1 /* 2 ** 2001-09-15 3 ** 4 ** The author disclaims copyright to this source code. In place of 5 ** a legal notice, here is a blessing: 6 ** 7 ** May you do good and not evil. 8 ** May you find forgiveness for yourself and forgive others. 9 ** May you share freely, never taking more than you give. 10 ** 11 ************************************************************************* 12 ** This header file defines the interface that the SQLite library 13 ** presents to client programs. If a C-function, structure, datatype, 14 ** or constant definition does not appear in this file, then it is 15 ** not a published API of SQLite, is subject to change without 16 ** notice, and should not be referenced by programs that use SQLite. 17 ** 18 ** Some of the definitions that are in this file are marked as 19 ** "experimental". Experimental interfaces are normally new 20 ** features recently added to SQLite. We do not anticipate changes 21 ** to experimental interfaces but reserve the right to make minor changes 22 ** if experience from use "in the wild" suggest such changes are prudent. 23 ** 24 ** The official C-language API documentation for SQLite is derived 25 ** from comments in this file. This file is the authoritative source 26 ** on how SQLite interfaces are supposed to operate. 27 ** 28 ** The name of this file under configuration management is "sqlite.h.in". 29 ** The makefile makes some minor changes to this file (such as inserting 30 ** the version number) and changes its name to "sqlite3.h" as 31 ** part of the build process. 32 */ 33 #ifndef SQLITE3_H 34 #define SQLITE3_H 35 #include <stdarg.h> /* Needed for the definition of va_list */ 36 37 /* 38 ** Make sure we can call this stuff from C++. 39 */ 40 #ifdef __cplusplus 41 extern "C" { 42 #endif 43 44 45 /* 46 ** Provide the ability to override linkage features of the interface. 47 */ 48 #ifndef SQLITE_EXTERN 49 # define SQLITE_EXTERN extern 50 #endif 51 #ifndef SQLITE_API 52 # define SQLITE_API 53 #endif 54 #ifndef SQLITE_CDECL 55 # define SQLITE_CDECL 56 #endif 57 #ifndef SQLITE_APICALL 58 # define SQLITE_APICALL 59 #endif 60 #ifndef SQLITE_STDCALL 61 # define SQLITE_STDCALL SQLITE_APICALL 62 #endif 63 #ifndef SQLITE_CALLBACK 64 # define SQLITE_CALLBACK 65 #endif 66 #ifndef SQLITE_SYSAPI 67 # define SQLITE_SYSAPI 68 #endif 69 70 /* 71 ** These no-op macros are used in front of interfaces to mark those 72 ** interfaces as either deprecated or experimental. New applications 73 ** should not use deprecated interfaces - they are supported for backwards 74 ** compatibility only. Application writers should be aware that 75 ** experimental interfaces are subject to change in point releases. 76 ** 77 ** These macros used to resolve to various kinds of compiler magic that 78 ** would generate warning messages when they were used. But that 79 ** compiler magic ended up generating such a flurry of bug reports 80 ** that we have taken it all out and gone back to using simple 81 ** noop macros. 82 */ 83 #define SQLITE_DEPRECATED 84 #define SQLITE_EXPERIMENTAL 85 86 /* 87 ** Ensure these symbols were not defined by some previous header file. 88 */ 89 #ifdef SQLITE_VERSION 90 # undef SQLITE_VERSION 91 #endif 92 #ifdef SQLITE_VERSION_NUMBER 93 # undef SQLITE_VERSION_NUMBER 94 #endif 95 96 /* 97 ** CAPI3REF: Compile-Time Library Version Numbers 98 ** 99 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 100 ** evaluates to a string literal that is the SQLite version in the 101 ** format "X.Y.Z" where X is the major version number (always 3 for 102 ** SQLite3) and Y is the minor version number and Z is the release number.)^ 103 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 104 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 105 ** numbers used in [SQLITE_VERSION].)^ 106 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 107 ** be larger than the release from which it is derived. Either Y will 108 ** be held constant and Z will be incremented or else Y will be incremented 109 ** and Z will be reset to zero. 110 ** 111 ** Since [version 3.6.18] ([dateof:3.6.18]), 112 ** SQLite source code has been stored in the 113 ** <a href="http://www.fossil-scm.org/">Fossil configuration management 114 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 115 ** a string which identifies a particular check-in of SQLite 116 ** within its configuration management system. ^The SQLITE_SOURCE_ID 117 ** string contains the date and time of the check-in (UTC) and a SHA1 118 ** or SHA3-256 hash of the entire source tree. If the source code has 119 ** been edited in any way since it was last checked in, then the last 120 ** four hexadecimal digits of the hash may be modified. 121 ** 122 ** See also: [sqlite3_libversion()], 123 ** [sqlite3_libversion_number()], [sqlite3_sourceid()], 124 ** [sqlite_version()] and [sqlite_source_id()]. 125 */ 126 #define SQLITE_VERSION "3.31.1" 127 #define SQLITE_VERSION_NUMBER 3031001 128 #define SQLITE_SOURCE_ID "2020-01-27 19:55:54 3bfa9cc97da10598521b342961df8f5f68c7388fa117345eeb516eaa837bb4d6" 129 130 /* 131 ** CAPI3REF: Run-Time Library Version Numbers 132 ** KEYWORDS: sqlite3_version sqlite3_sourceid 133 ** 134 ** These interfaces provide the same information as the [SQLITE_VERSION], 135 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 136 ** but are associated with the library instead of the header file. ^(Cautious 137 ** programmers might include assert() statements in their application to 138 ** verify that values returned by these interfaces match the macros in 139 ** the header, and thus ensure that the application is 140 ** compiled with matching library and header files. 141 ** 142 ** <blockquote><pre> 143 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 144 ** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 ); 145 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 146 ** </pre></blockquote>)^ 147 ** 148 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 149 ** macro. ^The sqlite3_libversion() function returns a pointer to the 150 ** to the sqlite3_version[] string constant. The sqlite3_libversion() 151 ** function is provided for use in DLLs since DLL users usually do not have 152 ** direct access to string constants within the DLL. ^The 153 ** sqlite3_libversion_number() function returns an integer equal to 154 ** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns 155 ** a pointer to a string constant whose value is the same as the 156 ** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built 157 ** using an edited copy of [the amalgamation], then the last four characters 158 ** of the hash might be different from [SQLITE_SOURCE_ID].)^ 159 ** 160 ** See also: [sqlite_version()] and [sqlite_source_id()]. 161 */ 162 SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 163 SQLITE_API const char *sqlite3_libversion(void); 164 SQLITE_API const char *sqlite3_sourceid(void); 165 SQLITE_API int sqlite3_libversion_number(void); 166 167 /* 168 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics 169 ** 170 ** ^The sqlite3_compileoption_used() function returns 0 or 1 171 ** indicating whether the specified option was defined at 172 ** compile time. ^The SQLITE_ prefix may be omitted from the 173 ** option name passed to sqlite3_compileoption_used(). 174 ** 175 ** ^The sqlite3_compileoption_get() function allows iterating 176 ** over the list of options that were defined at compile time by 177 ** returning the N-th compile time option string. ^If N is out of range, 178 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 179 ** prefix is omitted from any strings returned by 180 ** sqlite3_compileoption_get(). 181 ** 182 ** ^Support for the diagnostic functions sqlite3_compileoption_used() 183 ** and sqlite3_compileoption_get() may be omitted by specifying the 184 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 185 ** 186 ** See also: SQL functions [sqlite_compileoption_used()] and 187 ** [sqlite_compileoption_get()] and the [compile_options pragma]. 188 */ 189 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 190 SQLITE_API int sqlite3_compileoption_used(const char *zOptName); 191 SQLITE_API const char *sqlite3_compileoption_get(int N); 192 #else 193 # define sqlite3_compileoption_used(X) 0 194 # define sqlite3_compileoption_get(X) ((void*)0) 195 #endif 196 197 /* 198 ** CAPI3REF: Test To See If The Library Is Threadsafe 199 ** 200 ** ^The sqlite3_threadsafe() function returns zero if and only if 201 ** SQLite was compiled with mutexing code omitted due to the 202 ** [SQLITE_THREADSAFE] compile-time option being set to 0. 203 ** 204 ** SQLite can be compiled with or without mutexes. When 205 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 206 ** are enabled and SQLite is threadsafe. When the 207 ** [SQLITE_THREADSAFE] macro is 0, 208 ** the mutexes are omitted. Without the mutexes, it is not safe 209 ** to use SQLite concurrently from more than one thread. 210 ** 211 ** Enabling mutexes incurs a measurable performance penalty. 212 ** So if speed is of utmost importance, it makes sense to disable 213 ** the mutexes. But for maximum safety, mutexes should be enabled. 214 ** ^The default behavior is for mutexes to be enabled. 215 ** 216 ** This interface can be used by an application to make sure that the 217 ** version of SQLite that it is linking against was compiled with 218 ** the desired setting of the [SQLITE_THREADSAFE] macro. 219 ** 220 ** This interface only reports on the compile-time mutex setting 221 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 222 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 223 ** can be fully or partially disabled using a call to [sqlite3_config()] 224 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 225 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 226 ** sqlite3_threadsafe() function shows only the compile-time setting of 227 ** thread safety, not any run-time changes to that setting made by 228 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 229 ** is unchanged by calls to sqlite3_config().)^ 230 ** 231 ** See the [threading mode] documentation for additional information. 232 */ 233 SQLITE_API int sqlite3_threadsafe(void); 234 235 /* 236 ** CAPI3REF: Database Connection Handle 237 ** KEYWORDS: {database connection} {database connections} 238 ** 239 ** Each open SQLite database is represented by a pointer to an instance of 240 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 241 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 242 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 243 ** and [sqlite3_close_v2()] are its destructors. There are many other 244 ** interfaces (such as 245 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 246 ** [sqlite3_busy_timeout()] to name but three) that are methods on an 247 ** sqlite3 object. 248 */ 249 typedef struct sqlite3 sqlite3; 250 251 /* 252 ** CAPI3REF: 64-Bit Integer Types 253 ** KEYWORDS: sqlite_int64 sqlite_uint64 254 ** 255 ** Because there is no cross-platform way to specify 64-bit integer types 256 ** SQLite includes typedefs for 64-bit signed and unsigned integers. 257 ** 258 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 259 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards 260 ** compatibility only. 261 ** 262 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values 263 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 264 ** sqlite3_uint64 and sqlite_uint64 types can store integer values 265 ** between 0 and +18446744073709551615 inclusive. 266 */ 267 #ifdef SQLITE_INT64_TYPE 268 typedef SQLITE_INT64_TYPE sqlite_int64; 269 # ifdef SQLITE_UINT64_TYPE 270 typedef SQLITE_UINT64_TYPE sqlite_uint64; 271 # else 272 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 273 # endif 274 #elif defined(_MSC_VER) || defined(__BORLANDC__) 275 typedef __int64 sqlite_int64; 276 typedef unsigned __int64 sqlite_uint64; 277 #else 278 typedef long long int sqlite_int64; 279 typedef unsigned long long int sqlite_uint64; 280 #endif 281 typedef sqlite_int64 sqlite3_int64; 282 typedef sqlite_uint64 sqlite3_uint64; 283 284 /* 285 ** If compiling for a processor that lacks floating point support, 286 ** substitute integer for floating-point. 287 */ 288 #ifdef SQLITE_OMIT_FLOATING_POINT 289 # define double sqlite3_int64 290 #endif 291 292 /* 293 ** CAPI3REF: Closing A Database Connection 294 ** DESTRUCTOR: sqlite3 295 ** 296 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 297 ** for the [sqlite3] object. 298 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 299 ** the [sqlite3] object is successfully destroyed and all associated 300 ** resources are deallocated. 301 ** 302 ** ^If the database connection is associated with unfinalized prepared 303 ** statements or unfinished sqlite3_backup objects then sqlite3_close() 304 ** will leave the database connection open and return [SQLITE_BUSY]. 305 ** ^If sqlite3_close_v2() is called with unfinalized prepared statements 306 ** and/or unfinished sqlite3_backups, then the database connection becomes 307 ** an unusable "zombie" which will automatically be deallocated when the 308 ** last prepared statement is finalized or the last sqlite3_backup is 309 ** finished. The sqlite3_close_v2() interface is intended for use with 310 ** host languages that are garbage collected, and where the order in which 311 ** destructors are called is arbitrary. 312 ** 313 ** Applications should [sqlite3_finalize | finalize] all [prepared statements], 314 ** [sqlite3_blob_close | close] all [BLOB handles], and 315 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 316 ** with the [sqlite3] object prior to attempting to close the object. ^If 317 ** sqlite3_close_v2() is called on a [database connection] that still has 318 ** outstanding [prepared statements], [BLOB handles], and/or 319 ** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 320 ** of resources is deferred until all [prepared statements], [BLOB handles], 321 ** and [sqlite3_backup] objects are also destroyed. 322 ** 323 ** ^If an [sqlite3] object is destroyed while a transaction is open, 324 ** the transaction is automatically rolled back. 325 ** 326 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 327 ** must be either a NULL 328 ** pointer or an [sqlite3] object pointer obtained 329 ** from [sqlite3_open()], [sqlite3_open16()], or 330 ** [sqlite3_open_v2()], and not previously closed. 331 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 332 ** argument is a harmless no-op. 333 */ 334 SQLITE_API int sqlite3_close(sqlite3*); 335 SQLITE_API int sqlite3_close_v2(sqlite3*); 336 337 /* 338 ** The type for a callback function. 339 ** This is legacy and deprecated. It is included for historical 340 ** compatibility and is not documented. 