ^The sqlite3_update_hook() interface registers a callback function 6842 ** with the [database connection] identified by the first argument 6843 ** to be invoked whenever a row is updated, inserted or deleted in 6844 ** a [rowid table]. 6845 ** ^Any callback set by a previous call to this function 6846 ** for the same database connection is overridden. 6847 ** 6848 ** ^The second argument is a pointer to the function to invoke when a 6849 ** row is updated, inserted or deleted in a rowid table. 6850 ** ^The first argument to the callback is a copy of the third argument 6851 ** to sqlite3_update_hook(). 6852 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 6853 ** or [SQLITE_UPDATE], depending on the operation that caused the callback 6854 ** to be invoked. 6855 ** ^The third and fourth arguments to the callback contain pointers to the 6856 ** database and table name containing the affected row. 6857 ** ^The final callback parameter is the [rowid] of the row. 6858 ** ^In the case of an update, this is the [rowid] after the update takes place. 6859 ** 6860 ** ^(The update hook is not invoked when internal system tables are 6861 ** modified (i.e. sqlite_sequence).)^ 6862 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 6863 ** 6864 ** ^In the current implementation, the update hook 6865 ** is not invoked when conflicting rows are deleted because of an 6866 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 6867 ** invoked when rows are deleted using the [truncate optimization]. 6868 ** The exceptions defined in this paragraph might change in a future 6869 ** release of SQLite. 6870 ** 6871 ** The update hook implementation must not do anything that will modify 6872 ** the database connection that invoked the update hook. Any actions 6873 ** to modify the database connection must be deferred until after the 6874 ** completion of the [sqlite3_step()] call that triggered the update hook. 6875 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 6876 ** database connections for the meaning of "modify" in this paragraph. 6877 ** 6878 ** ^The sqlite3_update_hook(D,C,P) function 6879 ** returns the P argument from the previous call 6880 ** on the same [database connection] D, or NULL for 6881 ** the first call on D. 6882 ** 6883 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 6884 ** and [sqlite3_preupdate_hook()] interfaces. 6885 */ 6886 SQLITE_API void *sqlite3_update_hook( 6887 sqlite3*, 6888 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 6889 void* 6890 ); 6891 6892 /* 6893 ** CAPI3REF: Enable Or Disable Shared Pager Cache 6894 ** 6895 ** ^(This routine enables or disables the sharing of the database cache 6896 ** and schema data structures between [database connection | connections] 6897 ** to the same database. Sharing is enabled if the argument is true 6898 ** and disabled if the argument is false.)^ 6899 ** 6900 ** This interface is omitted if SQLite is compiled with 6901 ** [-DSQLITE_OMIT_SHARED_CACHE]. The [-DSQLITE_OMIT_SHARED_CACHE] 6902 ** compile-time option is recommended because the 6903 ** [use of shared cache mode is discouraged]. 6904 ** 6905 ** ^Cache sharing is enabled and disabled for an entire process. 6906 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 6907 ** In prior versions of SQLite, 6908 ** sharing was enabled or disabled for each thread separately. 6909 ** 6910 ** ^(The cache sharing mode set by this interface effects all subsequent 6911 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 6912 ** Existing database connections continue to use the sharing mode 6913 ** that was in effect at the time they were opened.)^ 6914 ** 6915 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 6916 ** successfully. An [error code] is returned otherwise.)^ 6917 ** 6918 ** ^Shared cache is disabled by default. It is recommended that it stay 6919 ** that way. In other words, do not use this routine. This interface 6920 ** continues to be provided for historical compatibility, but its use is 6921 ** discouraged. Any use of shared cache is discouraged. If shared cache 6922 ** must be used, it is recommended that shared cache only be enabled for 6923 ** individual database connections using the [sqlite3_open_v2()] interface 6924 ** with the [SQLITE_OPEN_SHAREDCACHE] flag. 6925 ** 6926 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 6927 ** and will always return SQLITE_MISUSE. On those systems, 6928 ** shared cache mode should be enabled per-database connection via 6929 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 6930 ** 6931 ** This interface is threadsafe on processors where writing a 6932 ** 32-bit integer is atomic. 6933 ** 6934 ** See Also: [SQLite Shared-Cache Mode] 6935 */ 6936 SQLITE_API int sqlite3_enable_shared_cache(int); 6937 6938 /* 6939 ** CAPI3REF: Attempt To Free Heap Memory 6940 ** 6941 ** ^The sqlite3_release_memory() interface attempts to free N bytes 6942 ** of heap memory by deallocating non-essential memory allocations 6943 ** held by the database library. Memory used to cache database 6944 ** pages to improve performance is an example of non-essential memory. 6945 ** ^sqlite3_release_memory() returns the number of bytes actually freed, 6946 ** which might be more or less than the amount requested. 6947 ** ^The sqlite3_release_memory() routine is a no-op returning zero 6948 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 6949 ** 6950 ** See also: [sqlite3_db_release_memory()] 6951 */ 6952 SQLITE_API int sqlite3_release_memory(int); 6953 6954 /* 6955 ** CAPI3REF: Free Memory Used By A Database Connection 6956 ** METHOD: sqlite3 6957 ** 6958 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 6959 ** memory as possible from database connection D. Unlike the 6960 ** [sqlite3_release_memory()] interface, this interface is in effect even 6961 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 6962 ** omitted. 6963 ** 6964 ** See also: [sqlite3_release_memory()] 6965 */ 6966 SQLITE_API int sqlite3_db_release_memory(sqlite3*); 6967 6968 /* 6969 ** CAPI3REF: Impose A Limit On Heap Size 6970 ** 6971 ** These interfaces impose limits on the amount of heap memory that will be 6972 ** by all database connections within a single process. 6973 ** 6974 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 6975 ** soft limit on the amount of heap memory that may be allocated by SQLite. 6976 ** ^SQLite strives to keep heap memory utilization below the soft heap 6977 ** limit by reducing the number of pages held in the page cache 6978 ** as heap memory usages approaches the limit. 6979 ** ^The soft heap limit is "soft" because even though SQLite strives to stay 6980 ** below the limit, it will exceed the limit rather than generate 6981 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 6982 ** is advisory only. 6983 ** 6984 ** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of 6985 ** N bytes on the amount of memory that will be allocated. ^The 6986 ** sqlite3_hard_heap_limit64(N) interface is similar to 6987 ** sqlite3_soft_heap_limit64(N) except that memory allocations will fail 6988 ** when the hard heap limit is reached. 6989 ** 6990 ** ^The return value from both sqlite3_soft_heap_limit64() and 6991 ** sqlite3_hard_heap_limit64() is the size of 6992 ** the heap limit prior to the call, or negative in the case of an 6993 ** error. ^If the argument N is negative 6994 ** then no change is made to the heap limit. Hence, the current 6995 ** size of heap limits can be determined by invoking 6996 ** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1). 6997 ** 6998 ** ^Setting the heap limits to zero disables the heap limiter mechanism. 6999 ** 7000 ** ^The soft heap limit may not be greater than the hard heap limit. 7001 ** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N) 7002 ** is invoked with a value of N that is greater than the hard heap limit, 7003 ** the soft heap limit is set to the value of the hard heap limit. 7004 ** ^The soft heap limit is automatically enabled whenever the hard heap 7005 ** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and 7006 ** the soft heap limit is outside the range of 1..N, then the soft heap 7007 ** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the 7008 ** hard heap limit is enabled makes the soft heap limit equal to the 7009 ** hard heap limit. 7010 ** 7011 ** The memory allocation limits can also be adjusted using 7012 ** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit]. 7013 ** 7014 ** ^(The heap limits are not enforced in the current implementation 7015 ** if one or more of following conditions are true: 7016 ** 7017 ** <ul> 7018 ** <li> The limit value is set to zero. 7019 ** <li> Memory accounting is disabled using a combination of the 7020 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 7021 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 7022 ** <li> An alternative page cache implementation is specified using 7023 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 7024 ** <li> The page cache allocates from its own memory pool supplied 7025 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 7026 ** from the heap. 7027 ** </ul>)^ 7028 ** 7029 ** The circumstances under which SQLite will enforce the heap limits may 7030 ** changes in future releases of SQLite. 7031 */ 7032 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 7033 SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N); 7034 7035 /* 7036 ** CAPI3REF: Deprecated Soft Heap Limit Interface 7037 ** DEPRECATED 7038 ** 7039 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 7040 ** interface. This routine is provided for historical compatibility 7041 ** only. All new applications should use the 7042 ** [sqlite3_soft_heap_limit64()] interface rather than this one. 7043 */ 7044 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 7045 7046 7047 /* 7048 ** CAPI3REF: Extract Metadata About A Column Of A Table 7049 ** METHOD: sqlite3 7050 ** 7051 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 7052 ** information about column C of table T in database D 7053 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 7054 ** interface returns SQLITE_OK and fills in the non-NULL pointers in 7055 ** the final five arguments with appropriate values if the specified 7056 ** column exists. ^The sqlite3_table_column_metadata() interface returns 7057 ** SQLITE_ERROR if the specified column does not exist. 7058 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a 7059 ** NULL pointer, then this routine simply checks for the existence of the 7060 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 7061 ** does not. If the table name parameter T in a call to 7062 ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 7063 ** undefined behavior. 7064 ** 7065 ** ^The column is identified by the second, third and fourth parameters to 7066 ** this function. ^(The second parameter is either the name of the database 7067 ** (i.e. "main", "temp", or an attached database) containing the specified 7068 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched 7069 ** for the table using the same algorithm used by the database engine to 7070 ** resolve unqualified table references. 7071 ** 7072 ** ^The third and fourth parameters to this function are the table and column 7073 ** name of the desired column, respectively. 7074 ** 7075 ** ^Metadata is returned by writing to the memory locations passed as the 5th 7076 ** and subsequent parameters to this function. ^Any of these arguments may be 7077 ** NULL, in which case the corresponding element of metadata is omitted. 7078 ** 7079 ** ^(<blockquote> 7080 ** <table border="1"> 7081 ** <tr><th> Parameter <th> Output<br>Type <th> Description 7082 ** 7083 ** <tr><td> 5th <td> const char* <td> Data type 7084 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 7085 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 7086 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 7087 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 7088 ** </table> 7089 ** </blockquote>)^ 7090 ** 7091 ** ^The memory pointed to by the character pointers returned for the 7092 ** declaration type and collation sequence is valid until the next 7093 ** call to any SQLite API function. 7094 ** 7095 ** ^If the specified table is actually a view, an [error code] is returned. 7096 ** 7097 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 7098 ** is not a [WITHOUT ROWID] table and an 7099 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 7100 ** parameters are set for the explicitly declared column. ^(If there is no 7101 ** [INTEGER PRIMARY KEY] column, then the outputs 7102 ** for the [rowid] are set as follows: 7103 ** 7104 ** <pre> 7105 ** data type: "INTEGER" 7106 ** collation sequence: "BINARY" 7107 ** not null: 0 7108 ** primary key: 1 7109 ** auto increment: 0 7110 ** </pre>)^ 7111 ** 7112 ** ^This function causes all database schemas to be read from disk and 7113 ** parsed, if that has not already been done, and returns an error if 7114 ** any errors are encountered while loading the schema. 7115 */ 7116 SQLITE_API int sqlite3_table_column_metadata( 7117 sqlite3 *db, /* Connection handle */ 7118 const char *zDbName, /* Database name or NULL */ 7119 const char *zTableName, /* Table name */ 7120 const char *zColumnName, /* Column name */ 7121 char const **pzDataType, /* OUTPUT: Declared data type */ 7122 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 7123 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 7124 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 7125 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 7126 ); 7127 7128 /* 7129 ** CAPI3REF: Load An Extension 7130 ** METHOD: sqlite3 7131 ** 7132 ** ^This interface loads an SQLite extension library from the named file. 7133 ** 7134 ** ^The sqlite3_load_extension() interface attempts to load an 7135 ** [SQLite extension] library contained in the file zFile. If 7136 ** the file cannot be loaded directly, attempts are made to load 7137 ** with various operating-system specific extensions added. 7138 ** So for example, if "samplelib" cannot be loaded, then names like 7139 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 7140 ** be tried also. 7141 ** 7142 ** ^The entry point is zProc. 7143 ** ^(zProc may be 0, in which case SQLite will try to come up with an 7144 ** entry point name on its own. It first tries "sqlite3_extension_init". 7145 ** If that does not work, it constructs a name "sqlite3_X_init" where the 7146 ** X is consists of the lower-case equivalent of all ASCII alphabetic 7147 ** characters in the filename from the last "/" to the first following 7148 ** "." and omitting any initial "lib".)^ 7149 ** ^The sqlite3_load_extension() interface returns 7150 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 7151 ** ^If an error occurs and pzErrMsg is not 0, then the 7152 ** [sqlite3_load_extension()] interface shall attempt to 7153 ** fill *pzErrMsg with error message text stored in memory 7154 ** obtained from [sqlite3_malloc()]. The calling function 7155 ** should free this memory by calling [sqlite3_free()]. 7156 ** 7157 ** ^Extension loading must be enabled using 7158 ** [sqlite3_enable_load_extension()] or 7159 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 7160 ** prior to calling this API, 7161 ** otherwise an error will be returned. 7162 ** 7163 ** <b>Security warning:</b> It is recommended that the 7164 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 7165 ** interface. The use of the [sqlite3_enable_load_extension()] interface 7166 ** should be avoided. This will keep the SQL function [load_extension()] 7167 ** disabled and prevent SQL injections from giving attackers 7168 ** access to extension loading capabilities. 7169 ** 7170 ** See also the [load_extension() SQL function]. 7171 */ 7172 SQLITE_API int sqlite3_load_extension( 7173 sqlite3 *db, /* Load the extension into this database connection */ 7174 const char *zFile, /* Name of the shared library containing extension */ 7175 const char *zProc, /* Entry point. Derived from zFile if 0 */ 7176 char **pzErrMsg /* Put error message here if not 0 */ 7177 ); 7178 7179 /* 7180 ** CAPI3REF: Enable Or Disable Extension Loading 7181 ** METHOD: sqlite3 7182 ** 7183 ** ^So as not to open security holes in older applications that are 7184 ** unprepared to deal with [extension loading], and as a means of disabling 7185 ** [extension loading] while evaluating user-entered SQL, the following API 7186 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 7187 ** 7188 ** ^Extension loading is off by default. 7189 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 7190 ** to turn extension loading on and call it with onoff==0 to turn 7191 ** it back off again. 7192 ** 7193 ** ^This interface enables or disables both the C-API 7194 ** [sqlite3_load_extension()] and the SQL function [load_extension()]. 7195 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 7196 ** to enable or disable only the C-API.)^ 7197 ** 7198 ** <b>Security warning:</b> It is recommended that extension loading 7199 ** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 7200 ** rather than this interface, so the [load_extension()] SQL function 7201 ** remains disabled. This will prevent SQL injections from giving attackers 7202 ** access to extension loading capabilities. 7203 */ 7204 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 7205 7206 /* 7207 ** CAPI3REF: Automatically Load Statically Linked Extensions 7208 ** 7209 ** ^This interface causes the xEntryPoint() function to be invoked for 7210 ** each new [database connection] that is created. The idea here is that 7211 ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 7212 ** that is to be automatically loaded into all new database connections. 7213 ** 7214 ** ^(Even though the function prototype shows that xEntryPoint() takes 7215 ** no arguments and returns void, SQLite invokes xEntryPoint() with three 7216 ** arguments and expects an integer result as if the signature of the 7217 ** entry point where as follows: 7218 ** 7219 ** <blockquote><pre> 7220 ** int xEntryPoint( 7221 ** sqlite3 *db, 7222 ** const char **pzErrMsg, 7223 ** const struct sqlite3_api_routines *pThunk 7224 ** ); 7225 ** </pre></blockquote>)^ 7226 ** 7227 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 7228 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 7229 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 7230 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 7231 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 7232 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 7233 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 7234 ** 7235 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 7236 ** on the list of automatic extensions is a harmless no-op. ^No entry point 7237 ** will be called more than once for each database connection that is opened. 7238 ** 7239 ** See also: [sqlite3_reset_auto_extension()] 7240 ** and [sqlite3_cancel_auto_extension()] 7241 */ 7242 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void)); 7243 7244 /* 7245 ** CAPI3REF: Cancel Automatic Extension Loading 7246 ** 7247 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 7248 ** initialization routine X that was registered using a prior call to 7249 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 7250 ** routine returns 1 if initialization routine X was successfully 7251 ** unregistered and it returns 0 if X was not on the list of initialization 7252 ** routines. 7253 */ 7254 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 7255 7256 /* 7257 ** CAPI3REF: Reset Automatic Extension Loading 7258 ** 7259 ** ^This interface disables all automatic extensions previously 7260 ** registered using [sqlite3_auto_extension()]. 7261 */ 7262 SQLITE_API void sqlite3_reset_auto_extension(void); 7263 7264 /* 7265 ** Structures used by the virtual table interface 7266 */ 7267 typedef struct sqlite3_vtab sqlite3_vtab; 7268 typedef struct sqlite3_index_info sqlite3_index_info; 7269 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 7270 typedef struct sqlite3_module sqlite3_module; 7271 7272 /* 7273 ** CAPI3REF: Virtual Table Object 7274 ** KEYWORDS: sqlite3_module {virtual table module} 7275 ** 7276 ** This structure, sometimes called a "virtual table module", 7277 ** defines the implementation of a [virtual table]. 7278 ** This structure consists mostly of methods for the module. 7279 ** 7280 ** ^A virtual table module is created by filling in a persistent 7281 ** instance of this structure and passing a pointer to that instance 7282 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 7283 ** ^The registration remains valid until it is replaced by a different 7284 ** module or until the [database connection] closes. The content 7285 ** of this structure must not change while it is registered with 7286 ** any database connection. 7287 */ 7288 struct sqlite3_module { 7289 int iVersion; 7290 int (*xCreate)(sqlite3*, void *pAux, 7291 int argc, const char *const*argv, 7292 sqlite3_vtab **ppVTab, char**); 7293 int (*xConnect)(sqlite3*, void *pAux, 7294 int argc, const char *const*argv, 7295 sqlite3_vtab **ppVTab, char**); 7296 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 7297 int (*xDisconnect)(sqlite3_vtab *pVTab); 7298 int (*xDestroy)(sqlite3_vtab *pVTab); 7299 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 7300 int (*xClose)(sqlite3_vtab_cursor*); 7301 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 7302 int argc, sqlite3_value **argv); 7303 int (*xNext)(sqlite3_vtab_cursor*); 7304 int (*xEof)(sqlite3_vtab_cursor*); 7305 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 7306 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 7307 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 7308 int (*xBegin)(sqlite3_vtab *pVTab); 7309 int (*xSync)(sqlite3_vtab *pVTab); 7310 int (*xCommit)(sqlite3_vtab *pVTab); 7311 int (*xRollback)(sqlite3_vtab *pVTab); 7312 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 7313 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 7314 void **ppArg); 7315 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 7316 /* The methods above are in version 1 of the sqlite_module object. Those 7317 ** below are for version 2 and greater. */ 7318 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 7319 int (*xRelease)(sqlite3_vtab *pVTab, int); 7320 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 7321 /* The methods above are in versions 1 and 2 of the sqlite_module object. 7322 ** Those below are for version 3 and greater. */ 7323 int (*xShadowName)(const char*); 7324 /* The methods above are in versions 1 through 3 of the sqlite_module object. 7325 ** Those below are for version 4 and greater. */ 7326 int (*xIntegrity)(sqlite3_vtab *pVTab, const char *zSchema, 7327 const char *zTabName, int mFlags, char **pzErr); 7328 }; 7329 7330 /* 7331 ** CAPI3REF: Virtual Table Indexing Information 7332 ** KEYWORDS: sqlite3_index_info 7333 ** 7334 ** The sqlite3_index_info structure and its substructures is used as part 7335 ** of the [virtual table] interface to 7336 ** pass information into and receive the reply from the [xBestIndex] 7337 ** method of a [virtual table module]. The fields under **Inputs** are the 7338 ** inputs to xBestIndex and are read-only. xBestIndex inserts its 7339 ** results into the **Outputs** fields. 7340 ** 7341 ** ^(The aConstraint[] array records WHERE clause constraints of the form: 7342 ** 7343 ** <blockquote>column OP expr</blockquote> 7344 ** 7345 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 7346 ** stored in aConstraint[].op using one of the 7347 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 7348 ** ^(The index of the column is stored in 7349 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 7350 ** expr on the right-hand side can be evaluated (and thus the constraint 7351 ** is usable) and false if it cannot.)^ 7352 ** 7353 ** ^The optimizer automatically inverts terms of the form "expr OP column" 7354 ** and makes other simplifications to the WHERE clause in an attempt to 7355 ** get as many WHERE clause terms into the form shown above as possible. 7356 ** ^The aConstraint[] array only reports WHERE clause terms that are 7357 ** relevant to the particular virtual table being queried. 7358 ** 7359 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 7360 ** ^Each term of aOrderBy records a column of the ORDER BY clause. 7361 ** 7362 ** The colUsed field indicates which columns of the virtual table may be 7363 ** required by the current scan. Virtual table columns are numbered from 7364 ** zero in the order in which they appear within the CREATE TABLE statement 7365 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 7366 ** the corresponding bit is set within the colUsed mask if the column may be 7367 ** required by SQLite. If the table has at least 64 columns and any column 7368 ** to the right of the first 63 is required, then bit 63 of colUsed is also 7369 ** set. In other words, column iCol may be required if the expression 7370 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 7371 ** non-zero. 7372 ** 7373 ** The [xBestIndex] method must fill aConstraintUsage[] with information 7374 ** about what parameters to pass to xFilter. ^If argvIndex>0 then 7375 ** the right-hand side of the corresponding aConstraint[] is evaluated 7376 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 7377 ** is true, then the constraint is assumed to be fully handled by the 7378 ** virtual table and might not be checked again by the byte code.)^ ^(The 7379 ** aConstraintUsage[].omit flag is an optimization hint. When the omit flag 7380 ** is left in its default setting of false, the constraint will always be 7381 ** checked separately in byte code. If the omit flag is change to true, then 7382 ** the constraint may or may not be checked in byte code. In other words, 7383 ** when the omit flag is true there is no guarantee that the constraint will 7384 ** not be checked again using byte code.)^ 7385 ** 7386 ** ^The idxNum and idxStr values are recorded and passed into the 7387 ** [xFilter] method. 7388 ** ^[sqlite3_free()] is used to free idxStr if and only if 7389 ** needToFreeIdxStr is true. 7390 ** 7391 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 7392 ** the correct order to satisfy the ORDER BY clause so that no separate 7393 ** sorting step is required. 7394 ** 7395 ** ^The estimatedCost value is an estimate of the cost of a particular 7396 ** strategy. A cost of N indicates that the cost of the strategy is similar 7397 ** to a linear scan of an SQLite table with N rows. A cost of log(N) 7398 ** indicates that the expense of the operation is similar to that of a 7399 ** binary search on a unique indexed field of an SQLite table with N rows. 7400 ** 7401 ** ^The estimatedRows value is an estimate of the number of rows that 7402 ** will be returned by the strategy. 7403 ** 7404 ** The xBestIndex method may optionally populate the idxFlags field with a 7405 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 7406 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 7407 ** assumes that the strategy may visit at most one row. 7408 ** 7409 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 7410 ** SQLite also assumes that if a call to the xUpdate() method is made as 7411 ** part of the same statement to delete or update a virtual table row and the 7412 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 7413 ** any database changes. In other words, if the xUpdate() returns 7414 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were 7415 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 7416 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 7417 ** the xUpdate method are automatically rolled back by SQLite. 7418 ** 7419 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 7420 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 7421 ** If a virtual table extension is 7422 ** used with an SQLite version earlier than 3.8.2, the results of attempting 7423 ** to read or write the estimatedRows field are undefined (but are likely 7424 ** to include crashing the application). The estimatedRows field should 7425 ** therefore only be used if [sqlite3_libversion_number()] returns a 7426 ** value greater than or equal to 3008002. Similarly, the idxFlags field 7427 ** was added for [version 3.9.0] ([dateof:3.9.0]). 7428 ** It may therefore only be used if 7429 ** sqlite3_libversion_number() returns a value greater than or equal to 7430 ** 3009000. 7431 */ 7432 struct sqlite3_index_info { 7433 /* Inputs */ 7434 int nConstraint; /* Number of entries in aConstraint */ 7435 struct sqlite3_index_constraint { 7436 int iColumn; /* Column constrained. -1 for ROWID */ 7437 unsigned char op; /* Constraint operator */ 7438 unsigned char usable; /* True if this constraint is usable */ 7439 int iTermOffset; /* Used internally - xBestIndex should ignore */ 7440 } *aConstraint; /* Table of WHERE clause constraints */ 7441 int nOrderBy; /* Number of terms in the ORDER BY clause */ 7442 struct sqlite3_index_orderby { 7443 int iColumn; /* Column number */ 7444 unsigned char desc; /* True for DESC. False for ASC. */ 7445 } *aOrderBy; /* The ORDER BY clause */ 7446 /* Outputs */ 7447 struct sqlite3_index_constraint_usage { 7448 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 7449 unsigned char omit; /* Do not code a test for this constraint */ 7450 } *aConstraintUsage; 7451 int idxNum; /* Number used to identify the index */ 7452 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 7453 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 7454 int orderByConsumed; /* True if output is already ordered */ 7455 double estimatedCost; /* Estimated cost of using this index */ 7456 /* Fields below are only available in SQLite 3.8.2 and later */ 7457 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 7458 /* Fields below are only available in SQLite 3.9.0 and later */ 7459 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 7460 /* Fields below are only available in SQLite 3.10.0 and later */ 7461 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 7462 }; 7463 7464 /* 7465 ** CAPI3REF: Virtual Table Scan Flags 7466 ** 7467 ** Virtual table implementations are allowed to set the 7468 ** [sqlite3_index_info].idxFlags field to some combination of 7469 ** these bits. 7470 */ 7471 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 7472 7473 /* 7474 ** CAPI3REF: Virtual Table Constraint Operator Codes 7475 ** 7476 ** These macros define the allowed values for the 7477 ** [sqlite3_index_info].aConstraint[].op field. Each value represents 7478 ** an operator that is part of a constraint term in the WHERE clause of 7479 ** a query that uses a [virtual table]. 7480 ** 7481 ** ^The left-hand operand of the operator is given by the corresponding 7482 ** aConstraint[].iColumn field. ^An iColumn of -1 indicates the left-hand 7483 ** operand is the rowid. 7484 ** The SQLITE_INDEX_CONSTRAINT_LIMIT and SQLITE_INDEX_CONSTRAINT_OFFSET 7485 ** operators have no left-hand operand, and so for those operators the 7486 ** corresponding aConstraint[].iColumn is meaningless and should not be 7487 ** used. 7488 ** 7489 ** All operator values from SQLITE_INDEX_CONSTRAINT_FUNCTION through 7490 ** value 255 are reserved to represent functions that are overloaded 7491 ** by the [xFindFunction|xFindFunction method] of the virtual table 7492 ** implementation. 7493 ** 7494 ** The right-hand operands for each constraint might be accessible using 7495 ** the [sqlite3_vtab_rhs_value()] interface. Usually the right-hand 7496 ** operand is only available if it appears as a single constant literal 7497 ** in the input SQL. If the right-hand operand is another column or an 7498 ** expression (even a constant expression) or a parameter, then the 7499 ** sqlite3_vtab_rhs_value() probably will not be able to extract it. 7500 ** ^The SQLITE_INDEX_CONSTRAINT_ISNULL and 7501 ** SQLITE_INDEX_CONSTRAINT_ISNOTNULL operators have no right-hand operand 7502 ** and hence calls to sqlite3_vtab_rhs_value() for those operators will 7503 ** always return SQLITE_NOTFOUND. 7504 ** 7505 ** The collating sequence to be used for comparison can be found using 7506 ** the [sqlite3_vtab_collation()] interface. For most real-world virtual 7507 ** tables, the collating sequence of constraints does not matter (for example 7508 ** because the constraints are numeric) and so the sqlite3_vtab_collation() 7509 ** interface is not commonly needed. 7510 */ 7511 #define SQLITE_INDEX_CONSTRAINT_EQ 2 7512 #define SQLITE_INDEX_CONSTRAINT_GT 4 7513 #define SQLITE_INDEX_CONSTRAINT_LE 8 7514 #define SQLITE_INDEX_CONSTRAINT_LT 16 7515 #define SQLITE_INDEX_CONSTRAINT_GE 32 7516 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 7517 #define SQLITE_INDEX_CONSTRAINT_LIKE 65 7518 #define SQLITE_INDEX_CONSTRAINT_GLOB 66 7519 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67 7520 #define SQLITE_INDEX_CONSTRAINT_NE 68 7521 #define SQLITE_INDEX_CONSTRAINT_ISNOT 69 7522 #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 7523 #define SQLITE_INDEX_CONSTRAINT_ISNULL 71 7524 #define SQLITE_INDEX_CONSTRAINT_IS 72 7525 #define SQLITE_INDEX_CONSTRAINT_LIMIT 73 7526 #define SQLITE_INDEX_CONSTRAINT_OFFSET 74 7527 #define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 7528 7529 /* 7530 ** CAPI3REF: Register A Virtual Table Implementation 7531 ** METHOD: sqlite3 7532 ** 7533 ** ^These routines are used to register a new [virtual table module] name. 7534 ** ^Module names must be registered before 7535 ** creating a new [virtual table] using the module and before using a 7536 ** preexisting [virtual table] for the module. 7537 ** 7538 ** ^The module name is registered on the [database connection] specified 7539 ** by the first parameter. ^The name of the module is given by the 7540 ** second parameter. ^The third parameter is a pointer to 7541 ** the implementation of the [virtual table module]. ^The fourth 7542 ** parameter is an arbitrary client data pointer that is passed through 7543 ** into the [xCreate] and [xConnect] methods of the virtual table module 7544 ** when a new virtual table is be being created or reinitialized. 7545 ** 7546 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 7547 ** is a pointer to a destructor for the pClientData. ^SQLite will 7548 ** invoke the destructor function (if it is not NULL) when SQLite 7549 ** no longer needs the pClientData pointer. ^The destructor will also 7550 ** be invoked if the call to sqlite3_create_module_v2() fails. 7551 ** ^The sqlite3_create_module() 7552 ** interface is equivalent to sqlite3_create_module_v2() with a NULL 7553 ** destructor. 7554 ** 7555 ** ^If the third parameter (the pointer to the sqlite3_module object) is 7556 ** NULL then no new module is created and any existing modules with the 7557 ** same name are dropped. 7558 ** 7559 ** See also: [sqlite3_drop_modules()] 7560 */ 7561 SQLITE_API int sqlite3_create_module( 7562 sqlite3 *db, /* SQLite connection to register module with */ 7563 const char *zName, /* Name of the module */ 7564 const sqlite3_module *p, /* Methods for the module */ 7565 void *pClientData /* Client data for xCreate/xConnect */ 7566 ); 7567 SQLITE_API int sqlite3_create_module_v2( 7568 sqlite3 *db, /* SQLite connection to register module with */ 7569 const char *zName, /* Name of the module */ 7570 const sqlite3_module *p, /* Methods for the module */ 7571 void *pClientData, /* Client data for xCreate/xConnect */ 7572 void(*xDestroy)(void*) /* Module destructor function */ 7573 ); 7574 7575 /* 7576 ** CAPI3REF: Remove Unnecessary Virtual Table Implementations 7577 ** METHOD: sqlite3 7578 ** 7579 ** ^The sqlite3_drop_modules(D,L) interface removes all virtual 7580 ** table modules from database connection D except those named on list L. 7581 ** The L parameter must be either NULL or a pointer to an array of pointers 7582 ** to strings where the array is terminated by a single NULL pointer. 7583 ** ^If the L parameter is NULL, then all virtual table modules are removed. 7584 ** 7585 ** See also: [sqlite3_create_module()] 7586 */ 7587 SQLITE_API int sqlite3_drop_modules( 7588 sqlite3 *db, /* Remove modules from this connection */ 7589 const char **azKeep /* Except, do not remove the ones named here */ 7590 ); 7591 7592 /* 7593 ** CAPI3REF: Virtual Table Instance Object 7594 ** KEYWORDS: sqlite3_vtab 7595 ** 7596 ** Every [virtual table module] implementation uses a subclass 7597 ** of this object to describe a particular instance 7598 ** of the [virtual table]. Each subclass will 7599 ** be tailored to the specific needs of the module implementation. 7600 ** The purpose of this superclass is to define certain fields that are 7601 ** common to all module implementations. 7602 ** 7603 ** ^Virtual tables methods can set an error message by assigning a 7604 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 7605 ** take care that any prior string is freed by a call to [sqlite3_free()] 7606 ** prior to assigning a new string to zErrMsg. ^After the error message 7607 ** is delivered up to the client application, the string will be automatically 7608 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 7609 */ 7610 struct sqlite3_vtab { 7611 const sqlite3_module *pModule; /* The module for this virtual table */ 7612 int nRef; /* Number of open cursors */ 7613 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 7614 /* Virtual table implementations will typically add additional fields */ 7615 }; 7616 7617 /* 7618 ** CAPI3REF: Virtual Table Cursor Object 7619 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 7620 ** 7621 ** Every [virtual table module] implementation uses a subclass of the 7622 ** following structure to describe cursors that point into the 7623 ** [virtual table] and are used 7624 ** to loop through the virtual table. Cursors are created using the 7625 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 7626 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 7627 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 7628 ** of the module. Each module implementation will define 7629 ** the content of a cursor structure to suit its own needs. 7630 ** 7631 ** This superclass exists in order to define fields of the cursor that 7632 ** are common to all implementations. 7633 */ 7634 struct sqlite3_vtab_cursor { 7635 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 7636 /* Virtual table implementations will typically add additional fields */ 7637 }; 7638 7639 /* 7640 ** CAPI3REF: Declare The Schema Of A Virtual Table 7641 ** 7642 ** ^The [xCreate] and [xConnect] methods of a 7643 ** [virtual table module] call this interface 7644 ** to declare the format (the names and datatypes of the columns) of 7645 ** the virtual tables they implement. 7646 */ 7647 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 7648 7649 /* 7650 ** CAPI3REF: Overload A Function For A Virtual Table 7651 ** METHOD: sqlite3 7652 ** 7653 ** ^(Virtual tables can provide alternative implementations of functions 7654 ** using the [xFindFunction] method of the [virtual table module]. 7655 ** But global versions of those functions 7656 ** must exist in order to be overloaded.)^ 7657 ** 7658 ** ^(This API makes sure a global version of a function with a particular 7659 ** name and number of parameters exists. If no such function exists 7660 ** before this API is called, a new function is created.)^ ^The implementation 7661 ** of the new function always causes an exception to be thrown. So 7662 ** the new function is not good for anything by itself. Its only 7663 ** purpose is to be a placeholder function that can be overloaded 7664 ** by a [virtual table]. 7665 */ 7666 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 7667 7668 /* 7669 ** CAPI3REF: A Handle To An Open BLOB 7670 ** KEYWORDS: {BLOB handle} {BLOB handles} 7671 ** 7672 ** An instance of this object represents an open BLOB on which 7673 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 7674 ** ^Objects of this type are created by [sqlite3_blob_open()] 7675 ** and destroyed by [sqlite3_blob_close()]. 7676 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 7677 ** can be used to read or write small subsections of the BLOB. 7678 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 7679 */ 7680 typedef struct sqlite3_blob sqlite3_blob; 7681 7682 /* 7683 ** CAPI3REF: Open A BLOB For Incremental I/O 7684 ** METHOD: sqlite3 7685 ** CONSTRUCTOR: sqlite3_blob 7686 ** 7687 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 7688 ** in row iRow, column zColumn, table zTable in database zDb; 7689 ** in other words, the same BLOB that would be selected by: 7690 ** 7691 ** <pre> 7692 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 7693 ** </pre>)^ 7694 ** 7695 ** ^(Parameter zDb is not the filename that contains the database, but 7696 ** rather the symbolic name of the database. For attached databases, this is 7697 ** the name that appears after the AS keyword in the [ATTACH] statement. 7698 ** For the main database file, the database name is "main". For TEMP 7699 ** tables, the database name is "temp".)^ 7700 ** 7701 ** ^If the flags parameter is non-zero, then the BLOB is opened for read 7702 ** and write access. ^If the flags parameter is zero, the BLOB is opened for 7703 ** read-only access. 7704 ** 7705 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 7706 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error 7707 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 7708 ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 7709 ** on *ppBlob after this function it returns. 7710 ** 7711 ** This function fails with SQLITE_ERROR if any of the following are true: 7712 ** <ul> 7713 ** <li> ^(Database zDb does not exist)^, 7714 ** <li> ^(Table zTable does not exist within database zDb)^, 7715 ** <li> ^(Table zTable is a WITHOUT ROWID table)^, 7716 ** <li> ^(Column zColumn does not exist)^, 7717 ** <li> ^(Row iRow is not present in the table)^, 7718 ** <li> ^(The specified column of row iRow contains a value that is not 7719 ** a TEXT or BLOB value)^, 7720 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 7721 ** constraint and the blob is being opened for read/write access)^, 7722 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 7723 ** column zColumn is part of a [child key] definition and the blob is 7724 ** being opened for read/write access)^. 7725 ** </ul> 7726 ** 7727 ** ^Unless it returns SQLITE_MISUSE, this function sets the 7728 ** [database connection] error code and message accessible via 7729 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7730 ** 7731 ** A BLOB referenced by sqlite3_blob_open() may be read using the 7732 ** [sqlite3_blob_read()] interface and modified by using 7733 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 7734 ** different row of the same table using the [sqlite3_blob_reopen()] 7735 ** interface. However, the column, table, or database of a [BLOB handle] 7736 ** cannot be changed after the [BLOB handle] is opened. 7737 ** 7738 ** ^(If the row that a BLOB handle points to is modified by an 7739 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 7740 ** then the BLOB handle is marked as "expired". 7741 ** This is true if any column of the row is changed, even a column 7742 ** other than the one the BLOB handle is open on.)^ 7743 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 7744 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 7745 ** ^(Changes written into a BLOB prior to the BLOB expiring are not 7746 ** rolled back by the expiration of the BLOB. Such changes will eventually 7747 ** commit if the transaction continues to completion.)^ 7748 ** 7749 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 7750 ** the opened blob. ^The size of a blob may not be changed by this 7751 ** interface. Use the [UPDATE] SQL command to change the size of a 7752 ** blob. 7753 ** 7754 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 7755 ** and the built-in [zeroblob] SQL function may be used to create a 7756 ** zero-filled blob to read or write using the incremental-blob interface. 7757 ** 7758 ** To avoid a resource leak, every open [BLOB handle] should eventually 7759 ** be released by a call to [sqlite3_blob_close()]. 7760 ** 7761 ** See also: [sqlite3_blob_close()], 7762 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 7763 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 7764 */ 7765 SQLITE_API int sqlite3_blob_open( 7766 sqlite3*, 7767 const char *zDb, 7768 const char *zTable, 7769 const char *zColumn, 7770 sqlite3_int64 iRow, 7771 int flags, 7772 sqlite3_blob **ppBlob 7773 ); 7774 7775 /* 7776 ** CAPI3REF: Move a BLOB Handle to a New Row 7777 ** METHOD: sqlite3_blob 7778 ** 7779 ** ^This function is used to move an existing [BLOB handle] so that it points 7780 ** to a different row of the same database table. ^The new row is identified 7781 ** by the rowid value passed as the second argument. Only the row can be 7782 ** changed. ^The database, table and column on which the blob handle is open 7783 ** remain the same. Moving an existing [BLOB handle] to a new row is 7784 ** faster than closing the existing handle and opening a new one. 7785 ** 7786 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 7787 ** it must exist and there must be either a blob or text value stored in 7788 ** the nominated column.)^ ^If the new row is not present in the table, or if 7789 ** it does not contain a blob or text value, or if another error occurs, an 7790 ** SQLite error code is returned and the blob handle is considered aborted. 7791 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 7792 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 7793 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 7794 ** always returns zero. 7795 ** 7796 ** ^This function sets the database handle error code and message. 7797 */ 7798 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 7799 7800 /* 7801 ** CAPI3REF: Close A BLOB Handle 7802 ** DESTRUCTOR: sqlite3_blob 7803 ** 7804 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 7805 ** unconditionally. Even if this routine returns an error code, the 7806 ** handle is still closed.)^ 7807 ** 7808 ** ^If the blob handle being closed was opened for read-write access, and if 7809 ** the database is in auto-commit mode and there are no other open read-write 7810 ** blob handles or active write statements, the current transaction is 7811 ** committed. ^If an error occurs while committing the transaction, an error 7812 ** code is returned and the transaction rolled back. 7813 ** 7814 ** Calling this function with an argument that is not a NULL pointer or an 7815 ** open blob handle results in undefined behavior. ^Calling this routine 7816 ** with a null pointer (such as would be returned by a failed call to 7817 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 7818 ** is passed a valid open blob handle, the values returned by the 7819 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 7820 */ 7821 SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 7822 7823 /* 7824 ** CAPI3REF: Return The Size Of An Open BLOB 7825 ** METHOD: sqlite3_blob 7826 ** 7827 ** ^Returns the size in bytes of the BLOB accessible via the 7828 ** successfully opened [BLOB handle] in its only argument. ^The 7829 ** incremental blob I/O routines can only read or overwriting existing 7830 ** blob content; they cannot change the size of a blob. 7831 ** 7832 ** This routine only works on a [BLOB handle] which has been created 7833 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7834 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7835 ** to this routine results in undefined and probably undesirable behavior. 7836 */ 7837 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 7838 7839 /* 7840 ** CAPI3REF: Read Data From A BLOB Incrementally 7841 ** METHOD: sqlite3_blob 7842 ** 7843 ** ^(This function is used to read data from an open [BLOB handle] into a 7844 ** caller-supplied buffer. N bytes of data are copied into buffer Z 7845 ** from the open BLOB, starting at offset iOffset.)^ 7846 ** 7847 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 7848 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 7849 ** less than zero, [SQLITE_ERROR] is returned and no data is read. 7850 ** ^The size of the blob (and hence the maximum value of N+iOffset) 7851 ** can be determined using the [sqlite3_blob_bytes()] interface. 7852 ** 7853 ** ^An attempt to read from an expired [BLOB handle] fails with an 7854 ** error code of [SQLITE_ABORT]. 7855 ** 7856 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 7857 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 7858 ** 7859 ** This routine only works on a [BLOB handle] which has been created 7860 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7861 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7862 ** to this routine results in undefined and probably undesirable behavior. 7863 ** 7864 ** See also: [sqlite3_blob_write()]. 7865 */ 7866 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 7867 7868 /* 7869 ** CAPI3REF: Write Data Into A BLOB Incrementally 7870 ** METHOD: sqlite3_blob 7871 ** 7872 ** ^(This function is used to write data into an open [BLOB handle] from a 7873 ** caller-supplied buffer. N bytes of data are copied from the buffer Z 7874 ** into the open BLOB, starting at offset iOffset.)^ 7875 ** 7876 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 7877 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 7878 ** ^Unless SQLITE_MISUSE is returned, this function sets the 7879 ** [database connection] error code and message accessible via 7880 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7881 ** 7882 ** ^If the [BLOB handle] passed as the first argument was not opened for 7883 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 7884 ** this function returns [SQLITE_READONLY]. 7885 ** 7886 ** This function may only modify the contents of the BLOB; it is 7887 ** not possible to increase the size of a BLOB using this API. 7888 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 7889 ** [SQLITE_ERROR] is returned and no data is written. The size of the 7890 ** BLOB (and hence the maximum value of N+iOffset) can be determined 7891 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 7892 ** than zero [SQLITE_ERROR] is returned and no data is written. 7893 ** 7894 ** ^An attempt to write to an expired [BLOB handle] fails with an 7895 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 7896 ** before the [BLOB handle] expired are not rolled back by the 7897 ** expiration of the handle, though of course those changes might 7898 ** have been overwritten by the statement that expired the BLOB handle 7899 ** or by other independent statements. 7900 ** 7901 ** This routine only works on a [BLOB handle] which has been created 7902 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7903 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7904 ** to this routine results in undefined and probably undesirable behavior. 7905 ** 7906 ** See also: [sqlite3_blob_read()]. 7907 */ 7908 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 7909 7910 /* 7911 ** CAPI3REF: Virtual File System Objects 7912 ** 7913 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 7914 ** that SQLite uses to interact 7915 ** with the underlying operating system. Most SQLite builds come with a 7916 ** single default VFS that is appropriate for the host computer. 7917 ** New VFSes can be registered and existing VFSes can be unregistered. 7918 ** The following interfaces are provided. 7919 ** 7920 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 7921 ** ^Names are case sensitive. 7922 ** ^Names are zero-terminated UTF-8 strings. 7923 ** ^If there is no match, a NULL pointer is returned. 7924 ** ^If zVfsName is NULL then the default VFS is returned. 7925 ** 7926 ** ^New VFSes are registered with sqlite3_vfs_register(). 7927 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 7928 ** ^The same VFS can be registered multiple times without injury. 7929 ** ^To make an existing VFS into the default VFS, register it again 7930 ** with the makeDflt flag set. If two different VFSes with the 7931 ** same name are registered, the behavior is undefined. If a 7932 ** VFS is registered with a name that is NULL or an empty string, 7933 ** then the behavior is undefined. 7934 ** 7935 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 7936 ** ^(If the default VFS is unregistered, another VFS is chosen as 7937 ** the default. The choice for the new VFS is arbitrary.)^ 7938 */ 7939 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 7940 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 7941 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 7942 7943 /* 7944 ** CAPI3REF: Mutexes 7945 ** 7946 ** The SQLite core uses these routines for thread 7947 ** synchronization. Though they are intended for internal 7948 ** use by SQLite, code that links against SQLite is 7949 ** permitted to use any of these routines. 7950 ** 7951 ** The SQLite source code contains multiple implementations 7952 ** of these mutex routines. An appropriate implementation 7953 ** is selected automatically at compile-time. The following 7954 ** implementations are available in the SQLite core: 7955 ** 7956 ** <ul> 7957 ** <li> SQLITE_MUTEX_PTHREADS 7958 ** <li> SQLITE_MUTEX_W32 7959 ** <li> SQLITE_MUTEX_NOOP 7960 ** </ul> 7961 ** 7962 ** The SQLITE_MUTEX_NOOP implementation is a set of routines 7963 ** that does no real locking and is appropriate for use in 7964 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 7965 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 7966 ** and Windows. 7967 ** 7968 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 7969 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 7970 ** implementation is included with the library. In this case the 7971 ** application must supply a custom mutex implementation using the 7972 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 7973 ** before calling sqlite3_initialize() or any other public sqlite3_ 7974 ** function that calls sqlite3_initialize(). 7975 ** 7976 ** ^The sqlite3_mutex_alloc() routine allocates a new 7977 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 7978 ** routine returns NULL if it is unable to allocate the requested 7979 ** mutex. The argument to sqlite3_mutex_alloc() must one of these 7980 ** integer constants: 7981 ** 7982 ** <ul> 7983 ** <li> SQLITE_MUTEX_FAST 7984 ** <li> SQLITE_MUTEX_RECURSIVE 7985 ** <li> SQLITE_MUTEX_STATIC_MAIN 7986 ** <li> SQLITE_MUTEX_STATIC_MEM 7987 ** <li> SQLITE_MUTEX_STATIC_OPEN 7988 ** <li> SQLITE_MUTEX_STATIC_PRNG 7989 ** <li> SQLITE_MUTEX_STATIC_LRU 7990 ** <li> SQLITE_MUTEX_STATIC_PMEM 7991 ** <li> SQLITE_MUTEX_STATIC_APP1 7992 ** <li> SQLITE_MUTEX_STATIC_APP2 7993 ** <li> SQLITE_MUTEX_STATIC_APP3 7994 ** <li> SQLITE_MUTEX_STATIC_VFS1 7995 ** <li> SQLITE_MUTEX_STATIC_VFS2 7996 ** <li> SQLITE_MUTEX_STATIC_VFS3 7997 ** </ul> 7998 ** 7999 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 8000 ** cause sqlite3_mutex_alloc() to create 8001 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 8002 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 8003 ** The mutex implementation does not need to make a distinction 8004 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 8005 ** not want to. SQLite will only request a recursive mutex in 8006 ** cases where it really needs one. If a faster non-recursive mutex 8007 ** implementation is available on the host platform, the mutex subsystem 8008 ** might return such a mutex in response to SQLITE_MUTEX_FAST. 8009 ** 8010 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 8011 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 8012 ** a pointer to a static preexisting mutex. ^Nine static mutexes are 8013 ** used by the current version of SQLite. Future versions of SQLite 8014 ** may add additional static mutexes. Static mutexes are for internal 8015 ** use by SQLite only. Applications that use SQLite mutexes should 8016 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 8017 ** SQLITE_MUTEX_RECURSIVE. 8018 ** 8019 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 8020 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 8021 ** returns a different mutex on every call. ^For the static 8022 ** mutex types, the same mutex is returned on every call that has 8023 ** the same type number. 8024 ** 8025 ** ^The sqlite3_mutex_free() routine deallocates a previously 8026 ** allocated dynamic mutex. Attempting to deallocate a static 8027 ** mutex results in undefined behavior. 8028 ** 8029 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 8030 ** to enter a mutex. ^If another thread is already within the mutex, 8031 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 8032 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 8033 ** upon successful entry. ^(Mutexes created using 8034 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 8035 ** In such cases, the 8036 ** mutex must be exited an equal number of times before another thread 8037 ** can enter.)^ If the same thread tries to enter any mutex other 8038 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 8039 ** 8040 ** ^(Some systems (for example, Windows 95) do not support the operation 8041 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 8042 ** will always return SQLITE_BUSY. In most cases the SQLite core only uses 8043 ** sqlite3_mutex_try() as an optimization, so this is acceptable 8044 ** behavior. The exceptions are unix builds that set the 8045 ** SQLITE_ENABLE_SETLK_TIMEOUT build option. In that case a working 8046 ** sqlite3_mutex_try() is required.)^ 8047 ** 8048 ** ^The sqlite3_mutex_leave() routine exits a mutex that was 8049 ** previously entered by the same thread. The behavior 8050 ** is undefined if the mutex is not currently entered by the 8051 ** calling thread or is not currently allocated. 8052 ** 8053 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), 8054 ** sqlite3_mutex_leave(), or sqlite3_mutex_free() is a NULL pointer, 8055 ** then any of the four routines behaves as a no-op. 8056 ** 8057 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 8058 */ 8059 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 8060 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 8061 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 8062 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 8063 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 8064 8065 /* 8066 ** CAPI3REF: Mutex Methods Object 8067 ** 8068 ** An instance of this structure defines the low-level routines 8069 ** used to allocate and use mutexes. 8070 ** 8071 ** Usually, the default mutex implementations provided by SQLite are 8072 ** sufficient, however the application has the option of substituting a custom 8073 ** implementation for specialized deployments or systems for which SQLite 8074 ** does not provide a suitable implementation. In this case, the application 8075 ** creates and populates an instance of this structure to pass 8076 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 8077 ** Additionally, an instance of this structure can be used as an 8078 ** output variable when querying the system for the current mutex 8079 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 8080 ** 8081 ** ^The xMutexInit method defined by this structure is invoked as 8082 ** part of system initialization by the sqlite3_initialize() function. 8083 ** ^The xMutexInit routine is called by SQLite exactly once for each 8084 ** effective call to [sqlite3_initialize()]. 8085 ** 8086 ** ^The xMutexEnd method defined by this structure is invoked as 8087 ** part of system shutdown by the sqlite3_shutdown() function. The 8088 ** implementation of this method is expected to release all outstanding 8089 ** resources obtained by the mutex methods implementation, especially 8090 ** those obtained by the xMutexInit method. ^The xMutexEnd() 8091 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 8092 ** 8093 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 8094 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 8095 ** xMutexNotheld) implement the following interfaces (respectively): 8096 ** 8097 ** <ul> 8098 ** <li> [sqlite3_mutex_alloc()] </li> 8099 ** <li> [sqlite3_mutex_free()] </li> 8100 ** <li> [sqlite3_mutex_enter()] </li> 8101 ** <li> [sqlite3_mutex_try()] </li> 8102 ** <li> [sqlite3_mutex_leave()] </li> 8103 ** <li> [sqlite3_mutex_held()] </li> 8104 ** <li> [sqlite3_mutex_notheld()] </li> 8105 ** </ul>)^ 8106 ** 8107 ** The only difference is that the public sqlite3_XXX functions enumerated 8108 ** above silently ignore any invocations that pass a NULL pointer instead 8109 ** of a valid mutex handle. The implementations of the methods defined 8110 ** by this structure are not required to handle this case. The results 8111 ** of passing a NULL pointer instead of a valid mutex handle are undefined 8112 ** (i.e. it is acceptable to provide an implementation that segfaults if 8113 ** it is passed a NULL pointer). 8114 ** 8115 ** The xMutexInit() method must be threadsafe. It must be harmless to 8116 ** invoke xMutexInit() multiple times within the same process and without 8117 ** intervening calls to xMutexEnd(). Second and subsequent calls to 8118 ** xMutexInit() must be no-ops. 8119 ** 8120 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 8121 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 8122 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 8123 ** memory allocation for a fast or recursive mutex. 8124 ** 8125 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 8126 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 8127 ** If xMutexInit fails in any way, it is expected to clean up after itself 8128 ** prior to returning. 8129 */ 8130 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 8131 struct sqlite3_mutex_methods { 8132 int (*xMutexInit)(void); 8133 int (*xMutexEnd)(void); 8134 sqlite3_mutex *(*xMutexAlloc)(int); 8135 void (*xMutexFree)(sqlite3_mutex *); 8136 void (*xMutexEnter)(sqlite3_mutex *); 8137 int (*xMutexTry)(sqlite3_mutex *); 8138 void (*xMutexLeave)(sqlite3_mutex *); 8139 int (*xMutexHeld)(sqlite3_mutex *); 8140 int (*xMutexNotheld)(sqlite3_mutex *); 8141 }; 8142 8143 /* 8144 ** CAPI3REF: Mutex Verification Routines 8145 ** 8146 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 8147 ** are intended for use inside assert() statements. The SQLite core 8148 ** never uses these routines except inside an assert() and applications 8149 ** are advised to follow the lead of the core. The SQLite core only 8150 ** provides implementations for these routines when it is compiled 8151 ** with the SQLITE_DEBUG flag. External mutex implementations 8152 ** are only required to provide these routines if SQLITE_DEBUG is 8153 ** defined and if NDEBUG is not defined. 8154 ** 8155 ** These routines should return true if the mutex in their argument 8156 ** is held or not held, respectively, by the calling thread. 8157 ** 8158 ** The implementation is not required to provide versions of these 8159 ** routines that actually work. If the implementation does not provide working 8160 ** versions of these routines, it should at least provide stubs that always 8161 ** return true so that one does not get spurious assertion failures. 8162 ** 8163 ** If the argument to sqlite3_mutex_held() is a NULL pointer then 8164 ** the routine should return 1. This seems counter-intuitive since 8165 ** clearly the mutex cannot be held if it does not exist. But 8166 ** the reason the mutex does not exist is because the build is not 8167 ** using mutexes. And we do not want the assert() containing the 8168 ** call to sqlite3_mutex_held() to fail, so a non-zero return is 8169 ** the appropriate thing to do. The sqlite3_mutex_notheld() 8170 ** interface should also return 1 when given a NULL pointer. 8171 */ 8172 #ifndef NDEBUG 8173 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 8174 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 8175 #endif 8176 8177 /* 8178 ** CAPI3REF: Mutex Types 8179 ** 8180 ** The [sqlite3_mutex_alloc()] interface takes a single argument 8181 ** which is one of these integer constants. 8182 ** 8183 ** The set of static mutexes may change from one SQLite release to the 8184 ** next. Applications that override the built-in mutex logic must be 8185 ** prepared to accommodate additional static mutexes. 8186 */ 8187 #define SQLITE_MUTEX_FAST 0 8188 #define SQLITE_MUTEX_RECURSIVE 1 8189 #define SQLITE_MUTEX_STATIC_MAIN 2 8190 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 8191 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 8192 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 8193 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 8194 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 8195 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 8196 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 8197 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 8198 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 8199 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 8200 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 8201 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 8202 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 8203 8204 /* Legacy compatibility: */ 8205 #define SQLITE_MUTEX_STATIC_MASTER 2 8206 8207 8208 /* 8209 ** CAPI3REF: Retrieve the mutex for a database connection 8210 ** METHOD: sqlite3 8211 ** 8212 ** ^This interface returns a pointer the [sqlite3_mutex] object that 8213 ** serializes access to the [database connection] given in the argument 8214 ** when the [threading mode] is Serialized. 8215 ** ^If the [threading mode] is Single-thread or Multi-thread then this 8216 ** routine returns a NULL pointer. 8217 */ 8218 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 8219 8220 /* 8221 ** CAPI3REF: Low-Level Control Of Database Files 8222 ** METHOD: sqlite3 8223 ** KEYWORDS: {file control} 8224 ** 8225 ** ^The [sqlite3_file_control()] interface makes a direct call to the 8226 ** xFileControl method for the [sqlite3_io_methods] object associated 8227 ** with a particular database identified by the second argument. ^The 8228 ** name of the database is "main" for the main database or "temp" for the 8229 ** TEMP database, or the name that appears after the AS keyword for 8230 ** databases that are added using the [ATTACH] SQL command. 8231 ** ^A NULL pointer can be used in place of "main" to refer to the 8232 ** main database file. 8233 ** ^The third and fourth parameters to this routine 8234 ** are passed directly through to the second and third parameters of 8235 ** the xFileControl method. ^The return value of the xFileControl 8236 ** method becomes the return value of this routine. 8237 ** 8238 ** A few opcodes for [sqlite3_file_control()] are handled directly 8239 ** by the SQLite core and never invoke the 8240 ** sqlite3_io_methods.xFileControl method. 8241 ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 8242 ** a pointer to the underlying [sqlite3_file] object to be written into 8243 ** the space pointed to by the 4th parameter. The 8244 ** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 8245 ** the [sqlite3_file] object associated with the journal file instead of 8246 ** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 8247 ** a pointer to the underlying [sqlite3_vfs] object for the file. 8248 ** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 8249 ** from the pager. 8250 ** 8251 ** ^If the second parameter (zDbName) does not match the name of any 8252 ** open database file, then SQLITE_ERROR is returned. ^This error 8253 ** code is not remembered and will not be recalled by [sqlite3_errcode()] 8254 ** or [sqlite3_errmsg()]. The underlying xFileControl method might 8255 ** also return SQLITE_ERROR. There is no way to distinguish between 8256 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 8257 ** xFileControl method. 8258 ** 8259 ** See also: [file control opcodes] 8260 */ 8261 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 8262 8263 /* 8264 ** CAPI3REF: Testing Interface 8265 ** 8266 ** ^The sqlite3_test_control() interface is used to read out internal 8267 ** state of SQLite and to inject faults into SQLite for testing 8268 ** purposes. ^The first parameter is an operation code that determines 8269 ** the number, meaning, and operation of all subsequent parameters. 8270 ** 8271 ** This interface is not for use by applications. It exists solely 8272 ** for verifying the correct operation of the SQLite library. Depending 8273 ** on how the SQLite library is compiled, this interface might not exist. 8274 ** 8275 ** The details of the operation codes, their meanings, the parameters 8276 ** they take, and what they do are all subject to change without notice. 8277 ** Unlike most of the SQLite API, this function is not guaranteed to 8278 ** operate consistently from one release to the next. 8279 */ 8280 SQLITE_API int sqlite3_test_control(int op, ...); 8281 8282 /* 8283 ** CAPI3REF: Testing Interface Operation Codes 8284 ** 8285 ** These constants are the valid operation code parameters used 8286 ** as the first argument to [sqlite3_test_control()]. 8287 ** 8288 ** These parameters and their meanings are subject to change 8289 ** without notice. These values are for testing purposes only. 8290 ** Applications should not use any of these parameters or the 8291 ** [sqlite3_test_control()] interface. 8292 */ 8293 #define SQLITE_TESTCTRL_FIRST 5 8294 #define SQLITE_TESTCTRL_PRNG_SAVE 5 8295 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 8296 #define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */ 8297 #define SQLITE_TESTCTRL_FK_NO_ACTION 7 8298 #define SQLITE_TESTCTRL_BITVEC_TEST 8 8299 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 8300 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 8301 #define SQLITE_TESTCTRL_PENDING_BYTE 11 8302 #define SQLITE_TESTCTRL_ASSERT 12 8303 #define SQLITE_TESTCTRL_ALWAYS 13 8304 #define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */ 8305 #define SQLITE_TESTCTRL_JSON_SELFCHECK 14 8306 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 8307 #define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 8308 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 8309 #define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 8310 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 8311 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 8312 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 8313 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 8314 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 8315 #define SQLITE_TESTCTRL_BYTEORDER 22 8316 #define SQLITE_TESTCTRL_ISINIT 23 8317 #define SQLITE_TESTCTRL_SORTER_MMAP 24 8318 #define SQLITE_TESTCTRL_IMPOSTER 25 8319 #define SQLITE_TESTCTRL_PARSER_COVERAGE 26 8320 #define SQLITE_TESTCTRL_RESULT_INTREAL 27 8321 #define SQLITE_TESTCTRL_PRNG_SEED 28 8322 #define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29 8323 #define SQLITE_TESTCTRL_SEEK_COUNT 30 8324 #define SQLITE_TESTCTRL_TRACEFLAGS 31 8325 #define SQLITE_TESTCTRL_TUNE 32 8326 #define SQLITE_TESTCTRL_LOGEST 33 8327 #define SQLITE_TESTCTRL_USELONGDOUBLE 34 8328 #define SQLITE_TESTCTRL_LAST 34 /* Largest TESTCTRL */ 8329 8330 /* 8331 ** CAPI3REF: SQL Keyword Checking 8332 ** 8333 ** These routines provide access to the set of SQL language keywords 8334 ** recognized by SQLite. Applications can uses these routines to determine 8335 ** whether or not a specific identifier needs to be escaped (for example, 8336 ** by enclosing in double-quotes) so as not to confuse the parser. 8337 ** 8338 ** The sqlite3_keyword_count() interface returns the number of distinct 8339 ** keywords understood by SQLite. 8340 ** 8341 ** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 8342 ** makes *Z point to that keyword expressed as UTF8 and writes the number 8343 ** of bytes in the keyword into *L. The string that *Z points to is not 8344 ** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 8345 ** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 8346 ** or L are NULL or invalid pointers then calls to 8347 ** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 8348 ** 8349 ** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 8350 ** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 8351 ** if it is and zero if not. 8352 ** 8353 ** The parser used by SQLite is forgiving. It is often possible to use 8354 ** a keyword as an identifier as long as such use does not result in a 8355 ** parsing ambiguity. For example, the statement 8356 ** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 8357 ** creates a new table named "BEGIN" with three columns named 8358 ** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 8359 ** using keywords as identifiers. Common techniques used to avoid keyword 8360 ** name collisions include: 8361 ** <ul> 8362 ** <li> Put all identifier names inside double-quotes. This is the official 8363 ** SQL way to escape identifier names. 8364 ** <li> Put identifier names inside [...]. This is not standard SQL, 8365 ** but it is what SQL Server does and so lots of programmers use this 8366 ** technique. 8367 ** <li> Begin every identifier with the letter "Z" as no SQL keywords start 8368 ** with "Z". 8369 ** <li> Include a digit somewhere in every identifier name. 8370 ** </ul> 8371 ** 8372 ** Note that the number of keywords understood by SQLite can depend on 8373 ** compile-time options. For example, "VACUUM" is not a keyword if 8374 ** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 8375 ** new keywords may be added to future releases of SQLite. 8376 */ 8377 SQLITE_API int sqlite3_keyword_count(void); 8378 SQLITE_API int sqlite3_keyword_name(int,const char**,int*); 8379 SQLITE_API int sqlite3_keyword_check(const char*,int); 8380 8381 /* 8382 ** CAPI3REF: Dynamic String Object 8383 ** KEYWORDS: {dynamic string} 8384 ** 8385 ** An instance of the sqlite3_str object contains a dynamically-sized 8386 ** string under construction. 8387 ** 8388 ** The lifecycle of an sqlite3_str object is as follows: 8389 ** <ol> 8390 ** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 8391 ** <li> ^Text is appended to the sqlite3_str object using various 8392 ** methods, such as [sqlite3_str_appendf()]. 8393 ** <li> ^The sqlite3_str object is destroyed and the string it created 8394 ** is returned using the [sqlite3_str_finish()] interface. 8395 ** </ol> 8396 */ 8397 typedef struct sqlite3_str sqlite3_str; 8398 8399 /* 8400 ** CAPI3REF: Create A New Dynamic String Object 8401 ** CONSTRUCTOR: sqlite3_str 8402 ** 8403 ** ^The [sqlite3_str_new(D)] interface allocates and initializes 8404 ** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 8405 ** [sqlite3_str_new()] must be freed by a subsequent call to 8406 ** [sqlite3_str_finish(X)]. 8407 ** 8408 ** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 8409 ** valid [sqlite3_str] object, though in the event of an out-of-memory 8410 ** error the returned object might be a special singleton that will 8411 ** silently reject new text, always return SQLITE_NOMEM from 8412 ** [sqlite3_str_errcode()], always return 0 for 8413 ** [sqlite3_str_length()], and always return NULL from 8414 ** [sqlite3_str_finish(X)]. It is always safe to use the value 8415 ** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 8416 ** to any of the other [sqlite3_str] methods. 8417 ** 8418 ** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 8419 ** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 8420 ** length of the string contained in the [sqlite3_str] object will be 8421 ** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 8422 ** of [SQLITE_MAX_LENGTH]. 8423 */ 8424 SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*); 8425 8426 /* 8427 ** CAPI3REF: Finalize A Dynamic String 8428 ** DESTRUCTOR: sqlite3_str 8429 ** 8430 ** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 8431 ** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 8432 ** that contains the constructed string. The calling application should 8433 ** pass the returned value to [sqlite3_free()] to avoid a memory leak. 8434 ** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 8435 ** errors were encountered during construction of the string. ^The 8436 ** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 8437 ** string in [sqlite3_str] object X is zero bytes long. 8438 */ 8439 SQLITE_API char *sqlite3_str_finish(sqlite3_str*); 8440 8441 /* 8442 ** CAPI3REF: Add Content To A Dynamic String 8443 ** METHOD: sqlite3_str 8444 ** 8445 ** These interfaces add content to an sqlite3_str object previously obtained 8446 ** from [sqlite3_str_new()]. 8447 ** 8448 ** ^The [sqlite3_str_appendf(X,F,...)] and 8449 ** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 8450 ** functionality of SQLite to append formatted text onto the end of 8451 ** [sqlite3_str] object X. 8452 ** 8453 ** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 8454 ** onto the end of the [sqlite3_str] object X. N must be non-negative. 8455 ** S must contain at least N non-zero bytes of content. To append a 8456 ** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 8457 ** method instead. 8458 ** 8459 ** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 8460 ** zero-terminated string S onto the end of [sqlite3_str] object X. 8461 ** 8462 ** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 8463 ** single-byte character C onto the end of [sqlite3_str] object X. 8464 ** ^This method can be used, for example, to add whitespace indentation. 8465 ** 8466 ** ^The [sqlite3_str_reset(X)] method resets the string under construction 8467 ** inside [sqlite3_str] object X back to zero bytes in length. 8468 ** 8469 ** These methods do not return a result code. ^If an error occurs, that fact 8470 ** is recorded in the [sqlite3_str] object and can be recovered by a 8471 ** subsequent call to [sqlite3_str_errcode(X)]. 8472 */ 8473 SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 8474 SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 8475 SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 8476 SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 8477 SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 8478 SQLITE_API void sqlite3_str_reset(sqlite3_str*); 8479 8480 /* 8481 ** CAPI3REF: Status Of A Dynamic String 8482 ** METHOD: sqlite3_str 8483 ** 8484 ** These interfaces return the current status of an [sqlite3_str] object. 