341 */ 342 typedef int (*sqlite3_callback)(void*,int,char**, char**); 343 344 /* 345 ** CAPI3REF: One-Step Query Execution Interface 346 ** METHOD: sqlite3 347 ** 348 ** The sqlite3_exec() interface is a convenience wrapper around 349 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 350 ** that allows an application to run multiple statements of SQL 351 ** without having to use a lot of C code. 352 ** 353 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 354 ** semicolon-separate SQL statements passed into its 2nd argument, 355 ** in the context of the [database connection] passed in as its 1st 356 ** argument. ^If the callback function of the 3rd argument to 357 ** sqlite3_exec() is not NULL, then it is invoked for each result row 358 ** coming out of the evaluated SQL statements. ^The 4th argument to 359 ** sqlite3_exec() is relayed through to the 1st argument of each 360 ** callback invocation. ^If the callback pointer to sqlite3_exec() 361 ** is NULL, then no callback is ever invoked and result rows are 362 ** ignored. 363 ** 364 ** ^If an error occurs while evaluating the SQL statements passed into 365 ** sqlite3_exec(), then execution of the current statement stops and 366 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 367 ** is not NULL then any error message is written into memory obtained 368 ** from [sqlite3_malloc()] and passed back through the 5th parameter. 369 ** To avoid memory leaks, the application should invoke [sqlite3_free()] 370 ** on error message strings returned through the 5th parameter of 371 ** sqlite3_exec() after the error message string is no longer needed. 372 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 373 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 374 ** NULL before returning. 375 ** 376 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 377 ** routine returns SQLITE_ABORT without invoking the callback again and 378 ** without running any subsequent SQL statements. 379 ** 380 ** ^The 2nd argument to the sqlite3_exec() callback function is the 381 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 382 ** callback is an array of pointers to strings obtained as if from 383 ** [sqlite3_column_text()], one for each column. ^If an element of a 384 ** result row is NULL then the corresponding string pointer for the 385 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 386 ** sqlite3_exec() callback is an array of pointers to strings where each 387 ** entry represents the name of corresponding result column as obtained 388 ** from [sqlite3_column_name()]. 389 ** 390 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 391 ** to an empty string, or a pointer that contains only whitespace and/or 392 ** SQL comments, then no SQL statements are evaluated and the database 393 ** is not changed. 394 ** 395 ** Restrictions: 396 ** 397 ** <ul> 398 ** <li> The application must ensure that the 1st parameter to sqlite3_exec() 399 ** is a valid and open [database connection]. 400 ** <li> The application must not close the [database connection] specified by 401 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 402 ** <li> The application must not modify the SQL statement text passed into 403 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 404 ** </ul> 405 */ 406 SQLITE_API int sqlite3_exec( 407 sqlite3*, /* An open database */ 408 const char *sql, /* SQL to be evaluated */ 409 int (*callback)(void*,int,char**,char**), /* Callback function */ 410 void *, /* 1st argument to callback */ 411 char **errmsg /* Error msg written here */ 412 ); 413 414 /* 415 ** CAPI3REF: Result Codes 416 ** KEYWORDS: {result code definitions} 417 ** 418 ** Many SQLite functions return an integer result code from the set shown 419 ** here in order to indicate success or failure. 420 ** 421 ** New error codes may be added in future versions of SQLite. 422 ** 423 ** See also: [extended result code definitions] 424 */ 425 #define SQLITE_OK 0 /* Successful result */ 426 /* beginning-of-error-codes */ 427 #define SQLITE_ERROR 1 /* Generic error */ 428 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 429 #define SQLITE_PERM 3 /* Access permission denied */ 430 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ 431 #define SQLITE_BUSY 5 /* The database file is locked */ 432 #define SQLITE_LOCKED 6 /* A table in the database is locked */ 433 #define SQLITE_NOMEM 7 /* A malloc() failed */ 434 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 435 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 436 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 437 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 438 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 439 #define SQLITE_FULL 13 /* Insertion failed because database is full */ 440 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 441 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 442 #define SQLITE_EMPTY 16 /* Internal use only */ 443 #define SQLITE_SCHEMA 17 /* The database schema changed */ 444 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 445 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 446 #define SQLITE_MISMATCH 20 /* Data type mismatch */ 447 #define SQLITE_MISUSE 21 /* Library used incorrectly */ 448 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 449 #define SQLITE_AUTH 23 /* Authorization denied */ 450 #define SQLITE_FORMAT 24 /* Not used */ 451 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 452 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ 453 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 454 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 455 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 456 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 457 /* end-of-error-codes */ 458 459 /* 460 ** CAPI3REF: Extended Result Codes 461 ** KEYWORDS: {extended result code definitions} 462 ** 463 ** In its default configuration, SQLite API routines return one of 30 integer 464 ** [result codes]. However, experience has shown that many of 465 ** these result codes are too coarse-grained. They do not provide as 466 ** much information about problems as programmers might like. In an effort to 467 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 468 ** and later) include 469 ** support for additional result codes that provide more detailed information 470 ** about errors. These [extended result codes] are enabled or disabled 471 ** on a per database connection basis using the 472 ** [sqlite3_extended_result_codes()] API. Or, the extended code for 473 ** the most recent error can be obtained using 474 ** [sqlite3_extended_errcode()]. 475 */ 476 #define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 477 #define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 478 #define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8)) 479 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 480 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 481 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 482 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 483 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 484 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 485 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 486 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 487 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 488 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 489 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 490 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 491 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 492 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 493 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 494 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 495 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 496 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 497 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 498 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 499 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 500 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 501 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 502 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 503 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 504 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 505 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 506 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 507 #define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 508 #define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 509 #define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 510 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 511 #define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 512 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 513 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 514 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 515 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 516 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 517 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 518 #define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 519 #define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8)) 520 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 521 #define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 522 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 523 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 524 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 525 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 526 #define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 527 #define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 528 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 529 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 530 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 531 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 532 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 533 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 534 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 535 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 536 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 537 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 538 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 539 #define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8)) 540 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 541 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 542 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 543 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 544 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 545 #define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) 546 547 /* 548 ** CAPI3REF: Flags For File Open Operations 549 ** 550 ** These bit values are intended for use in the 551 ** 3rd parameter to the [sqlite3_open_v2()] interface and 552 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 553 */ 554 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 555 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 556 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 557 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 558 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 559 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 560 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 561 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 562 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 563 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 564 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 565 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 566 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 567 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 568 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 569 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 570 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 571 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 572 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 573 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 574 #define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */ 575 576 /* Reserved: 0x00F00000 */ 577 578 /* 579 ** CAPI3REF: Device Characteristics 580 ** 581 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 582 ** object returns an integer which is a vector of these 583 ** bit values expressing I/O characteristics of the mass storage 584 ** device that holds the file that the [sqlite3_io_methods] 585 ** refers to. 586 ** 587 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 588 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 589 ** mean that writes of blocks that are nnn bytes in size and 590 ** are aligned to an address which is an integer multiple of 591 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 592 ** that when data is appended to a file, the data is appended 593 ** first then the size of the file is extended, never the other 594 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 595 ** information is written to disk in the same order as calls 596 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 597 ** after reboot following a crash or power loss, the only bytes in a 598 ** file that were written at the application level might have changed 599 ** and that adjacent bytes, even bytes within the same sector are 600 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 601 ** flag indicates that a file cannot be deleted when open. The 602 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 603 ** read-only media and cannot be changed even by processes with 604 ** elevated privileges. 605 ** 606 ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 607 ** filesystem supports doing multiple write operations atomically when those 608 ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 609 ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 610 */ 611 #define SQLITE_IOCAP_ATOMIC 0x00000001 612 #define SQLITE_IOCAP_ATOMIC512 0x00000002 613 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 614 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 615 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 616 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 617 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 618 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 619 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 620 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 621 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 622 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 623 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 624 #define SQLITE_IOCAP_IMMUTABLE 0x00002000 625 #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 626 627 /* 628 ** CAPI3REF: File Locking Levels 629 ** 630 ** SQLite uses one of these integer values as the second 631 ** argument to calls it makes to the xLock() and xUnlock() methods 632 ** of an [sqlite3_io_methods] object. 