8485 ** 8486 ** ^If any prior errors have occurred while constructing the dynamic string 8487 ** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 8488 ** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 8489 ** [SQLITE_NOMEM] following any out-of-memory error, or 8490 ** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 8491 ** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 8492 ** 8493 ** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 8494 ** of the dynamic string under construction in [sqlite3_str] object X. 8495 ** ^The length returned by [sqlite3_str_length(X)] does not include the 8496 ** zero-termination byte. 8497 ** 8498 ** ^The [sqlite3_str_value(X)] method returns a pointer to the current 8499 ** content of the dynamic string under construction in X. The value 8500 ** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 8501 ** and might be freed or altered by any subsequent method on the same 8502 ** [sqlite3_str] object. Applications must not used the pointer returned 8503 ** [sqlite3_str_value(X)] after any subsequent method call on the same 8504 ** object. ^Applications may change the content of the string returned 8505 ** by [sqlite3_str_value(X)] as long as they do not write into any bytes 8506 ** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 8507 ** write any byte after any subsequent sqlite3_str method call. 8508 */ 8509 SQLITE_API int sqlite3_str_errcode(sqlite3_str*); 8510 SQLITE_API int sqlite3_str_length(sqlite3_str*); 8511 SQLITE_API char *sqlite3_str_value(sqlite3_str*); 8512 8513 /* 8514 ** CAPI3REF: SQLite Runtime Status 8515 ** 8516 ** ^These interfaces are used to retrieve runtime status information 8517 ** about the performance of SQLite, and optionally to reset various 8518 ** highwater marks. ^The first argument is an integer code for 8519 ** the specific parameter to measure. ^(Recognized integer codes 8520 ** are of the form [status parameters | SQLITE_STATUS_...].)^ 8521 ** ^The current value of the parameter is returned into *pCurrent. 8522 ** ^The highest recorded value is returned in *pHighwater. ^If the 8523 ** resetFlag is true, then the highest record value is reset after 8524 ** *pHighwater is written. ^(Some parameters do not record the highest 8525 ** value. For those parameters 8526 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 8527 ** ^(Other parameters record only the highwater mark and not the current 8528 ** value. For these latter parameters nothing is written into *pCurrent.)^ 8529 ** 8530 ** ^The sqlite3_status() and sqlite3_status64() routines return 8531 ** SQLITE_OK on success and a non-zero [error code] on failure. 8532 ** 8533 ** If either the current value or the highwater mark is too large to 8534 ** be represented by a 32-bit integer, then the values returned by 8535 ** sqlite3_status() are undefined. 8536 ** 8537 ** See also: [sqlite3_db_status()] 8538 */ 8539 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 8540 SQLITE_API int sqlite3_status64( 8541 int op, 8542 sqlite3_int64 *pCurrent, 8543 sqlite3_int64 *pHighwater, 8544 int resetFlag 8545 ); 8546 8547 8548 /* 8549 ** CAPI3REF: Status Parameters 8550 ** KEYWORDS: {status parameters} 8551 ** 8552 ** These integer constants designate various run-time status parameters 8553 ** that can be returned by [sqlite3_status()]. 8554 ** 8555 ** <dl> 8556 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 8557 ** <dd>This parameter is the current amount of memory checked out 8558 ** using [sqlite3_malloc()], either directly or indirectly. The 8559 ** figure includes calls made to [sqlite3_malloc()] by the application 8560 ** and internal memory usage by the SQLite library. Auxiliary page-cache 8561 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 8562 ** this parameter. The amount returned is the sum of the allocation 8563 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 8564 ** 8565 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 8566 ** <dd>This parameter records the largest memory allocation request 8567 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 8568 ** internal equivalents). Only the value returned in the 8569 ** *pHighwater parameter to [sqlite3_status()] is of interest. 8570 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 8571 ** 8572 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 8573 ** <dd>This parameter records the number of separate memory allocations 8574 ** currently checked out.</dd>)^ 8575 ** 8576 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 8577 ** <dd>This parameter returns the number of pages used out of the 8578 ** [pagecache memory allocator] that was configured using 8579 ** [SQLITE_CONFIG_PAGECACHE]. The 8580 ** value returned is in pages, not in bytes.</dd>)^ 8581 ** 8582 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 8583 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 8584 ** <dd>This parameter returns the number of bytes of page cache 8585 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 8586 ** buffer and where forced to overflow to [sqlite3_malloc()]. The 8587 ** returned value includes allocations that overflowed because they 8588 ** where too large (they were larger than the "sz" parameter to 8589 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 8590 ** no space was left in the page cache.</dd>)^ 8591 ** 8592 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 8593 ** <dd>This parameter records the largest memory allocation request 8594 ** handed to the [pagecache memory allocator]. Only the value returned in the 8595 ** *pHighwater parameter to [sqlite3_status()] is of interest. 8596 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 8597 ** 8598 ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 8599 ** <dd>No longer used.</dd> 8600 ** 8601 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 8602 ** <dd>No longer used.</dd> 8603 ** 8604 ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 8605 ** <dd>No longer used.</dd> 8606 ** 8607 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 8608 ** <dd>The *pHighwater parameter records the deepest parser stack. 8609 ** The *pCurrent value is undefined. The *pHighwater value is only 8610 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 8611 ** </dl> 8612 ** 8613 ** New status parameters may be added from time to time. 8614 */ 8615 #define SQLITE_STATUS_MEMORY_USED 0 8616 #define SQLITE_STATUS_PAGECACHE_USED 1 8617 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 8618 #define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 8619 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 8620 #define SQLITE_STATUS_MALLOC_SIZE 5 8621 #define SQLITE_STATUS_PARSER_STACK 6 8622 #define SQLITE_STATUS_PAGECACHE_SIZE 7 8623 #define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 8624 #define SQLITE_STATUS_MALLOC_COUNT 9 8625 8626 /* 8627 ** CAPI3REF: Database Connection Status 8628 ** METHOD: sqlite3 8629 ** 8630 ** ^This interface is used to retrieve runtime status information 8631 ** about a single [database connection]. ^The first argument is the 8632 ** database connection object to be interrogated. ^The second argument 8633 ** is an integer constant, taken from the set of 8634 ** [SQLITE_DBSTATUS options], that 8635 ** determines the parameter to interrogate. The set of 8636 ** [SQLITE_DBSTATUS options] is likely 8637 ** to grow in future releases of SQLite. 8638 ** 8639 ** ^The current value of the requested parameter is written into *pCur 8640 ** and the highest instantaneous value is written into *pHiwtr. ^If 8641 ** the resetFlg is true, then the highest instantaneous value is 8642 ** reset back down to the current value. 8643 ** 8644 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 8645 ** non-zero [error code] on failure. 8646 ** 8647 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 8648 */ 8649 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 8650 8651 /* 8652 ** CAPI3REF: Status Parameters for database connections 8653 ** KEYWORDS: {SQLITE_DBSTATUS options} 8654 ** 8655 ** These constants are the available integer "verbs" that can be passed as 8656 ** the second argument to the [sqlite3_db_status()] interface. 8657 ** 8658 ** New verbs may be added in future releases of SQLite. Existing verbs 8659 ** might be discontinued. Applications should check the return code from 8660 ** [sqlite3_db_status()] to make sure that the call worked. 8661 ** The [sqlite3_db_status()] interface will return a non-zero error code 8662 ** if a discontinued or unsupported verb is invoked. 8663 ** 8664 ** <dl> 8665 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 8666 ** <dd>This parameter returns the number of lookaside memory slots currently 8667 ** checked out.</dd>)^ 8668 ** 8669 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 8670 ** <dd>This parameter returns the number of malloc attempts that were 8671 ** satisfied using lookaside memory. Only the high-water value is meaningful; 8672 ** the current value is always zero.)^ 8673 ** 8674 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 8675 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 8676 ** <dd>This parameter returns the number malloc attempts that might have 8677 ** been satisfied using lookaside memory but failed due to the amount of 8678 ** memory requested being larger than the lookaside slot size. 8679 ** Only the high-water value is meaningful; 8680 ** the current value is always zero.)^ 8681 ** 8682 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 8683 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 8684 ** <dd>This parameter returns the number malloc attempts that might have 8685 ** been satisfied using lookaside memory but failed due to all lookaside 8686 ** memory already being in use. 8687 ** Only the high-water value is meaningful; 8688 ** the current value is always zero.)^ 8689 ** 8690 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 8691 ** <dd>This parameter returns the approximate number of bytes of heap 8692 ** memory used by all pager caches associated with the database connection.)^ 8693 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 8694 ** 8695 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 8696 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 8697 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 8698 ** pager cache is shared between two or more connections the bytes of heap 8699 ** memory used by that pager cache is divided evenly between the attached 8700 ** connections.)^ In other words, if none of the pager caches associated 8701 ** with the database connection are shared, this request returns the same 8702 ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 8703 ** shared, the value returned by this call will be smaller than that returned 8704 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 8705 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 8706 ** 8707 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 8708 ** <dd>This parameter returns the approximate number of bytes of heap 8709 ** memory used to store the schema for all databases associated 8710 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 8711 ** ^The full amount of memory used by the schemas is reported, even if the 8712 ** schema memory is shared with other database connections due to 8713 ** [shared cache mode] being enabled. 8714 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 8715 ** 8716 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 8717 ** <dd>This parameter returns the approximate number of bytes of heap 8718 ** and lookaside memory used by all prepared statements associated with 8719 ** the database connection.)^ 8720 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 8721 ** </dd> 8722 ** 8723 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 8724 ** <dd>This parameter returns the number of pager cache hits that have 8725 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 8726 ** is always 0. 8727 ** </dd> 8728 ** 8729 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 8730 ** <dd>This parameter returns the number of pager cache misses that have 8731 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 8732 ** is always 0. 8733 ** </dd> 8734 ** 8735 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 8736 ** <dd>This parameter returns the number of dirty cache entries that have 8737 ** been written to disk. Specifically, the number of pages written to the 8738 ** wal file in wal mode databases, or the number of pages written to the 8739 ** database file in rollback mode databases. Any pages written as part of 8740 ** transaction rollback or database recovery operations are not included. 8741 ** If an IO or other error occurs while writing a page to disk, the effect 8742 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 8743 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 8744 ** </dd> 8745 ** 8746 ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 8747 ** <dd>This parameter returns the number of dirty cache entries that have 8748 ** been written to disk in the middle of a transaction due to the page 8749 ** cache overflowing. Transactions are more efficient if they are written 8750 ** to disk all at once. When pages spill mid-transaction, that introduces 8751 ** additional overhead. This parameter can be used help identify 8752 ** inefficiencies that can be resolved by increasing the cache size. 8753 ** </dd> 8754 ** 8755 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 8756 ** <dd>This parameter returns zero for the current value if and only if 8757 ** all foreign key constraints (deferred or immediate) have been 8758 ** resolved.)^ ^The highwater mark is always 0. 8759 ** </dd> 8760 ** </dl> 8761 */ 8762 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 8763 #define SQLITE_DBSTATUS_CACHE_USED 1 8764 #define SQLITE_DBSTATUS_SCHEMA_USED 2 8765 #define SQLITE_DBSTATUS_STMT_USED 3 8766 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 8767 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 8768 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 8769 #define SQLITE_DBSTATUS_CACHE_HIT 7 8770 #define SQLITE_DBSTATUS_CACHE_MISS 8 8771 #define SQLITE_DBSTATUS_CACHE_WRITE 9 8772 #define SQLITE_DBSTATUS_DEFERRED_FKS 10 8773 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 8774 #define SQLITE_DBSTATUS_CACHE_SPILL 12 8775 #define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 8776 8777 8778 /* 8779 ** CAPI3REF: Prepared Statement Status 8780 ** METHOD: sqlite3_stmt 8781 ** 8782 ** ^(Each prepared statement maintains various 8783 ** [SQLITE_STMTSTATUS counters] that measure the number 8784 ** of times it has performed specific operations.)^ These counters can 8785 ** be used to monitor the performance characteristics of the prepared 8786 ** statements. For example, if the number of table steps greatly exceeds 8787 ** the number of table searches or result rows, that would tend to indicate 8788 ** that the prepared statement is using a full table scan rather than 8789 ** an index. 8790 ** 8791 ** ^(This interface is used to retrieve and reset counter values from 8792 ** a [prepared statement]. The first argument is the prepared statement 8793 ** object to be interrogated. The second argument 8794 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 8795 ** to be interrogated.)^ 8796 ** ^The current value of the requested counter is returned. 8797 ** ^If the resetFlg is true, then the counter is reset to zero after this 8798 ** interface call returns. 8799 ** 8800 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 8801 */ 8802 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 8803 8804 /* 8805 ** CAPI3REF: Status Parameters for prepared statements 8806 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 8807 ** 8808 ** These preprocessor macros define integer codes that name counter 8809 ** values associated with the [sqlite3_stmt_status()] interface. 8810 ** The meanings of the various counters are as follows: 8811 ** 8812 ** <dl> 8813 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 8814 ** <dd>^This is the number of times that SQLite has stepped forward in 8815 ** a table as part of a full table scan. Large numbers for this counter 8816 ** may indicate opportunities for performance improvement through 8817 ** careful use of indices.</dd> 8818 ** 8819 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 8820 ** <dd>^This is the number of sort operations that have occurred. 8821 ** A non-zero value in this counter may indicate an opportunity to 8822 ** improvement performance through careful use of indices.</dd> 8823 ** 8824 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 8825 ** <dd>^This is the number of rows inserted into transient indices that 8826 ** were created automatically in order to help joins run faster. 8827 ** A non-zero value in this counter may indicate an opportunity to 8828 ** improvement performance by adding permanent indices that do not 8829 ** need to be reinitialized each time the statement is run.</dd> 8830 ** 8831 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 8832 ** <dd>^This is the number of virtual machine operations executed 8833 ** by the prepared statement if that number is less than or equal 8834 ** to 2147483647. The number of virtual machine operations can be 8835 ** used as a proxy for the total work done by the prepared statement. 8836 ** If the number of virtual machine operations exceeds 2147483647 8837 ** then the value returned by this statement status code is undefined. 8838 ** 8839 ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 8840 ** <dd>^This is the number of times that the prepare statement has been 8841 ** automatically regenerated due to schema changes or changes to 8842 ** [bound parameters] that might affect the query plan. 8843 ** 8844 ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 8845 ** <dd>^This is the number of times that the prepared statement has 8846 ** been run. A single "run" for the purposes of this counter is one 8847 ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 8848 ** The counter is incremented on the first [sqlite3_step()] call of each 8849 ** cycle. 8850 ** 8851 ** [[SQLITE_STMTSTATUS_FILTER_MISS]] 8852 ** [[SQLITE_STMTSTATUS_FILTER HIT]] 8853 ** <dt>SQLITE_STMTSTATUS_FILTER_HIT<br> 8854 ** SQLITE_STMTSTATUS_FILTER_MISS</dt> 8855 ** <dd>^SQLITE_STMTSTATUS_FILTER_HIT is the number of times that a join 8856 ** step was bypassed because a Bloom filter returned not-found. The 8857 ** corresponding SQLITE_STMTSTATUS_FILTER_MISS value is the number of 8858 ** times that the Bloom filter returned a find, and thus the join step 8859 ** had to be processed as normal. 8860 ** 8861 ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 8862 ** <dd>^This is the approximate number of bytes of heap memory 8863 ** used to store the prepared statement. ^This value is not actually 8864 ** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 8865 ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 8866 ** </dd> 8867 ** </dl> 8868 */ 8869 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 8870 #define SQLITE_STMTSTATUS_SORT 2 8871 #define SQLITE_STMTSTATUS_AUTOINDEX 3 8872 #define SQLITE_STMTSTATUS_VM_STEP 4 8873 #define SQLITE_STMTSTATUS_REPREPARE 5 8874 #define SQLITE_STMTSTATUS_RUN 6 8875 #define SQLITE_STMTSTATUS_FILTER_MISS 7 8876 #define SQLITE_STMTSTATUS_FILTER_HIT 8 8877 #define SQLITE_STMTSTATUS_MEMUSED 99 8878 8879 /* 8880 ** CAPI3REF: Custom Page Cache Object 8881 ** 8882 ** The sqlite3_pcache type is opaque. It is implemented by 8883 ** the pluggable module. The SQLite core has no knowledge of 8884 ** its size or internal structure and never deals with the 8885 ** sqlite3_pcache object except by holding and passing pointers 8886 ** to the object. 8887 ** 8888 ** See [sqlite3_pcache_methods2] for additional information. 8889 */ 8890 typedef struct sqlite3_pcache sqlite3_pcache; 8891 8892 /* 8893 ** CAPI3REF: Custom Page Cache Object 8894 ** 8895 ** The sqlite3_pcache_page object represents a single page in the 8896 ** page cache. The page cache will allocate instances of this 8897 ** object. Various methods of the page cache use pointers to instances 8898 ** of this object as parameters or as their return value. 8899 ** 8900 ** See [sqlite3_pcache_methods2] for additional information. 8901 */ 8902 typedef struct sqlite3_pcache_page sqlite3_pcache_page; 8903 struct sqlite3_pcache_page { 8904 void *pBuf; /* The content of the page */ 8905 void *pExtra; /* Extra information associated with the page */ 8906 }; 8907 8908 /* 8909 ** CAPI3REF: Application Defined Page Cache. 8910 ** KEYWORDS: {page cache} 8911 ** 8912 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 8913 ** register an alternative page cache implementation by passing in an 8914 ** instance of the sqlite3_pcache_methods2 structure.)^ 8915 ** In many applications, most of the heap memory allocated by 8916 ** SQLite is used for the page cache. 8917 ** By implementing a 8918 ** custom page cache using this API, an application can better control 8919 ** the amount of memory consumed by SQLite, the way in which 8920 ** that memory is allocated and released, and the policies used to 8921 ** determine exactly which parts of a database file are cached and for 8922 ** how long. 8923 ** 8924 ** The alternative page cache mechanism is an 8925 ** extreme measure that is only needed by the most demanding applications. 8926 ** The built-in page cache is recommended for most uses. 8927 ** 8928 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 8929 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 8930 ** the application may discard the parameter after the call to 8931 ** [sqlite3_config()] returns.)^ 8932 ** 8933 ** [[the xInit() page cache method]] 8934 ** ^(The xInit() method is called once for each effective 8935 ** call to [sqlite3_initialize()])^ 8936 ** (usually only once during the lifetime of the process). ^(The xInit() 8937 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 8938 ** The intent of the xInit() method is to set up global data structures 8939 ** required by the custom page cache implementation. 8940 ** ^(If the xInit() method is NULL, then the 8941 ** built-in default page cache is used instead of the application defined 8942 ** page cache.)^ 8943 ** 8944 ** [[the xShutdown() page cache method]] 8945 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 8946 ** It can be used to clean up 8947 ** any outstanding resources before process shutdown, if required. 8948 ** ^The xShutdown() method may be NULL. 8949 ** 8950 ** ^SQLite automatically serializes calls to the xInit method, 8951 ** so the xInit method need not be threadsafe. ^The 8952 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 8953 ** not need to be threadsafe either. All other methods must be threadsafe 8954 ** in multithreaded applications. 8955 ** 8956 ** ^SQLite will never invoke xInit() more than once without an intervening 8957 ** call to xShutdown(). 8958 ** 8959 ** [[the xCreate() page cache methods]] 8960 ** ^SQLite invokes the xCreate() method to construct a new cache instance. 8961 ** SQLite will typically create one cache instance for each open database file, 8962 ** though this is not guaranteed. ^The 8963 ** first parameter, szPage, is the size in bytes of the pages that must 8964 ** be allocated by the cache. ^szPage will always a power of two. ^The 8965 ** second parameter szExtra is a number of bytes of extra storage 8966 ** associated with each page cache entry. ^The szExtra parameter will 8967 ** a number less than 250. SQLite will use the 8968 ** extra szExtra bytes on each page to store metadata about the underlying 8969 ** database page on disk. The value passed into szExtra depends 8970 ** on the SQLite version, the target platform, and how SQLite was compiled. 8971 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 8972 ** created will be used to cache database pages of a file stored on disk, or 8973 ** false if it is used for an in-memory database. The cache implementation 8974 ** does not have to do anything special based with the value of bPurgeable; 8975 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 8976 ** never invoke xUnpin() except to deliberately delete a page. 8977 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 8978 ** false will always have the "discard" flag set to true. 8979 ** ^Hence, a cache created with bPurgeable false will 8980 ** never contain any unpinned pages. 8981 ** 8982 ** [[the xCachesize() page cache method]] 8983 ** ^(The xCachesize() method may be called at any time by SQLite to set the 8984 ** suggested maximum cache-size (number of pages stored by) the cache 8985 ** instance passed as the first argument. This is the value configured using 8986 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 8987 ** parameter, the implementation is not required to do anything with this 8988 ** value; it is advisory only. 8989 ** 8990 ** [[the xPagecount() page cache methods]] 8991 ** The xPagecount() method must return the number of pages currently 8992 ** stored in the cache, both pinned and unpinned. 8993 ** 8994 ** [[the xFetch() page cache methods]] 8995 ** The xFetch() method locates a page in the cache and returns a pointer to 8996 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 8997 ** The pBuf element of the returned sqlite3_pcache_page object will be a 8998 ** pointer to a buffer of szPage bytes used to store the content of a 8999 ** single database page. The pExtra element of sqlite3_pcache_page will be 9000 ** a pointer to the szExtra bytes of extra storage that SQLite has requested 9001 ** for each entry in the page cache. 9002 ** 9003 ** The page to be fetched is determined by the key. ^The minimum key value 9004 ** is 1. After it has been retrieved using xFetch, the page is considered 9005 ** to be "pinned". 9006 ** 9007 ** If the requested page is already in the page cache, then the page cache 9008 ** implementation must return a pointer to the page buffer with its content 9009 ** intact. If the requested page is not already in the cache, then the 9010 ** cache implementation should use the value of the createFlag 9011 ** parameter to help it determined what action to take: 9012 ** 9013 ** <table border=1 width=85% align=center> 9014 ** <tr><th> createFlag <th> Behavior when page is not already in cache 9015 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 9016 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 9017 ** Otherwise return NULL. 9018 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 9019 ** NULL if allocating a new page is effectively impossible. 9020 ** </table> 9021 ** 9022 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 9023 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 9024 ** failed.)^ In between the xFetch() calls, SQLite may 9025 ** attempt to unpin one or more cache pages by spilling the content of 9026 ** pinned pages to disk and synching the operating system disk cache. 9027 ** 9028 ** [[the xUnpin() page cache method]] 9029 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 9030 ** as its second argument. If the third parameter, discard, is non-zero, 9031 ** then the page must be evicted from the cache. 9032 ** ^If the discard parameter is 9033 ** zero, then the page may be discarded or retained at the discretion of 9034 ** page cache implementation. ^The page cache implementation 9035 ** may choose to evict unpinned pages at any time. 9036 ** 9037 ** The cache must not perform any reference counting. A single 9038 ** call to xUnpin() unpins the page regardless of the number of prior calls 9039 ** to xFetch(). 9040 ** 9041 ** [[the xRekey() page cache methods]] 9042 ** The xRekey() method is used to change the key value associated with the 9043 ** page passed as the second argument. If the cache 9044 ** previously contains an entry associated with newKey, it must be 9045 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 9046 ** to be pinned. 9047 ** 9048 ** When SQLite calls the xTruncate() method, the cache must discard all 9049 ** existing cache entries with page numbers (keys) greater than or equal 9050 ** to the value of the iLimit parameter passed to xTruncate(). If any 9051 ** of these pages are pinned, they are implicitly unpinned, meaning that 9052 ** they can be safely discarded. 9053 ** 9054 ** [[the xDestroy() page cache method]] 9055 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 9056 ** All resources associated with the specified cache should be freed. ^After 9057 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 9058 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 9059 ** functions. 9060 ** 9061 ** [[the xShrink() page cache method]] 9062 ** ^SQLite invokes the xShrink() method when it wants the page cache to 9063 ** free up as much of heap memory as possible. The page cache implementation 9064 ** is not obligated to free any memory, but well-behaved implementations should 9065 ** do their best. 9066 */ 9067 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 9068 struct sqlite3_pcache_methods2 { 9069 int iVersion; 9070 void *pArg; 9071 int (*xInit)(void*); 9072 void (*xShutdown)(void*); 9073 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 9074 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 9075 int (*xPagecount)(sqlite3_pcache*); 9076 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 9077 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 9078 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 9079 unsigned oldKey, unsigned newKey); 9080 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 9081 void (*xDestroy)(sqlite3_pcache*); 9082 void (*xShrink)(sqlite3_pcache*); 9083 }; 9084 9085 /* 9086 ** This is the obsolete pcache_methods object that has now been replaced 9087 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 9088 ** retained in the header file for backwards compatibility only. 9089 */ 9090 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 9091 struct sqlite3_pcache_methods { 9092 void *pArg; 9093 int (*xInit)(void*); 9094 void (*xShutdown)(void*); 9095 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 9096 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 9097 int (*xPagecount)(sqlite3_pcache*); 9098 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 9099 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 9100 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 9101 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 9102 void (*xDestroy)(sqlite3_pcache*); 9103 }; 9104 9105 9106 /* 9107 ** CAPI3REF: Online Backup Object 9108 ** 9109 ** The sqlite3_backup object records state information about an ongoing 9110 ** online backup operation. ^The sqlite3_backup object is created by 9111 ** a call to [sqlite3_backup_init()] and is destroyed by a call to 9112 ** [sqlite3_backup_finish()]. 9113 ** 9114 ** See Also: [Using the SQLite Online Backup API] 9115 */ 9116 typedef struct sqlite3_backup sqlite3_backup; 9117 9118 /* 9119 ** CAPI3REF: Online Backup API. 9120 ** 9121 ** The backup API copies the content of one database into another. 9122 ** It is useful either for creating backups of databases or 9123 ** for copying in-memory databases to or from persistent files. 9124 ** 9125 ** See Also: [Using the SQLite Online Backup API] 9126 ** 9127 ** ^SQLite holds a write transaction open on the destination database file 9128 ** for the duration of the backup operation. 9129 ** ^The source database is read-locked only while it is being read; 9130 ** it is not locked continuously for the entire backup operation. 9131 ** ^Thus, the backup may be performed on a live source database without 9132 ** preventing other database connections from 9133 ** reading or writing to the source database while the backup is underway. 9134 ** 9135 ** ^(To perform a backup operation: 9136 ** <ol> 9137 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 9138 ** backup, 9139 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 9140 ** the data between the two databases, and finally 9141 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 9142 ** associated with the backup operation. 9143 ** </ol>)^ 9144 ** There should be exactly one call to sqlite3_backup_finish() for each 9145 ** successful call to sqlite3_backup_init(). 9146 ** 9147 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 9148 ** 9149 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 9150 ** [database connection] associated with the destination database 9151 ** and the database name, respectively. 9152 ** ^The database name is "main" for the main database, "temp" for the 9153 ** temporary database, or the name specified after the AS keyword in 9154 ** an [ATTACH] statement for an attached database. 9155 ** ^The S and M arguments passed to 9156 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 9157 ** and database name of the source database, respectively. 9158 ** ^The source and destination [database connections] (parameters S and D) 9159 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 9160 ** an error. 9161 ** 9162 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if 9163 ** there is already a read or read-write transaction open on the 9164 ** destination database. 9165 ** 9166 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 9167 ** returned and an error code and error message are stored in the 9168 ** destination [database connection] D. 9169 ** ^The error code and message for the failed call to sqlite3_backup_init() 9170 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 9171 ** [sqlite3_errmsg16()] functions. 9172 ** ^A successful call to sqlite3_backup_init() returns a pointer to an 9173 ** [sqlite3_backup] object. 9174 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 9175 ** sqlite3_backup_finish() functions to perform the specified backup 9176 ** operation. 9177 ** 9178 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 9179 ** 9180 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 9181 ** the source and destination databases specified by [sqlite3_backup] object B. 9182 ** ^If N is negative, all remaining source pages are copied. 9183 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 9184 ** are still more pages to be copied, then the function returns [SQLITE_OK]. 9185 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 9186 ** from source to destination, then it returns [SQLITE_DONE]. 9187 ** ^If an error occurs while running sqlite3_backup_step(B,N), 9188 ** then an [error code] is returned. ^As well as [SQLITE_OK] and 9189 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 9190 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 9191 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 9192 ** 9193 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 9194 ** <ol> 9195 ** <li> the destination database was opened read-only, or 9196 ** <li> the destination database is using write-ahead-log journaling 9197 ** and the destination and source page sizes differ, or 9198 ** <li> the destination database is an in-memory database and the 9199 ** destination and source page sizes differ. 9200 ** </ol>)^ 9201 ** 9202 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 9203 ** the [sqlite3_busy_handler | busy-handler function] 9204 ** is invoked (if one is specified). ^If the 9205 ** busy-handler returns non-zero before the lock is available, then 9206 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 9207 ** sqlite3_backup_step() can be retried later. ^If the source 9208 ** [database connection] 9209 ** is being used to write to the source database when sqlite3_backup_step() 9210 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 9211 ** case the call to sqlite3_backup_step() can be retried later on. ^(If 9212 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 9213 ** [SQLITE_READONLY] is returned, then 9214 ** there is no point in retrying the call to sqlite3_backup_step(). These 9215 ** errors are considered fatal.)^ The application must accept 9216 ** that the backup operation has failed and pass the backup operation handle 9217 ** to the sqlite3_backup_finish() to release associated resources. 9218 ** 9219 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 9220 ** on the destination file. ^The exclusive lock is not released until either 9221 ** sqlite3_backup_finish() is called or the backup operation is complete 9222 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 9223 ** sqlite3_backup_step() obtains a [shared lock] on the source database that 9224 ** lasts for the duration of the sqlite3_backup_step() call. 9225 ** ^Because the source database is not locked between calls to 9226 ** sqlite3_backup_step(), the source database may be modified mid-way 9227 ** through the backup process. ^If the source database is modified by an 9228 ** external process or via a database connection other than the one being 9229 ** used by the backup operation, then the backup will be automatically 9230 ** restarted by the next call to sqlite3_backup_step(). ^If the source 9231 ** database is modified by the using the same database connection as is used 9232 ** by the backup operation, then the backup database is automatically 9233 ** updated at the same time. 9234 ** 9235 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 9236 ** 9237 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 9238 ** application wishes to abandon the backup operation, the application 9239 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 9240 ** ^The sqlite3_backup_finish() interfaces releases all 9241 ** resources associated with the [sqlite3_backup] object. 9242 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 9243 ** active write-transaction on the destination database is rolled back. 9244 ** The [sqlite3_backup] object is invalid 9245 ** and may not be used following a call to sqlite3_backup_finish(). 9246 ** 9247 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 9248 ** sqlite3_backup_step() errors occurred, regardless or whether or not 9249 ** sqlite3_backup_step() completed. 9250 ** ^If an out-of-memory condition or IO error occurred during any prior 9251 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 9252 ** sqlite3_backup_finish() returns the corresponding [error code]. 9253 ** 9254 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 9255 ** is not a permanent error and does not affect the return value of 9256 ** sqlite3_backup_finish(). 9257 ** 9258 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 9259 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 9260 ** 9261 ** ^The sqlite3_backup_remaining() routine returns the number of pages still 9262 ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 9263 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages 9264 ** in the source database at the conclusion of the most recent 9265 ** sqlite3_backup_step(). 9266 ** ^(The values returned by these functions are only updated by 9267 ** sqlite3_backup_step(). If the source database is modified in a way that 9268 ** changes the size of the source database or the number of pages remaining, 9269 ** those changes are not reflected in the output of sqlite3_backup_pagecount() 9270 ** and sqlite3_backup_remaining() until after the next 9271 ** sqlite3_backup_step().)^ 9272 ** 9273 ** <b>Concurrent Usage of Database Handles</b> 9274 ** 9275 ** ^The source [database connection] may be used by the application for other 9276 ** purposes while a backup operation is underway or being initialized. 9277 ** ^If SQLite is compiled and configured to support threadsafe database 9278 ** connections, then the source database connection may be used concurrently 9279 ** from within other threads. 