633 */ 634 #define SQLITE_LOCK_NONE 0 635 #define SQLITE_LOCK_SHARED 1 636 #define SQLITE_LOCK_RESERVED 2 637 #define SQLITE_LOCK_PENDING 3 638 #define SQLITE_LOCK_EXCLUSIVE 4 639 640 /* 641 ** CAPI3REF: Synchronization Type Flags 642 ** 643 ** When SQLite invokes the xSync() method of an 644 ** [sqlite3_io_methods] object it uses a combination of 645 ** these integer values as the second argument. 646 ** 647 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 648 ** sync operation only needs to flush data to mass storage. Inode 649 ** information need not be flushed. If the lower four bits of the flag 650 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 651 ** If the lower four bits equal SQLITE_SYNC_FULL, that means 652 ** to use Mac OS X style fullsync instead of fsync(). 653 ** 654 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 655 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 656 ** settings. The [synchronous pragma] determines when calls to the 657 ** xSync VFS method occur and applies uniformly across all platforms. 658 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 659 ** energetic or rigorous or forceful the sync operations are and 660 ** only make a difference on Mac OSX for the default SQLite code. 661 ** (Third-party VFS implementations might also make the distinction 662 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 663 ** operating systems natively supported by SQLite, only Mac OSX 664 ** cares about the difference.) 665 */ 666 #define SQLITE_SYNC_NORMAL 0x00002 667 #define SQLITE_SYNC_FULL 0x00003 668 #define SQLITE_SYNC_DATAONLY 0x00010 669 670 /* 671 ** CAPI3REF: OS Interface Open File Handle 672 ** 673 ** An [sqlite3_file] object represents an open file in the 674 ** [sqlite3_vfs | OS interface layer]. Individual OS interface 675 ** implementations will 676 ** want to subclass this object by appending additional fields 677 ** for their own use. The pMethods entry is a pointer to an 678 ** [sqlite3_io_methods] object that defines methods for performing 679 ** I/O operations on the open file. 680 */ 681 typedef struct sqlite3_file sqlite3_file; 682 struct sqlite3_file { 683 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 684 }; 685 686 /* 687 ** CAPI3REF: OS Interface File Virtual Methods Object 688 ** 689 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 690 ** [sqlite3_file] object (or, more commonly, a subclass of the 691 ** [sqlite3_file] object) with a pointer to an instance of this object. 692 ** This object defines the methods used to perform various operations 693 ** against the open file represented by the [sqlite3_file] object. 694 ** 695 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 696 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 697 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 698 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 699 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 700 ** to NULL. 701 ** 702 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 703 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 704 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 705 ** flag may be ORed in to indicate that only the data of the file 706 ** and not its inode needs to be synced. 707 ** 708 ** The integer values to xLock() and xUnlock() are one of 709 ** <ul> 710 ** <li> [SQLITE_LOCK_NONE], 711 ** <li> [SQLITE_LOCK_SHARED], 712 ** <li> [SQLITE_LOCK_RESERVED], 713 ** <li> [SQLITE_LOCK_PENDING], or 714 ** <li> [SQLITE_LOCK_EXCLUSIVE]. 715 ** </ul> 716 ** xLock() increases the lock. xUnlock() decreases the lock. 717 ** The xCheckReservedLock() method checks whether any database connection, 718 ** either in this process or in some other process, is holding a RESERVED, 719 ** PENDING, or EXCLUSIVE lock on the file. It returns true 720 ** if such a lock exists and false otherwise. 721 ** 722 ** The xFileControl() method is a generic interface that allows custom 723 ** VFS implementations to directly control an open file using the 724 ** [sqlite3_file_control()] interface. The second "op" argument is an 725 ** integer opcode. The third argument is a generic pointer intended to 726 ** point to a structure that may contain arguments or space in which to 727 ** write return values. Potential uses for xFileControl() might be 728 ** functions to enable blocking locks with timeouts, to change the 729 ** locking strategy (for example to use dot-file locks), to inquire 730 ** about the status of a lock, or to break stale locks. The SQLite 731 ** core reserves all opcodes less than 100 for its own use. 732 ** A [file control opcodes | list of opcodes] less than 100 is available. 733 ** Applications that define a custom xFileControl method should use opcodes 734 ** greater than 100 to avoid conflicts. VFS implementations should 735 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 736 ** recognize. 737 ** 738 ** The xSectorSize() method returns the sector size of the 739 ** device that underlies the file. The sector size is the 740 ** minimum write that can be performed without disturbing 741 ** other bytes in the file. The xDeviceCharacteristics() 742 ** method returns a bit vector describing behaviors of the 743 ** underlying device: 744 ** 745 ** <ul> 746 ** <li> [SQLITE_IOCAP_ATOMIC] 747 ** <li> [SQLITE_IOCAP_ATOMIC512] 748 ** <li> [SQLITE_IOCAP_ATOMIC1K] 749 ** <li> [SQLITE_IOCAP_ATOMIC2K] 750 ** <li> [SQLITE_IOCAP_ATOMIC4K] 751 ** <li> [SQLITE_IOCAP_ATOMIC8K] 752 ** <li> [SQLITE_IOCAP_ATOMIC16K] 753 ** <li> [SQLITE_IOCAP_ATOMIC32K] 754 ** <li> [SQLITE_IOCAP_ATOMIC64K] 755 ** <li> [SQLITE_IOCAP_SAFE_APPEND] 756 ** <li> [SQLITE_IOCAP_SEQUENTIAL] 757 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 758 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 759 ** <li> [SQLITE_IOCAP_IMMUTABLE] 760 ** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 761 ** </ul> 762 ** 763 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 764 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 765 ** mean that writes of blocks that are nnn bytes in size and 766 ** are aligned to an address which is an integer multiple of 767 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 768 ** that when data is appended to a file, the data is appended 769 ** first then the size of the file is extended, never the other 770 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 771 ** information is written to disk in the same order as calls 772 ** to xWrite(). 773 ** 774 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 775 ** in the unread portions of the buffer with zeros. A VFS that 776 ** fails to zero-fill short reads might seem to work. However, 777 ** failure to zero-fill short reads will eventually lead to 778 ** database corruption. 779 */ 780 typedef struct sqlite3_io_methods sqlite3_io_methods; 781 struct sqlite3_io_methods { 782 int iVersion; 783 int (*xClose)(sqlite3_file*); 784 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 785 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 786 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 787 int (*xSync)(sqlite3_file*, int flags); 788 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 789 int (*xLock)(sqlite3_file*, int); 790 int (*xUnlock)(sqlite3_file*, int); 791 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 792 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 793 int (*xSectorSize)(sqlite3_file*); 794 int (*xDeviceCharacteristics)(sqlite3_file*); 795 /* Methods above are valid for version 1 */ 796 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 797 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 798 void (*xShmBarrier)(sqlite3_file*); 799 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 800 /* Methods above are valid for version 2 */ 801 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 802 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 803 /* Methods above are valid for version 3 */ 804 /* Additional methods may be added in future releases */ 805 }; 806 807 /* 808 ** CAPI3REF: Standard File Control Opcodes 809 ** KEYWORDS: {file control opcodes} {file control opcode} 810 ** 811 ** These integer constants are opcodes for the xFileControl method 812 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 813 ** interface. 814 ** 815 ** <ul> 816 ** <li>[[SQLITE_FCNTL_LOCKSTATE]] 817 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 818 ** opcode causes the xFileControl method to write the current state of 819 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 820 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 821 ** into an integer that the pArg argument points to. This capability 822 ** is used during testing and is only available when the SQLITE_TEST 823 ** compile-time option is used. 824 ** 825 ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 826 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 827 ** layer a hint of how large the database file will grow to be during the 828 ** current transaction. This hint is not guaranteed to be accurate but it 829 ** is often close. The underlying VFS might choose to preallocate database 830 ** file space based on this hint in order to help writes to the database 831 ** file run faster. 832 ** 833 ** <li>[[SQLITE_FCNTL_SIZE_LIMIT]] 834 ** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that 835 ** implements [sqlite3_deserialize()] to set an upper bound on the size 836 ** of the in-memory database. The argument is a pointer to a [sqlite3_int64]. 837 ** If the integer pointed to is negative, then it is filled in with the 838 ** current limit. Otherwise the limit is set to the larger of the value 839 ** of the integer pointed to and the current database size. The integer 840 ** pointed to is set to the new limit. 841 ** 842 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 843 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 844 ** extends and truncates the database file in chunks of a size specified 845 ** by the user. The fourth argument to [sqlite3_file_control()] should 846 ** point to an integer (type int) containing the new chunk-size to use 847 ** for the nominated database. Allocating database file space in large 848 ** chunks (say 1MB at a time), may reduce file-system fragmentation and 849 ** improve performance on some systems. 850 ** 851 ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 852 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 853 ** to the [sqlite3_file] object associated with a particular database 854 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 855 ** 856 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 857 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 858 ** to the [sqlite3_file] object associated with the journal file (either 859 ** the [rollback journal] or the [write-ahead log]) for a particular database 860 ** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 861 ** 862 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 863 ** No longer in use. 864 ** 865 ** <li>[[SQLITE_FCNTL_SYNC]] 866 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 867 ** sent to the VFS immediately before the xSync method is invoked on a 868 ** database file descriptor. Or, if the xSync method is not invoked 869 ** because the user has configured SQLite with 870 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 871 ** of the xSync method. In most cases, the pointer argument passed with 872 ** this file-control is NULL. However, if the database file is being synced 873 ** as part of a multi-database commit, the argument points to a nul-terminated 874 ** string containing the transactions master-journal file name. VFSes that 875 ** do not need this signal should silently ignore this opcode. Applications 876 ** should not call [sqlite3_file_control()] with this opcode as doing so may 877 ** disrupt the operation of the specialized VFSes that do require it. 878 ** 879 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 880 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 881 ** and sent to the VFS after a transaction has been committed immediately 882 ** but before the database is unlocked. VFSes that do not need this signal 883 ** should silently ignore this opcode. Applications should not call 884 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 885 ** operation of the specialized VFSes that do require it. 886 ** 887 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 888 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 889 ** retry counts and intervals for certain disk I/O operations for the 890 ** windows [VFS] in order to provide robustness in the presence of 891 ** anti-virus programs. By default, the windows VFS will retry file read, 892 ** file write, and file delete operations up to 10 times, with a delay 893 ** of 25 milliseconds before the first retry and with the delay increasing 894 ** by an additional 25 milliseconds with each subsequent retry. This 895 ** opcode allows these two values (10 retries and 25 milliseconds of delay) 896 ** to be adjusted. The values are changed for all database connections 897 ** within the same process. The argument is a pointer to an array of two 898 ** integers where the first integer is the new retry count and the second 899 ** integer is the delay. If either integer is negative, then the setting 900 ** is not changed but instead the prior value of that setting is written 901 ** into the array entry, allowing the current retry settings to be 902 ** interrogated. The zDbName parameter is ignored. 903 ** 904 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 905 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 906 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 907 ** write ahead log ([WAL file]) and shared memory 908 ** files used for transaction control 909 ** are automatically deleted when the latest connection to the database 910 ** closes. Setting persistent WAL mode causes those files to persist after 911 ** close. Persisting the files is useful when other processes that do not 912 ** have write permission on the directory containing the database file want 913 ** to read the database file, as the WAL and shared memory files must exist 914 ** in order for the database to be readable. The fourth parameter to 915 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 916 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 917 ** WAL mode. If the integer is -1, then it is overwritten with the current 918 ** WAL persistence setting. 919 ** 920 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 921 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 922 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 923 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 924 ** xDeviceCharacteristics methods. The fourth parameter to 925 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 926 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 927 ** mode. If the integer is -1, then it is overwritten with the current 928 ** zero-damage mode setting. 929 ** 930 ** <li>[[SQLITE_FCNTL_OVERWRITE]] 931 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 932 ** a write transaction to indicate that, unless it is rolled back for some 933 ** reason, the entire database file will be overwritten by the current 934 ** transaction. This is used by VACUUM operations. 935 ** 936 ** <li>[[SQLITE_FCNTL_VFSNAME]] 937 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 938 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the 939 ** final bottom-level VFS are written into memory obtained from 940 ** [sqlite3_malloc()] and the result is stored in the char* variable 941 ** that the fourth parameter of [sqlite3_file_control()] points to. 942 ** The caller is responsible for freeing the memory when done. As with 943 ** all file-control actions, there is no guarantee that this will actually 944 ** do anything. Callers should initialize the char* variable to a NULL 945 ** pointer in case this file-control is not implemented. This file-control 946 ** is intended for diagnostic use only. 947 ** 948 ** <li>[[SQLITE_FCNTL_VFS_POINTER]] 949 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 950 ** [VFSes] currently in use. ^(The argument X in 951 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 952 ** of type "[sqlite3_vfs] **". This opcodes will set *X 953 ** to a pointer to the top-level VFS.)^ 954 ** ^When there are multiple VFS shims in the stack, this opcode finds the 955 ** upper-most shim only. 956 ** 957 ** <li>[[SQLITE_FCNTL_PRAGMA]] 958 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 959 ** file control is sent to the open [sqlite3_file] object corresponding 960 ** to the database file to which the pragma statement refers. ^The argument 961 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 962 ** pointers to strings (char**) in which the second element of the array 963 ** is the name of the pragma and the third element is the argument to the 964 ** pragma or NULL if the pragma has no argument. ^The handler for an 965 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 966 ** of the char** argument point to a string obtained from [sqlite3_mprintf()] 967 ** or the equivalent and that string will become the result of the pragma or 968 ** the error message if the pragma fails. ^If the 969 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 970 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 971 ** file control returns [SQLITE_OK], then the parser assumes that the 972 ** VFS has handled the PRAGMA itself and the parser generates a no-op 973 ** prepared statement if result string is NULL, or that returns a copy 974 ** of the result string if the string is non-NULL. 975 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 976 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 977 ** that the VFS encountered an error while handling the [PRAGMA] and the 978 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 979 ** file control occurs at the beginning of pragma statement analysis and so 980 ** it is able to override built-in [PRAGMA] statements. 981 ** 982 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 983 ** ^The [SQLITE_FCNTL_BUSYHANDLER] 984 ** file-control may be invoked by SQLite on the database file handle 985 ** shortly after it is opened in order to provide a custom VFS with access 986 ** to the connection's busy-handler callback. The argument is of type (void**) 987 ** - an array of two (void *) values. The first (void *) actually points 988 ** to a function of type (int (*)(void *)). In order to invoke the connection's 989 ** busy-handler, this function should be invoked with the second (void *) in 990 ** the array as the only argument. If it returns non-zero, then the operation 991 ** should be retried. If it returns zero, the custom VFS should abandon the 992 ** current operation. 993 ** 994 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 995 ** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 996 ** to have SQLite generate a 997 ** temporary filename using the same algorithm that is followed to generate 998 ** temporary filenames for TEMP tables and other internal uses. The 999 ** argument should be a char** which will be filled with the filename 1000 ** written into memory obtained from [sqlite3_malloc()]. The caller should 1001 ** invoke [sqlite3_free()] on the result to avoid a memory leak. 1002 ** 1003 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 1004 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 1005 ** maximum number of bytes that will be used for memory-mapped I/O. 1006 ** The argument is a pointer to a value of type sqlite3_int64 that 1007 ** is an advisory maximum number of bytes in the file to memory map. The 1008 ** pointer is overwritten with the old value. The limit is not changed if 1009 ** the value originally pointed to is negative, and so the current limit 1010 ** can be queried by passing in a pointer to a negative number. This 1011 ** file-control is used internally to implement [PRAGMA mmap_size]. 1012 ** 1013 ** <li>[[SQLITE_FCNTL_TRACE]] 1014 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information 1015 ** to the VFS about what the higher layers of the SQLite stack are doing. 1016 ** This file control is used by some VFS activity tracing [shims]. 1017 ** The argument is a zero-terminated string. Higher layers in the 1018 ** SQLite stack may generate instances of this file control if 1019 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1020 ** 1021 ** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1022 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1023 ** pointer to an integer and it writes a boolean into that integer depending 1024 ** on whether or not the file has been renamed, moved, or deleted since it 1025 ** was first opened. 1026 ** 1027 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1028 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1029 ** underlying native file handle associated with a file handle. This file 1030 ** control interprets its argument as a pointer to a native file handle and 1031 ** writes the resulting value there. 1032 ** 1033 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1034 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1035 ** opcode causes the xFileControl method to swap the file handle with the one 1036 ** pointed to by the pArg argument. This capability is used during testing 1037 ** and only needs to be supported when SQLITE_TEST is defined. 1038 ** 1039 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1040 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1041 ** be advantageous to block on the next WAL lock if the lock is not immediately 1042 ** available. The WAL subsystem issues this signal during rare 1043 ** circumstances in order to fix a problem with priority inversion. 1044 ** Applications should <em>not</em> use this file-control. 1045 ** 1046 ** <li>[[SQLITE_FCNTL_ZIPVFS]] 1047 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1048 ** VFS should return SQLITE_NOTFOUND for this opcode. 1049 ** 1050 ** <li>[[SQLITE_FCNTL_RBU]] 1051 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1052 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1053 ** this opcode. 1054 ** 1055 ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1056 ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1057 ** the file descriptor is placed in "batch write mode", which 1058 ** means all subsequent write operations will be deferred and done 1059 ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1060 ** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1061 ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1062 ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1063 ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1064 ** no VFS interface calls on the same [sqlite3_file] file descriptor 1065 ** except for calls to the xWrite method and the xFileControl method 1066 ** with [SQLITE_FCNTL_SIZE_HINT]. 1067 ** 1068 ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1069 ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1070 ** operations since the previous successful call to 1071 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1072 ** This file control returns [SQLITE_OK] if and only if the writes were 1073 ** all performed successfully and have been committed to persistent storage. 1074 ** ^Regardless of whether or not it is successful, this file control takes 1075 ** the file descriptor out of batch write mode so that all subsequent 1076 ** write operations are independent. 1077 ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1078 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1079 ** 1080 ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1081 ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1082 ** operations since the previous successful call to 1083 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1084 ** ^This file control takes the file descriptor out of batch write mode 1085 ** so that all subsequent write operations are independent. 1086 ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1087 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1088 ** 1089 ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1090 ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode causes attempts to obtain 1091 ** a file lock using the xLock or xShmLock methods of the VFS to wait 1092 ** for up to M milliseconds before failing, where M is the single 1093 ** unsigned integer parameter. 1094 ** 1095 ** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1096 ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1097 ** a database file. The argument is a pointer to a 32-bit unsigned integer. 1098 ** The "data version" for the pager is written into the pointer. The 1099 ** "data version" changes whenever any change occurs to the corresponding 1100 ** database file, either through SQL statements on the same database 1101 ** connection or through transactions committed by separate database 1102 ** connections possibly in other processes. The [sqlite3_total_changes()] 1103 ** interface can be used to find if any database on the connection has changed, 1104 ** but that interface responds to changes on TEMP as well as MAIN and does 1105 ** not provide a mechanism to detect changes to MAIN only. Also, the 1106 ** [sqlite3_total_changes()] interface responds to internal changes only and 1107 ** omits changes made by other database connections. The 1108 ** [PRAGMA data_version] command provides a mechanism to detect changes to 1109 ** a single attached database that occur due to other database connections, 1110 ** but omits changes implemented by the database connection on which it is 1111 ** called. This file control is the only mechanism to detect changes that 1112 ** happen either internally or externally and that are associated with 1113 ** a particular attached database. 1114 ** 1115 ** <li>[[SQLITE_FCNTL_CKPT_DONE]] 1116 ** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint 1117 ** in wal mode after the client has finished copying pages from the wal 1118 ** file to the database file, but before the *-shm file is updated to 1119 ** record the fact that the pages have been checkpointed. 1120 ** </ul> 1121 */ 1122 #define SQLITE_FCNTL_LOCKSTATE 1 1123 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1124 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1125 #define SQLITE_FCNTL_LAST_ERRNO 4 1126 #define SQLITE_FCNTL_SIZE_HINT 5 1127 #define SQLITE_FCNTL_CHUNK_SIZE 6 1128 #define SQLITE_FCNTL_FILE_POINTER 7 1129 #define SQLITE_FCNTL_SYNC_OMITTED 8 1130 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 1131 #define SQLITE_FCNTL_PERSIST_WAL 10 1132 #define SQLITE_FCNTL_OVERWRITE 11 1133 #define SQLITE_FCNTL_VFSNAME 12 1134 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1135 #define SQLITE_FCNTL_PRAGMA 14 1136 #define SQLITE_FCNTL_BUSYHANDLER 15 1137 #define SQLITE_FCNTL_TEMPFILENAME 16 1138 #define SQLITE_FCNTL_MMAP_SIZE 18 1139 #define SQLITE_FCNTL_TRACE 19 1140 #define SQLITE_FCNTL_HAS_MOVED 20 1141 #define SQLITE_FCNTL_SYNC 21 1142 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 1143 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1144 #define SQLITE_FCNTL_WAL_BLOCK 24 1145 #define SQLITE_FCNTL_ZIPVFS 25 1146 #define SQLITE_FCNTL_RBU 26 1147 #define SQLITE_FCNTL_VFS_POINTER 27 1148 #define SQLITE_FCNTL_JOURNAL_POINTER 28 1149 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1150 #define SQLITE_FCNTL_PDB 30 1151 #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1152 #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1153 #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1154 #define SQLITE_FCNTL_LOCK_TIMEOUT 34 1155 #define SQLITE_FCNTL_DATA_VERSION 35 1156 #define SQLITE_FCNTL_SIZE_LIMIT 36 1157 #define SQLITE_FCNTL_CKPT_DONE 37 1158 1159 /* deprecated names */ 1160 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1161 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1162 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1163 1164 1165 /* 1166 ** CAPI3REF: Mutex Handle 1167 ** 1168 ** The mutex module within SQLite defines [sqlite3_mutex] to be an 1169 ** abstract type for a mutex object. The SQLite core never looks 1170 ** at the internal representation of an [sqlite3_mutex]. It only 1171 ** deals with pointers to the [sqlite3_mutex] object. 1172 ** 1173 ** Mutexes are created using [sqlite3_mutex_alloc()]. 1174 */ 1175 typedef struct sqlite3_mutex sqlite3_mutex; 1176 1177 /* 1178 ** CAPI3REF: Loadable Extension Thunk 1179 ** 1180 ** A pointer to the opaque sqlite3_api_routines structure is passed as 1181 ** the third parameter to entry points of [loadable extensions]. This 1182 ** structure must be typedefed in order to work around compiler warnings 1183 ** on some platforms. 1184 */ 1185 typedef struct sqlite3_api_routines sqlite3_api_routines; 1186 1187 /* 1188 ** CAPI3REF: OS Interface Object 1189 ** 1190 ** An instance of the sqlite3_vfs object defines the interface between 1191 ** the SQLite core and the underlying operating system. The "vfs" 1192 ** in the name of the object stands for "virtual file system". See 1193 ** the [VFS | VFS documentation] for further information. 