9280 ** 9281 ** However, the application must guarantee that the destination 9282 ** [database connection] is not passed to any other API (by any thread) after 9283 ** sqlite3_backup_init() is called and before the corresponding call to 9284 ** sqlite3_backup_finish(). SQLite does not currently check to see 9285 ** if the application incorrectly accesses the destination [database connection] 9286 ** and so no error code is reported, but the operations may malfunction 9287 ** nevertheless. Use of the destination database connection while a 9288 ** backup is in progress might also cause a mutex deadlock. 9289 ** 9290 ** If running in [shared cache mode], the application must 9291 ** guarantee that the shared cache used by the destination database 9292 ** is not accessed while the backup is running. In practice this means 9293 ** that the application must guarantee that the disk file being 9294 ** backed up to is not accessed by any connection within the process, 9295 ** not just the specific connection that was passed to sqlite3_backup_init(). 9296 ** 9297 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 9298 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 9299 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 9300 ** APIs are not strictly speaking threadsafe. If they are invoked at the 9301 ** same time as another thread is invoking sqlite3_backup_step() it is 9302 ** possible that they return invalid values. 9303 */ 9304 SQLITE_API sqlite3_backup *sqlite3_backup_init( 9305 sqlite3 *pDest, /* Destination database handle */ 9306 const char *zDestName, /* Destination database name */ 9307 sqlite3 *pSource, /* Source database handle */ 9308 const char *zSourceName /* Source database name */ 9309 ); 9310 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 9311 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 9312 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 9313 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 9314 9315 /* 9316 ** CAPI3REF: Unlock Notification 9317 ** METHOD: sqlite3 9318 ** 9319 ** ^When running in shared-cache mode, a database operation may fail with 9320 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 9321 ** individual tables within the shared-cache cannot be obtained. See 9322 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 9323 ** ^This API may be used to register a callback that SQLite will invoke 9324 ** when the connection currently holding the required lock relinquishes it. 9325 ** ^This API is only available if the library was compiled with the 9326 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 9327 ** 9328 ** See Also: [Using the SQLite Unlock Notification Feature]. 9329 ** 9330 ** ^Shared-cache locks are released when a database connection concludes 9331 ** its current transaction, either by committing it or rolling it back. 9332 ** 9333 ** ^When a connection (known as the blocked connection) fails to obtain a 9334 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 9335 ** identity of the database connection (the blocking connection) that 9336 ** has locked the required resource is stored internally. ^After an 9337 ** application receives an SQLITE_LOCKED error, it may call the 9338 ** sqlite3_unlock_notify() method with the blocked connection handle as 9339 ** the first argument to register for a callback that will be invoked 9340 ** when the blocking connections current transaction is concluded. ^The 9341 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 9342 ** call that concludes the blocking connection's transaction. 9343 ** 9344 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 9345 ** there is a chance that the blocking connection will have already 9346 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 9347 ** If this happens, then the specified callback is invoked immediately, 9348 ** from within the call to sqlite3_unlock_notify().)^ 9349 ** 9350 ** ^If the blocked connection is attempting to obtain a write-lock on a 9351 ** shared-cache table, and more than one other connection currently holds 9352 ** a read-lock on the same table, then SQLite arbitrarily selects one of 9353 ** the other connections to use as the blocking connection. 9354 ** 9355 ** ^(There may be at most one unlock-notify callback registered by a 9356 ** blocked connection. If sqlite3_unlock_notify() is called when the 9357 ** blocked connection already has a registered unlock-notify callback, 9358 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 9359 ** called with a NULL pointer as its second argument, then any existing 9360 ** unlock-notify callback is canceled. ^The blocked connections 9361 ** unlock-notify callback may also be canceled by closing the blocked 9362 ** connection using [sqlite3_close()]. 9363 ** 9364 ** The unlock-notify callback is not reentrant. If an application invokes 9365 ** any sqlite3_xxx API functions from within an unlock-notify callback, a 9366 ** crash or deadlock may be the result. 9367 ** 9368 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 9369 ** returns SQLITE_OK. 9370 ** 9371 ** <b>Callback Invocation Details</b> 9372 ** 9373 ** When an unlock-notify callback is registered, the application provides a 9374 ** single void* pointer that is passed to the callback when it is invoked. 9375 ** However, the signature of the callback function allows SQLite to pass 9376 ** it an array of void* context pointers. The first argument passed to 9377 ** an unlock-notify callback is a pointer to an array of void* pointers, 9378 ** and the second is the number of entries in the array. 9379 ** 9380 ** When a blocking connection's transaction is concluded, there may be 9381 ** more than one blocked connection that has registered for an unlock-notify 9382 ** callback. ^If two or more such blocked connections have specified the 9383 ** same callback function, then instead of invoking the callback function 9384 ** multiple times, it is invoked once with the set of void* context pointers 9385 ** specified by the blocked connections bundled together into an array. 9386 ** This gives the application an opportunity to prioritize any actions 9387 ** related to the set of unblocked database connections. 9388 ** 9389 ** <b>Deadlock Detection</b> 9390 ** 9391 ** Assuming that after registering for an unlock-notify callback a 9392 ** database waits for the callback to be issued before taking any further 9393 ** action (a reasonable assumption), then using this API may cause the 9394 ** application to deadlock. For example, if connection X is waiting for 9395 ** connection Y's transaction to be concluded, and similarly connection 9396 ** Y is waiting on connection X's transaction, then neither connection 9397 ** will proceed and the system may remain deadlocked indefinitely. 9398 ** 9399 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 9400 ** detection. ^If a given call to sqlite3_unlock_notify() would put the 9401 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 9402 ** unlock-notify callback is registered. The system is said to be in 9403 ** a deadlocked state if connection A has registered for an unlock-notify 9404 ** callback on the conclusion of connection B's transaction, and connection 9405 ** B has itself registered for an unlock-notify callback when connection 9406 ** A's transaction is concluded. ^Indirect deadlock is also detected, so 9407 ** the system is also considered to be deadlocked if connection B has 9408 ** registered for an unlock-notify callback on the conclusion of connection 9409 ** C's transaction, where connection C is waiting on connection A. ^Any 9410 ** number of levels of indirection are allowed. 9411 ** 9412 ** <b>The "DROP TABLE" Exception</b> 9413 ** 9414 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 9415 ** always appropriate to call sqlite3_unlock_notify(). There is however, 9416 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 9417 ** SQLite checks if there are any currently executing SELECT statements 9418 ** that belong to the same connection. If there are, SQLITE_LOCKED is 9419 ** returned. In this case there is no "blocking connection", so invoking 9420 ** sqlite3_unlock_notify() results in the unlock-notify callback being 9421 ** invoked immediately. If the application then re-attempts the "DROP TABLE" 9422 ** or "DROP INDEX" query, an infinite loop might be the result. 9423 ** 9424 ** One way around this problem is to check the extended error code returned 9425 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 9426 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 9427 ** the special "DROP TABLE/INDEX" case, the extended error code is just 9428 ** SQLITE_LOCKED.)^ 9429 */ 9430 SQLITE_API int sqlite3_unlock_notify( 9431 sqlite3 *pBlocked, /* Waiting connection */ 9432 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 9433 void *pNotifyArg /* Argument to pass to xNotify */ 9434 ); 9435 9436 9437 /* 9438 ** CAPI3REF: String Comparison 9439 ** 9440 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 9441 ** and extensions to compare the contents of two buffers containing UTF-8 9442 ** strings in a case-independent fashion, using the same definition of "case 9443 ** independence" that SQLite uses internally when comparing identifiers. 9444 */ 9445 SQLITE_API int sqlite3_stricmp(const char *, const char *); 9446 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 9447 9448 /* 9449 ** CAPI3REF: String Globbing 9450 * 9451 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 9452 ** string X matches the [GLOB] pattern P. 9453 ** ^The definition of [GLOB] pattern matching used in 9454 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 9455 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 9456 ** is case sensitive. 9457 ** 9458 ** Note that this routine returns zero on a match and non-zero if the strings 9459 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 9460 ** 9461 ** See also: [sqlite3_strlike()]. 9462 */ 9463 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 9464 9465 /* 9466 ** CAPI3REF: String LIKE Matching 9467 * 9468 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 9469 ** string X matches the [LIKE] pattern P with escape character E. 9470 ** ^The definition of [LIKE] pattern matching used in 9471 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 9472 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 9473 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 9474 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 9475 ** insensitive - equivalent upper and lower case ASCII characters match 9476 ** one another. 9477 ** 9478 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 9479 ** only ASCII characters are case folded. 9480 ** 9481 ** Note that this routine returns zero on a match and non-zero if the strings 9482 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 9483 ** 9484 ** See also: [sqlite3_strglob()]. 9485 */ 9486 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 9487 9488 /* 9489 ** CAPI3REF: Error Logging Interface 9490 ** 9491 ** ^The [sqlite3_log()] interface writes a message into the [error log] 9492 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 9493 ** ^If logging is enabled, the zFormat string and subsequent arguments are 9494 ** used with [sqlite3_snprintf()] to generate the final output string. 9495 ** 9496 ** The sqlite3_log() interface is intended for use by extensions such as 9497 ** virtual tables, collating functions, and SQL functions. While there is 9498 ** nothing to prevent an application from calling sqlite3_log(), doing so 9499 ** is considered bad form. 9500 ** 9501 ** The zFormat string must not be NULL. 9502 ** 9503 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 9504 ** will not use dynamically allocated memory. The log message is stored in 9505 ** a fixed-length buffer on the stack. If the log message is longer than 9506 ** a few hundred characters, it will be truncated to the length of the 9507 ** buffer. 9508 */ 9509 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 9510 9511 /* 9512 ** CAPI3REF: Write-Ahead Log Commit Hook 9513 ** METHOD: sqlite3 9514 ** 9515 ** ^The [sqlite3_wal_hook()] function is used to register a callback that 9516 ** is invoked each time data is committed to a database in wal mode. 9517 ** 9518 ** ^(The callback is invoked by SQLite after the commit has taken place and 9519 ** the associated write-lock on the database released)^, so the implementation 9520 ** may read, write or [checkpoint] the database as required. 9521 ** 9522 ** ^The first parameter passed to the callback function when it is invoked 9523 ** is a copy of the third parameter passed to sqlite3_wal_hook() when 9524 ** registering the callback. ^The second is a copy of the database handle. 9525 ** ^The third parameter is the name of the database that was written to - 9526 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 9527 ** is the number of pages currently in the write-ahead log file, 9528 ** including those that were just committed. 9529 ** 9530 ** The callback function should normally return [SQLITE_OK]. ^If an error 9531 ** code is returned, that error will propagate back up through the 9532 ** SQLite code base to cause the statement that provoked the callback 9533 ** to report an error, though the commit will have still occurred. If the 9534 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 9535 ** that does not correspond to any valid SQLite error code, the results 9536 ** are undefined. 9537 ** 9538 ** A single database handle may have at most a single write-ahead log callback 9539 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 9540 ** previously registered write-ahead log callback. ^The return value is 9541 ** a copy of the third parameter from the previous call, if any, or 0. 9542 ** ^Note that the [sqlite3_wal_autocheckpoint()] interface and the 9543 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 9544 ** overwrite any prior [sqlite3_wal_hook()] settings. 9545 */ 9546 SQLITE_API void *sqlite3_wal_hook( 9547 sqlite3*, 9548 int(*)(void *,sqlite3*,const char*,int), 9549 void* 9550 ); 9551 9552 /* 9553 ** CAPI3REF: Configure an auto-checkpoint 9554 ** METHOD: sqlite3 9555 ** 9556 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 9557 ** [sqlite3_wal_hook()] that causes any database on [database connection] D 9558 ** to automatically [checkpoint] 9559 ** after committing a transaction if there are N or 9560 ** more frames in the [write-ahead log] file. ^Passing zero or 9561 ** a negative value as the nFrame parameter disables automatic 9562 ** checkpoints entirely. 9563 ** 9564 ** ^The callback registered by this function replaces any existing callback 9565 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 9566 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 9567 ** configured by this function. 9568 ** 9569 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 9570 ** from SQL. 9571 ** 9572 ** ^Checkpoints initiated by this mechanism are 9573 ** [sqlite3_wal_checkpoint_v2|PASSIVE]. 9574 ** 9575 ** ^Every new [database connection] defaults to having the auto-checkpoint 9576 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 9577 ** pages. The use of this interface 9578 ** is only necessary if the default setting is found to be suboptimal 9579 ** for a particular application. 9580 */ 9581 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 9582 9583 /* 9584 ** CAPI3REF: Checkpoint a database 9585 ** METHOD: sqlite3 9586 ** 9587 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 9588 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 9589 ** 9590 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 9591 ** [write-ahead log] for database X on [database connection] D to be 9592 ** transferred into the database file and for the write-ahead log to 9593 ** be reset. See the [checkpointing] documentation for addition 9594 ** information. 9595 ** 9596 ** This interface used to be the only way to cause a checkpoint to 9597 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 9598 ** interface was added. This interface is retained for backwards 9599 ** compatibility and as a convenience for applications that need to manually 9600 ** start a callback but which do not need the full power (and corresponding 9601 ** complication) of [sqlite3_wal_checkpoint_v2()]. 9602 */ 9603 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 9604 9605 /* 9606 ** CAPI3REF: Checkpoint a database 9607 ** METHOD: sqlite3 9608 ** 9609 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 9610 ** operation on database X of [database connection] D in mode M. Status 9611 ** information is written back into integers pointed to by L and C.)^ 9612 ** ^(The M parameter must be a valid [checkpoint mode]:)^ 9613 ** 9614 ** <dl> 9615 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 9616 ** ^Checkpoint as many frames as possible without waiting for any database 9617 ** readers or writers to finish, then sync the database file if all frames 9618 ** in the log were checkpointed. ^The [busy-handler callback] 9619 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 9620 ** ^On the other hand, passive mode might leave the checkpoint unfinished 9621 ** if there are concurrent readers or writers. 9622 ** 9623 ** <dt>SQLITE_CHECKPOINT_FULL<dd> 9624 ** ^This mode blocks (it invokes the 9625 ** [sqlite3_busy_handler|busy-handler callback]) until there is no 9626 ** database writer and all readers are reading from the most recent database 9627 ** snapshot. ^It then checkpoints all frames in the log file and syncs the 9628 ** database file. ^This mode blocks new database writers while it is pending, 9629 ** but new database readers are allowed to continue unimpeded. 9630 ** 9631 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 9632 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 9633 ** that after checkpointing the log file it blocks (calls the 9634 ** [busy-handler callback]) 9635 ** until all readers are reading from the database file only. ^This ensures 9636 ** that the next writer will restart the log file from the beginning. 9637 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 9638 ** database writer attempts while it is pending, but does not impede readers. 9639 ** 9640 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 9641 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 9642 ** addition that it also truncates the log file to zero bytes just prior 9643 ** to a successful return. 9644 ** </dl> 9645 ** 9646 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 9647 ** the log file or to -1 if the checkpoint could not run because 9648 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 9649 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 9650 ** log file (including any that were already checkpointed before the function 9651 ** was called) or to -1 if the checkpoint could not run due to an error or 9652 ** because the database is not in WAL mode. ^Note that upon successful 9653 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 9654 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 9655 ** 9656 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 9657 ** any other process is running a checkpoint operation at the same time, the 9658 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 9659 ** busy-handler configured, it will not be invoked in this case. 9660 ** 9661 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 9662 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be 9663 ** obtained immediately, and a busy-handler is configured, it is invoked and 9664 ** the writer lock retried until either the busy-handler returns 0 or the lock 9665 ** is successfully obtained. ^The busy-handler is also invoked while waiting for 9666 ** database readers as described above. ^If the busy-handler returns 0 before 9667 ** the writer lock is obtained or while waiting for database readers, the 9668 ** checkpoint operation proceeds from that point in the same way as 9669 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 9670 ** without blocking any further. ^SQLITE_BUSY is returned in this case. 9671 ** 9672 ** ^If parameter zDb is NULL or points to a zero length string, then the 9673 ** specified operation is attempted on all WAL databases [attached] to 9674 ** [database connection] db. In this case the 9675 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 9676 ** an SQLITE_BUSY error is encountered when processing one or more of the 9677 ** attached WAL databases, the operation is still attempted on any remaining 9678 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other 9679 ** error occurs while processing an attached database, processing is abandoned 9680 ** and the error code is returned to the caller immediately. ^If no error 9681 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 9682 ** databases, SQLITE_OK is returned. 9683 ** 9684 ** ^If database zDb is the name of an attached database that is not in WAL 9685 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 9686 ** zDb is not NULL (or a zero length string) and is not the name of any 9687 ** attached database, SQLITE_ERROR is returned to the caller. 9688 ** 9689 ** ^Unless it returns SQLITE_MISUSE, 9690 ** the sqlite3_wal_checkpoint_v2() interface 9691 ** sets the error information that is queried by 9692 ** [sqlite3_errcode()] and [sqlite3_errmsg()]. 9693 ** 9694 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 9695 ** from SQL. 9696 */ 9697 SQLITE_API int sqlite3_wal_checkpoint_v2( 9698 sqlite3 *db, /* Database handle */ 9699 const char *zDb, /* Name of attached database (or NULL) */ 9700 int eMode, /* SQLITE_CHECKPOINT_* value */ 9701 int *pnLog, /* OUT: Size of WAL log in frames */ 9702 int *pnCkpt /* OUT: Total number of frames checkpointed */ 9703 ); 9704 9705 /* 9706 ** CAPI3REF: Checkpoint Mode Values 9707 ** KEYWORDS: {checkpoint mode} 9708 ** 9709 ** These constants define all valid values for the "checkpoint mode" passed 9710 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 9711 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 9712 ** meaning of each of these checkpoint modes. 9713 */ 9714 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 9715 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 9716 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for readers */ 9717 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 9718 9719 /* 9720 ** CAPI3REF: Virtual Table Interface Configuration 9721 ** 9722 ** This function may be called by either the [xConnect] or [xCreate] method 9723 ** of a [virtual table] implementation to configure 9724 ** various facets of the virtual table interface. 9725 ** 9726 ** If this interface is invoked outside the context of an xConnect or 9727 ** xCreate virtual table method then the behavior is undefined. 9728 ** 9729 ** In the call sqlite3_vtab_config(D,C,...) the D parameter is the 9730 ** [database connection] in which the virtual table is being created and 9731 ** which is passed in as the first argument to the [xConnect] or [xCreate] 9732 ** method that is invoking sqlite3_vtab_config(). The C parameter is one 9733 ** of the [virtual table configuration options]. The presence and meaning 9734 ** of parameters after C depend on which [virtual table configuration option] 9735 ** is used. 9736 */ 9737 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 9738 9739 /* 9740 ** CAPI3REF: Virtual Table Configuration Options 9741 ** KEYWORDS: {virtual table configuration options} 9742 ** KEYWORDS: {virtual table configuration option} 9743 ** 9744 ** These macros define the various options to the 9745 ** [sqlite3_vtab_config()] interface that [virtual table] implementations 9746 ** can use to customize and optimize their behavior. 9747 ** 9748 ** <dl> 9749 ** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] 9750 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt> 9751 ** <dd>Calls of the form 9752 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 9753 ** where X is an integer. If X is zero, then the [virtual table] whose 9754 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 9755 ** support constraints. In this configuration (which is the default) if 9756 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 9757 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 9758 ** specified as part of the users SQL statement, regardless of the actual 9759 ** ON CONFLICT mode specified. 9760 ** 9761 ** If X is non-zero, then the virtual table implementation guarantees 9762 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 9763 ** any modifications to internal or persistent data structures have been made. 9764 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 9765 ** is able to roll back a statement or database transaction, and abandon 9766 ** or continue processing the current SQL statement as appropriate. 9767 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 9768 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 9769 ** had been ABORT. 9770 ** 9771 ** Virtual table implementations that are required to handle OR REPLACE 9772 ** must do so within the [xUpdate] method. If a call to the 9773 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 9774 ** CONFLICT policy is REPLACE, the virtual table implementation should 9775 ** silently replace the appropriate rows within the xUpdate callback and 9776 ** return SQLITE_OK. Or, if this is not possible, it may return 9777 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 9778 ** constraint handling. 9779 ** </dd> 9780 ** 9781 ** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt> 9782 ** <dd>Calls of the form 9783 ** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the 9784 ** the [xConnect] or [xCreate] methods of a [virtual table] implementation 9785 ** prohibits that virtual table from being used from within triggers and 9786 ** views. 9787 ** </dd> 9788 ** 9789 ** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt> 9790 ** <dd>Calls of the form 9791 ** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the 9792 ** the [xConnect] or [xCreate] methods of a [virtual table] implementation 9793 ** identify that virtual table as being safe to use from within triggers 9794 ** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the 9795 ** virtual table can do no serious harm even if it is controlled by a 9796 ** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS 9797 ** flag unless absolutely necessary. 9798 ** </dd> 9799 ** 9800 ** [[SQLITE_VTAB_USES_ALL_SCHEMAS]]<dt>SQLITE_VTAB_USES_ALL_SCHEMAS</dt> 9801 ** <dd>Calls of the form 9802 ** [sqlite3_vtab_config](db,SQLITE_VTAB_USES_ALL_SCHEMA) from within the 9803 ** the [xConnect] or [xCreate] methods of a [virtual table] implementation 9804 ** instruct the query planner to begin at least a read transaction on 9805 ** all schemas ("main", "temp", and any ATTACH-ed databases) whenever the 9806 ** virtual table is used. 9807 ** </dd> 9808 ** </dl> 9809 */ 9810 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 9811 #define SQLITE_VTAB_INNOCUOUS 2 9812 #define SQLITE_VTAB_DIRECTONLY 3 9813 #define SQLITE_VTAB_USES_ALL_SCHEMAS 4 9814 9815 /* 9816 ** CAPI3REF: Determine The Virtual Table Conflict Policy 9817 ** 9818 ** This function may only be called from within a call to the [xUpdate] method 9819 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 9820 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 9821 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 9822 ** of the SQL statement that triggered the call to the [xUpdate] method of the 9823 ** [virtual table]. 9824 */ 9825 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 9826 9827 /* 9828 ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 9829 ** 9830 ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 9831 ** method of a [virtual table], then it might return true if the 9832 ** column is being fetched as part of an UPDATE operation during which the 9833 ** column value will not change. The virtual table implementation can use 9834 ** this hint as permission to substitute a return value that is less 9835 ** expensive to compute and that the corresponding 9836 ** [xUpdate] method understands as a "no-change" value. 9837 ** 9838 ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 9839 ** the column is not changed by the UPDATE statement, then the xColumn 9840 ** method can optionally return without setting a result, without calling 9841 ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 9842 ** In that case, [sqlite3_value_nochange(X)] will return true for the 9843 ** same column in the [xUpdate] method. 9844 ** 9845 ** The sqlite3_vtab_nochange() routine is an optimization. Virtual table 9846 ** implementations should continue to give a correct answer even if the 9847 ** sqlite3_vtab_nochange() interface were to always return false. In the 9848 ** current implementation, the sqlite3_vtab_nochange() interface does always 9849 ** returns false for the enhanced [UPDATE FROM] statement. 9850 */ 9851 SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*); 9852 9853 /* 9854 ** CAPI3REF: Determine The Collation For a Virtual Table Constraint 9855 ** METHOD: sqlite3_index_info 9856 ** 9857 ** This function may only be called from within a call to the [xBestIndex] 9858 ** method of a [virtual table]. This function returns a pointer to a string 9859 ** that is the name of the appropriate collation sequence to use for text 9860 ** comparisons on the constraint identified by its arguments. 9861 ** 9862 ** The first argument must be the pointer to the [sqlite3_index_info] object 9863 ** that is the first parameter to the xBestIndex() method. The second argument 9864 ** must be an index into the aConstraint[] array belonging to the 9865 ** sqlite3_index_info structure passed to xBestIndex. 9866 ** 9867 ** Important: 9868 ** The first parameter must be the same pointer that is passed into the 9869 ** xBestMethod() method. The first parameter may not be a pointer to a 9870 ** different [sqlite3_index_info] object, even an exact copy. 9871 ** 9872 ** The return value is computed as follows: 9873 ** 9874 ** <ol> 9875 ** <li><p> If the constraint comes from a WHERE clause expression that contains 9876 ** a [COLLATE operator], then the name of the collation specified by 9877 ** that COLLATE operator is returned. 9878 ** <li><p> If there is no COLLATE operator, but the column that is the subject 9879 ** of the constraint specifies an alternative collating sequence via 9880 ** a [COLLATE clause] on the column definition within the CREATE TABLE 9881 ** statement that was passed into [sqlite3_declare_vtab()], then the 9882 ** name of that alternative collating sequence is returned. 9883 ** <li><p> Otherwise, "BINARY" is returned. 9884 ** </ol> 9885 */ 9886 SQLITE_API const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 9887 9888 /* 9889 ** CAPI3REF: Determine if a virtual table query is DISTINCT 9890 ** METHOD: sqlite3_index_info 9891 ** 9892 ** This API may only be used from within an [xBestIndex|xBestIndex method] 9893 ** of a [virtual table] implementation. The result of calling this 9894 ** interface from outside of xBestIndex() is undefined and probably harmful. 9895 ** 9896 ** ^The sqlite3_vtab_distinct() interface returns an integer between 0 and 9897 ** 3. The integer returned by sqlite3_vtab_distinct() 9898 ** gives the virtual table additional information about how the query 9899 ** planner wants the output to be ordered. As long as the virtual table 9900 ** can meet the ordering requirements of the query planner, it may set 9901 ** the "orderByConsumed" flag. 9902 ** 9903 ** <ol><li value="0"><p> 9904 ** ^If the sqlite3_vtab_distinct() interface returns 0, that means 9905 ** that the query planner needs the virtual table to return all rows in the 9906 ** sort order defined by the "nOrderBy" and "aOrderBy" fields of the 9907 ** [sqlite3_index_info] object. This is the default expectation. If the 9908 ** virtual table outputs all rows in sorted order, then it is always safe for 9909 ** the xBestIndex method to set the "orderByConsumed" flag, regardless of 9910 ** the return value from sqlite3_vtab_distinct(). 9911 ** <li value="1"><p> 9912 ** ^(If the sqlite3_vtab_distinct() interface returns 1, that means 9913 ** that the query planner does not need the rows to be returned in sorted order 9914 ** as long as all rows with the same values in all columns identified by the 9915 ** "aOrderBy" field are adjacent.)^ This mode is used when the query planner 9916 ** is doing a GROUP BY. 9917 ** <li value="2"><p> 9918 ** ^(If the sqlite3_vtab_distinct() interface returns 2, that means 9919 ** that the query planner does not need the rows returned in any particular 9920 ** order, as long as rows with the same values in all "aOrderBy" columns 9921 ** are adjacent.)^ ^(Furthermore, only a single row for each particular 9922 ** combination of values in the columns identified by the "aOrderBy" field 9923 ** needs to be returned.)^ ^It is always ok for two or more rows with the same 9924 ** values in all "aOrderBy" columns to be returned, as long as all such rows 9925 ** are adjacent. ^The virtual table may, if it chooses, omit extra rows 9926 ** that have the same value for all columns identified by "aOrderBy". 9927 ** ^However omitting the extra rows is optional. 9928 ** This mode is used for a DISTINCT query. 9929 ** <li value="3"><p> 9930 ** ^(If the sqlite3_vtab_distinct() interface returns 3, that means 9931 ** that the query planner needs only distinct rows but it does need the 9932 ** rows to be sorted.)^ ^The virtual table implementation is free to omit 9933 ** rows that are identical in all aOrderBy columns, if it wants to, but 9934 ** it is not required to omit any rows. This mode is used for queries 9935 ** that have both DISTINCT and ORDER BY clauses. 9936 ** </ol> 9937 ** 9938 ** ^For the purposes of comparing virtual table output values to see if the 9939 ** values are same value for sorting purposes, two NULL values are considered 9940 ** to be the same. In other words, the comparison operator is "IS" 9941 ** (or "IS NOT DISTINCT FROM") and not "==". 9942 ** 9943 ** If a virtual table implementation is unable to meet the requirements 9944 ** specified above, then it must not set the "orderByConsumed" flag in the 9945 ** [sqlite3_index_info] object or an incorrect answer may result. 9946 ** 9947 ** ^A virtual table implementation is always free to return rows in any order 9948 ** it wants, as long as the "orderByConsumed" flag is not set. ^When the 9949 ** the "orderByConsumed" flag is unset, the query planner will add extra 9950 ** [bytecode] to ensure that the final results returned by the SQL query are 9951 ** ordered correctly. The use of the "orderByConsumed" flag and the 9952 ** sqlite3_vtab_distinct() interface is merely an optimization. ^Careful 9953 ** use of the sqlite3_vtab_distinct() interface and the "orderByConsumed" 9954 ** flag might help queries against a virtual table to run faster. Being 9955 ** overly aggressive and setting the "orderByConsumed" flag when it is not 9956 ** valid to do so, on the other hand, might cause SQLite to return incorrect 9957 ** results. 9958 */ 9959 SQLITE_API int sqlite3_vtab_distinct(sqlite3_index_info*); 9960 9961 /* 9962 ** CAPI3REF: Identify and handle IN constraints in xBestIndex 9963 ** 9964 ** This interface may only be used from within an 9965 ** [xBestIndex|xBestIndex() method] of a [virtual table] implementation. 9966 ** The result of invoking this interface from any other context is 9967 ** undefined and probably harmful. 9968 ** 9969 ** ^(A constraint on a virtual table of the form 9970 ** "[IN operator|column IN (...)]" is 9971 ** communicated to the xBestIndex method as a 9972 ** [SQLITE_INDEX_CONSTRAINT_EQ] constraint.)^ If xBestIndex wants to use 9973 ** this constraint, it must set the corresponding 9974 ** aConstraintUsage[].argvIndex to a positive integer. ^(Then, under 9975 ** the usual mode of handling IN operators, SQLite generates [bytecode] 9976 ** that invokes the [xFilter|xFilter() method] once for each value 9977 ** on the right-hand side of the IN operator.)^ Thus the virtual table 9978 ** only sees a single value from the right-hand side of the IN operator 9979 ** at a time. 9980 ** 9981 ** In some cases, however, it would be advantageous for the virtual 9982 ** table to see all values on the right-hand of the IN operator all at 9983 ** once. The sqlite3_vtab_in() interfaces facilitates this in two ways: 9984 ** 9985 ** <ol> 9986 ** <li><p> 9987 ** ^A call to sqlite3_vtab_in(P,N,-1) will return true (non-zero) 9988 ** if and only if the [sqlite3_index_info|P->aConstraint][N] constraint 9989 ** is an [IN operator] that can be processed all at once. ^In other words, 9990 ** sqlite3_vtab_in() with -1 in the third argument is a mechanism 9991 ** by which the virtual table can ask SQLite if all-at-once processing 9992 ** of the IN operator is even possible. 9993 ** 9994 ** <li><p> 9995 ** ^A call to sqlite3_vtab_in(P,N,F) with F==1 or F==0 indicates 9996 ** to SQLite that the virtual table does or does not want to process 9997 ** the IN operator all-at-once, respectively. ^Thus when the third 9998 ** parameter (F) is non-negative, this interface is the mechanism by 9999 ** which the virtual table tells SQLite how it wants to process the 10000 ** IN operator. 10001 ** </ol> 10002 ** 10003 ** ^The sqlite3_vtab_in(P,N,F) interface can be invoked multiple times 10004 ** within the same xBestIndex method call. ^For any given P,N pair, 10005 ** the return value from sqlite3_vtab_in(P,N,F) will always be the same 10006 ** within the same xBestIndex call. ^If the interface returns true 10007 ** (non-zero), that means that the constraint is an IN operator 10008 ** that can be processed all-at-once. ^If the constraint is not an IN 10009 ** operator or cannot be processed all-at-once, then the interface returns 10010 ** false. 10011 ** 10012 ** ^(All-at-once processing of the IN operator is selected if both of the 10013 ** following conditions are met: 10014 ** 10015 ** <ol> 10016 ** <li><p> The P->aConstraintUsage[N].argvIndex value is set to a positive 10017 ** integer. This is how the virtual table tells SQLite that it wants to 10018 ** use the N-th constraint. 10019 ** 10020 ** <li><p> The last call to sqlite3_vtab_in(P,N,F) for which F was 10021 ** non-negative had F>=1. 10022 ** </ol>)^ 10023 ** 10024 ** ^If either or both of the conditions above are false, then SQLite uses 10025 ** the traditional one-at-a-time processing strategy for the IN constraint. 10026 ** ^If both conditions are true, then the argvIndex-th parameter to the 10027 ** xFilter method will be an [sqlite3_value] that appears to be NULL, 10028 ** but which can be passed to [sqlite3_vtab_in_first()] and 10029 ** [sqlite3_vtab_in_next()] to find all values on the right-hand side 10030 ** of the IN constraint. 10031 */ 10032 SQLITE_API int sqlite3_vtab_in(sqlite3_index_info*, int iCons, int bHandle); 10033 10034 /* 10035 ** CAPI3REF: Find all elements on the right-hand side of an IN constraint. 10036 ** 10037 ** These interfaces are only useful from within the 10038 ** [xFilter|xFilter() method] of a [virtual table] implementation. 10039 ** The result of invoking these interfaces from any other context 10040 ** is undefined and probably harmful. 