1194 ** 1195 ** The VFS interface is sometimes extended by adding new methods onto 1196 ** the end. Each time such an extension occurs, the iVersion field 1197 ** is incremented. The iVersion value started out as 1 in 1198 ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1199 ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1200 ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1201 ** may be appended to the sqlite3_vfs object and the iVersion value 1202 ** may increase again in future versions of SQLite. 1203 ** Note that due to an oversight, the structure 1204 ** of the sqlite3_vfs object changed in the transition from 1205 ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1206 ** and yet the iVersion field was not increased. 1207 ** 1208 ** The szOsFile field is the size of the subclassed [sqlite3_file] 1209 ** structure used by this VFS. mxPathname is the maximum length of 1210 ** a pathname in this VFS. 1211 ** 1212 ** Registered sqlite3_vfs objects are kept on a linked list formed by 1213 ** the pNext pointer. The [sqlite3_vfs_register()] 1214 ** and [sqlite3_vfs_unregister()] interfaces manage this list 1215 ** in a thread-safe way. The [sqlite3_vfs_find()] interface 1216 ** searches the list. Neither the application code nor the VFS 1217 ** implementation should use the pNext pointer. 1218 ** 1219 ** The pNext field is the only field in the sqlite3_vfs 1220 ** structure that SQLite will ever modify. SQLite will only access 1221 ** or modify this field while holding a particular static mutex. 1222 ** The application should never modify anything within the sqlite3_vfs 1223 ** object once the object has been registered. 1224 ** 1225 ** The zName field holds the name of the VFS module. The name must 1226 ** be unique across all VFS modules. 1227 ** 1228 ** [[sqlite3_vfs.xOpen]] 1229 ** ^SQLite guarantees that the zFilename parameter to xOpen 1230 ** is either a NULL pointer or string obtained 1231 ** from xFullPathname() with an optional suffix added. 1232 ** ^If a suffix is added to the zFilename parameter, it will 1233 ** consist of a single "-" character followed by no more than 1234 ** 11 alphanumeric and/or "-" characters. 1235 ** ^SQLite further guarantees that 1236 ** the string will be valid and unchanged until xClose() is 1237 ** called. Because of the previous sentence, 1238 ** the [sqlite3_file] can safely store a pointer to the 1239 ** filename if it needs to remember the filename for some reason. 1240 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1241 ** must invent its own temporary name for the file. ^Whenever the 1242 ** xFilename parameter is NULL it will also be the case that the 1243 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1244 ** 1245 ** The flags argument to xOpen() includes all bits set in 1246 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1247 ** or [sqlite3_open16()] is used, then flags includes at least 1248 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1249 ** If xOpen() opens a file read-only then it sets *pOutFlags to 1250 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1251 ** 1252 ** ^(SQLite will also add one of the following flags to the xOpen() 1253 ** call, depending on the object being opened: 1254 ** 1255 ** <ul> 1256 ** <li> [SQLITE_OPEN_MAIN_DB] 1257 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1258 ** <li> [SQLITE_OPEN_TEMP_DB] 1259 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1260 ** <li> [SQLITE_OPEN_TRANSIENT_DB] 1261 ** <li> [SQLITE_OPEN_SUBJOURNAL] 1262 ** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1263 ** <li> [SQLITE_OPEN_WAL] 1264 ** </ul>)^ 1265 ** 1266 ** The file I/O implementation can use the object type flags to 1267 ** change the way it deals with files. For example, an application 1268 ** that does not care about crash recovery or rollback might make 1269 ** the open of a journal file a no-op. Writes to this journal would 1270 ** also be no-ops, and any attempt to read the journal would return 1271 ** SQLITE_IOERR. Or the implementation might recognize that a database 1272 ** file will be doing page-aligned sector reads and writes in a random 1273 ** order and set up its I/O subsystem accordingly. 1274 ** 1275 ** SQLite might also add one of the following flags to the xOpen method: 1276 ** 1277 ** <ul> 1278 ** <li> [SQLITE_OPEN_DELETEONCLOSE] 1279 ** <li> [SQLITE_OPEN_EXCLUSIVE] 1280 ** </ul> 1281 ** 1282 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1283 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1284 ** will be set for TEMP databases and their journals, transient 1285 ** databases, and subjournals. 1286 ** 1287 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1288 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1289 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1290 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1291 ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1292 ** be created, and that it is an error if it already exists. 1293 ** It is <i>not</i> used to indicate the file should be opened 1294 ** for exclusive access. 1295 ** 1296 ** ^At least szOsFile bytes of memory are allocated by SQLite 1297 ** to hold the [sqlite3_file] structure passed as the third 1298 ** argument to xOpen. The xOpen method does not have to 1299 ** allocate the structure; it should just fill it in. Note that 1300 ** the xOpen method must set the sqlite3_file.pMethods to either 1301 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1302 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1303 ** element will be valid after xOpen returns regardless of the success 1304 ** or failure of the xOpen call. 1305 ** 1306 ** [[sqlite3_vfs.xAccess]] 1307 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1308 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1309 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1310 ** to test whether a file is at least readable. The SQLITE_ACCESS_READ 1311 ** flag is never actually used and is not implemented in the built-in 1312 ** VFSes of SQLite. The file is named by the second argument and can be a 1313 ** directory. The xAccess method returns [SQLITE_OK] on success or some 1314 ** non-zero error code if there is an I/O error or if the name of 1315 ** the file given in the second argument is illegal. If SQLITE_OK 1316 ** is returned, then non-zero or zero is written into *pResOut to indicate 1317 ** whether or not the file is accessible. 1318 ** 1319 ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1320 ** output buffer xFullPathname. The exact size of the output buffer 1321 ** is also passed as a parameter to both methods. If the output buffer 1322 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1323 ** handled as a fatal error by SQLite, vfs implementations should endeavor 1324 ** to prevent this by setting mxPathname to a sufficiently large value. 1325 ** 1326 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1327 ** interfaces are not strictly a part of the filesystem, but they are 1328 ** included in the VFS structure for completeness. 1329 ** The xRandomness() function attempts to return nBytes bytes 1330 ** of good-quality randomness into zOut. The return value is 1331 ** the actual number of bytes of randomness obtained. 1332 ** The xSleep() method causes the calling thread to sleep for at 1333 ** least the number of microseconds given. ^The xCurrentTime() 1334 ** method returns a Julian Day Number for the current date and time as 1335 ** a floating point value. 1336 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1337 ** Day Number multiplied by 86400000 (the number of milliseconds in 1338 ** a 24-hour day). 1339 ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1340 ** date and time if that method is available (if iVersion is 2 or 1341 ** greater and the function pointer is not NULL) and will fall back 1342 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1343 ** 1344 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1345 ** are not used by the SQLite core. These optional interfaces are provided 1346 ** by some VFSes to facilitate testing of the VFS code. By overriding 1347 ** system calls with functions under its control, a test program can 1348 ** simulate faults and error conditions that would otherwise be difficult 1349 ** or impossible to induce. The set of system calls that can be overridden 1350 ** varies from one VFS to another, and from one version of the same VFS to the 1351 ** next. Applications that use these interfaces must be prepared for any 1352 ** or all of these interfaces to be NULL or for their behavior to change 1353 ** from one release to the next. Applications must not attempt to access 1354 ** any of these methods if the iVersion of the VFS is less than 3. 1355 */ 1356 typedef struct sqlite3_vfs sqlite3_vfs; 1357 typedef void (*sqlite3_syscall_ptr)(void); 1358 struct sqlite3_vfs { 1359 int iVersion; /* Structure version number (currently 3) */ 1360 int szOsFile; /* Size of subclassed sqlite3_file */ 1361 int mxPathname; /* Maximum file pathname length */ 1362 sqlite3_vfs *pNext; /* Next registered VFS */ 1363 const char *zName; /* Name of this virtual file system */ 1364 void *pAppData; /* Pointer to application-specific data */ 1365 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1366 int flags, int *pOutFlags); 1367 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1368 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1369 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1370 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1371 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1372 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1373 void (*xDlClose)(sqlite3_vfs*, void*); 1374 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1375 int (*xSleep)(sqlite3_vfs*, int microseconds); 1376 int (*xCurrentTime)(sqlite3_vfs*, double*); 1377 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1378 /* 1379 ** The methods above are in version 1 of the sqlite_vfs object 1380 ** definition. Those that follow are added in version 2 or later 1381 */ 1382 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1383 /* 1384 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1385 ** Those below are for version 3 and greater. 1386 */ 1387 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1388 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1389 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1390 /* 1391 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1392 ** New fields may be appended in future versions. The iVersion 1393 ** value will increment whenever this happens. 1394 */ 1395 }; 1396 1397 /* 1398 ** CAPI3REF: Flags for the xAccess VFS method 1399 ** 1400 ** These integer constants can be used as the third parameter to 1401 ** the xAccess method of an [sqlite3_vfs] object. They determine 1402 ** what kind of permissions the xAccess method is looking for. 1403 ** With SQLITE_ACCESS_EXISTS, the xAccess method 1404 ** simply checks whether the file exists. 1405 ** With SQLITE_ACCESS_READWRITE, the xAccess method 1406 ** checks whether the named directory is both readable and writable 1407 ** (in other words, if files can be added, removed, and renamed within 1408 ** the directory). 1409 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1410 ** [temp_store_directory pragma], though this could change in a future 1411 ** release of SQLite. 1412 ** With SQLITE_ACCESS_READ, the xAccess method 1413 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1414 ** currently unused, though it might be used in a future release of 1415 ** SQLite. 1416 */ 1417 #define SQLITE_ACCESS_EXISTS 0 1418 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1419 #define SQLITE_ACCESS_READ 2 /* Unused */ 1420 1421 /* 1422 ** CAPI3REF: Flags for the xShmLock VFS method 1423 ** 1424 ** These integer constants define the various locking operations 1425 ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1426 ** following are the only legal combinations of flags to the 1427 ** xShmLock method: 1428 ** 1429 ** <ul> 1430 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1431 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1432 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1433 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1434 ** </ul> 1435 ** 1436 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1437 ** was given on the corresponding lock. 1438 ** 1439 ** The xShmLock method can transition between unlocked and SHARED or 1440 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1441 ** and EXCLUSIVE. 1442 */ 1443 #define SQLITE_SHM_UNLOCK 1 1444 #define SQLITE_SHM_LOCK 2 1445 #define SQLITE_SHM_SHARED 4 1446 #define SQLITE_SHM_EXCLUSIVE 8 1447 1448 /* 1449 ** CAPI3REF: Maximum xShmLock index 1450 ** 1451 ** The xShmLock method on [sqlite3_io_methods] may use values 1452 ** between 0 and this upper bound as its "offset" argument. 1453 ** The SQLite core will never attempt to acquire or release a 1454 ** lock outside of this range 1455 */ 1456 #define SQLITE_SHM_NLOCK 8 1457 1458 1459 /* 1460 ** CAPI3REF: Initialize The SQLite Library 1461 ** 1462 ** ^The sqlite3_initialize() routine initializes the 1463 ** SQLite library. ^The sqlite3_shutdown() routine 1464 ** deallocates any resources that were allocated by sqlite3_initialize(). 1465 ** These routines are designed to aid in process initialization and 1466 ** shutdown on embedded systems. Workstation applications using 1467 ** SQLite normally do not need to invoke either of these routines. 1468 ** 1469 ** A call to sqlite3_initialize() is an "effective" call if it is 1470 ** the first time sqlite3_initialize() is invoked during the lifetime of 1471 ** the process, or if it is the first time sqlite3_initialize() is invoked 1472 ** following a call to sqlite3_shutdown(). ^(Only an effective call 1473 ** of sqlite3_initialize() does any initialization. All other calls 1474 ** are harmless no-ops.)^ 1475 ** 1476 ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1477 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1478 ** an effective call to sqlite3_shutdown() does any deinitialization. 1479 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1480 ** 1481 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1482 ** is not. The sqlite3_shutdown() interface must only be called from a 1483 ** single thread. All open [database connections] must be closed and all 1484 ** other SQLite resources must be deallocated prior to invoking 1485 ** sqlite3_shutdown(). 1486 ** 1487 ** Among other things, ^sqlite3_initialize() will invoke 1488 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1489 ** will invoke sqlite3_os_end(). 1490 ** 1491 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1492 ** ^If for some reason, sqlite3_initialize() is unable to initialize 1493 ** the library (perhaps it is unable to allocate a needed resource such 1494 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1495 ** 1496 ** ^The sqlite3_initialize() routine is called internally by many other 1497 ** SQLite interfaces so that an application usually does not need to 1498 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1499 ** calls sqlite3_initialize() so the SQLite library will be automatically 1500 ** initialized when [sqlite3_open()] is called if it has not be initialized 1501 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1502 ** compile-time option, then the automatic calls to sqlite3_initialize() 1503 ** are omitted and the application must call sqlite3_initialize() directly 1504 ** prior to using any other SQLite interface. For maximum portability, 1505 ** it is recommended that applications always invoke sqlite3_initialize() 1506 ** directly prior to using any other SQLite interface. Future releases 1507 ** of SQLite may require this. In other words, the behavior exhibited 1508 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1509 ** default behavior in some future release of SQLite. 1510 ** 1511 ** The sqlite3_os_init() routine does operating-system specific 1512 ** initialization of the SQLite library. The sqlite3_os_end() 1513 ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1514 ** performed by these routines include allocation or deallocation 1515 ** of static resources, initialization of global variables, 1516 ** setting up a default [sqlite3_vfs] module, or setting up 1517 ** a default configuration using [sqlite3_config()]. 1518 ** 1519 ** The application should never invoke either sqlite3_os_init() 1520 ** or sqlite3_os_end() directly. The application should only invoke 1521 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1522 ** interface is called automatically by sqlite3_initialize() and 1523 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1524 ** implementations for sqlite3_os_init() and sqlite3_os_end() 1525 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1526 ** When [custom builds | built for other platforms] 1527 ** (using the [SQLITE_OS_OTHER=1] compile-time 1528 ** option) the application must supply a suitable implementation for 1529 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1530 ** implementation of sqlite3_os_init() or sqlite3_os_end() 1531 ** must return [SQLITE_OK] on success and some other [error code] upon 1532 ** failure. 1533 */ 1534 SQLITE_API int sqlite3_initialize(void); 1535 SQLITE_API int sqlite3_shutdown(void); 1536 SQLITE_API int sqlite3_os_init(void); 1537 SQLITE_API int sqlite3_os_end(void); 1538 1539 /* 1540 ** CAPI3REF: Configuring The SQLite Library 1541 ** 1542 ** The sqlite3_config() interface is used to make global configuration 1543 ** changes to SQLite in order to tune SQLite to the specific needs of 1544 ** the application. The default configuration is recommended for most 1545 ** applications and so this routine is usually not necessary. It is 1546 ** provided to support rare applications with unusual needs. 1547 ** 1548 ** <b>The sqlite3_config() interface is not threadsafe. The application 1549 ** must ensure that no other SQLite interfaces are invoked by other 1550 ** threads while sqlite3_config() is running.</b> 1551 ** 1552 ** The sqlite3_config() interface 1553 ** may only be invoked prior to library initialization using 1554 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1555 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1556 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1557 ** Note, however, that ^sqlite3_config() can be called as part of the 1558 ** implementation of an application-defined [sqlite3_os_init()]. 1559 ** 1560 ** The first argument to sqlite3_config() is an integer 1561 ** [configuration option] that determines 1562 ** what property of SQLite is to be configured. Subsequent arguments 1563 ** vary depending on the [configuration option] 1564 ** in the first argument. 1565 ** 1566 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1567 ** ^If the option is unknown or SQLite is unable to set the option 1568 ** then this routine returns a non-zero [error code]. 1569 */ 1570 SQLITE_API int sqlite3_config(int, ...); 1571 1572 /* 1573 ** CAPI3REF: Configure database connections 1574 ** METHOD: sqlite3 1575 ** 1576 ** The sqlite3_db_config() interface is used to make configuration 1577 ** changes to a [database connection]. The interface is similar to 1578 ** [sqlite3_config()] except that the changes apply to a single 1579 ** [database connection] (specified in the first argument). 1580 ** 1581 ** The second argument to sqlite3_db_config(D,V,...) is the 1582 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1583 ** that indicates what aspect of the [database connection] is being configured. 1584 ** Subsequent arguments vary depending on the configuration verb. 1585 ** 1586 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1587 ** the call is considered successful. 1588 */ 1589 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1590 1591 /* 1592 ** CAPI3REF: Memory Allocation Routines 1593 ** 1594 ** An instance of this object defines the interface between SQLite 1595 ** and low-level memory allocation routines. 1596 ** 1597 ** This object is used in only one place in the SQLite interface. 1598 ** A pointer to an instance of this object is the argument to 1599 ** [sqlite3_config()] when the configuration option is 1600 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1601 ** By creating an instance of this object 1602 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1603 ** during configuration, an application can specify an alternative 1604 ** memory allocation subsystem for SQLite to use for all of its 1605 ** dynamic memory needs. 1606 ** 1607 ** Note that SQLite comes with several [built-in memory allocators] 1608 ** that are perfectly adequate for the overwhelming majority of applications 1609 ** and that this object is only useful to a tiny minority of applications 1610 ** with specialized memory allocation requirements. This object is 1611 ** also used during testing of SQLite in order to specify an alternative 1612 ** memory allocator that simulates memory out-of-memory conditions in 1613 ** order to verify that SQLite recovers gracefully from such 1614 ** conditions. 1615 ** 1616 ** The xMalloc, xRealloc, and xFree methods must work like the 1617 ** malloc(), realloc() and free() functions from the standard C library. 1618 ** ^SQLite guarantees that the second argument to 1619 ** xRealloc is always a value returned by a prior call to xRoundup. 1620 ** 1621 ** xSize should return the allocated size of a memory allocation 1622 ** previously obtained from xMalloc or xRealloc. The allocated size 1623 ** is always at least as big as the requested size but may be larger. 1624 ** 1625 ** The xRoundup method returns what would be the allocated size of 1626 ** a memory allocation given a particular requested size. Most memory 1627 ** allocators round up memory allocations at least to the next multiple 1628 ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1629 ** Every memory allocation request coming in through [sqlite3_malloc()] 1630 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1631 ** that causes the corresponding memory allocation to fail. 1632 ** 1633 ** The xInit method initializes the memory allocator. For example, 1634 ** it might allocate any required mutexes or initialize internal data 1635 ** structures. The xShutdown method is invoked (indirectly) by 1636 ** [sqlite3_shutdown()] and should deallocate any resources acquired 1637 ** by xInit. The pAppData pointer is used as the only parameter to 1638 ** xInit and xShutdown. 1639 ** 1640 ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1641 ** the xInit method, so the xInit method need not be threadsafe. The 1642 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1643 ** not need to be threadsafe either. For all other methods, SQLite 1644 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1645 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1646 ** it is by default) and so the methods are automatically serialized. 1647 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1648 ** methods must be threadsafe or else make their own arrangements for 1649 ** serialization. 1650 ** 1651 ** SQLite will never invoke xInit() more than once without an intervening 1652 ** call to xShutdown(). 1653 */ 1654 typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1655 struct sqlite3_mem_methods { 1656 void *(*xMalloc)(int); /* Memory allocation function */ 1657 void (*xFree)(void*); /* Free a prior allocation */ 1658 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1659 int (*xSize)(void*); /* Return the size of an allocation */ 1660 int (*xRoundup)(int); /* Round up request size to allocation size */ 1661 int (*xInit)(void*); /* Initialize the memory allocator */ 1662 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1663 void *pAppData; /* Argument to xInit() and xShutdown() */ 1664 }; 1665 1666 /* 1667 ** CAPI3REF: Configuration Options 1668 ** KEYWORDS: {configuration option} 1669 ** 1670 ** These constants are the available integer configuration options that 1671 ** can be passed as the first argument to the [sqlite3_config()] interface. 1672 ** 1673 ** New configuration options may be added in future releases of SQLite. 1674 ** Existing configuration options might be discontinued. Applications 1675 ** should check the return code from [sqlite3_config()] to make sure that 1676 ** the call worked. The [sqlite3_config()] interface will return a 1677 ** non-zero [error code] if a discontinued or unsupported configuration option 1678 ** is invoked. 1679 ** 1680 ** <dl> 1681 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1682 ** <dd>There are no arguments to this option. ^This option sets the 1683 ** [threading mode] to Single-thread. In other words, it disables 1684 ** all mutexing and puts SQLite into a mode where it can only be used 1685 ** by a single thread. ^If SQLite is compiled with 1686 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1687 ** it is not possible to change the [threading mode] from its default 1688 ** value of Single-thread and so [sqlite3_config()] will return 1689 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1690 ** configuration option.</dd> 1691 ** 1692 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1693 ** <dd>There are no arguments to this option. ^This option sets the 1694 ** [threading mode] to Multi-thread. In other words, it disables 1695 ** mutexing on [database connection] and [prepared statement] objects. 1696 ** The application is responsible for serializing access to 1697 ** [database connections] and [prepared statements]. But other mutexes 1698 ** are enabled so that SQLite will be safe to use in a multi-threaded 1699 ** environment as long as no two threads attempt to use the same 1700 ** [database connection] at the same time. ^If SQLite is compiled with 1701 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1702 ** it is not possible to set the Multi-thread [threading mode] and 1703 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1704 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1705 ** 1706 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1707 ** <dd>There are no arguments to this option. ^This option sets the 1708 ** [threading mode] to Serialized. In other words, this option enables 1709 ** all mutexes including the recursive 1710 ** mutexes on [database connection] and [prepared statement] objects. 1711 ** In this mode (which is the default when SQLite is compiled with 1712 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1713 ** to [database connections] and [prepared statements] so that the 1714 ** application is free to use the same [database connection] or the 1715 ** same [prepared statement] in different threads at the same time. 1716 ** ^If SQLite is compiled with 1717 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1718 ** it is not possible to set the Serialized [threading mode] and 1719 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1720 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1721 ** 1722 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1723 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1724 ** a pointer to an instance of the [sqlite3_mem_methods] structure. 1725 ** The argument specifies 1726 ** alternative low-level memory allocation routines to be used in place of 1727 ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1728 ** its own private copy of the content of the [sqlite3_mem_methods] structure 1729 ** before the [sqlite3_config()] call returns.</dd> 1730 ** 1731 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1732 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1733 ** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1734 ** The [sqlite3_mem_methods] 1735 ** structure is filled with the currently defined memory allocation routines.)^ 1736 ** This option can be used to overload the default memory allocation 1737 ** routines with a wrapper that simulations memory allocation failure or 1738 ** tracks memory usage, for example. </dd> 1739 ** 1740 ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1741 ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1742 ** type int, interpreted as a boolean, which if true provides a hint to 1743 ** SQLite that it should avoid large memory allocations if possible. 1744 ** SQLite will run faster if it is free to make large memory allocations, 1745 ** but some application might prefer to run slower in exchange for 1746 ** guarantees about memory fragmentation that are possible if large 1747 ** allocations are avoided. This hint is normally off. 1748 ** </dd> 1749 ** 1750 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1751 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1752 ** interpreted as a boolean, which enables or disables the collection of 1753 ** memory allocation statistics. ^(When memory allocation statistics are 1754 ** disabled, the following SQLite interfaces become non-operational: 1755 ** <ul> 1756 ** <li> [sqlite3_hard_heap_limit64()] 1757 ** <li> [sqlite3_memory_used()] 1758 ** <li> [sqlite3_memory_highwater()] 1759 ** <li> [sqlite3_soft_heap_limit64()] 1760 ** <li> [sqlite3_status64()] 1761 ** </ul>)^ 1762 ** ^Memory allocation statistics are enabled by default unless SQLite is 1763 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1764 ** allocation statistics are disabled by default. 