10041 ** 10042 ** The X parameter in a call to sqlite3_vtab_in_first(X,P) or 10043 ** sqlite3_vtab_in_next(X,P) should be one of the parameters to the 10044 ** xFilter method which invokes these routines, and specifically 10045 ** a parameter that was previously selected for all-at-once IN constraint 10046 ** processing use the [sqlite3_vtab_in()] interface in the 10047 ** [xBestIndex|xBestIndex method]. ^(If the X parameter is not 10048 ** an xFilter argument that was selected for all-at-once IN constraint 10049 ** processing, then these routines return [SQLITE_ERROR].)^ 10050 ** 10051 ** ^(Use these routines to access all values on the right-hand side 10052 ** of the IN constraint using code like the following: 10053 ** 10054 ** <blockquote><pre> 10055 ** for(rc=sqlite3_vtab_in_first(pList, &pVal); 10056 ** rc==SQLITE_OK && pVal; 10057 ** rc=sqlite3_vtab_in_next(pList, &pVal) 10058 ** ){ 10059 ** // do something with pVal 10060 ** } 10061 ** if( rc!=SQLITE_OK ){ 10062 ** // an error has occurred 10063 ** } 10064 ** </pre></blockquote>)^ 10065 ** 10066 ** ^On success, the sqlite3_vtab_in_first(X,P) and sqlite3_vtab_in_next(X,P) 10067 ** routines return SQLITE_OK and set *P to point to the first or next value 10068 ** on the RHS of the IN constraint. ^If there are no more values on the 10069 ** right hand side of the IN constraint, then *P is set to NULL and these 10070 ** routines return [SQLITE_DONE]. ^The return value might be 10071 ** some other value, such as SQLITE_NOMEM, in the event of a malfunction. 10072 ** 10073 ** The *ppOut values returned by these routines are only valid until the 10074 ** next call to either of these routines or until the end of the xFilter 10075 ** method from which these routines were called. If the virtual table 10076 ** implementation needs to retain the *ppOut values for longer, it must make 10077 ** copies. The *ppOut values are [protected sqlite3_value|protected]. 10078 */ 10079 SQLITE_API int sqlite3_vtab_in_first(sqlite3_value *pVal, sqlite3_value **ppOut); 10080 SQLITE_API int sqlite3_vtab_in_next(sqlite3_value *pVal, sqlite3_value **ppOut); 10081 10082 /* 10083 ** CAPI3REF: Constraint values in xBestIndex() 10084 ** METHOD: sqlite3_index_info 10085 ** 10086 ** This API may only be used from within the [xBestIndex|xBestIndex method] 10087 ** of a [virtual table] implementation. The result of calling this interface 10088 ** from outside of an xBestIndex method are undefined and probably harmful. 10089 ** 10090 ** ^When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within 10091 ** the [xBestIndex] method of a [virtual table] implementation, with P being 10092 ** a copy of the [sqlite3_index_info] object pointer passed into xBestIndex and 10093 ** J being a 0-based index into P->aConstraint[], then this routine 10094 ** attempts to set *V to the value of the right-hand operand of 10095 ** that constraint if the right-hand operand is known. ^If the 10096 ** right-hand operand is not known, then *V is set to a NULL pointer. 10097 ** ^The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if 10098 ** and only if *V is set to a value. ^The sqlite3_vtab_rhs_value(P,J,V) 10099 ** inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th 10100 ** constraint is not available. ^The sqlite3_vtab_rhs_value() interface 10101 ** can return an result code other than SQLITE_OK or SQLITE_NOTFOUND if 10102 ** something goes wrong. 10103 ** 10104 ** The sqlite3_vtab_rhs_value() interface is usually only successful if 10105 ** the right-hand operand of a constraint is a literal value in the original 10106 ** SQL statement. If the right-hand operand is an expression or a reference 10107 ** to some other column or a [host parameter], then sqlite3_vtab_rhs_value() 10108 ** will probably return [SQLITE_NOTFOUND]. 10109 ** 10110 ** ^(Some constraints, such as [SQLITE_INDEX_CONSTRAINT_ISNULL] and 10111 ** [SQLITE_INDEX_CONSTRAINT_ISNOTNULL], have no right-hand operand. For such 10112 ** constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.)^ 10113 ** 10114 ** ^The [sqlite3_value] object returned in *V is a protected sqlite3_value 10115 ** and remains valid for the duration of the xBestIndex method call. 10116 ** ^When xBestIndex returns, the sqlite3_value object returned by 10117 ** sqlite3_vtab_rhs_value() is automatically deallocated. 10118 ** 10119 ** The "_rhs_" in the name of this routine is an abbreviation for 10120 ** "Right-Hand Side". 10121 */ 10122 SQLITE_API int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal); 10123 10124 /* 10125 ** CAPI3REF: Conflict resolution modes 10126 ** KEYWORDS: {conflict resolution mode} 10127 ** 10128 ** These constants are returned by [sqlite3_vtab_on_conflict()] to 10129 ** inform a [virtual table] implementation what the [ON CONFLICT] mode 10130 ** is for the SQL statement being evaluated. 10131 ** 10132 ** Note that the [SQLITE_IGNORE] constant is also used as a potential 10133 ** return value from the [sqlite3_set_authorizer()] callback and that 10134 ** [SQLITE_ABORT] is also a [result code]. 10135 */ 10136 #define SQLITE_ROLLBACK 1 10137 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 10138 #define SQLITE_FAIL 3 10139 /* #define SQLITE_ABORT 4 // Also an error code */ 10140 #define SQLITE_REPLACE 5 10141 10142 /* 10143 ** CAPI3REF: Prepared Statement Scan Status Opcodes 10144 ** KEYWORDS: {scanstatus options} 10145 ** 10146 ** The following constants can be used for the T parameter to the 10147 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 10148 ** different metric for sqlite3_stmt_scanstatus() to return. 10149 ** 10150 ** When the value returned to V is a string, space to hold that string is 10151 ** managed by the prepared statement S and will be automatically freed when 10152 ** S is finalized. 10153 ** 10154 ** Not all values are available for all query elements. When a value is 10155 ** not available, the output variable is set to -1 if the value is numeric, 10156 ** or to NULL if it is a string (SQLITE_SCANSTAT_NAME). 10157 ** 10158 ** <dl> 10159 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 10160 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be 10161 ** set to the total number of times that the X-th loop has run.</dd> 10162 ** 10163 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 10164 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set 10165 ** to the total number of rows examined by all iterations of the X-th loop.</dd> 10166 ** 10167 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 10168 ** <dd>^The "double" variable pointed to by the V parameter will be set to the 10169 ** query planner's estimate for the average number of rows output from each 10170 ** iteration of the X-th loop. If the query planner's estimates was accurate, 10171 ** then this value will approximate the quotient NVISIT/NLOOP and the 10172 ** product of this value for all prior loops with the same SELECTID will 10173 ** be the NLOOP value for the current loop. 10174 ** 10175 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 10176 ** <dd>^The "const char *" variable pointed to by the V parameter will be set 10177 ** to a zero-terminated UTF-8 string containing the name of the index or table 10178 ** used for the X-th loop. 10179 ** 10180 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 10181 ** <dd>^The "const char *" variable pointed to by the V parameter will be set 10182 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 10183 ** description for the X-th loop. 10184 ** 10185 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECTID</dt> 10186 ** <dd>^The "int" variable pointed to by the V parameter will be set to the 10187 ** id for the X-th query plan element. The id value is unique within the 10188 ** statement. The select-id is the same value as is output in the first 10189 ** column of an [EXPLAIN QUERY PLAN] query. 10190 ** 10191 ** [[SQLITE_SCANSTAT_PARENTID]] <dt>SQLITE_SCANSTAT_PARENTID</dt> 10192 ** <dd>The "int" variable pointed to by the V parameter will be set to the 10193 ** the id of the parent of the current query element, if applicable, or 10194 ** to zero if the query element has no parent. This is the same value as 10195 ** returned in the second column of an [EXPLAIN QUERY PLAN] query. 10196 ** 10197 ** [[SQLITE_SCANSTAT_NCYCLE]] <dt>SQLITE_SCANSTAT_NCYCLE</dt> 10198 ** <dd>The sqlite3_int64 output value is set to the number of cycles, 10199 ** according to the processor time-stamp counter, that elapsed while the 10200 ** query element was being processed. This value is not available for 10201 ** all query elements - if it is unavailable the output variable is 10202 ** set to -1. 10203 ** </dl> 10204 */ 10205 #define SQLITE_SCANSTAT_NLOOP 0 10206 #define SQLITE_SCANSTAT_NVISIT 1 10207 #define SQLITE_SCANSTAT_EST 2 10208 #define SQLITE_SCANSTAT_NAME 3 10209 #define SQLITE_SCANSTAT_EXPLAIN 4 10210 #define SQLITE_SCANSTAT_SELECTID 5 10211 #define SQLITE_SCANSTAT_PARENTID 6 10212 #define SQLITE_SCANSTAT_NCYCLE 7 10213 10214 /* 10215 ** CAPI3REF: Prepared Statement Scan Status 10216 ** METHOD: sqlite3_stmt 10217 ** 10218 ** These interfaces return information about the predicted and measured 10219 ** performance for pStmt. Advanced applications can use this 10220 ** interface to compare the predicted and the measured performance and 10221 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 10222 ** 10223 ** Since this interface is expected to be rarely used, it is only 10224 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 10225 ** compile-time option. 10226 ** 10227 ** The "iScanStatusOp" parameter determines which status information to return. 10228 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 10229 ** of this interface is undefined. ^The requested measurement is written into 10230 ** a variable pointed to by the "pOut" parameter. 10231 ** 10232 ** The "flags" parameter must be passed a mask of flags. At present only 10233 ** one flag is defined - SQLITE_SCANSTAT_COMPLEX. If SQLITE_SCANSTAT_COMPLEX 10234 ** is specified, then status information is available for all elements 10235 ** of a query plan that are reported by "EXPLAIN QUERY PLAN" output. If 10236 ** SQLITE_SCANSTAT_COMPLEX is not specified, then only query plan elements 10237 ** that correspond to query loops (the "SCAN..." and "SEARCH..." elements of 10238 ** the EXPLAIN QUERY PLAN output) are available. Invoking API 10239 ** sqlite3_stmt_scanstatus() is equivalent to calling 10240 ** sqlite3_stmt_scanstatus_v2() with a zeroed flags parameter. 10241 ** 10242 ** Parameter "idx" identifies the specific query element to retrieve statistics 10243 ** for. Query elements are numbered starting from zero. A value of -1 may be 10244 ** to query for statistics regarding the entire query. ^If idx is out of range 10245 ** - less than -1 or greater than or equal to the total number of query 10246 ** elements used to implement the statement - a non-zero value is returned and 10247 ** the variable that pOut points to is unchanged. 10248 ** 10249 ** See also: [sqlite3_stmt_scanstatus_reset()] 10250 */ 10251 SQLITE_API int sqlite3_stmt_scanstatus( 10252 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 10253 int idx, /* Index of loop to report on */ 10254 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 10255 void *pOut /* Result written here */ 10256 ); 10257 SQLITE_API int sqlite3_stmt_scanstatus_v2( 10258 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 10259 int idx, /* Index of loop to report on */ 10260 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 10261 int flags, /* Mask of flags defined below */ 10262 void *pOut /* Result written here */ 10263 ); 10264 10265 /* 10266 ** CAPI3REF: Prepared Statement Scan Status 10267 ** KEYWORDS: {scan status flags} 10268 */ 10269 #define SQLITE_SCANSTAT_COMPLEX 0x0001 10270 10271 /* 10272 ** CAPI3REF: Zero Scan-Status Counters 10273 ** METHOD: sqlite3_stmt 10274 ** 10275 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 10276 ** 10277 ** This API is only available if the library is built with pre-processor 10278 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 10279 */ 10280 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 10281 10282 /* 10283 ** CAPI3REF: Flush caches to disk mid-transaction 10284 ** METHOD: sqlite3 10285 ** 10286 ** ^If a write-transaction is open on [database connection] D when the 10287 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 10288 ** pages in the pager-cache that are not currently in use are written out 10289 ** to disk. A dirty page may be in use if a database cursor created by an 10290 ** active SQL statement is reading from it, or if it is page 1 of a database 10291 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 10292 ** interface flushes caches for all schemas - "main", "temp", and 10293 ** any [attached] databases. 10294 ** 10295 ** ^If this function needs to obtain extra database locks before dirty pages 10296 ** can be flushed to disk, it does so. ^If those locks cannot be obtained 10297 ** immediately and there is a busy-handler callback configured, it is invoked 10298 ** in the usual manner. ^If the required lock still cannot be obtained, then 10299 ** the database is skipped and an attempt made to flush any dirty pages 10300 ** belonging to the next (if any) database. ^If any databases are skipped 10301 ** because locks cannot be obtained, but no other error occurs, this 10302 ** function returns SQLITE_BUSY. 10303 ** 10304 ** ^If any other error occurs while flushing dirty pages to disk (for 10305 ** example an IO error or out-of-memory condition), then processing is 10306 ** abandoned and an SQLite [error code] is returned to the caller immediately. 10307 ** 10308 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 10309 ** 10310 ** ^This function does not set the database handle error code or message 10311 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 10312 */ 10313 SQLITE_API int sqlite3_db_cacheflush(sqlite3*); 10314 10315 /* 10316 ** CAPI3REF: The pre-update hook. 10317 ** METHOD: sqlite3 10318 ** 10319 ** ^These interfaces are only available if SQLite is compiled using the 10320 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 10321 ** 10322 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function 10323 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 10324 ** on a database table. 10325 ** ^At most one preupdate hook may be registered at a time on a single 10326 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 10327 ** the previous setting. 10328 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 10329 ** with a NULL pointer as the second parameter. 10330 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 10331 ** the first parameter to callbacks. 10332 ** 10333 ** ^The preupdate hook only fires for changes to real database tables; the 10334 ** preupdate hook is not invoked for changes to [virtual tables] or to 10335 ** system tables like sqlite_sequence or sqlite_stat1. 10336 ** 10337 ** ^The second parameter to the preupdate callback is a pointer to 10338 ** the [database connection] that registered the preupdate hook. 10339 ** ^The third parameter to the preupdate callback is one of the constants 10340 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 10341 ** kind of update operation that is about to occur. 10342 ** ^(The fourth parameter to the preupdate callback is the name of the 10343 ** database within the database connection that is being modified. This 10344 ** will be "main" for the main database or "temp" for TEMP tables or 10345 ** the name given after the AS keyword in the [ATTACH] statement for attached 10346 ** databases.)^ 10347 ** ^The fifth parameter to the preupdate callback is the name of the 10348 ** table that is being modified. 10349 ** 10350 ** For an UPDATE or DELETE operation on a [rowid table], the sixth 10351 ** parameter passed to the preupdate callback is the initial [rowid] of the 10352 ** row being modified or deleted. For an INSERT operation on a rowid table, 10353 ** or any operation on a WITHOUT ROWID table, the value of the sixth 10354 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the 10355 ** seventh parameter is the final rowid value of the row being inserted 10356 ** or updated. The value of the seventh parameter passed to the callback 10357 ** function is not defined for operations on WITHOUT ROWID tables, or for 10358 ** DELETE operations on rowid tables. 10359 ** 10360 ** ^The sqlite3_preupdate_hook(D,C,P) function returns the P argument from 10361 ** the previous call on the same [database connection] D, or NULL for 10362 ** the first call on D. 10363 ** 10364 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 10365 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 10366 ** provide additional information about a preupdate event. These routines 10367 ** may only be called from within a preupdate callback. Invoking any of 10368 ** these routines from outside of a preupdate callback or with a 10369 ** [database connection] pointer that is different from the one supplied 10370 ** to the preupdate callback results in undefined and probably undesirable 10371 ** behavior. 10372 ** 10373 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 10374 ** in the row that is being inserted, updated, or deleted. 10375 ** 10376 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 10377 ** a [protected sqlite3_value] that contains the value of the Nth column of 10378 ** the table row before it is updated. The N parameter must be between 0 10379 ** and one less than the number of columns or the behavior will be 10380 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 10381 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 10382 ** behavior is undefined. The [sqlite3_value] that P points to 10383 ** will be destroyed when the preupdate callback returns. 10384 ** 10385 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 10386 ** a [protected sqlite3_value] that contains the value of the Nth column of 10387 ** the table row after it is updated. The N parameter must be between 0 10388 ** and one less than the number of columns or the behavior will be 10389 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 10390 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 10391 ** behavior is undefined. The [sqlite3_value] that P points to 10392 ** will be destroyed when the preupdate callback returns. 10393 ** 10394 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 10395 ** callback was invoked as a result of a direct insert, update, or delete 10396 ** operation; or 1 for inserts, updates, or deletes invoked by top-level 10397 ** triggers; or 2 for changes resulting from triggers called by top-level 10398 ** triggers; and so forth. 10399 ** 10400 ** When the [sqlite3_blob_write()] API is used to update a blob column, 10401 ** the pre-update hook is invoked with SQLITE_DELETE. This is because the 10402 ** in this case the new values are not available. In this case, when a 10403 ** callback made with op==SQLITE_DELETE is actually a write using the 10404 ** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns 10405 ** the index of the column being written. In other cases, where the 10406 ** pre-update hook is being invoked for some other reason, including a 10407 ** regular DELETE, sqlite3_preupdate_blobwrite() returns -1. 10408 ** 10409 ** See also: [sqlite3_update_hook()] 10410 */ 10411 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 10412 SQLITE_API void *sqlite3_preupdate_hook( 10413 sqlite3 *db, 10414 void(*xPreUpdate)( 10415 void *pCtx, /* Copy of third arg to preupdate_hook() */ 10416 sqlite3 *db, /* Database handle */ 10417 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 10418 char const *zDb, /* Database name */ 10419 char const *zName, /* Table name */ 10420 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 10421 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 10422 ), 10423 void* 10424 ); 10425 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 10426 SQLITE_API int sqlite3_preupdate_count(sqlite3 *); 10427 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *); 10428 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 10429 SQLITE_API int sqlite3_preupdate_blobwrite(sqlite3 *); 10430 #endif 10431 10432 /* 10433 ** CAPI3REF: Low-level system error code 10434 ** METHOD: sqlite3 10435 ** 10436 ** ^Attempt to return the underlying operating system error code or error 10437 ** number that caused the most recent I/O error or failure to open a file. 10438 ** The return value is OS-dependent. For example, on unix systems, after 10439 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 10440 ** called to get back the underlying "errno" that caused the problem, such 10441 ** as ENOSPC, EAUTH, EISDIR, and so forth. 10442 */ 10443 SQLITE_API int sqlite3_system_errno(sqlite3*); 10444 10445 /* 10446 ** CAPI3REF: Database Snapshot 10447 ** KEYWORDS: {snapshot} {sqlite3_snapshot} 10448 ** 10449 ** An instance of the snapshot object records the state of a [WAL mode] 10450 ** database for some specific point in history. 10451 ** 10452 ** In [WAL mode], multiple [database connections] that are open on the 10453 ** same database file can each be reading a different historical version 10454 ** of the database file. When a [database connection] begins a read 10455 ** transaction, that connection sees an unchanging copy of the database 10456 ** as it existed for the point in time when the transaction first started. 10457 ** Subsequent changes to the database from other connections are not seen 10458 ** by the reader until a new read transaction is started. 10459 ** 10460 ** The sqlite3_snapshot object records state information about an historical 10461 ** version of the database file so that it is possible to later open a new read 10462 ** transaction that sees that historical version of the database rather than 10463 ** the most recent version. 10464 */ 10465 typedef struct sqlite3_snapshot { 10466 unsigned char hidden[48]; 10467 } sqlite3_snapshot; 10468 10469 /* 10470 ** CAPI3REF: Record A Database Snapshot 10471 ** CONSTRUCTOR: sqlite3_snapshot 10472 ** 10473 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 10474 ** new [sqlite3_snapshot] object that records the current state of 10475 ** schema S in database connection D. ^On success, the 10476 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 10477 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 10478 ** If there is not already a read-transaction open on schema S when 10479 ** this function is called, one is opened automatically. 10480 ** 10481 ** The following must be true for this function to succeed. If any of 10482 ** the following statements are false when sqlite3_snapshot_get() is 10483 ** called, SQLITE_ERROR is returned. The final value of *P is undefined 10484 ** in this case. 10485 ** 10486 ** <ul> 10487 ** <li> The database handle must not be in [autocommit mode]. 10488 ** 10489 ** <li> Schema S of [database connection] D must be a [WAL mode] database. 10490 ** 10491 ** <li> There must not be a write transaction open on schema S of database 10492 ** connection D. 10493 ** 10494 ** <li> One or more transactions must have been written to the current wal 10495 ** file since it was created on disk (by any connection). This means 10496 ** that a snapshot cannot be taken on a wal mode database with no wal 10497 ** file immediately after it is first opened. At least one transaction 10498 ** must be written to it first. 10499 ** </ul> 10500 ** 10501 ** This function may also return SQLITE_NOMEM. If it is called with the 10502 ** database handle in autocommit mode but fails for some other reason, 10503 ** whether or not a read transaction is opened on schema S is undefined. 10504 ** 10505 ** The [sqlite3_snapshot] object returned from a successful call to 10506 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 10507 ** to avoid a memory leak. 10508 ** 10509 ** The [sqlite3_snapshot_get()] interface is only available when the 10510 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10511 */ 10512 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 10513 sqlite3 *db, 10514 const char *zSchema, 10515 sqlite3_snapshot **ppSnapshot 10516 ); 10517 10518 /* 10519 ** CAPI3REF: Start a read transaction on an historical snapshot 10520 ** METHOD: sqlite3_snapshot 10521 ** 10522 ** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 10523 ** transaction or upgrades an existing one for schema S of 10524 ** [database connection] D such that the read transaction refers to 10525 ** historical [snapshot] P, rather than the most recent change to the 10526 ** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 10527 ** on success or an appropriate [error code] if it fails. 10528 ** 10529 ** ^In order to succeed, the database connection must not be in 10530 ** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 10531 ** is already a read transaction open on schema S, then the database handle 10532 ** must have no active statements (SELECT statements that have been passed 10533 ** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 10534 ** SQLITE_ERROR is returned if either of these conditions is violated, or 10535 ** if schema S does not exist, or if the snapshot object is invalid. 10536 ** 10537 ** ^A call to sqlite3_snapshot_open() will fail to open if the specified 10538 ** snapshot has been overwritten by a [checkpoint]. In this case 10539 ** SQLITE_ERROR_SNAPSHOT is returned. 10540 ** 10541 ** If there is already a read transaction open when this function is 10542 ** invoked, then the same read transaction remains open (on the same 10543 ** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 10544 ** is returned. If another error code - for example SQLITE_PROTOCOL or an 10545 ** SQLITE_IOERR error code - is returned, then the final state of the 10546 ** read transaction is undefined. If SQLITE_OK is returned, then the 10547 ** read transaction is now open on database snapshot P. 10548 ** 10549 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 10550 ** database connection D does not know that the database file for 10551 ** schema S is in [WAL mode]. A database connection might not know 10552 ** that the database file is in [WAL mode] if there has been no prior 10553 ** I/O on that database connection, or if the database entered [WAL mode] 10554 ** after the most recent I/O on the database connection.)^ 10555 ** (Hint: Run "[PRAGMA application_id]" against a newly opened 10556 ** database connection in order to make it ready to use snapshots.) 10557 ** 10558 ** The [sqlite3_snapshot_open()] interface is only available when the 10559 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10560 */ 10561 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 10562 sqlite3 *db, 10563 const char *zSchema, 10564 sqlite3_snapshot *pSnapshot 10565 ); 10566 10567 /* 10568 ** CAPI3REF: Destroy a snapshot 10569 ** DESTRUCTOR: sqlite3_snapshot 10570 ** 10571 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 10572 ** The application must eventually free every [sqlite3_snapshot] object 10573 ** using this routine to avoid a memory leak. 10574 ** 10575 ** The [sqlite3_snapshot_free()] interface is only available when the 10576 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10577 */ 10578 SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 10579 10580 /* 10581 ** CAPI3REF: Compare the ages of two snapshot handles. 10582 ** METHOD: sqlite3_snapshot 10583 ** 10584 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 10585 ** of two valid snapshot handles. 10586 ** 10587 ** If the two snapshot handles are not associated with the same database 10588 ** file, the result of the comparison is undefined. 10589 ** 10590 ** Additionally, the result of the comparison is only valid if both of the 10591 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 10592 ** last time the wal file was deleted. The wal file is deleted when the 10593 ** database is changed back to rollback mode or when the number of database 10594 ** clients drops to zero. If either snapshot handle was obtained before the 10595 ** wal file was last deleted, the value returned by this function 10596 ** is undefined. 10597 ** 10598 ** Otherwise, this API returns a negative value if P1 refers to an older 10599 ** snapshot than P2, zero if the two handles refer to the same database 10600 ** snapshot, and a positive value if P1 is a newer snapshot than P2. 10601 ** 10602 ** This interface is only available if SQLite is compiled with the 10603 ** [SQLITE_ENABLE_SNAPSHOT] option. 10604 */ 10605 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 10606 sqlite3_snapshot *p1, 10607 sqlite3_snapshot *p2 10608 ); 10609 10610 /* 10611 ** CAPI3REF: Recover snapshots from a wal file 10612 ** METHOD: sqlite3_snapshot 10613 ** 10614 ** If a [WAL file] remains on disk after all database connections close 10615 ** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 10616 ** or because the last process to have the database opened exited without 10617 ** calling [sqlite3_close()]) and a new connection is subsequently opened 10618 ** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 10619 ** will only be able to open the last transaction added to the WAL file 10620 ** even though the WAL file contains other valid transactions. 10621 ** 10622 ** This function attempts to scan the WAL file associated with database zDb 10623 ** of database handle db and make all valid snapshots available to 10624 ** sqlite3_snapshot_open(). It is an error if there is already a read 10625 ** transaction open on the database, or if the database is not a WAL mode 10626 ** database. 10627 ** 10628 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 10629 ** 10630 ** This interface is only available if SQLite is compiled with the 10631 ** [SQLITE_ENABLE_SNAPSHOT] option. 10632 */ 10633 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 10634 10635 /* 10636 ** CAPI3REF: Serialize a database 10637 ** 10638 ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 10639 ** that is a serialization of the S database on [database connection] D. 10640 ** If P is not a NULL pointer, then the size of the database in bytes 10641 ** is written into *P. 10642 ** 10643 ** For an ordinary on-disk database file, the serialization is just a 10644 ** copy of the disk file. For an in-memory database or a "TEMP" database, 10645 ** the serialization is the same sequence of bytes which would be written 10646 ** to disk if that database where backed up to disk. 10647 ** 10648 ** The usual case is that sqlite3_serialize() copies the serialization of 10649 ** the database into memory obtained from [sqlite3_malloc64()] and returns 10650 ** a pointer to that memory. The caller is responsible for freeing the 10651 ** returned value to avoid a memory leak. However, if the F argument 10652 ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 10653 ** are made, and the sqlite3_serialize() function will return a pointer 10654 ** to the contiguous memory representation of the database that SQLite 10655 ** is currently using for that database, or NULL if the no such contiguous 10656 ** memory representation of the database exists. A contiguous memory 10657 ** representation of the database will usually only exist if there has 10658 ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 10659 ** values of D and S. 10660 ** The size of the database is written into *P even if the 10661 ** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 10662 ** of the database exists. 10663 ** 10664 ** After the call, if the SQLITE_SERIALIZE_NOCOPY bit had been set, 10665 ** the returned buffer content will remain accessible and unchanged 10666 ** until either the next write operation on the connection or when 10667 ** the connection is closed, and applications must not modify the 10668 ** buffer. If the bit had been clear, the returned buffer will not 10669 ** be accessed by SQLite after the call. 10670 ** 10671 ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 10672 ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 10673 ** allocation error occurs. 10674 ** 10675 ** This interface is omitted if SQLite is compiled with the 10676 ** [SQLITE_OMIT_DESERIALIZE] option. 10677 */ 10678 SQLITE_API unsigned char *sqlite3_serialize( 10679 sqlite3 *db, /* The database connection */ 10680 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 10681 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 10682 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 10683 ); 10684 10685 /* 10686 ** CAPI3REF: Flags for sqlite3_serialize 10687 ** 10688 ** Zero or more of the following constants can be OR-ed together for 10689 ** the F argument to [sqlite3_serialize(D,S,P,F)]. 10690 ** 10691 ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 10692 ** a pointer to contiguous in-memory database that it is currently using, 10693 ** without making a copy of the database. If SQLite is not currently using 10694 ** a contiguous in-memory database, then this option causes 10695 ** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 10696 ** using a contiguous in-memory database if it has been initialized by a 10697 ** prior call to [sqlite3_deserialize()]. 10698 */ 10699 #define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 10700 10701 /* 10702 ** CAPI3REF: Deserialize a database 10703 ** 10704 ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 10705 ** [database connection] D to disconnect from database S and then 10706 ** reopen S as an in-memory database based on the serialization contained 10707 ** in P. The serialized database P is N bytes in size. M is the size of 10708 ** the buffer P, which might be larger than N. If M is larger than N, and 10709 ** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 10710 ** permitted to add content to the in-memory database as long as the total 10711 ** size does not exceed M bytes. 10712 ** 10713 ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 10714 ** invoke sqlite3_free() on the serialization buffer when the database 10715 ** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 10716 ** SQLite will try to increase the buffer size using sqlite3_realloc64() 10717 ** if writes on the database cause it to grow larger than M bytes. 10718 ** 10719 ** Applications must not modify the buffer P or invalidate it before 10720 ** the database connection D is closed. 10721 ** 10722 ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 10723 ** database is currently in a read transaction or is involved in a backup 10724 ** operation. 10725 ** 10726 ** It is not possible to deserialized into the TEMP database. If the 10727 ** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the 10728 ** function returns SQLITE_ERROR. 10729 ** 10730 ** The deserialized database should not be in [WAL mode]. If the database 10731 ** is in WAL mode, then any attempt to use the database file will result 10732 ** in an [SQLITE_CANTOPEN] error. The application can set the 10733 ** [file format version numbers] (bytes 18 and 19) of the input database P 10734 ** to 0x01 prior to invoking sqlite3_deserialize(D,S,P,N,M,F) to force the 10735 ** database file into rollback mode and work around this limitation. 10736 ** 10737 ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 10738 ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 10739 ** [sqlite3_free()] is invoked on argument P prior to returning. 10740 ** 10741 ** This interface is omitted if SQLite is compiled with the 10742 ** [SQLITE_OMIT_DESERIALIZE] option. 10743 */ 10744 SQLITE_API int sqlite3_deserialize( 10745 sqlite3 *db, /* The database connection */ 10746 const char *zSchema, /* Which DB to reopen with the deserialization */ 10747 unsigned char *pData, /* The serialized database content */ 10748 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 10749 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 10750 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 10751 ); 10752 10753 /* 10754 ** CAPI3REF: Flags for sqlite3_deserialize() 10755 ** 10756 ** The following are allowed values for 6th argument (the F argument) to 10757 ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 10758 ** 10759 ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 10760 ** in the P argument is held in memory obtained from [sqlite3_malloc64()] 10761 ** and that SQLite should take ownership of this memory and automatically 10762 ** free it when it has finished using it. Without this flag, the caller 10763 ** is responsible for freeing any dynamically allocated memory. 10764 ** 10765 ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 10766 ** grow the size of the database using calls to [sqlite3_realloc64()]. This 10767 ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 10768 ** Without this flag, the deserialized database cannot increase in size beyond 10769 ** the number of bytes specified by the M parameter. 10770 ** 10771 ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 10772 ** should be treated as read-only. 10773 */ 10774 #define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 10775 #define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 10776 #define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 10777 10778 /* 10779 ** Undo the hack that converts floating point types to integer for 10780 ** builds on processors without floating point support. 10781 */ 10782 #ifdef SQLITE_OMIT_FLOATING_POINT 10783 # undef double 10784 #endif 10785 10786 #if defined(__wasi__) 10787 # undef SQLITE_WASI 10788 # define SQLITE_WASI 1 10789 # undef SQLITE_OMIT_WAL 10790 # define SQLITE_OMIT_WAL 1/* because it requires shared memory APIs */ 10791 # ifndef SQLITE_OMIT_LOAD_EXTENSION 10792 # define SQLITE_OMIT_LOAD_EXTENSION 10793 # endif 10794 # ifndef SQLITE_THREADSAFE 10795 # define SQLITE_THREADSAFE 0 10796 # endif 10797 #endif 10798 10799 #ifdef __cplusplus 10800 } /* End of the 'extern "C"' block */ 10801 #endif 10802 #endif /* SQLITE3_H */ 10803 10804 /******** Begin file sqlite3rtree.h *********/ 10805 /* 10806 ** 2010 August 30 10807 ** 10808 ** The author disclaims copyright to this source code. In place of 10809 ** a legal notice, here is a blessing: 10810 ** 10811 ** May you do good and not evil. 10812 ** May you find forgiveness for yourself and forgive others. 10813 ** May you share freely, never taking more than you give. 10814 ** 10815 ************************************************************************* 10816 */ 10817 10818 #ifndef _SQLITE3RTREE_H_ 10819 #define _SQLITE3RTREE_H_ 10820 10821 10822 #ifdef __cplusplus 10823 extern "C" { 10824 #endif 10825 10826 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 10827 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 10828 10829 /* The double-precision datatype used by RTree depends on the 10830 ** SQLITE_RTREE_INT_ONLY compile-time option. 10831 */ 10832 #ifdef SQLITE_RTREE_INT_ONLY 10833 typedef sqlite3_int64 sqlite3_rtree_dbl; 10834 #else 10835 typedef double sqlite3_rtree_dbl; 10836 #endif 10837 10838 /* 10839 ** Register a geometry callback named zGeom that can be used as part of an 10840 ** R-Tree geometry query as follows: 10841 ** 10842 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 10843 */ 10844 SQLITE_API int sqlite3_rtree_geometry_callback( 10845 sqlite3 *db, 10846 const char *zGeom, 10847 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 10848 void *pContext 10849 ); 10850 10851 10852 /* 10853 ** A pointer to a structure of the following type is passed as the first 10854 ** argument to callbacks registered using rtree_geometry_callback(). 