1765 ** </dd> 1766 ** 1767 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1768 ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1769 ** </dd> 1770 ** 1771 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1772 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1773 ** that SQLite can use for the database page cache with the default page 1774 ** cache implementation. 1775 ** This configuration option is a no-op if an application-defined page 1776 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1777 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1778 ** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1779 ** and the number of cache lines (N). 1780 ** The sz argument should be the size of the largest database page 1781 ** (a power of two between 512 and 65536) plus some extra bytes for each 1782 ** page header. ^The number of extra bytes needed by the page header 1783 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1784 ** ^It is harmless, apart from the wasted memory, 1785 ** for the sz parameter to be larger than necessary. The pMem 1786 ** argument must be either a NULL pointer or a pointer to an 8-byte 1787 ** aligned block of memory of at least sz*N bytes, otherwise 1788 ** subsequent behavior is undefined. 1789 ** ^When pMem is not NULL, SQLite will strive to use the memory provided 1790 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1791 ** a page cache line is larger than sz bytes or if all of the pMem buffer 1792 ** is exhausted. 1793 ** ^If pMem is NULL and N is non-zero, then each database connection 1794 ** does an initial bulk allocation for page cache memory 1795 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1796 ** of -1024*N bytes if N is negative, . ^If additional 1797 ** page cache memory is needed beyond what is provided by the initial 1798 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1799 ** additional cache line. </dd> 1800 ** 1801 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1802 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1803 ** that SQLite will use for all of its dynamic memory allocation needs 1804 ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1805 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1806 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1807 ** [SQLITE_ERROR] if invoked otherwise. 1808 ** ^There are three arguments to SQLITE_CONFIG_HEAP: 1809 ** An 8-byte aligned pointer to the memory, 1810 ** the number of bytes in the memory buffer, and the minimum allocation size. 1811 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1812 ** to using its default memory allocator (the system malloc() implementation), 1813 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1814 ** memory pointer is not NULL then the alternative memory 1815 ** allocator is engaged to handle all of SQLites memory allocation needs. 1816 ** The first pointer (the memory pointer) must be aligned to an 8-byte 1817 ** boundary or subsequent behavior of SQLite will be undefined. 1818 ** The minimum allocation size is capped at 2**12. Reasonable values 1819 ** for the minimum allocation size are 2**5 through 2**8.</dd> 1820 ** 1821 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1822 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1823 ** pointer to an instance of the [sqlite3_mutex_methods] structure. 1824 ** The argument specifies alternative low-level mutex routines to be used 1825 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1826 ** the content of the [sqlite3_mutex_methods] structure before the call to 1827 ** [sqlite3_config()] returns. ^If SQLite is compiled with 1828 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1829 ** the entire mutexing subsystem is omitted from the build and hence calls to 1830 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1831 ** return [SQLITE_ERROR].</dd> 1832 ** 1833 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1834 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1835 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1836 ** [sqlite3_mutex_methods] 1837 ** structure is filled with the currently defined mutex routines.)^ 1838 ** This option can be used to overload the default mutex allocation 1839 ** routines with a wrapper used to track mutex usage for performance 1840 ** profiling or testing, for example. ^If SQLite is compiled with 1841 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1842 ** the entire mutexing subsystem is omitted from the build and hence calls to 1843 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1844 ** return [SQLITE_ERROR].</dd> 1845 ** 1846 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1847 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1848 ** the default size of lookaside memory on each [database connection]. 1849 ** The first argument is the 1850 ** size of each lookaside buffer slot and the second is the number of 1851 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1852 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1853 ** option to [sqlite3_db_config()] can be used to change the lookaside 1854 ** configuration on individual connections.)^ </dd> 1855 ** 1856 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1857 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1858 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1859 ** the interface to a custom page cache implementation.)^ 1860 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1861 ** 1862 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1863 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1864 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1865 ** the current page cache implementation into that object.)^ </dd> 1866 ** 1867 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1868 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1869 ** global [error log]. 1870 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1871 ** function with a call signature of void(*)(void*,int,const char*), 1872 ** and a pointer to void. ^If the function pointer is not NULL, it is 1873 ** invoked by [sqlite3_log()] to process each logging event. ^If the 1874 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1875 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1876 ** passed through as the first parameter to the application-defined logger 1877 ** function whenever that function is invoked. ^The second parameter to 1878 ** the logger function is a copy of the first parameter to the corresponding 1879 ** [sqlite3_log()] call and is intended to be a [result code] or an 1880 ** [extended result code]. ^The third parameter passed to the logger is 1881 ** log message after formatting via [sqlite3_snprintf()]. 1882 ** The SQLite logging interface is not reentrant; the logger function 1883 ** supplied by the application must not invoke any SQLite interface. 1884 ** In a multi-threaded application, the application-defined logger 1885 ** function must be threadsafe. </dd> 1886 ** 1887 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1888 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1889 ** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1890 ** then URI handling is globally disabled.)^ ^If URI handling is globally 1891 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1892 ** [sqlite3_open16()] or 1893 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1894 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1895 ** connection is opened. ^If it is globally disabled, filenames are 1896 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1897 ** database connection is opened. ^(By default, URI handling is globally 1898 ** disabled. The default value may be changed by compiling with the 1899 ** [SQLITE_USE_URI] symbol defined.)^ 1900 ** 1901 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1902 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1903 ** argument which is interpreted as a boolean in order to enable or disable 1904 ** the use of covering indices for full table scans in the query optimizer. 1905 ** ^The default setting is determined 1906 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1907 ** if that compile-time option is omitted. 1908 ** The ability to disable the use of covering indices for full table scans 1909 ** is because some incorrectly coded legacy applications might malfunction 1910 ** when the optimization is enabled. Providing the ability to 1911 ** disable the optimization allows the older, buggy application code to work 1912 ** without change even with newer versions of SQLite. 1913 ** 1914 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1915 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1916 ** <dd> These options are obsolete and should not be used by new code. 1917 ** They are retained for backwards compatibility but are now no-ops. 1918 ** </dd> 1919 ** 1920 ** [[SQLITE_CONFIG_SQLLOG]] 1921 ** <dt>SQLITE_CONFIG_SQLLOG 1922 ** <dd>This option is only available if sqlite is compiled with the 1923 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1924 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1925 ** The second should be of type (void*). The callback is invoked by the library 1926 ** in three separate circumstances, identified by the value passed as the 1927 ** fourth parameter. If the fourth parameter is 0, then the database connection 1928 ** passed as the second argument has just been opened. The third argument 1929 ** points to a buffer containing the name of the main database file. If the 1930 ** fourth parameter is 1, then the SQL statement that the third parameter 1931 ** points to has just been executed. Or, if the fourth parameter is 2, then 1932 ** the connection being passed as the second parameter is being closed. The 1933 ** third parameter is passed NULL In this case. An example of using this 1934 ** configuration option can be seen in the "test_sqllog.c" source file in 1935 ** the canonical SQLite source tree.</dd> 1936 ** 1937 ** [[SQLITE_CONFIG_MMAP_SIZE]] 1938 ** <dt>SQLITE_CONFIG_MMAP_SIZE 1939 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1940 ** that are the default mmap size limit (the default setting for 1941 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1942 ** ^The default setting can be overridden by each database connection using 1943 ** either the [PRAGMA mmap_size] command, or by using the 1944 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1945 ** will be silently truncated if necessary so that it does not exceed the 1946 ** compile-time maximum mmap size set by the 1947 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1948 ** ^If either argument to this option is negative, then that argument is 1949 ** changed to its compile-time default. 1950 ** 1951 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1952 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1953 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1954 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1955 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1956 ** that specifies the maximum size of the created heap. 1957 ** 1958 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1959 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1960 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1961 ** is a pointer to an integer and writes into that integer the number of extra 1962 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1963 ** The amount of extra space required can change depending on the compiler, 1964 ** target platform, and SQLite version. 1965 ** 1966 ** [[SQLITE_CONFIG_PMASZ]] 1967 ** <dt>SQLITE_CONFIG_PMASZ 1968 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1969 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1970 ** sorter to that integer. The default minimum PMA Size is set by the 1971 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1972 ** to help with sort operations when multithreaded sorting 1973 ** is enabled (using the [PRAGMA threads] command) and the amount of content 1974 ** to be sorted exceeds the page size times the minimum of the 1975 ** [PRAGMA cache_size] setting and this value. 1976 ** 1977 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1978 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1979 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1980 ** becomes the [statement journal] spill-to-disk threshold. 1981 ** [Statement journals] are held in memory until their size (in bytes) 1982 ** exceeds this threshold, at which point they are written to disk. 1983 ** Or if the threshold is -1, statement journals are always held 1984 ** exclusively in memory. 1985 ** Since many statement journals never become large, setting the spill 1986 ** threshold to a value such as 64KiB can greatly reduce the amount of 1987 ** I/O required to support statement rollback. 1988 ** The default value for this setting is controlled by the 1989 ** [SQLITE_STMTJRNL_SPILL] compile-time option. 1990 ** 1991 ** [[SQLITE_CONFIG_SORTERREF_SIZE]] 1992 ** <dt>SQLITE_CONFIG_SORTERREF_SIZE 1993 ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 1994 ** of type (int) - the new value of the sorter-reference size threshold. 1995 ** Usually, when SQLite uses an external sort to order records according 1996 ** to an ORDER BY clause, all fields required by the caller are present in the 1997 ** sorted records. However, if SQLite determines based on the declared type 1998 ** of a table column that its values are likely to be very large - larger 1999 ** than the configured sorter-reference size threshold - then a reference 2000 ** is stored in each sorted record and the required column values loaded 2001 ** from the database as records are returned in sorted order. The default 2002 ** value for this option is to never use this optimization. Specifying a 2003 ** negative value for this option restores the default behaviour. 2004 ** This option is only available if SQLite is compiled with the 2005 ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 2006 ** 2007 ** [[SQLITE_CONFIG_MEMDB_MAXSIZE]] 2008 ** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE 2009 ** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter 2010 ** [sqlite3_int64] parameter which is the default maximum size for an in-memory 2011 ** database created using [sqlite3_deserialize()]. This default maximum 2012 ** size can be adjusted up or down for individual databases using the 2013 ** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this 2014 ** configuration setting is never used, then the default maximum is determined 2015 ** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that 2016 ** compile-time option is not set, then the default maximum is 1073741824. 