10855 */ 10856 struct sqlite3_rtree_geometry { 10857 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 10858 int nParam; /* Size of array aParam[] */ 10859 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 10860 void *pUser; /* Callback implementation user data */ 10861 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 10862 }; 10863 10864 /* 10865 ** Register a 2nd-generation geometry callback named zScore that can be 10866 ** used as part of an R-Tree geometry query as follows: 10867 ** 10868 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 10869 */ 10870 SQLITE_API int sqlite3_rtree_query_callback( 10871 sqlite3 *db, 10872 const char *zQueryFunc, 10873 int (*xQueryFunc)(sqlite3_rtree_query_info*), 10874 void *pContext, 10875 void (*xDestructor)(void*) 10876 ); 10877 10878 10879 /* 10880 ** A pointer to a structure of the following type is passed as the 10881 ** argument to scored geometry callback registered using 10882 ** sqlite3_rtree_query_callback(). 10883 ** 10884 ** Note that the first 5 fields of this structure are identical to 10885 ** sqlite3_rtree_geometry. This structure is a subclass of 10886 ** sqlite3_rtree_geometry. 10887 */ 10888 struct sqlite3_rtree_query_info { 10889 void *pContext; /* pContext from when function registered */ 10890 int nParam; /* Number of function parameters */ 10891 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 10892 void *pUser; /* callback can use this, if desired */ 10893 void (*xDelUser)(void*); /* function to free pUser */ 10894 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 10895 unsigned int *anQueue; /* Number of pending entries in the queue */ 10896 int nCoord; /* Number of coordinates */ 10897 int iLevel; /* Level of current node or entry */ 10898 int mxLevel; /* The largest iLevel value in the tree */ 10899 sqlite3_int64 iRowid; /* Rowid for current entry */ 10900 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 10901 int eParentWithin; /* Visibility of parent node */ 10902 int eWithin; /* OUT: Visibility */ 10903 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 10904 /* The following fields are only available in 3.8.11 and later */ 10905 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 10906 }; 10907 10908 /* 10909 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 10910 */ 10911 #define NOT_WITHIN 0 /* Object completely outside of query region */ 10912 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 10913 #define FULLY_WITHIN 2 /* Object fully contained within query region */ 10914 10915 10916 #ifdef __cplusplus 10917 } /* end of the 'extern "C"' block */ 10918 #endif 10919 10920 #endif /* ifndef _SQLITE3RTREE_H_ */ 10921 10922 /******** End of sqlite3rtree.h *********/ 10923 /******** Begin file sqlite3session.h *********/ 10924 10925 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 10926 #define __SQLITESESSION_H_ 1 10927 10928 /* 10929 ** Make sure we can call this stuff from C++. 10930 */ 10931 #ifdef __cplusplus 10932 extern "C" { 10933 #endif 10934 10935 10936 /* 10937 ** CAPI3REF: Session Object Handle 10938 ** 10939 ** An instance of this object is a [session] that can be used to 10940 ** record changes to a database. 10941 */ 10942 typedef struct sqlite3_session sqlite3_session; 10943 10944 /* 10945 ** CAPI3REF: Changeset Iterator Handle 10946 ** 10947 ** An instance of this object acts as a cursor for iterating 10948 ** over the elements of a [changeset] or [patchset]. 10949 */ 10950 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 10951 10952 /* 10953 ** CAPI3REF: Create A New Session Object 10954 ** CONSTRUCTOR: sqlite3_session 10955 ** 10956 ** Create a new session object attached to database handle db. If successful, 10957 ** a pointer to the new object is written to *ppSession and SQLITE_OK is 10958 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite 10959 ** error code (e.g. SQLITE_NOMEM) is returned. 10960 ** 10961 ** It is possible to create multiple session objects attached to a single 10962 ** database handle. 10963 ** 10964 ** Session objects created using this function should be deleted using the 10965 ** [sqlite3session_delete()] function before the database handle that they 10966 ** are attached to is itself closed. If the database handle is closed before 10967 ** the session object is deleted, then the results of calling any session 10968 ** module function, including [sqlite3session_delete()] on the session object 10969 ** are undefined. 10970 ** 10971 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it 10972 ** is not possible for an application to register a pre-update hook on a 10973 ** database handle that has one or more session objects attached. Nor is 10974 ** it possible to create a session object attached to a database handle for 10975 ** which a pre-update hook is already defined. The results of attempting 10976 ** either of these things are undefined. 10977 ** 10978 ** The session object will be used to create changesets for tables in 10979 ** database zDb, where zDb is either "main", or "temp", or the name of an 10980 ** attached database. It is not an error if database zDb is not attached 10981 ** to the database when the session object is created. 10982 */ 10983 SQLITE_API int sqlite3session_create( 10984 sqlite3 *db, /* Database handle */ 10985 const char *zDb, /* Name of db (e.g. "main") */ 10986 sqlite3_session **ppSession /* OUT: New session object */ 10987 ); 10988 10989 /* 10990 ** CAPI3REF: Delete A Session Object 10991 ** DESTRUCTOR: sqlite3_session 10992 ** 10993 ** Delete a session object previously allocated using 10994 ** [sqlite3session_create()]. Once a session object has been deleted, the 10995 ** results of attempting to use pSession with any other session module 10996 ** function are undefined. 10997 ** 10998 ** Session objects must be deleted before the database handle to which they 10999 ** are attached is closed. Refer to the documentation for 11000 ** [sqlite3session_create()] for details. 11001 */ 11002 SQLITE_API void sqlite3session_delete(sqlite3_session *pSession); 11003 11004 /* 11005 ** CAPI3REF: Configure a Session Object 11006 ** METHOD: sqlite3_session 11007 ** 11008 ** This method is used to configure a session object after it has been 11009 ** created. At present the only valid values for the second parameter are 11010 ** [SQLITE_SESSION_OBJCONFIG_SIZE] and [SQLITE_SESSION_OBJCONFIG_ROWID]. 11011 ** 11012 */ 11013 SQLITE_API int sqlite3session_object_config(sqlite3_session*, int op, void *pArg); 11014 11015 /* 11016 ** CAPI3REF: Options for sqlite3session_object_config 11017 ** 11018 ** The following values may passed as the the 2nd parameter to 11019 ** sqlite3session_object_config(). 11020 ** 11021 ** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd> 11022 ** This option is used to set, clear or query the flag that enables 11023 ** the [sqlite3session_changeset_size()] API. Because it imposes some 11024 ** computational overhead, this API is disabled by default. Argument 11025 ** pArg must point to a value of type (int). If the value is initially 11026 ** 0, then the sqlite3session_changeset_size() API is disabled. If it 11027 ** is greater than 0, then the same API is enabled. Or, if the initial 11028 ** value is less than zero, no change is made. In all cases the (int) 11029 ** variable is set to 1 if the sqlite3session_changeset_size() API is 11030 ** enabled following the current call, or 0 otherwise. 11031 ** 11032 ** It is an error (SQLITE_MISUSE) to attempt to modify this setting after 11033 ** the first table has been attached to the session object. 11034 ** 11035 ** <dt>SQLITE_SESSION_OBJCONFIG_ROWID <dd> 11036 ** This option is used to set, clear or query the flag that enables 11037 ** collection of data for tables with no explicit PRIMARY KEY. 11038 ** 11039 ** Normally, tables with no explicit PRIMARY KEY are simply ignored 11040 ** by the sessions module. However, if this flag is set, it behaves 11041 ** as if such tables have a column "_rowid_ INTEGER PRIMARY KEY" inserted 11042 ** as their leftmost columns. 11043 ** 11044 ** It is an error (SQLITE_MISUSE) to attempt to modify this setting after 11045 ** the first table has been attached to the session object. 11046 */ 11047 #define SQLITE_SESSION_OBJCONFIG_SIZE 1 11048 #define SQLITE_SESSION_OBJCONFIG_ROWID 2 11049 11050 /* 11051 ** CAPI3REF: Enable Or Disable A Session Object 11052 ** METHOD: sqlite3_session 11053 ** 11054 ** Enable or disable the recording of changes by a session object. When 11055 ** enabled, a session object records changes made to the database. When 11056 ** disabled - it does not. A newly created session object is enabled. 11057 ** Refer to the documentation for [sqlite3session_changeset()] for further 11058 ** details regarding how enabling and disabling a session object affects 11059 ** the eventual changesets. 11060 ** 11061 ** Passing zero to this function disables the session. Passing a value 11062 ** greater than zero enables it. Passing a value less than zero is a 11063 ** no-op, and may be used to query the current state of the session. 11064 ** 11065 ** The return value indicates the final state of the session object: 0 if 11066 ** the session is disabled, or 1 if it is enabled. 11067 */ 11068 SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 11069 11070 /* 11071 ** CAPI3REF: Set Or Clear the Indirect Change Flag 11072 ** METHOD: sqlite3_session 11073 ** 11074 ** Each change recorded by a session object is marked as either direct or 11075 ** indirect. A change is marked as indirect if either: 11076 ** 11077 ** <ul> 11078 ** <li> The session object "indirect" flag is set when the change is 11079 ** made, or 11080 ** <li> The change is made by an SQL trigger or foreign key action 11081 ** instead of directly as a result of a users SQL statement. 11082 ** </ul> 11083 ** 11084 ** If a single row is affected by more than one operation within a session, 11085 ** then the change is considered indirect if all operations meet the criteria 11086 ** for an indirect change above, or direct otherwise. 11087 ** 11088 ** This function is used to set, clear or query the session object indirect 11089 ** flag. If the second argument passed to this function is zero, then the 11090 ** indirect flag is cleared. If it is greater than zero, the indirect flag 11091 ** is set. Passing a value less than zero does not modify the current value 11092 ** of the indirect flag, and may be used to query the current state of the 11093 ** indirect flag for the specified session object. 11094 ** 11095 ** The return value indicates the final state of the indirect flag: 0 if 11096 ** it is clear, or 1 if it is set. 11097 */ 11098 SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 11099 11100 /* 11101 ** CAPI3REF: Attach A Table To A Session Object 11102 ** METHOD: sqlite3_session 11103 ** 11104 ** If argument zTab is not NULL, then it is the name of a table to attach 11105 ** to the session object passed as the first argument. All subsequent changes 11106 ** made to the table while the session object is enabled will be recorded. See 11107 ** documentation for [sqlite3session_changeset()] for further details. 11108 ** 11109 ** Or, if argument zTab is NULL, then changes are recorded for all tables 11110 ** in the database. If additional tables are added to the database (by 11111 ** executing "CREATE TABLE" statements) after this call is made, changes for 11112 ** the new tables are also recorded. 11113 ** 11114 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 11115 ** defined as part of their CREATE TABLE statement. It does not matter if the 11116 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 11117 ** KEY may consist of a single column, or may be a composite key. 11118 ** 11119 ** It is not an error if the named table does not exist in the database. Nor 11120 ** is it an error if the named table does not have a PRIMARY KEY. However, 11121 ** no changes will be recorded in either of these scenarios. 11122 ** 11123 ** Changes are not recorded for individual rows that have NULL values stored 11124 ** in one or more of their PRIMARY KEY columns. 11125 ** 11126 ** SQLITE_OK is returned if the call completes without error. Or, if an error 11127 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 11128 ** 11129 ** <h3>Special sqlite_stat1 Handling</h3> 11130 ** 11131 ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to 11132 ** some of the rules above. In SQLite, the schema of sqlite_stat1 is: 11133 ** <pre> 11134 ** CREATE TABLE sqlite_stat1(tbl,idx,stat) 11135 ** </pre> 11136 ** 11137 ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are 11138 ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes 11139 ** are recorded for rows for which (idx IS NULL) is true. However, for such 11140 ** rows a zero-length blob (SQL value X'') is stored in the changeset or 11141 ** patchset instead of a NULL value. This allows such changesets to be 11142 ** manipulated by legacy implementations of sqlite3changeset_invert(), 11143 ** concat() and similar. 11144 ** 11145 ** The sqlite3changeset_apply() function automatically converts the 11146 ** zero-length blob back to a NULL value when updating the sqlite_stat1 11147 ** table. However, if the application calls sqlite3changeset_new(), 11148 ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset 11149 ** iterator directly (including on a changeset iterator passed to a 11150 ** conflict-handler callback) then the X'' value is returned. The application 11151 ** must translate X'' to NULL itself if required. 11152 ** 11153 ** Legacy (older than 3.22.0) versions of the sessions module cannot capture 11154 ** changes made to the sqlite_stat1 table. Legacy versions of the 11155 ** sqlite3changeset_apply() function silently ignore any modifications to the 11156 ** sqlite_stat1 table that are part of a changeset or patchset. 11157 */ 11158 SQLITE_API int sqlite3session_attach( 11159 sqlite3_session *pSession, /* Session object */ 11160 const char *zTab /* Table name */ 11161 ); 11162 11163 /* 11164 ** CAPI3REF: Set a table filter on a Session Object. 11165 ** METHOD: sqlite3_session 11166 ** 11167 ** The second argument (xFilter) is the "filter callback". For changes to rows 11168 ** in tables that are not attached to the Session object, the filter is called 11169 ** to determine whether changes to the table's rows should be tracked or not. 11170 ** If xFilter returns 0, changes are not tracked. Note that once a table is 11171 ** attached, xFilter will not be called again. 11172 */ 11173 SQLITE_API void sqlite3session_table_filter( 11174 sqlite3_session *pSession, /* Session object */ 11175 int(*xFilter)( 11176 void *pCtx, /* Copy of third arg to _filter_table() */ 11177 const char *zTab /* Table name */ 11178 ), 11179 void *pCtx /* First argument passed to xFilter */ 11180 ); 11181 11182 /* 11183 ** CAPI3REF: Generate A Changeset From A Session Object 11184 ** METHOD: sqlite3_session 11185 ** 11186 ** Obtain a changeset containing changes to the tables attached to the 11187 ** session object passed as the first argument. If successful, 11188 ** set *ppChangeset to point to a buffer containing the changeset 11189 ** and *pnChangeset to the size of the changeset in bytes before returning 11190 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 11191 ** zero and return an SQLite error code. 11192 ** 11193 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 11194 ** each representing a change to a single row of an attached table. An INSERT 11195 ** change contains the values of each field of a new database row. A DELETE 11196 ** contains the original values of each field of a deleted database row. An 11197 ** UPDATE change contains the original values of each field of an updated 11198 ** database row along with the updated values for each updated non-primary-key 11199 ** column. It is not possible for an UPDATE change to represent a change that 11200 ** modifies the values of primary key columns. If such a change is made, it 11201 ** is represented in a changeset as a DELETE followed by an INSERT. 11202 ** 11203 ** Changes are not recorded for rows that have NULL values stored in one or 11204 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 11205 ** no corresponding change is present in the changesets returned by this 11206 ** function. If an existing row with one or more NULL values stored in 11207 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 11208 ** only an INSERT is appears in the changeset. Similarly, if an existing row 11209 ** with non-NULL PRIMARY KEY values is updated so that one or more of its 11210 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 11211 ** DELETE change only. 11212 ** 11213 ** The contents of a changeset may be traversed using an iterator created 11214 ** using the [sqlite3changeset_start()] API. A changeset may be applied to 11215 ** a database with a compatible schema using the [sqlite3changeset_apply()] 11216 ** API. 11217 ** 11218 ** Within a changeset generated by this function, all changes related to a 11219 ** single table are grouped together. In other words, when iterating through 11220 ** a changeset or when applying a changeset to a database, all changes related 11221 ** to a single table are processed before moving on to the next table. Tables 11222 ** are sorted in the same order in which they were attached (or auto-attached) 11223 ** to the sqlite3_session object. The order in which the changes related to 11224 ** a single table are stored is undefined. 11225 ** 11226 ** Following a successful call to this function, it is the responsibility of 11227 ** the caller to eventually free the buffer that *ppChangeset points to using 11228 ** [sqlite3_free()]. 11229 ** 11230 ** <h3>Changeset Generation</h3> 11231 ** 11232 ** Once a table has been attached to a session object, the session object 11233 ** records the primary key values of all new rows inserted into the table. 11234 ** It also records the original primary key and other column values of any 11235 ** deleted or updated rows. For each unique primary key value, data is only 11236 ** recorded once - the first time a row with said primary key is inserted, 11237 ** updated or deleted in the lifetime of the session. 11238 ** 11239 ** There is one exception to the previous paragraph: when a row is inserted, 11240 ** updated or deleted, if one or more of its primary key columns contain a 11241 ** NULL value, no record of the change is made. 11242 ** 11243 ** The session object therefore accumulates two types of records - those 11244 ** that consist of primary key values only (created when the user inserts 11245 ** a new record) and those that consist of the primary key values and the 11246 ** original values of other table columns (created when the users deletes 11247 ** or updates a record). 11248 ** 11249 ** When this function is called, the requested changeset is created using 11250 ** both the accumulated records and the current contents of the database 11251 ** file. Specifically: 11252 ** 11253 ** <ul> 11254 ** <li> For each record generated by an insert, the database is queried 11255 ** for a row with a matching primary key. If one is found, an INSERT 11256 ** change is added to the changeset. If no such row is found, no change 11257 ** is added to the changeset. 11258 ** 11259 ** <li> For each record generated by an update or delete, the database is 11260 ** queried for a row with a matching primary key. If such a row is 11261 ** found and one or more of the non-primary key fields have been 11262 ** modified from their original values, an UPDATE change is added to 11263 ** the changeset. Or, if no such row is found in the table, a DELETE 11264 ** change is added to the changeset. If there is a row with a matching 11265 ** primary key in the database, but all fields contain their original 11266 ** values, no change is added to the changeset. 11267 ** </ul> 11268 ** 11269 ** This means, amongst other things, that if a row is inserted and then later 11270 ** deleted while a session object is active, neither the insert nor the delete 11271 ** will be present in the changeset. Or if a row is deleted and then later a 11272 ** row with the same primary key values inserted while a session object is 11273 ** active, the resulting changeset will contain an UPDATE change instead of 11274 ** a DELETE and an INSERT. 11275 ** 11276 ** When a session object is disabled (see the [sqlite3session_enable()] API), 11277 ** it does not accumulate records when rows are inserted, updated or deleted. 11278 ** This may appear to have some counter-intuitive effects if a single row 11279 ** is written to more than once during a session. For example, if a row 11280 ** is inserted while a session object is enabled, then later deleted while 11281 ** the same session object is disabled, no INSERT record will appear in the 11282 ** changeset, even though the delete took place while the session was disabled. 11283 ** Or, if one field of a row is updated while a session is disabled, and 11284 ** another field of the same row is updated while the session is enabled, the 11285 ** resulting changeset will contain an UPDATE change that updates both fields. 11286 */ 11287 SQLITE_API int sqlite3session_changeset( 11288 sqlite3_session *pSession, /* Session object */ 11289 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 11290 void **ppChangeset /* OUT: Buffer containing changeset */ 11291 ); 11292 11293 /* 11294 ** CAPI3REF: Return An Upper-limit For The Size Of The Changeset 11295 ** METHOD: sqlite3_session 11296 ** 11297 ** By default, this function always returns 0. For it to return 11298 ** a useful result, the sqlite3_session object must have been configured 11299 ** to enable this API using sqlite3session_object_config() with the 11300 ** SQLITE_SESSION_OBJCONFIG_SIZE verb. 11301 ** 11302 ** When enabled, this function returns an upper limit, in bytes, for the size 11303 ** of the changeset that might be produced if sqlite3session_changeset() were 11304 ** called. The final changeset size might be equal to or smaller than the 11305 ** size in bytes returned by this function. 11306 */ 11307 SQLITE_API sqlite3_int64 sqlite3session_changeset_size(sqlite3_session *pSession); 11308 11309 /* 11310 ** CAPI3REF: Load The Difference Between Tables Into A Session 11311 ** METHOD: sqlite3_session 11312 ** 11313 ** If it is not already attached to the session object passed as the first 11314 ** argument, this function attaches table zTbl in the same manner as the 11315 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it 11316 ** does not have a primary key, this function is a no-op (but does not return 11317 ** an error). 11318 ** 11319 ** Argument zFromDb must be the name of a database ("main", "temp" etc.) 11320 ** attached to the same database handle as the session object that contains 11321 ** a table compatible with the table attached to the session by this function. 11322 ** A table is considered compatible if it: 11323 ** 11324 ** <ul> 11325 ** <li> Has the same name, 11326 ** <li> Has the same set of columns declared in the same order, and 11327 ** <li> Has the same PRIMARY KEY definition. 11328 ** </ul> 11329 ** 11330 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 11331 ** are compatible but do not have any PRIMARY KEY columns, it is not an error 11332 ** but no changes are added to the session object. As with other session 11333 ** APIs, tables without PRIMARY KEYs are simply ignored. 11334 ** 11335 ** This function adds a set of changes to the session object that could be 11336 ** used to update the table in database zFrom (call this the "from-table") 11337 ** so that its content is the same as the table attached to the session 11338 ** object (call this the "to-table"). Specifically: 11339 ** 11340 ** <ul> 11341 ** <li> For each row (primary key) that exists in the to-table but not in 11342 ** the from-table, an INSERT record is added to the session object. 11343 ** 11344 ** <li> For each row (primary key) that exists in the to-table but not in 11345 ** the from-table, a DELETE record is added to the session object. 11346 ** 11347 ** <li> For each row (primary key) that exists in both tables, but features 11348 ** different non-PK values in each, an UPDATE record is added to the 11349 ** session. 11350 ** </ul> 11351 ** 11352 ** To clarify, if this function is called and then a changeset constructed 11353 ** using [sqlite3session_changeset()], then after applying that changeset to 11354 ** database zFrom the contents of the two compatible tables would be 11355 ** identical. 11356 ** 11357 ** It an error if database zFrom does not exist or does not contain the 11358 ** required compatible table. 11359 ** 11360 ** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite 11361 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 11362 ** may be set to point to a buffer containing an English language error 11363 ** message. It is the responsibility of the caller to free this buffer using 11364 ** sqlite3_free(). 11365 */ 11366 SQLITE_API int sqlite3session_diff( 11367 sqlite3_session *pSession, 11368 const char *zFromDb, 11369 const char *zTbl, 11370 char **pzErrMsg 11371 ); 11372 11373 11374 /* 11375 ** CAPI3REF: Generate A Patchset From A Session Object 11376 ** METHOD: sqlite3_session 11377 ** 11378 ** The differences between a patchset and a changeset are that: 11379 ** 11380 ** <ul> 11381 ** <li> DELETE records consist of the primary key fields only. The 11382 ** original values of other fields are omitted. 11383 ** <li> The original values of any modified fields are omitted from 11384 ** UPDATE records. 11385 ** </ul> 11386 ** 11387 ** A patchset blob may be used with up to date versions of all 11388 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 11389 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 11390 ** attempting to use a patchset blob with old versions of the 11391 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 11392 ** 11393 ** Because the non-primary key "old.*" fields are omitted, no 11394 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 11395 ** is passed to the sqlite3changeset_apply() API. Other conflict types work 11396 ** in the same way as for changesets. 11397 ** 11398 ** Changes within a patchset are ordered in the same way as for changesets 11399 ** generated by the sqlite3session_changeset() function (i.e. all changes for 11400 ** a single table are grouped together, tables appear in the order in which 11401 ** they were attached to the session object). 11402 */ 11403 SQLITE_API int sqlite3session_patchset( 11404 sqlite3_session *pSession, /* Session object */ 11405 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */ 11406 void **ppPatchset /* OUT: Buffer containing patchset */ 11407 ); 11408 11409 /* 11410 ** CAPI3REF: Test if a changeset has recorded any changes. 11411 ** 11412 ** Return non-zero if no changes to attached tables have been recorded by 11413 ** the session object passed as the first argument. Otherwise, if one or 11414 ** more changes have been recorded, return zero. 11415 ** 11416 ** Even if this function returns zero, it is possible that calling 11417 ** [sqlite3session_changeset()] on the session handle may still return a 11418 ** changeset that contains no changes. This can happen when a row in 11419 ** an attached table is modified and then later on the original values 11420 ** are restored. However, if this function returns non-zero, then it is 11421 ** guaranteed that a call to sqlite3session_changeset() will return a 11422 ** changeset containing zero changes. 11423 */ 11424 SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession); 11425 11426 /* 11427 ** CAPI3REF: Query for the amount of heap memory used by a session object. 11428 ** 11429 ** This API returns the total amount of heap memory in bytes currently 11430 ** used by the session object passed as the only argument. 11431 */ 11432 SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession); 11433 11434 /* 11435 ** CAPI3REF: Create An Iterator To Traverse A Changeset 11436 ** CONSTRUCTOR: sqlite3_changeset_iter 11437 ** 11438 ** Create an iterator used to iterate through the contents of a changeset. 11439 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK 11440 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an 11441 ** SQLite error code is returned. 11442 ** 11443 ** The following functions can be used to advance and query a changeset 11444 ** iterator created by this function: 11445 ** 11446 ** <ul> 11447 ** <li> [sqlite3changeset_next()] 11448 ** <li> [sqlite3changeset_op()] 11449 ** <li> [sqlite3changeset_new()] 11450 ** <li> [sqlite3changeset_old()] 11451 ** </ul> 11452 ** 11453 ** It is the responsibility of the caller to eventually destroy the iterator 11454 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 11455 ** changeset (pChangeset) must remain valid until after the iterator is 11456 ** destroyed. 11457 ** 11458 ** Assuming the changeset blob was created by one of the 11459 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 11460 ** [sqlite3changeset_invert()] functions, all changes within the changeset 11461 ** that apply to a single table are grouped together. This means that when 11462 ** an application iterates through a changeset using an iterator created by 11463 ** this function, all changes that relate to a single table are visited 11464 ** consecutively. There is no chance that the iterator will visit a change 11465 ** the applies to table X, then one for table Y, and then later on visit 11466 ** another change for table X. 11467 ** 11468 ** The behavior of sqlite3changeset_start_v2() and its streaming equivalent 11469 ** may be modified by passing a combination of 11470 ** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter. 11471 ** 11472 ** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b> 11473 ** and therefore subject to change. 11474 */ 11475 SQLITE_API int sqlite3changeset_start( 11476 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 11477 int nChangeset, /* Size of changeset blob in bytes */ 11478 void *pChangeset /* Pointer to blob containing changeset */ 11479 ); 11480 SQLITE_API int sqlite3changeset_start_v2( 11481 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 11482 int nChangeset, /* Size of changeset blob in bytes */ 11483 void *pChangeset, /* Pointer to blob containing changeset */ 11484 int flags /* SESSION_CHANGESETSTART_* flags */ 11485 ); 11486 11487 /* 11488 ** CAPI3REF: Flags for sqlite3changeset_start_v2 11489 ** 11490 ** The following flags may passed via the 4th parameter to 11491 ** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]: 11492 ** 11493 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 11494 ** Invert the changeset while iterating through it. This is equivalent to 11495 ** inverting a changeset using sqlite3changeset_invert() before applying it. 11496 ** It is an error to specify this flag with a patchset. 11497 */ 11498 #define SQLITE_CHANGESETSTART_INVERT 0x0002 11499 11500 11501 /* 11502 ** CAPI3REF: Advance A Changeset Iterator 11503 ** METHOD: sqlite3_changeset_iter 11504 ** 11505 ** This function may only be used with iterators created by the function 11506 ** [sqlite3changeset_start()]. If it is called on an iterator passed to 11507 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 11508 ** is returned and the call has no effect. 11509 ** 11510 ** Immediately after an iterator is created by sqlite3changeset_start(), it 11511 ** does not point to any change in the changeset. Assuming the changeset 11512 ** is not empty, the first call to this function advances the iterator to 11513 ** point to the first change in the changeset. Each subsequent call advances 11514 ** the iterator to point to the next change in the changeset (if any). If 11515 ** no error occurs and the iterator points to a valid change after a call 11516 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 11517 ** Otherwise, if all changes in the changeset have already been visited, 11518 ** SQLITE_DONE is returned. 11519 ** 11520 ** If an error occurs, an SQLite error code is returned. Possible error 11521 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 11522 ** SQLITE_NOMEM. 11523 */ 11524 SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 11525 11526 /* 11527 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 11528 ** METHOD: sqlite3_changeset_iter 11529 ** 11530 ** The pIter argument passed to this function may either be an iterator 11531 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 11532 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 11533 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 11534 ** is not the case, this function returns [SQLITE_MISUSE]. 11535 ** 11536 ** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three 11537 ** outputs are set through these pointers: 11538 ** 11539 ** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], 11540 ** depending on the type of change that the iterator currently points to; 11541 ** 11542 ** *pnCol is set to the number of columns in the table affected by the change; and 11543 ** 11544 ** *pzTab is set to point to a nul-terminated utf-8 encoded string containing 11545 ** the name of the table affected by the current change. The buffer remains 11546 ** valid until either sqlite3changeset_next() is called on the iterator 11547 ** or until the conflict-handler function returns. 11548 ** 11549 ** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change 11550 ** is an indirect change, or false (0) otherwise. See the documentation for 11551 ** [sqlite3session_indirect()] for a description of direct and indirect 11552 ** changes. 11553 ** 11554 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an 11555 ** SQLite error code is returned. The values of the output variables may not 11556 ** be trusted in this case. 11557 */ 11558 SQLITE_API int sqlite3changeset_op( 11559 sqlite3_changeset_iter *pIter, /* Iterator object */ 11560 const char **pzTab, /* OUT: Pointer to table name */ 11561 int *pnCol, /* OUT: Number of columns in table */ 11562 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 11563 int *pbIndirect /* OUT: True for an 'indirect' change */ 11564 ); 11565 11566 /* 11567 ** CAPI3REF: Obtain The Primary Key Definition Of A Table 11568 ** METHOD: sqlite3_changeset_iter 11569 ** 11570 ** For each modified table, a changeset includes the following: 11571 ** 11572 ** <ul> 11573 ** <li> The number of columns in the table, and 11574 ** <li> Which of those columns make up the tables PRIMARY KEY. 11575 ** </ul> 11576 ** 11577 ** This function is used to find which columns comprise the PRIMARY KEY of 11578 ** the table modified by the change that iterator pIter currently points to. 11579 ** If successful, *pabPK is set to point to an array of nCol entries, where 11580 ** nCol is the number of columns in the table. Elements of *pabPK are set to 11581 ** 0x01 if the corresponding column is part of the tables primary key, or 11582 ** 0x00 if it is not. 11583 ** 11584 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns 11585 ** in the table. 11586 ** 11587 ** If this function is called when the iterator does not point to a valid 11588 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 11589 ** SQLITE_OK is returned and the output variables populated as described 11590 ** above. 11591 */ 11592 SQLITE_API int sqlite3changeset_pk( 11593 sqlite3_changeset_iter *pIter, /* Iterator object */ 11594 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 11595 int *pnCol /* OUT: Number of entries in output array */ 11596 ); 11597 11598 /* 11599 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator 11600 ** METHOD: sqlite3_changeset_iter 11601 ** 11602 ** The pIter argument passed to this function may either be an iterator 11603 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 11604 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 11605 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 11606 ** Furthermore, it may only be called if the type of change that the iterator 11607 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 11608 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 11609 ** 11610 ** Argument iVal must be greater than or equal to 0, and less than the number 11611 ** of columns in the table affected by the current change. Otherwise, 11612 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 11613 ** 11614 ** If successful, this function sets *ppValue to point to a protected 11615 ** sqlite3_value object containing the iVal'th value from the vector of 11616 ** original row values stored as part of the UPDATE or DELETE change and 11617 ** returns SQLITE_OK. The name of the function comes from the fact that this 11618 ** is similar to the "old.*" columns available to update or delete triggers. 11619 ** 11620 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 11621 ** is returned and *ppValue is set to NULL. 11622 */ 11623 SQLITE_API int sqlite3changeset_old( 11624 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11625 int iVal, /* Column number */ 11626 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 11627 ); 11628 11629 /* 11630 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator 11631 ** METHOD: sqlite3_changeset_iter 11632 ** 11633 ** The pIter argument passed to this function may either be an iterator 11634 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 11635 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 11636 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 11637 ** Furthermore, it may only be called if the type of change that the iterator 11638 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 11639 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 11640 ** 11641 ** Argument iVal must be greater than or equal to 0, and less than the number 11642 ** of columns in the table affected by the current change. Otherwise, 11643 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 11644 ** 11645 ** If successful, this function sets *ppValue to point to a protected 11646 ** sqlite3_value object containing the iVal'th value from the vector of 11647 ** new row values stored as part of the UPDATE or INSERT change and 11648 ** returns SQLITE_OK. If the change is an UPDATE and does not include 11649 ** a new value for the requested column, *ppValue is set to NULL and 11650 ** SQLITE_OK returned. The name of the function comes from the fact that 11651 ** this is similar to the "new.*" columns available to update or delete 11652 ** triggers. 11653 ** 11654 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 11655 ** is returned and *ppValue is set to NULL. 11656 */ 11657 SQLITE_API int sqlite3changeset_new( 11658 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11659 int iVal, /* Column number */ 11660 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 11661 ); 11662 11663 /* 11664 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 11665 ** METHOD: sqlite3_changeset_iter 11666 ** 11667 ** This function should only be used with iterator objects passed to a 11668 ** conflict-handler callback by [sqlite3changeset_apply()] with either 11669 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 11670 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 11671 ** is set to NULL. 11672 ** 11673 ** Argument iVal must be greater than or equal to 0, and less than the number 11674 ** of columns in the table affected by the current change. Otherwise, 11675 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 11676 ** 11677 ** If successful, this function sets *ppValue to point to a protected 11678 ** sqlite3_value object containing the iVal'th value from the 11679 ** "conflicting row" associated with the current conflict-handler callback 11680 ** and returns SQLITE_OK. 11681 ** 11682 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 11683 ** is returned and *ppValue is set to NULL. 11684 */ 11685 SQLITE_API int sqlite3changeset_conflict( 11686 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11687 int iVal, /* Column number */ 11688 sqlite3_value **ppValue /* OUT: Value from conflicting row */ 11689 ); 11690 11691 /* 11692 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 11693 ** METHOD: sqlite3_changeset_iter 11694 ** 11695 ** This function may only be called with an iterator passed to an 11696 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 11697 ** it sets the output variable to the total number of known foreign key 11698 ** violations in the destination database and returns SQLITE_OK. 11699 ** 11700 ** In all other cases this function returns SQLITE_MISUSE. 11701 */ 11702 SQLITE_API int sqlite3changeset_fk_conflicts( 11703 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11704 int *pnOut /* OUT: Number of FK violations */ 11705 ); 11706 11707 11708 /* 11709 ** CAPI3REF: Finalize A Changeset Iterator 11710 ** METHOD: sqlite3_changeset_iter 11711 ** 11712 ** This function is used to finalize an iterator allocated with 11713 ** [sqlite3changeset_start()]. 11714 ** 11715 ** This function should only be called on iterators created using the 11716 ** [sqlite3changeset_start()] function. If an application calls this 11717 ** function with an iterator passed to a conflict-handler by 11718 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 11719 ** call has no effect. 11720 ** 11721 ** If an error was encountered within a call to an sqlite3changeset_xxx() 11722 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 11723 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 11724 ** to that error is returned by this function. Otherwise, SQLITE_OK is 11725 ** returned. This is to allow the following pattern (pseudo-code): 11726 ** 11727 ** <pre> 11728 ** sqlite3changeset_start(); 11729 ** while( SQLITE_ROW==sqlite3changeset_next() ){ 11730 ** // Do something with change. 11731 ** } 11732 ** rc = sqlite3changeset_finalize(); 11733 ** if( rc!=SQLITE_OK ){ 11734 ** // An error has occurred 11735 ** } 11736 ** </pre> 11737 */ 11738 SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 11739 11740 /* 11741 ** CAPI3REF: Invert A Changeset 11742 ** 11743 ** This function is used to "invert" a changeset object. Applying an inverted 11744 ** changeset to a database reverses the effects of applying the uninverted 11745 ** changeset. Specifically: 11746 ** 11747 ** <ul> 11748 ** <li> Each DELETE change is changed to an INSERT, and 11749 ** <li> Each INSERT change is changed to a DELETE, and 11750 ** <li> For each UPDATE change, the old.* and new.* values are exchanged. 11751 ** </ul> 11752 ** 11753 ** This function does not change the order in which changes appear within 11754 ** the changeset. It merely reverses the sense of each individual change. 11755 ** 11756 ** If successful, a pointer to a buffer containing the inverted changeset 11757 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 11758 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 11759 ** zeroed and an SQLite error code returned. 11760 ** 11761 ** It is the responsibility of the caller to eventually call sqlite3_free() 11762 ** on the *ppOut pointer to free the buffer allocation following a successful 11763 ** call to this function. 11764 ** 11765 ** WARNING/TODO: This function currently assumes that the input is a valid 11766 ** changeset. If it is not, the results are undefined. 11767 */ 11768 SQLITE_API int sqlite3changeset_invert( 11769 int nIn, const void *pIn, /* Input changeset */ 11770 int *pnOut, void **ppOut /* OUT: Inverse of input */ 11771 ); 11772 11773 /* 11774 ** CAPI3REF: Concatenate Two Changeset Objects 11775 ** 11776 ** This function is used to concatenate two changesets, A and B, into a 11777 ** single changeset. The result is a changeset equivalent to applying 11778 ** changeset A followed by changeset B. 11779 ** 11780 ** This function combines the two input changesets using an 11781 ** sqlite3_changegroup object. Calling it produces similar results as the 11782 ** following code fragment: 11783 ** 11784 ** <pre> 11785 ** sqlite3_changegroup *pGrp; 11786 ** rc = sqlite3_changegroup_new(&pGrp); 11787 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 11788 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 11789 ** if( rc==SQLITE_OK ){ 11790 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 11791 ** }else{ 11792 ** *ppOut = 0; 11793 ** *pnOut = 0; 11794 ** } 11795 ** </pre> 11796 ** 11797 ** Refer to the sqlite3_changegroup documentation below for details. 11798 */ 11799 SQLITE_API int sqlite3changeset_concat( 11800 int nA, /* Number of bytes in buffer pA */ 11801 void *pA, /* Pointer to buffer containing changeset A */ 11802 int nB, /* Number of bytes in buffer pB */ 11803 void *pB, /* Pointer to buffer containing changeset B */ 11804 int *pnOut, /* OUT: Number of bytes in output changeset */ 11805 void **ppOut /* OUT: Buffer containing output changeset */ 11806 ); 11807 11808 11809 /* 11810 ** CAPI3REF: Upgrade the Schema of a Changeset/Patchset 11811 */ 11812 SQLITE_API int sqlite3changeset_upgrade( 11813 sqlite3 *db, 11814 const char *zDb, 11815 int nIn, const void *pIn, /* Input changeset */ 11816 int *pnOut, void **ppOut /* OUT: Inverse of input */ 11817 ); 11818 11819 11820 11821 /* 11822 ** CAPI3REF: Changegroup Handle 11823 ** 11824 ** A changegroup is an object used to combine two or more 11825 ** [changesets] or [patchsets] 11826 */ 11827 typedef struct sqlite3_changegroup sqlite3_changegroup; 11828 11829 /* 11830 ** CAPI3REF: Create A New Changegroup Object 11831 ** CONSTRUCTOR: sqlite3_changegroup 11832 ** 11833 ** An sqlite3_changegroup object is used to combine two or more changesets 11834 ** (or patchsets) into a single changeset (or patchset). A single changegroup 11835 ** object may combine changesets or patchsets, but not both. The output is 11836 ** always in the same format as the input. 11837 ** 11838 ** If successful, this function returns SQLITE_OK and populates (*pp) with 11839 ** a pointer to a new sqlite3_changegroup object before returning. The caller 11840 ** should eventually free the returned object using a call to 11841 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 11842 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 11843 ** 11844 ** The usual usage pattern for an sqlite3_changegroup object is as follows: 11845 ** 11846 ** <ul> 11847 ** <li> It is created using a call to sqlite3changegroup_new(). 11848 ** 11849 ** <li> Zero or more changesets (or patchsets) are added to the object 11850 ** by calling sqlite3changegroup_add(). 11851 ** 11852 ** <li> The result of combining all input changesets together is obtained 11853 ** by the application via a call to sqlite3changegroup_output(). 11854 ** 11855 ** <li> The object is deleted using a call to sqlite3changegroup_delete(). 11856 ** </ul> 11857 ** 11858 ** Any number of calls to add() and output() may be made between the calls to 11859 ** new() and delete(), and in any order. 11860 ** 11861 ** As well as the regular sqlite3changegroup_add() and 11862 ** sqlite3changegroup_output() functions, also available are the streaming 11863 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 11864 */ 11865 SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp); 11866 11867 /* 11868 ** CAPI3REF: Add a Schema to a Changegroup 11869 ** METHOD: sqlite3_changegroup_schema 11870 ** 11871 ** This method may be used to optionally enforce the rule that the changesets 11872 ** added to the changegroup handle must match the schema of database zDb 11873 ** ("main", "temp", or the name of an attached database). If 11874 ** sqlite3changegroup_add() is called to add a changeset that is not compatible 11875 ** with the configured schema, SQLITE_SCHEMA is returned and the changegroup 11876 ** object is left in an undefined state. 11877 ** 11878 ** A changeset schema is considered compatible with the database schema in 11879 ** the same way as for sqlite3changeset_apply(). Specifically, for each 11880 ** table in the changeset, there exists a database table with: 11881 ** 11882 ** <ul> 11883 ** <li> The name identified by the changeset, and 11884 ** <li> at least as many columns as recorded in the changeset, and 11885 ** <li> the primary key columns in the same position as recorded in 11886 ** the changeset. 11887 ** </ul> 11888 ** 11889 ** The output of the changegroup object always has the same schema as the 11890 ** database nominated using this function. In cases where changesets passed 11891 ** to sqlite3changegroup_add() have fewer columns than the corresponding table 11892 ** in the database schema, these are filled in using the default column 11893 ** values from the database schema. This makes it possible to combined 11894 ** changesets that have different numbers of columns for a single table 11895 ** within a changegroup, provided that they are otherwise compatible. 11896 */ 11897 SQLITE_API int sqlite3changegroup_schema(sqlite3_changegroup*, sqlite3*, const char *zDb); 11898 11899 /* 11900 ** CAPI3REF: Add A Changeset To A Changegroup 11901 ** METHOD: sqlite3_changegroup 11902 ** 11903 ** Add all changes within the changeset (or patchset) in buffer pData (size 11904 ** nData bytes) to the changegroup. 11905 ** 11906 ** If the buffer contains a patchset, then all prior calls to this function 11907 ** on the same changegroup object must also have specified patchsets. Or, if 11908 ** the buffer contains a changeset, so must have the earlier calls to this 11909 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added 11910 ** to the changegroup. 11911 ** 11912 ** Rows within the changeset and changegroup are identified by the values in 11913 ** their PRIMARY KEY columns. A change in the changeset is considered to 11914 ** apply to the same row as a change already present in the changegroup if 11915 ** the two rows have the same primary key. 11916 ** 11917 ** Changes to rows that do not already appear in the changegroup are 11918 ** simply copied into it. Or, if both the new changeset and the changegroup 11919 ** contain changes that apply to a single row, the final contents of the 11920 ** changegroup depends on the type of each change, as follows: 11921 ** 11922 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 11923 ** <tr><th style="white-space:pre">Existing Change </th> 11924 ** <th style="white-space:pre">New Change </th> 11925 ** <th>Output Change 11926 ** <tr><td>INSERT <td>INSERT <td> 11927 ** The new change is ignored. This case does not occur if the new 11928 ** changeset was recorded immediately after the changesets already 11929 ** added to the changegroup. 11930 ** <tr><td>INSERT <td>UPDATE <td> 11931 ** The INSERT change remains in the changegroup. The values in the 11932 ** INSERT change are modified as if the row was inserted by the 11933 ** existing change and then updated according to the new change. 11934 ** <tr><td>INSERT <td>DELETE <td> 11935 ** The existing INSERT is removed from the changegroup. The DELETE is 11936 ** not added. 11937 ** <tr><td>UPDATE <td>INSERT <td> 11938 ** The new change is ignored. This case does not occur if the new 11939 ** changeset was recorded immediately after the changesets already 11940 ** added to the changegroup. 11941 ** <tr><td>UPDATE <td>UPDATE <td> 11942 ** The existing UPDATE remains within the changegroup. It is amended 11943 ** so that the accompanying values are as if the row was updated once 11944 ** by the existing change and then again by the new change. 11945 ** <tr><td>UPDATE <td>DELETE <td> 11946 ** The existing UPDATE is replaced by the new DELETE within the 11947 ** changegroup. 11948 ** <tr><td>DELETE <td>INSERT <td> 11949 ** If one or more of the column values in the row inserted by the 11950 ** new change differ from those in the row deleted by the existing 11951 ** change, the existing DELETE is replaced by an UPDATE within the 11952 ** changegroup. Otherwise, if the inserted row is exactly the same 11953 ** as the deleted row, the existing DELETE is simply discarded. 11954 ** <tr><td>DELETE <td>UPDATE <td> 11955 ** The new change is ignored. This case does not occur if the new 11956 ** changeset was recorded immediately after the changesets already 11957 ** added to the changegroup. 11958 ** <tr><td>DELETE <td>DELETE <td> 11959 ** The new change is ignored. This case does not occur if the new 11960 ** changeset was recorded immediately after the changesets already 11961 ** added to the changegroup. 11962 ** </table> 11963 ** 11964 ** If the new changeset contains changes to a table that is already present 11965 ** in the changegroup, then the number of columns and the position of the 11966 ** primary key columns for the table must be consistent. If this is not the 11967 ** case, this function fails with SQLITE_SCHEMA. Except, if the changegroup 11968 ** object has been configured with a database schema using the 11969 ** sqlite3changegroup_schema() API, then it is possible to combine changesets 11970 ** with different numbers of columns for a single table, provided that 11971 ** they are otherwise compatible. 11972 ** 11973 ** If the input changeset appears to be corrupt and the corruption is 11974 ** detected, SQLITE_CORRUPT is returned. Or, if an out-of-memory condition 11975 ** occurs during processing, this function returns SQLITE_NOMEM. 11976 ** 11977 ** In all cases, if an error occurs the state of the final contents of the 11978 ** changegroup is undefined. If no error occurs, SQLITE_OK is returned. 11979 */ 11980 SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 11981 11982 /* 11983 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup 11984 ** METHOD: sqlite3_changegroup 11985 ** 11986 ** Obtain a buffer containing a changeset (or patchset) representing the 11987 ** current contents of the changegroup. If the inputs to the changegroup 11988 ** were themselves changesets, the output is a changeset. Or, if the 11989 ** inputs were patchsets, the output is also a patchset. 11990 ** 11991 ** As with the output of the sqlite3session_changeset() and 11992 ** sqlite3session_patchset() functions, all changes related to a single 11993 ** table are grouped together in the output of this function. Tables appear 11994 ** in the same order as for the very first changeset added to the changegroup. 11995 ** If the second or subsequent changesets added to the changegroup contain 11996 ** changes for tables that do not appear in the first changeset, they are 11997 ** appended onto the end of the output changeset, again in the order in 11998 ** which they are first encountered. 11999 ** 12000 ** If an error occurs, an SQLite error code is returned and the output 12001 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 12002 ** is returned and the output variables are set to the size of and a 12003 ** pointer to the output buffer, respectively. In this case it is the 12004 ** responsibility of the caller to eventually free the buffer using a 12005 ** call to sqlite3_free(). 12006 */ 12007 SQLITE_API int sqlite3changegroup_output( 12008 sqlite3_changegroup*, 12009 int *pnData, /* OUT: Size of output buffer in bytes */ 12010 void **ppData /* OUT: Pointer to output buffer */ 12011 ); 12012 12013 /* 12014 ** CAPI3REF: Delete A Changegroup Object 12015 ** DESTRUCTOR: sqlite3_changegroup 12016 */ 12017 SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*); 12018 12019 /* 12020 ** CAPI3REF: Apply A Changeset To A Database 12021 ** 12022 ** Apply a changeset or patchset to a database. These functions attempt to 12023 ** update the "main" database attached to handle db with the changes found in 12024 ** the changeset passed via the second and third arguments. 12025 ** 12026 ** The fourth argument (xFilter) passed to these functions is the "filter 12027 ** callback". If it is not NULL, then for each table affected by at least one 12028 ** change in the changeset, the filter callback is invoked with 12029 ** the table name as the second argument, and a copy of the context pointer 12030 ** passed as the sixth argument as the first. If the "filter callback" 12031 ** returns zero, then no attempt is made to apply any changes to the table. 12032 ** Otherwise, if the return value is non-zero or the xFilter argument to 12033 ** is NULL, all changes related to the table are attempted. 12034 ** 12035 ** For each table that is not excluded by the filter callback, this function 12036 ** tests that the target database contains a compatible table. A table is 12037 ** considered compatible if all of the following are true: 12038 ** 12039 ** <ul> 12040 ** <li> The table has the same name as the name recorded in the 12041 ** changeset, and 12042 ** <li> The table has at least as many columns as recorded in the 12043 ** changeset, and 12044 ** <li> The table has primary key columns in the same position as 12045 ** recorded in the changeset. 12046 ** </ul> 12047 ** 12048 ** If there is no compatible table, it is not an error, but none of the 12049 ** changes associated with the table are applied. A warning message is issued 12050 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 12051 ** one such warning is issued for each table in the changeset. 12052 ** 12053 ** For each change for which there is a compatible table, an attempt is made 12054 ** to modify the table contents according to the UPDATE, INSERT or DELETE 12055 ** change. If a change cannot be applied cleanly, the conflict handler 12056 ** function passed as the fifth argument to sqlite3changeset_apply() may be 12057 ** invoked. A description of exactly when the conflict handler is invoked for 12058 ** each type of change is below. 12059 ** 12060 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results 12061 ** of passing anything other than a valid function pointer as the xConflict 12062 ** argument are undefined. 12063 ** 12064 ** Each time the conflict handler function is invoked, it must return one 12065 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 12066 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 12067 ** if the second argument passed to the conflict handler is either 12068 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 12069 ** returns an illegal value, any changes already made are rolled back and 12070 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 12071 ** actions are taken by sqlite3changeset_apply() depending on the value 12072 ** returned by each invocation of the conflict-handler function. Refer to 12073 ** the documentation for the three 12074 ** [SQLITE_CHANGESET_OMIT|available return values] for details. 12075 ** 12076 ** <dl> 12077 ** <dt>DELETE Changes<dd> 12078 ** For each DELETE change, the function checks if the target database 12079 ** contains a row with the same primary key value (or values) as the 12080 ** original row values stored in the changeset. If it does, and the values 12081 ** stored in all non-primary key columns also match the values stored in 12082 ** the changeset the row is deleted from the target database. 12083 ** 12084 ** If a row with matching primary key values is found, but one or more of 12085 ** the non-primary key fields contains a value different from the original 12086 ** row value stored in the changeset, the conflict-handler function is 12087 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the 12088 ** database table has more columns than are recorded in the changeset, 12089 ** only the values of those non-primary key fields are compared against 12090 ** the current database contents - any trailing database table columns 12091 ** are ignored. 12092 ** 12093 ** If no row with matching primary key values is found in the database, 12094 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 12095 ** passed as the second argument. 12096 ** 12097 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 12098 ** (which can only happen if a foreign key constraint is violated), the 12099 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 12100 ** passed as the second argument. This includes the case where the DELETE 12101 ** operation is attempted because an earlier call to the conflict handler 12102 ** function returned [SQLITE_CHANGESET_REPLACE]. 12103 ** 12104 ** <dt>INSERT Changes<dd> 12105 ** For each INSERT change, an attempt is made to insert the new row into 12106 ** the database. If the changeset row contains fewer fields than the 12107 ** database table, the trailing fields are populated with their default 12108 ** values. 12109 ** 12110 ** If the attempt to insert the row fails because the database already 12111 ** contains a row with the same primary key values, the conflict handler 12112 ** function is invoked with the second argument set to 12113 ** [SQLITE_CHANGESET_CONFLICT]. 12114 ** 12115 ** If the attempt to insert the row fails because of some other constraint 12116 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 12117 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 12118 ** This includes the case where the INSERT operation is re-attempted because 12119 ** an earlier call to the conflict handler function returned 12120 ** [SQLITE_CHANGESET_REPLACE]. 12121 ** 12122 ** <dt>UPDATE Changes<dd> 12123 ** For each UPDATE change, the function checks if the target database 12124 ** contains a row with the same primary key value (or values) as the 12125 ** original row values stored in the changeset. If it does, and the values 12126 ** stored in all modified non-primary key columns also match the values 12127 ** stored in the changeset the row is updated within the target database. 12128 ** 12129 ** If a row with matching primary key values is found, but one or more of 12130 ** the modified non-primary key fields contains a value different from an 12131 ** original row value stored in the changeset, the conflict-handler function 12132 ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 12133 ** UPDATE changes only contain values for non-primary key fields that are 12134 ** to be modified, only those fields need to match the original values to 12135 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 12136 ** 12137 ** If no row with matching primary key values is found in the database, 12138 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 12139 ** passed as the second argument. 12140 ** 12141 ** If the UPDATE operation is attempted, but SQLite returns 12142 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 12143 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 12144 ** This includes the case where the UPDATE operation is attempted after 12145 ** an earlier call to the conflict handler function returned 12146 ** [SQLITE_CHANGESET_REPLACE]. 12147 ** </dl> 12148 ** 12149 ** It is safe to execute SQL statements, including those that write to the 12150 ** table that the callback related to, from within the xConflict callback. 12151 ** This can be used to further customize the application's conflict 12152 ** resolution strategy. 12153 ** 12154 ** All changes made by these functions are enclosed in a savepoint transaction. 12155 ** If any other error (aside from a constraint failure when attempting to 12156 ** write to the target database) occurs, then the savepoint transaction is 12157 ** rolled back, restoring the target database to its original state, and an 12158 ** SQLite error code returned. 12159 ** 12160 ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and 12161 ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2() 12162 ** may set (*ppRebase) to point to a "rebase" that may be used with the 12163 ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase) 12164 ** is set to the size of the buffer in bytes. It is the responsibility of the 12165 ** caller to eventually free any such buffer using sqlite3_free(). The buffer 12166 ** is only allocated and populated if one or more conflicts were encountered 12167 ** while applying the patchset. See comments surrounding the sqlite3_rebaser 12168 ** APIs for further details. 12169 ** 12170 ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent 12171 ** may be modified by passing a combination of 12172 ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter. 12173 ** 12174 ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b> 12175 ** and therefore subject to change. 12176 */ 12177 SQLITE_API int sqlite3changeset_apply( 12178 sqlite3 *db, /* Apply change to "main" db of this handle */ 12179 int nChangeset, /* Size of changeset in bytes */ 12180 void *pChangeset, /* Changeset blob */ 12181 int(*xFilter)( 12182 void *pCtx, /* Copy of sixth arg to _apply() */ 12183 const char *zTab /* Table name */ 12184 ), 12185 int(*xConflict)( 12186 void *pCtx, /* Copy of sixth arg to _apply() */ 12187 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 12188 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 12189 ), 12190 void *pCtx /* First argument passed to xConflict */ 12191 ); 12192 SQLITE_API int sqlite3changeset_apply_v2( 12193 sqlite3 *db, /* Apply change to "main" db of this handle */ 12194 int nChangeset, /* Size of changeset in bytes */ 12195 void *pChangeset, /* Changeset blob */ 12196 int(*xFilter)( 12197 void *pCtx, /* Copy of sixth arg to _apply() */ 12198 const char *zTab /* Table name */ 12199 ), 12200 int(*xConflict)( 12201 void *pCtx, /* Copy of sixth arg to _apply() */ 12202 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 12203 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 12204 ), 12205 void *pCtx, /* First argument passed to xConflict */ 12206 void **ppRebase, int *pnRebase, /* OUT: Rebase data */ 12207 int flags /* SESSION_CHANGESETAPPLY_* flags */ 12208 ); 12209 12210 /* 12211 ** CAPI3REF: Flags for sqlite3changeset_apply_v2 12212 ** 12213 ** The following flags may passed via the 9th parameter to 12214 ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]: 12215 ** 12216 ** <dl> 12217 ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd> 12218 ** Usually, the sessions module encloses all operations performed by 12219 ** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The 12220 ** SAVEPOINT is committed if the changeset or patchset is successfully 12221 ** applied, or rolled back if an error occurs. Specifying this flag 12222 ** causes the sessions module to omit this savepoint. In this case, if the 12223 ** caller has an open transaction or savepoint when apply_v2() is called, 12224 ** it may revert the partially applied changeset by rolling it back. 12225 ** 12226 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 12227 ** Invert the changeset before applying it. This is equivalent to inverting 12228 ** a changeset using sqlite3changeset_invert() before applying it. It is 12229 ** an error to specify this flag with a patchset. 12230 ** 12231 ** <dt>SQLITE_CHANGESETAPPLY_IGNORENOOP <dd> 12232 ** Do not invoke the conflict handler callback for any changes that 12233 ** would not actually modify the database even if they were applied. 12234 ** Specifically, this means that the conflict handler is not invoked 12235 ** for: 12236 ** <ul> 12237 ** <li>a delete change if the row being deleted cannot be found, 12238 ** <li>an update change if the modified fields are already set to 12239 ** their new values in the conflicting row, or 12240 ** <li>an insert change if all fields of the conflicting row match 12241 ** the row being inserted. 12242 ** </ul> 12243 ** 12244 ** <dt>SQLITE_CHANGESETAPPLY_FKNOACTION <dd> 12245 ** If this flag it set, then all foreign key constraints in the target 12246 ** database behave as if they were declared with "ON UPDATE NO ACTION ON 12247 ** DELETE NO ACTION", even if they are actually CASCADE, RESTRICT, SET NULL 12248 ** or SET DEFAULT. 12249 */ 12250 #define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001 12251 #define SQLITE_CHANGESETAPPLY_INVERT 0x0002 12252 #define SQLITE_CHANGESETAPPLY_IGNORENOOP 0x0004 12253 #define SQLITE_CHANGESETAPPLY_FKNOACTION 0x0008 12254 12255 /* 12256 ** CAPI3REF: Constants Passed To The Conflict Handler 12257 ** 12258 ** Values that may be passed as the second argument to a conflict-handler. 12259 ** 12260 ** <dl> 12261 ** <dt>SQLITE_CHANGESET_DATA<dd> 12262 ** The conflict handler is invoked with CHANGESET_DATA as the second argument 12263 ** when processing a DELETE or UPDATE change if a row with the required 12264 ** PRIMARY KEY fields is present in the database, but one or more other 12265 ** (non primary-key) fields modified by the update do not contain the 12266 ** expected "before" values. 12267 ** 12268 ** The conflicting row, in this case, is the database row with the matching 12269 ** primary key. 12270 ** 12271 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 12272 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 12273 ** argument when processing a DELETE or UPDATE change if a row with the 12274 ** required PRIMARY KEY fields is not present in the database. 12275 ** 12276 ** There is no conflicting row in this case. The results of invoking the 12277 ** sqlite3changeset_conflict() API are undefined. 12278 ** 12279 ** <dt>SQLITE_CHANGESET_CONFLICT<dd> 12280 ** CHANGESET_CONFLICT is passed as the second argument to the conflict 12281 ** handler while processing an INSERT change if the operation would result 12282 ** in duplicate primary key values. 12283 ** 12284 ** The conflicting row in this case is the database row with the matching 12285 ** primary key. 12286 ** 12287 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 12288 ** If foreign key handling is enabled, and applying a changeset leaves the 12289 ** database in a state containing foreign key violations, the conflict 12290 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 12291 ** exactly once before the changeset is committed. If the conflict handler 12292 ** returns CHANGESET_OMIT, the changes, including those that caused the 12293 ** foreign key constraint violation, are committed. Or, if it returns 12294 ** CHANGESET_ABORT, the changeset is rolled back. 12295 ** 12296 ** No current or conflicting row information is provided. The only function 12297 ** it is possible to call on the supplied sqlite3_changeset_iter handle 12298 ** is sqlite3changeset_fk_conflicts(). 12299 ** 12300 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 12301 ** If any other constraint violation occurs while applying a change (i.e. 12302 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 12303 ** invoked with CHANGESET_CONSTRAINT as the second argument. 12304 ** 12305 ** There is no conflicting row in this case. The results of invoking the 12306 ** sqlite3changeset_conflict() API are undefined. 12307 ** 12308 ** </dl> 12309 */ 12310 #define SQLITE_CHANGESET_DATA 1 12311 #define SQLITE_CHANGESET_NOTFOUND 2 12312 #define SQLITE_CHANGESET_CONFLICT 3 12313 #define SQLITE_CHANGESET_CONSTRAINT 4 12314 #define SQLITE_CHANGESET_FOREIGN_KEY 5 12315 12316 /* 12317 ** CAPI3REF: Constants Returned By The Conflict Handler 12318 ** 12319 ** A conflict handler callback must return one of the following three values. 12320 ** 12321 ** <dl> 12322 ** <dt>SQLITE_CHANGESET_OMIT<dd> 12323 ** If a conflict handler returns this value no special action is taken. The 12324 ** change that caused the conflict is not applied. The session module 12325 ** continues to the next change in the changeset. 12326 ** 12327 ** <dt>SQLITE_CHANGESET_REPLACE<dd> 12328 ** This value may only be returned if the second argument to the conflict 12329 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 12330 ** is not the case, any changes applied so far are rolled back and the 12331 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 12332 ** 12333 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 12334 ** handler, then the conflicting row is either updated or deleted, depending 12335 ** on the type of change. 12336 ** 12337 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 12338 ** handler, then the conflicting row is removed from the database and a 12339 ** second attempt to apply the change is made. If this second attempt fails, 12340 ** the original row is restored to the database before continuing. 12341 ** 12342 ** <dt>SQLITE_CHANGESET_ABORT<dd> 12343 ** If this value is returned, any changes applied so far are rolled back 12344 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 12345 ** </dl> 12346 */ 12347 #define SQLITE_CHANGESET_OMIT 0 12348 #define SQLITE_CHANGESET_REPLACE 1 12349 #define SQLITE_CHANGESET_ABORT 2 12350 12351 /* 12352 ** CAPI3REF: Rebasing changesets 12353 ** EXPERIMENTAL 12354 ** 12355 ** Suppose there is a site hosting a database in state S0. And that 12356 ** modifications are made that move that database to state S1 and a 12357 ** changeset recorded (the "local" changeset). Then, a changeset based 12358 ** on S0 is received from another site (the "remote" changeset) and 12359 ** applied to the database. The database is then in state 12360 ** (S1+"remote"), where the exact state depends on any conflict 12361 ** resolution decisions (OMIT or REPLACE) made while applying "remote". 12362 ** Rebasing a changeset is to update it to take those conflict 12363 ** resolution decisions into account, so that the same conflicts 12364 ** do not have to be resolved elsewhere in the network. 12365 ** 12366 ** For example, if both the local and remote changesets contain an 12367 ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)": 12368 ** 12369 ** local: INSERT INTO t1 VALUES(1, 'v1'); 12370 ** remote: INSERT INTO t1 VALUES(1, 'v2'); 12371 ** 12372 ** and the conflict resolution is REPLACE, then the INSERT change is 12373 ** removed from the local changeset (it was overridden). Or, if the 12374 ** conflict resolution was "OMIT", then the local changeset is modified 12375 ** to instead contain: 12376 ** 12377 ** UPDATE t1 SET b = 'v2' WHERE a=1; 12378 ** 12379 ** Changes within the local changeset are rebased as follows: 12380 ** 12381 ** <dl> 12382 ** <dt>Local INSERT<dd> 12383 ** This may only conflict with a remote INSERT. If the conflict 12384 ** resolution was OMIT, then add an UPDATE change to the rebased 12385 ** changeset. Or, if the conflict resolution was REPLACE, add 12386 ** nothing to the rebased changeset. 12387 ** 12388 ** <dt>Local DELETE<dd> 12389 ** This may conflict with a remote UPDATE or DELETE. In both cases the 12390 ** only possible resolution is OMIT. If the remote operation was a 12391 ** DELETE, then add no change to the rebased changeset. If the remote 12392 ** operation was an UPDATE, then the old.* fields of change are updated 12393 ** to reflect the new.* values in the UPDATE. 12394 ** 12395 ** <dt>Local UPDATE<dd> 12396 ** This may conflict with a remote UPDATE or DELETE. If it conflicts 12397 ** with a DELETE, and the conflict resolution was OMIT, then the update 12398 ** is changed into an INSERT. Any undefined values in the new.* record 12399 ** from the update change are filled in using the old.* values from 12400 ** the conflicting DELETE. Or, if the conflict resolution was REPLACE, 12401 ** the UPDATE change is simply omitted from the rebased changeset. 12402 ** 12403 ** If conflict is with a remote UPDATE and the resolution is OMIT, then 12404 ** the old.* values are rebased using the new.* values in the remote 12405 ** change. Or, if the resolution is REPLACE, then the change is copied 12406 ** into the rebased changeset with updates to columns also updated by 12407 ** the conflicting remote UPDATE removed. If this means no columns would 12408 ** be updated, the change is omitted. 12409 ** </dl> 12410 ** 12411 ** A local change may be rebased against multiple remote changes 12412 ** simultaneously. If a single key is modified by multiple remote 12413 ** changesets, they are combined as follows before the local changeset 12414 ** is rebased: 12415 ** 12416 ** <ul> 12417 ** <li> If there has been one or more REPLACE resolutions on a 12418 ** key, it is rebased according to a REPLACE. 12419 ** 12420 ** <li> If there have been no REPLACE resolutions on a key, then 12421 ** the local changeset is rebased according to the most recent 12422 ** of the OMIT resolutions. 12423 ** </ul> 12424 ** 12425 ** Note that conflict resolutions from multiple remote changesets are 12426 ** combined on a per-field basis, not per-row. This means that in the 12427 ** case of multiple remote UPDATE operations, some fields of a single 12428 ** local change may be rebased for REPLACE while others are rebased for 12429 ** OMIT. 12430 ** 12431 ** In order to rebase a local changeset, the remote changeset must first 12432 ** be applied to the local database using sqlite3changeset_apply_v2() and 12433 ** the buffer of rebase information captured. Then: 12434 ** 12435 ** <ol> 12436 ** <li> An sqlite3_rebaser object is created by calling 12437 ** sqlite3rebaser_create(). 12438 ** <li> The new object is configured with the rebase buffer obtained from 12439 ** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure(). 12440 ** If the local changeset is to be rebased against multiple remote 12441 ** changesets, then sqlite3rebaser_configure() should be called 12442 ** multiple times, in the same order that the multiple 12443 ** sqlite3changeset_apply_v2() calls were made. 12444 ** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase(). 12445 ** <li> The sqlite3_rebaser object is deleted by calling 12446 ** sqlite3rebaser_delete(). 12447 ** </ol> 12448 */ 12449 typedef struct sqlite3_rebaser sqlite3_rebaser; 12450 12451 /* 12452 ** CAPI3REF: Create a changeset rebaser object. 12453 ** EXPERIMENTAL 12454 ** 12455 ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to 12456 ** point to the new object and return SQLITE_OK. Otherwise, if an error 12457 ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew) 12458 ** to NULL. 12459 */ 12460 SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew); 12461 12462 /* 12463 ** CAPI3REF: Configure a changeset rebaser object. 12464 ** EXPERIMENTAL 12465 ** 12466 ** Configure the changeset rebaser object to rebase changesets according 12467 ** to the conflict resolutions described by buffer pRebase (size nRebase 12468 ** bytes), which must have been obtained from a previous call to 12469 ** sqlite3changeset_apply_v2(). 12470 */ 12471 SQLITE_API int sqlite3rebaser_configure( 12472 sqlite3_rebaser*, 12473 int nRebase, const void *pRebase 12474 ); 12475 12476 /* 12477 ** CAPI3REF: Rebase a changeset 12478 ** EXPERIMENTAL 12479 ** 12480 ** Argument pIn must point to a buffer containing a changeset nIn bytes 12481 ** in size. This function allocates and populates a buffer with a copy 12482 ** of the changeset rebased according to the configuration of the 12483 ** rebaser object passed as the first argument. If successful, (*ppOut) 12484 ** is set to point to the new buffer containing the rebased changeset and 12485 ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the 12486 ** responsibility of the caller to eventually free the new buffer using 12487 ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut) 12488 ** are set to zero and an SQLite error code returned. 12489 */ 12490 SQLITE_API int sqlite3rebaser_rebase( 12491 sqlite3_rebaser*, 12492 int nIn, const void *pIn, 12493 int *pnOut, void **ppOut 12494 ); 12495 12496 /* 12497 ** CAPI3REF: Delete a changeset rebaser object. 12498 ** EXPERIMENTAL 12499 ** 12500 ** Delete the changeset rebaser object and all associated resources. There 12501 ** should be one call to this function for each successful invocation 12502 ** of sqlite3rebaser_create(). 12503 */ 12504 SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p); 12505 12506 /* 12507 ** CAPI3REF: Streaming Versions of API functions. 12508 ** 12509 ** The six streaming API xxx_strm() functions serve similar purposes to the 12510 ** corresponding non-streaming API functions: 12511 ** 12512 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 12513 ** <tr><th>Streaming function<th>Non-streaming equivalent</th> 12514 ** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply] 12515 ** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2] 12516 ** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat] 12517 ** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert] 12518 ** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start] 12519 ** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset] 12520 ** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset] 12521 ** </table> 12522 ** 12523 ** Non-streaming functions that accept changesets (or patchsets) as input 12524 ** require that the entire changeset be stored in a single buffer in memory. 12525 ** Similarly, those that return a changeset or patchset do so by returning 12526 ** a pointer to a single large buffer allocated using sqlite3_malloc(). 12527 ** Normally this is convenient. However, if an application running in a 12528 ** low-memory environment is required to handle very large changesets, the 12529 ** large contiguous memory allocations required can become onerous. 12530 ** 12531 ** In order to avoid this problem, instead of a single large buffer, input 12532 ** is passed to a streaming API functions by way of a callback function that 12533 ** the sessions module invokes to incrementally request input data as it is 12534 ** required. In all cases, a pair of API function parameters such as 12535 ** 12536 ** <pre> 12537 ** int nChangeset, 12538 ** void *pChangeset, 12539 ** </pre> 12540 ** 12541 ** Is replaced by: 12542 ** 12543 ** <pre> 12544 ** int (*xInput)(void *pIn, void *pData, int *pnData), 12545 ** void *pIn, 12546 ** </pre> 12547 ** 12548 ** Each time the xInput callback is invoked by the sessions module, the first 12549 ** argument passed is a copy of the supplied pIn context pointer. The second 12550 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 12551 ** error occurs the xInput method should copy up to (*pnData) bytes of data 12552 ** into the buffer and set (*pnData) to the actual number of bytes copied 12553 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 12554 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite 12555 ** error code should be returned. In all cases, if an xInput callback returns 12556 ** an error, all processing is abandoned and the streaming API function 12557 ** returns a copy of the error code to the caller. 12558 ** 12559 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be 12560 ** invoked by the sessions module at any point during the lifetime of the 12561 ** iterator. If such an xInput callback returns an error, the iterator enters 12562 ** an error state, whereby all subsequent calls to iterator functions 12563 ** immediately fail with the same error code as returned by xInput. 12564 ** 12565 ** Similarly, streaming API functions that return changesets (or patchsets) 12566 ** return them in chunks by way of a callback function instead of via a 12567 ** pointer to a single large buffer. In this case, a pair of parameters such 12568 ** as: 12569 ** 12570 ** <pre> 12571 ** int *pnChangeset, 12572 ** void **ppChangeset, 12573 ** </pre> 12574 ** 12575 ** Is replaced by: 12576 ** 12577 ** <pre> 12578 ** int (*xOutput)(void *pOut, const void *pData, int nData), 12579 ** void *pOut 12580 ** </pre> 12581 ** 12582 ** The xOutput callback is invoked zero or more times to return data to 12583 ** the application. The first parameter passed to each call is a copy of the 12584 ** pOut pointer supplied by the application. The second parameter, pData, 12585 ** points to a buffer nData bytes in size containing the chunk of output 12586 ** data being returned. If the xOutput callback successfully processes the 12587 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 12588 ** it should return some other SQLite error code. In this case processing 12589 ** is immediately abandoned and the streaming API function returns a copy 12590 ** of the xOutput error code to the application. 12591 ** 12592 ** The sessions module never invokes an xOutput callback with the third 12593 ** parameter set to a value less than or equal to zero. Other than this, 12594 ** no guarantees are made as to the size of the chunks of data returned. 12595 */ 12596 SQLITE_API int sqlite3changeset_apply_strm( 12597 sqlite3 *db, /* Apply change to "main" db of this handle */ 12598 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 12599 void *pIn, /* First arg for xInput */ 12600 int(*xFilter)( 12601 void *pCtx, /* Copy of sixth arg to _apply() */ 12602 const char *zTab /* Table name */ 12603 ), 12604 int(*xConflict)( 12605 void *pCtx, /* Copy of sixth arg to _apply() */ 12606 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 12607 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 12608 ), 12609 void *pCtx /* First argument passed to xConflict */ 12610 ); 12611 SQLITE_API int sqlite3changeset_apply_v2_strm( 12612 sqlite3 *db, /* Apply change to "main" db of this handle */ 12613 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 12614 void *pIn, /* First arg for xInput */ 12615 int(*xFilter)( 12616 void *pCtx, /* Copy of sixth arg to _apply() */ 12617 const char *zTab /* Table name */ 12618 ), 12619 int(*xConflict)( 12620 void *pCtx, /* Copy of sixth arg to _apply() */ 12621 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 12622 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 12623 ), 12624 void *pCtx, /* First argument passed to xConflict */ 12625 void **ppRebase, int *pnRebase, 12626 int flags 12627 ); 12628 SQLITE_API int sqlite3changeset_concat_strm( 12629 int (*xInputA)(void *pIn, void *pData, int *pnData), 12630 void *pInA, 12631 int (*xInputB)(void *pIn, void *pData, int *pnData), 12632 void *pInB, 12633 int (*xOutput)(void *pOut, const void *pData, int nData), 12634 void *pOut 12635 ); 12636 SQLITE_API int sqlite3changeset_invert_strm( 12637 int (*xInput)(void *pIn, void *pData, int *pnData), 12638 void *pIn, 12639 int (*xOutput)(void *pOut, const void *pData, int nData), 12640 void *pOut 12641 ); 12642 SQLITE_API int sqlite3changeset_start_strm( 12643 sqlite3_changeset_iter **pp, 12644 int (*xInput)(void *pIn, void *pData, int *pnData), 12645 void *pIn 12646 ); 12647 SQLITE_API int sqlite3changeset_start_v2_strm( 12648 sqlite3_changeset_iter **pp, 12649 int (*xInput)(void *pIn, void *pData, int *pnData), 12650 void *pIn, 12651 int flags 12652 ); 12653 SQLITE_API int sqlite3session_changeset_strm( 12654 sqlite3_session *pSession, 12655 int (*xOutput)(void *pOut, const void *pData, int nData), 12656 void *pOut 12657 ); 12658 SQLITE_API int sqlite3session_patchset_strm( 12659 sqlite3_session *pSession, 12660 int (*xOutput)(void *pOut, const void *pData, int nData), 12661 void *pOut 12662 ); 12663 SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*, 12664 int (*xInput)(void *pIn, void *pData, int *pnData), 12665 void *pIn 12666 ); 12667 SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*, 12668 int (*xOutput)(void *pOut, const void *pData, int nData), 12669 void *pOut 12670 ); 12671 SQLITE_API int sqlite3rebaser_rebase_strm( 12672 sqlite3_rebaser *pRebaser, 12673 int (*xInput)(void *pIn, void *pData, int *pnData), 12674 void *pIn, 12675 int (*xOutput)(void *pOut, const void *pData, int nData), 12676 void *pOut 12677 ); 12678 12679 /* 12680 ** CAPI3REF: Configure global parameters 12681 ** 12682 ** The sqlite3session_config() interface is used to make global configuration 12683 ** changes to the sessions module in order to tune it to the specific needs 12684 ** of the application. 12685 ** 12686 ** The sqlite3session_config() interface is not threadsafe. If it is invoked 12687 ** while any other thread is inside any other sessions method then the 12688 ** results are undefined. Furthermore, if it is invoked after any sessions 12689 ** related objects have been created, the results are also undefined. 12690 ** 12691 ** The first argument to the sqlite3session_config() function must be one 12692 ** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The 12693 ** interpretation of the (void*) value passed as the second parameter and 12694 ** the effect of calling this function depends on the value of the first 12695 ** parameter. 12696 ** 12697 ** <dl> 12698 ** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd> 12699 ** By default, the sessions module streaming interfaces attempt to input 12700 ** and output data in approximately 1 KiB chunks. This operand may be used 12701 ** to set and query the value of this configuration setting. The pointer 12702 ** passed as the second argument must point to a value of type (int). 12703 ** If this value is greater than 0, it is used as the new streaming data 12704 ** chunk size for both input and output. Before returning, the (int) value 12705 ** pointed to by pArg is set to the final value of the streaming interface 12706 ** chunk size. 12707 ** </dl> 12708 ** 12709 ** This function returns SQLITE_OK if successful, or an SQLite error code 12710 ** otherwise. 12711 */ 12712 SQLITE_API int sqlite3session_config(int op, void *pArg); 12713 12714 /* 12715 ** CAPI3REF: Values for sqlite3session_config(). 12716 */ 12717 #define SQLITE_SESSION_CONFIG_STRMSIZE 1 12718 12719 /* 12720 ** Make sure we can call this stuff from C++. 12721 */ 12722 #ifdef __cplusplus 12723 } 12724 #endif 12725 12726 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 12727 12728 /******** End of sqlite3session.h *********/ 12729 /******** Begin file fts5.h *********/ 12730 /* 12731 ** 2014 May 31 12732 ** 12733 ** The author disclaims copyright to this source code. In place of 12734 ** a legal notice, here is a blessing: 12735 ** 12736 ** May you do good and not evil. 12737 ** May you find forgiveness for yourself and forgive others. 12738 ** May you share freely, never taking more than you give. 12739 ** 12740 ****************************************************************************** 12741 ** 12742 ** Interfaces to extend FTS5. Using the interfaces defined in this file, 12743 ** FTS5 may be extended with: 12744 ** 12745 ** * custom tokenizers, and 12746 ** * custom auxiliary functions. 12747 */ 12748 12749 12750 #ifndef _FTS5_H 12751 #define _FTS5_H 12752 12753 12754 #ifdef __cplusplus 12755 extern "C" { 12756 #endif 12757 12758 /************************************************************************* 12759 ** CUSTOM AUXILIARY FUNCTIONS 12760 ** 12761 ** Virtual table implementations may overload SQL functions by implementing 12762 ** the sqlite3_module.xFindFunction() method. 12763 */ 12764 12765 typedef struct Fts5ExtensionApi Fts5ExtensionApi; 12766 typedef struct Fts5Context Fts5Context; 12767 typedef struct Fts5PhraseIter Fts5PhraseIter; 12768 12769 typedef void (*fts5_extension_function)( 12770 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 12771 Fts5Context *pFts, /* First arg to pass to pApi functions */ 12772 sqlite3_context *pCtx, /* Context for returning result/error */ 12773 int nVal, /* Number of values in apVal[] array */ 12774 sqlite3_value **apVal /* Array of trailing arguments */ 12775 ); 12776 12777 struct Fts5PhraseIter { 12778 const unsigned char *a; 12779 const unsigned char *b; 12780 }; 12781 12782 /* 12783 ** EXTENSION API FUNCTIONS 12784 ** 12785 ** xUserData(pFts): 12786 ** Return a copy of the context pointer the extension function was 12787 ** registered with. 12788 ** 12789 ** xColumnTotalSize(pFts, iCol, pnToken): 12790 ** If parameter iCol is less than zero, set output variable *pnToken 12791 ** to the total number of tokens in the FTS5 table. Or, if iCol is 12792 ** non-negative but less than the number of columns in the table, return 12793 ** the total number of tokens in column iCol, considering all rows in 12794 ** the FTS5 table. 12795 ** 12796 ** If parameter iCol is greater than or equal to the number of columns 12797 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 12798 ** an OOM condition or IO error), an appropriate SQLite error code is 12799 ** returned. 12800 ** 12801 ** xColumnCount(pFts): 12802 ** Return the number of columns in the table. 12803 ** 12804 ** xColumnSize(pFts, iCol, pnToken): 12805 ** If parameter iCol is less than zero, set output variable *pnToken 12806 ** to the total number of tokens in the current row. Or, if iCol is 12807 ** non-negative but less than the number of columns in the table, set 12808 ** *pnToken to the number of tokens in column iCol of the current row. 12809 ** 12810 ** If parameter iCol is greater than or equal to the number of columns 12811 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 12812 ** an OOM condition or IO error), an appropriate SQLite error code is 12813 ** returned. 12814 ** 12815 ** This function may be quite inefficient if used with an FTS5 table 12816 ** created with the "columnsize=0" option. 12817 ** 12818 ** xColumnText: 12819 ** If parameter iCol is less than zero, or greater than or equal to the 12820 ** number of columns in the table, SQLITE_RANGE is returned. 12821 ** 12822 ** Otherwise, this function attempts to retrieve the text of column iCol of 12823 ** the current document. If successful, (*pz) is set to point to a buffer 12824 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 12825 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 12826 ** if an error occurs, an SQLite error code is returned and the final values 12827 ** of (*pz) and (*pn) are undefined. 12828 ** 12829 ** xPhraseCount: 12830 ** Returns the number of phrases in the current query expression. 12831 ** 12832 ** xPhraseSize: 12833 ** If parameter iCol is less than zero, or greater than or equal to the 12834 ** number of phrases in the current query, as returned by xPhraseCount, 12835 ** 0 is returned. Otherwise, this function returns the number of tokens in 12836 ** phrase iPhrase of the query. Phrases are numbered starting from zero. 12837 ** 12838 ** xInstCount: 12839 ** Set *pnInst to the total number of occurrences of all phrases within 12840 ** the query within the current row. Return SQLITE_OK if successful, or 12841 ** an error code (i.e. SQLITE_NOMEM) if an error occurs. 12842 ** 12843 ** This API can be quite slow if used with an FTS5 table created with the 12844 ** "detail=none" or "detail=column" option. If the FTS5 table is created 12845 ** with either "detail=none" or "detail=column" and "content=" option 12846 ** (i.e. if it is a contentless table), then this API always returns 0. 12847 ** 12848 ** xInst: 12849 ** Query for the details of phrase match iIdx within the current row. 12850 ** Phrase matches are numbered starting from zero, so the iIdx argument 12851 ** should be greater than or equal to zero and smaller than the value 12852 ** output by xInstCount(). If iIdx is less than zero or greater than 12853 ** or equal to the value returned by xInstCount(), SQLITE_RANGE is returned. 12854 ** 12855 ** Otherwise, output parameter *piPhrase is set to the phrase number, *piCol 12856 ** to the column in which it occurs and *piOff the token offset of the 12857 ** first token of the phrase. SQLITE_OK is returned if successful, or an 12858 ** error code (i.e. SQLITE_NOMEM) if an error occurs. 12859 ** 12860 ** This API can be quite slow if used with an FTS5 table created with the 12861 ** "detail=none" or "detail=column" option. 12862 ** 12863 ** xRowid: 12864 ** Returns the rowid of the current row. 12865 ** 12866 ** xTokenize: 12867 ** Tokenize text using the tokenizer belonging to the FTS5 table. 12868 ** 12869 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 12870 ** This API function is used to query the FTS table for phrase iPhrase 12871 ** of the current query. Specifically, a query equivalent to: 12872 ** 12873 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 12874 ** 12875 ** with $p set to a phrase equivalent to the phrase iPhrase of the 12876 ** current query is executed. Any column filter that applies to 12877 ** phrase iPhrase of the current query is included in $p. For each 12878 ** row visited, the callback function passed as the fourth argument 12879 ** is invoked. The context and API objects passed to the callback 12880 ** function may be used to access the properties of each matched row. 12881 ** Invoking Api.xUserData() returns a copy of the pointer passed as 12882 ** the third argument to pUserData. 12883 ** 12884 ** If parameter iPhrase is less than zero, or greater than or equal to 12885 ** the number of phrases in the query, as returned by xPhraseCount(), 12886 ** this function returns SQLITE_RANGE. 12887 ** 12888 ** If the callback function returns any value other than SQLITE_OK, the 12889 ** query is abandoned and the xQueryPhrase function returns immediately. 12890 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 12891 ** Otherwise, the error code is propagated upwards. 12892 ** 12893 ** If the query runs to completion without incident, SQLITE_OK is returned. 12894 ** Or, if some error occurs before the query completes or is aborted by 12895 ** the callback, an SQLite error code is returned. 12896 ** 12897 ** 12898 ** xSetAuxdata(pFts5, pAux, xDelete) 12899 ** 12900 ** Save the pointer passed as the second argument as the extension function's 12901 ** "auxiliary data". The pointer may then be retrieved by the current or any 12902 ** future invocation of the same fts5 extension function made as part of 12903 ** the same MATCH query using the xGetAuxdata() API. 12904 ** 12905 ** Each extension function is allocated a single auxiliary data slot for 12906 ** each FTS query (MATCH expression). If the extension function is invoked 12907 ** more than once for a single FTS query, then all invocations share a 12908 ** single auxiliary data context. 12909 ** 12910 ** If there is already an auxiliary data pointer when this function is 12911 ** invoked, then it is replaced by the new pointer. If an xDelete callback 12912 ** was specified along with the original pointer, it is invoked at this 12913 ** point. 12914 ** 12915 ** The xDelete callback, if one is specified, is also invoked on the 12916 ** auxiliary data pointer after the FTS5 query has finished. 12917 ** 12918 ** If an error (e.g. an OOM condition) occurs within this function, 12919 ** the auxiliary data is set to NULL and an error code returned. If the 12920 ** xDelete parameter was not NULL, it is invoked on the auxiliary data 12921 ** pointer before returning. 12922 ** 12923 ** 12924 ** xGetAuxdata(pFts5, bClear) 12925 ** 12926 ** Returns the current auxiliary data pointer for the fts5 extension 12927 ** function. See the xSetAuxdata() method for details. 12928 ** 12929 ** If the bClear argument is non-zero, then the auxiliary data is cleared 12930 ** (set to NULL) before this function returns. In this case the xDelete, 12931 ** if any, is not invoked. 12932 ** 12933 ** 12934 ** xRowCount(pFts5, pnRow) 12935 ** 12936 ** This function is used to retrieve the total number of rows in the table. 12937 ** In other words, the same value that would be returned by: 12938 ** 12939 ** SELECT count(*) FROM ftstable; 12940 ** 12941 ** xPhraseFirst() 12942 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext 12943 ** method, to iterate through all instances of a single query phrase within 12944 ** the current row. This is the same information as is accessible via the 12945 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 12946 ** to use, this API may be faster under some circumstances. To iterate 12947 ** through instances of phrase iPhrase, use the following code: 12948 ** 12949 ** Fts5PhraseIter iter; 12950 ** int iCol, iOff; 12951 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 12952 ** iCol>=0; 12953 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 12954 ** ){ 12955 ** // An instance of phrase iPhrase at offset iOff of column iCol 12956 ** } 12957 ** 12958 ** The Fts5PhraseIter structure is defined above. Applications should not 12959 ** modify this structure directly - it should only be used as shown above 12960 ** with the xPhraseFirst() and xPhraseNext() API methods (and by 12961 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 12962 ** 12963 ** This API can be quite slow if used with an FTS5 table created with the 12964 ** "detail=none" or "detail=column" option. If the FTS5 table is created 12965 ** with either "detail=none" or "detail=column" and "content=" option 12966 ** (i.e. if it is a contentless table), then this API always iterates 12967 ** through an empty set (all calls to xPhraseFirst() set iCol to -1). 12968 ** 12969 ** xPhraseNext() 12970 ** See xPhraseFirst above. 12971 ** 12972 ** xPhraseFirstColumn() 12973 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 12974 ** and xPhraseNext() APIs described above. The difference is that instead 12975 ** of iterating through all instances of a phrase in the current row, these 12976 ** APIs are used to iterate through the set of columns in the current row 12977 ** that contain one or more instances of a specified phrase. For example: 12978 ** 12979 ** Fts5PhraseIter iter; 12980 ** int iCol; 12981 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 12982 ** iCol>=0; 12983 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 12984 ** ){ 12985 ** // Column iCol contains at least one instance of phrase iPhrase 12986 ** } 12987 ** 12988 ** This API can be quite slow if used with an FTS5 table created with the 12989 ** "detail=none" option. If the FTS5 table is created with either 12990 ** "detail=none" "content=" option (i.e. if it is a contentless table), 12991 ** then this API always iterates through an empty set (all calls to 12992 ** xPhraseFirstColumn() set iCol to -1). 12993 ** 12994 ** The information accessed using this API and its companion 12995 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 12996 ** (or xInst/xInstCount). The chief advantage of this API is that it is 12997 ** significantly more efficient than those alternatives when used with 12998 ** "detail=column" tables. 12999 ** 13000 ** xPhraseNextColumn() 13001 ** See xPhraseFirstColumn above. 13002 ** 13003 ** xQueryToken(pFts5, iPhrase, iToken, ppToken, pnToken) 13004 ** This is used to access token iToken of phrase iPhrase of the current 13005 ** query. Before returning, output parameter *ppToken is set to point 13006 ** to a buffer containing the requested token, and *pnToken to the 13007 ** size of this buffer in bytes. 13008 ** 13009 ** If iPhrase or iToken are less than zero, or if iPhrase is greater than 13010 ** or equal to the number of phrases in the query as reported by 13011 ** xPhraseCount(), or if iToken is equal to or greater than the number of 13012 ** tokens in the phrase, SQLITE_RANGE is returned and *ppToken and *pnToken 13013 are both zeroed. 13014 ** 13015 ** The output text is not a copy of the query text that specified the 13016 ** token. It is the output of the tokenizer module. For tokendata=1 13017 ** tables, this includes any embedded 0x00 and trailing data. 13018 ** 13019 ** xInstToken(pFts5, iIdx, iToken, ppToken, pnToken) 13020 ** This is used to access token iToken of phrase hit iIdx within the 13021 ** current row. If iIdx is less than zero or greater than or equal to the 13022 ** value returned by xInstCount(), SQLITE_RANGE is returned. Otherwise, 13023 ** output variable (*ppToken) is set to point to a buffer containing the 13024 ** matching document token, and (*pnToken) to the size of that buffer in 13025 ** bytes. This API is not available if the specified token matches a 13026 ** prefix query term. In that case both output variables are always set 13027 ** to 0. 13028 ** 13029 ** The output text is not a copy of the document text that was tokenized. 13030 ** It is the output of the tokenizer module. For tokendata=1 tables, this 13031 ** includes any embedded 0x00 and trailing data. 13032 ** 13033 ** This API can be quite slow if used with an FTS5 table created with the 13034 ** "detail=none" or "detail=column" option. 13035 */ 13036 struct Fts5ExtensionApi { 13037 int iVersion; /* Currently always set to 3 */ 13038 13039 void *(*xUserData)(Fts5Context*); 13040 13041 int (*xColumnCount)(Fts5Context*); 13042 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 13043 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 13044 13045 int (*xTokenize)(Fts5Context*, 13046 const char *pText, int nText, /* Text to tokenize */ 13047 void *pCtx, /* Context passed to xToken() */ 13048 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 13049 ); 13050 13051 int (*xPhraseCount)(Fts5Context*); 13052 int (*xPhraseSize)(Fts5Context*, int iPhrase); 13053 13054 int (*xInstCount)(Fts5Context*, int *pnInst); 13055 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 13056 13057 sqlite3_int64 (*xRowid)(Fts5Context*); 13058 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 13059 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 13060 13061 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 13062 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 13063 ); 13064 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 13065 void *(*xGetAuxdata)(Fts5Context*, int bClear); 13066 13067 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 13068 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 13069 13070 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 13071 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 13072 13073 /* Below this point are iVersion>=3 only */ 13074 int (*xQueryToken)(Fts5Context*, 13075 int iPhrase, int iToken, 13076 const char **ppToken, int *pnToken 13077 ); 13078 int (*xInstToken)(Fts5Context*, int iIdx, int iToken, const char**, int*); 13079 }; 13080 13081 /* 13082 ** CUSTOM AUXILIARY FUNCTIONS 13083 *************************************************************************/ 13084 13085 /************************************************************************* 13086 ** CUSTOM TOKENIZERS 13087 ** 13088 ** Applications may also register custom tokenizer types. A tokenizer 13089 ** is registered by providing fts5 with a populated instance of the 13090 ** following structure. All structure methods must be defined, setting 13091 ** any member of the fts5_tokenizer struct to NULL leads to undefined 13092 ** behaviour. The structure methods are expected to function as follows: 13093 ** 13094 ** xCreate: 13095 ** This function is used to allocate and initialize a tokenizer instance. 13096 ** A tokenizer instance is required to actually tokenize text. 13097 ** 13098 ** The first argument passed to this function is a copy of the (void*) 13099 ** pointer provided by the application when the fts5_tokenizer object 13100 ** was registered with FTS5 (the third argument to xCreateTokenizer()). 13101 ** The second and third arguments are an array of nul-terminated strings 13102 ** containing the tokenizer arguments, if any, specified following the 13103 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 13104 ** to create the FTS5 table. 13105 ** 13106 ** The final argument is an output variable. If successful, (*ppOut) 13107 ** should be set to point to the new tokenizer handle and SQLITE_OK 13108 ** returned. If an error occurs, some value other than SQLITE_OK should 13109 ** be returned. In this case, fts5 assumes that the final value of *ppOut 13110 ** is undefined. 13111 ** 13112 ** xDelete: 13113 ** This function is invoked to delete a tokenizer handle previously 13114 ** allocated using xCreate(). Fts5 guarantees that this function will 13115 ** be invoked exactly once for each successful call to xCreate(). 13116 ** 13117 ** xTokenize: 13118 ** This function is expected to tokenize the nText byte string indicated 13119 ** by argument pText. pText may or may not be nul-terminated. The first 13120 ** argument passed to this function is a pointer to an Fts5Tokenizer object 13121 ** returned by an earlier call to xCreate(). 13122 ** 13123 ** The second argument indicates the reason that FTS5 is requesting 13124 ** tokenization of the supplied text. This is always one of the following 13125 ** four values: 13126 ** 13127 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 13128 ** or removed from the FTS table. The tokenizer is being invoked to 13129 ** determine the set of tokens to add to (or delete from) the 13130 ** FTS index. 13131 ** 13132 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 13133 ** against the FTS index. The tokenizer is being called to tokenize 13134 ** a bareword or quoted string specified as part of the query. 13135 ** 13136 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 13137 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 13138 ** followed by a "*" character, indicating that the last token 13139 ** returned by the tokenizer will be treated as a token prefix. 13140 ** 13141 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 13142 ** satisfy an fts5_api.xTokenize() request made by an auxiliary 13143 ** function. Or an fts5_api.xColumnSize() request made by the same 13144 ** on a columnsize=0 database. 13145 ** </ul> 13146 ** 13147 ** For each token in the input string, the supplied callback xToken() must 13148 ** be invoked. The first argument to it should be a copy of the pointer 13149 ** passed as the second argument to xTokenize(). The third and fourth 13150 ** arguments are a pointer to a buffer containing the token text, and the 13151 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets 13152 ** of the first byte of and first byte immediately following the text from 13153 ** which the token is derived within the input. 13154 ** 13155 ** The second argument passed to the xToken() callback ("tflags") should 13156 ** normally be set to 0. The exception is if the tokenizer supports 13157 ** synonyms. In this case see the discussion below for details. 13158 ** 13159 ** FTS5 assumes the xToken() callback is invoked for each token in the 13160 ** order that they occur within the input text. 13161 ** 13162 ** If an xToken() callback returns any value other than SQLITE_OK, then 13163 ** the tokenization should be abandoned and the xTokenize() method should 13164 ** immediately return a copy of the xToken() return value. Or, if the 13165 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 13166 ** if an error occurs with the xTokenize() implementation itself, it 13167 ** may abandon the tokenization and return any error code other than 13168 ** SQLITE_OK or SQLITE_DONE. 13169 ** 13170 ** SYNONYM SUPPORT 13171 ** 13172 ** Custom tokenizers may also support synonyms. Consider a case in which a 13173 ** user wishes to query for a phrase such as "first place". Using the 13174 ** built-in tokenizers, the FTS5 query 'first + place' will match instances 13175 ** of "first place" within the document set, but not alternative forms 13176 ** such as "1st place". In some applications, it would be better to match 13177 ** all instances of "first place" or "1st place" regardless of which form 13178 ** the user specified in the MATCH query text. 13179 ** 13180 ** There are several ways to approach this in FTS5: 13181 ** 13182 ** <ol><li> By mapping all synonyms to a single token. In this case, using 13183 ** the above example, this means that the tokenizer returns the 13184 ** same token for inputs "first" and "1st". Say that token is in 13185 ** fact "first", so that when the user inserts the document "I won 13186 ** 1st place" entries are added to the index for tokens "i", "won", 13187 ** "first" and "place". If the user then queries for '1st + place', 13188 ** the tokenizer substitutes "first" for "1st" and the query works 13189 ** as expected. 13190 ** 13191 ** <li> By querying the index for all synonyms of each query term 13192 ** separately. In this case, when tokenizing query text, the 13193 ** tokenizer may provide multiple synonyms for a single term 13194 ** within the document. FTS5 then queries the index for each 13195 ** synonym individually. For example, faced with the query: 13196 ** 13197 ** <codeblock> 13198 ** ... MATCH 'first place'</codeblock> 13199 ** 13200 ** the tokenizer offers both "1st" and "first" as synonyms for the 13201 ** first token in the MATCH query and FTS5 effectively runs a query 13202 ** similar to: 13203 ** 13204 ** <codeblock> 13205 ** ... MATCH '(first OR 1st) place'</codeblock> 13206 ** 13207 ** except that, for the purposes of auxiliary functions, the query 13208 ** still appears to contain just two phrases - "(first OR 1st)" 13209 ** being treated as a single phrase. 13210 ** 13211 ** <li> By adding multiple synonyms for a single term to the FTS index. 13212 ** Using this method, when tokenizing document text, the tokenizer 13213 ** provides multiple synonyms for each token. So that when a 13214 ** document such as "I won first place" is tokenized, entries are 13215 ** added to the FTS index for "i", "won", "first", "1st" and 13216 ** "place". 13217 ** 13218 ** This way, even if the tokenizer does not provide synonyms 13219 ** when tokenizing query text (it should not - to do so would be 13220 ** inefficient), it doesn't matter if the user queries for 13221 ** 'first + place' or '1st + place', as there are entries in the 13222 ** FTS index corresponding to both forms of the first token. 13223 ** </ol> 13224 ** 13225 ** Whether it is parsing document or query text, any call to xToken that 13226 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 13227 ** is considered to supply a synonym for the previous token. For example, 13228 ** when parsing the document "I won first place", a tokenizer that supports 13229 ** synonyms would call xToken() 5 times, as follows: 13230 ** 13231 ** <codeblock> 13232 ** xToken(pCtx, 0, "i", 1, 0, 1); 13233 ** xToken(pCtx, 0, "won", 3, 2, 5); 13234 ** xToken(pCtx, 0, "first", 5, 6, 11); 13235 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 13236 ** xToken(pCtx, 0, "place", 5, 12, 17); 13237 **</codeblock> 13238 ** 13239 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 13240 ** xToken() is called. Multiple synonyms may be specified for a single token 13241 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 13242 ** There is no limit to the number of synonyms that may be provided for a 13243 ** single token. 13244 ** 13245 ** In many cases, method (1) above is the best approach. It does not add 13246 ** extra data to the FTS index or require FTS5 to query for multiple terms, 13247 ** so it is efficient in terms of disk space and query speed. However, it 13248 ** does not support prefix queries very well. If, as suggested above, the 13249 ** token "first" is substituted for "1st" by the tokenizer, then the query: 13250 ** 13251 ** <codeblock> 13252 ** ... MATCH '1s*'</codeblock> 13253 ** 13254 ** will not match documents that contain the token "1st" (as the tokenizer 13255 ** will probably not map "1s" to any prefix of "first"). 13256 ** 13257 ** For full prefix support, method (3) may be preferred. In this case, 13258 ** because the index contains entries for both "first" and "1st", prefix 13259 ** queries such as 'fi*' or '1s*' will match correctly. However, because 13260 ** extra entries are added to the FTS index, this method uses more space 13261 ** within the database. 13262 ** 13263 ** Method (2) offers a midpoint between (1) and (3). Using this method, 13264 ** a query such as '1s*' will match documents that contain the literal 13265 ** token "1st", but not "first" (assuming the tokenizer is not able to 13266 ** provide synonyms for prefixes). However, a non-prefix query like '1st' 13267 ** will match against "1st" and "first". This method does not require 13268 ** extra disk space, as no extra entries are added to the FTS index. 13269 ** On the other hand, it may require more CPU cycles to run MATCH queries, 13270 ** as separate queries of the FTS index are required for each synonym. 13271 ** 13272 ** When using methods (2) or (3), it is important that the tokenizer only 13273 ** provide synonyms when tokenizing document text (method (3)) or query 13274 ** text (method (2)), not both. Doing so will not cause any errors, but is 13275 ** inefficient. 13276 */ 13277 typedef struct Fts5Tokenizer Fts5Tokenizer; 13278 typedef struct fts5_tokenizer fts5_tokenizer; 13279 struct fts5_tokenizer { 13280 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 13281 void (*xDelete)(Fts5Tokenizer*); 13282 int (*xTokenize)(Fts5Tokenizer*, 13283 void *pCtx, 13284 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 13285 const char *pText, int nText, 13286 int (*xToken)( 13287 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 13288 int tflags, /* Mask of FTS5_TOKEN_* flags */ 13289 const char *pToken, /* Pointer to buffer containing token */ 13290 int nToken, /* Size of token in bytes */ 13291 int iStart, /* Byte offset of token within input text */ 13292 int iEnd /* Byte offset of end of token within input text */ 13293 ) 13294 ); 13295 }; 13296 13297 /* Flags that may be passed as the third argument to xTokenize() */ 13298 #define FTS5_TOKENIZE_QUERY 0x0001 13299 #define FTS5_TOKENIZE_PREFIX 0x0002 13300 #define FTS5_TOKENIZE_DOCUMENT 0x0004 13301 #define FTS5_TOKENIZE_AUX 0x0008 13302 13303 /* Flags that may be passed by the tokenizer implementation back to FTS5 13304 ** as the third argument to the supplied xToken callback. */ 13305 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 13306 13307 /* 13308 ** END OF CUSTOM TOKENIZERS 13309 *************************************************************************/ 13310 13311 /************************************************************************* 13312 ** FTS5 EXTENSION REGISTRATION API 13313 */ 13314 typedef struct fts5_api fts5_api; 13315 struct fts5_api { 13316 int iVersion; /* Currently always set to 2 */ 13317 13318 /* Create a new tokenizer */ 13319 int (*xCreateTokenizer)( 13320 fts5_api *pApi, 13321 const char *zName, 13322 void *pUserData, 13323 fts5_tokenizer *pTokenizer, 13324 void (*xDestroy)(void*) 13325 ); 13326 13327 /* Find an existing tokenizer */ 13328 int (*xFindTokenizer)( 13329 fts5_api *pApi, 13330 const char *zName, 13331 void **ppUserData, 13332 fts5_tokenizer *pTokenizer 13333 ); 13334 13335 /* Create a new auxiliary function */ 13336 int (*xCreateFunction)( 13337 fts5_api *pApi, 13338 const char *zName, 13339 void *pUserData, 13340 fts5_extension_function xFunction, 13341 void (*xDestroy)(void*) 13342 ); 13343 }; 13344 13345 /* 13346 ** END OF REGISTRATION API 13347 *************************************************************************/ 13348 13349 #ifdef __cplusplus 13350 } /* end of the 'extern "C"' block */ 13351 #endif 13352 13353 #endif /* _FTS5_H */ 13354 13355 /******** End of fts5.h *********/ 13356