2017 ** </dl> 2018 */ 2019 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 2020 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 2021 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 2022 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 2023 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 2024 #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 2025 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 2026 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 2027 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 2028 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 2029 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 2030 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 2031 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 2032 #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 2033 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 2034 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 2035 #define SQLITE_CONFIG_URI 17 /* int */ 2036 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 2037 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 2038 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 2039 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 2040 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 2041 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 2042 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2043 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2044 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2045 #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2046 #define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2047 #define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */ 2048 2049 /* 2050 ** CAPI3REF: Database Connection Configuration Options 2051 ** 2052 ** These constants are the available integer configuration options that 2053 ** can be passed as the second argument to the [sqlite3_db_config()] interface. 2054 ** 2055 ** New configuration options may be added in future releases of SQLite. 2056 ** Existing configuration options might be discontinued. Applications 2057 ** should check the return code from [sqlite3_db_config()] to make sure that 2058 ** the call worked. ^The [sqlite3_db_config()] interface will return a 2059 ** non-zero [error code] if a discontinued or unsupported configuration option 2060 ** is invoked. 2061 ** 2062 ** <dl> 2063 ** [[SQLITE_DBCONFIG_LOOKASIDE]] 2064 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2065 ** <dd> ^This option takes three additional arguments that determine the 2066 ** [lookaside memory allocator] configuration for the [database connection]. 2067 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2068 ** pointer to a memory buffer to use for lookaside memory. 2069 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2070 ** may be NULL in which case SQLite will allocate the 2071 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2072 ** size of each lookaside buffer slot. ^The third argument is the number of 2073 ** slots. The size of the buffer in the first argument must be greater than 2074 ** or equal to the product of the second and third arguments. The buffer 2075 ** must be aligned to an 8-byte boundary. ^If the second argument to 2076 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2077 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2078 ** configuration for a database connection can only be changed when that 2079 ** connection is not currently using lookaside memory, or in other words 2080 ** when the "current value" returned by 2081 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 2082 ** Any attempt to change the lookaside memory configuration when lookaside 2083 ** memory is in use leaves the configuration unchanged and returns 2084 ** [SQLITE_BUSY].)^</dd> 2085 ** 2086 ** [[SQLITE_DBCONFIG_ENABLE_FKEY]] 2087 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2088 ** <dd> ^This option is used to enable or disable the enforcement of 2089 ** [foreign key constraints]. There should be two additional arguments. 2090 ** The first argument is an integer which is 0 to disable FK enforcement, 2091 ** positive to enable FK enforcement or negative to leave FK enforcement 2092 ** unchanged. The second parameter is a pointer to an integer into which 2093 ** is written 0 or 1 to indicate whether FK enforcement is off or on 2094 ** following this call. The second parameter may be a NULL pointer, in 2095 ** which case the FK enforcement setting is not reported back. </dd> 2096 ** 2097 ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] 2098 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2099 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2100 ** There should be two additional arguments. 2101 ** The first argument is an integer which is 0 to disable triggers, 2102 ** positive to enable triggers or negative to leave the setting unchanged. 2103 ** The second parameter is a pointer to an integer into which 2104 ** is written 0 or 1 to indicate whether triggers are disabled or enabled 2105 ** following this call. The second parameter may be a NULL pointer, in 2106 ** which case the trigger setting is not reported back. </dd> 2107 ** 2108 ** [[SQLITE_DBCONFIG_ENABLE_VIEW]] 2109 ** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt> 2110 ** <dd> ^This option is used to enable or disable [CREATE VIEW | views]. 2111 ** There should be two additional arguments. 2112 ** The first argument is an integer which is 0 to disable views, 2113 ** positive to enable views or negative to leave the setting unchanged. 2114 ** The second parameter is a pointer to an integer into which 2115 ** is written 0 or 1 to indicate whether views are disabled or enabled 2116 ** following this call. The second parameter may be a NULL pointer, in 2117 ** which case the view setting is not reported back. </dd> 2118 ** 2119 ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] 2120 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2121 ** <dd> ^This option is used to enable or disable the 2122 ** [fts3_tokenizer()] function which is part of the 2123 ** [FTS3] full-text search engine extension. 2124 ** There should be two additional arguments. 2125 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2126 ** positive to enable fts3_tokenizer() or negative to leave the setting 2127 ** unchanged. 2128 ** The second parameter is a pointer to an integer into which 2129 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2130 ** following this call. The second parameter may be a NULL pointer, in 2131 ** which case the new setting is not reported back. </dd> 2132 ** 2133 ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] 2134 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2135 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2136 ** interface independently of the [load_extension()] SQL function. 2137 ** The [sqlite3_enable_load_extension()] API enables or disables both the 2138 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2139 ** There should be two additional arguments. 2140 ** When the first argument to this interface is 1, then only the C-API is 2141 ** enabled and the SQL function remains disabled. If the first argument to 2142 ** this interface is 0, then both the C-API and the SQL function are disabled. 2143 ** If the first argument is -1, then no changes are made to state of either the 2144 ** C-API or the SQL function. 2145 ** The second parameter is a pointer to an integer into which 2146 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2147 ** is disabled or enabled following this call. The second parameter may 2148 ** be a NULL pointer, in which case the new setting is not reported back. 2149 ** </dd> 2150 ** 2151 ** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2152 ** <dd> ^This option is used to change the name of the "main" database 2153 ** schema. ^The sole argument is a pointer to a constant UTF8 string 2154 ** which will become the new schema name in place of "main". ^SQLite 2155 ** does not make a copy of the new main schema name string, so the application 2156 ** must ensure that the argument passed into this DBCONFIG option is unchanged 2157 ** until after the database connection closes. 2158 ** </dd> 2159 ** 2160 ** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] 2161 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2162 ** <dd> Usually, when a database in wal mode is closed or detached from a 2163 ** database handle, SQLite checks if this will mean that there are now no 2164 ** connections at all to the database. If so, it performs a checkpoint 2165 ** operation before closing the connection. This option may be used to 2166 ** override this behaviour. The first parameter passed to this operation 2167 ** is an integer - positive to disable checkpoints-on-close, or zero (the 2168 ** default) to enable them, and negative to leave the setting unchanged. 2169 ** The second parameter is a pointer to an integer 2170 ** into which is written 0 or 1 to indicate whether checkpoints-on-close 2171 ** have been disabled - 0 if they are not disabled, 1 if they are. 2172 ** </dd> 2173 ** 2174 ** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2175 ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2176 ** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2177 ** a single SQL query statement will always use the same algorithm regardless 2178 ** of values of [bound parameters].)^ The QPSG disables some query optimizations 2179 ** that look at the values of bound parameters, which can make some queries 2180 ** slower. But the QPSG has the advantage of more predictable behavior. With 2181 ** the QPSG active, SQLite will always use the same query plan in the field as 2182 ** was used during testing in the lab. 2183 ** The first argument to this setting is an integer which is 0 to disable 2184 ** the QPSG, positive to enable QPSG, or negative to leave the setting 2185 ** unchanged. The second parameter is a pointer to an integer into which 2186 ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2187 ** following this call. 2188 ** </dd> 2189 ** 2190 ** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2191 ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2192 ** include output for any operations performed by trigger programs. This 2193 ** option is used to set or clear (the default) a flag that governs this 2194 ** behavior. The first parameter passed to this operation is an integer - 2195 ** positive to enable output for trigger programs, or zero to disable it, 2196 ** or negative to leave the setting unchanged. 2197 ** The second parameter is a pointer to an integer into which is written 2198 ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2199 ** it is not disabled, 1 if it is. 2200 ** </dd> 2201 ** 2202 ** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2203 ** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2204 ** [VACUUM] in order to reset a database back to an empty database 2205 ** with no schema and no content. The following process works even for 2206 ** a badly corrupted database file: 2207 ** <ol> 2208 ** <li> If the database connection is newly opened, make sure it has read the 2209 ** database schema by preparing then discarding some query against the 2210 ** database, or calling sqlite3_table_column_metadata(), ignoring any 2211 ** errors. This step is only necessary if the application desires to keep 2212 ** the database in WAL mode after the reset if it was in WAL mode before 2213 ** the reset. 2214 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2215 ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2216 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2217 ** </ol> 2218 ** Because resetting a database is destructive and irreversible, the 2219 ** process requires the use of this obscure API and multiple steps to help 2220 ** ensure that it does not happen by accident. 2221 ** 2222 ** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt> 2223 ** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the 2224 ** "defensive" flag for a database connection. When the defensive 2225 ** flag is enabled, language features that allow ordinary SQL to 2226 ** deliberately corrupt the database file are disabled. The disabled 2227 ** features include but are not limited to the following: 2228 ** <ul> 2229 ** <li> The [PRAGMA writable_schema=ON] statement. 2230 ** <li> The [PRAGMA journal_mode=OFF] statement. 2231 ** <li> Writes to the [sqlite_dbpage] virtual table. 2232 ** <li> Direct writes to [shadow tables]. 2233 ** </ul> 2234 ** </dd> 2235 ** 2236 ** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt> 2237 ** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the 2238 ** "writable_schema" flag. This has the same effect and is logically equivalent 2239 ** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF]. 2240 ** The first argument to this setting is an integer which is 0 to disable 2241 ** the writable_schema, positive to enable writable_schema, or negative to 2242 ** leave the setting unchanged. The second parameter is a pointer to an 2243 ** integer into which is written 0 or 1 to indicate whether the writable_schema 2244 ** is enabled or disabled following this call. 2245 ** </dd> 2246 ** 2247 ** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]] 2248 ** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt> 2249 ** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates 2250 ** the legacy behavior of the [ALTER TABLE RENAME] command such it 2251 ** behaves as it did prior to [version 3.24.0] (2018-06-04). See the 2252 ** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for 2253 ** additional information. This feature can also be turned on and off 2254 ** using the [PRAGMA legacy_alter_table] statement. 2255 ** </dd> 2256 ** 2257 ** [[SQLITE_DBCONFIG_DQS_DML]] 2258 ** <dt>SQLITE_DBCONFIG_DQS_DML</td> 2259 ** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates 2260 ** the legacy [double-quoted string literal] misfeature for DML statements 2261 ** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The 2262 ** default value of this setting is determined by the [-DSQLITE_DQS] 2263 ** compile-time option. 2264 ** </dd> 2265 ** 2266 ** [[SQLITE_DBCONFIG_DQS_DDL]] 2267 ** <dt>SQLITE_DBCONFIG_DQS_DDL</td> 2268 ** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates 2269 ** the legacy [double-quoted string literal] misfeature for DDL statements, 2270 ** such as CREATE TABLE and CREATE INDEX. The 2271 ** default value of this setting is determined by the [-DSQLITE_DQS] 2272 ** compile-time option. 2273 ** </dd> 2274 ** 2275 ** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]] 2276 ** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</td> 2277 ** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to 2278 ** assume that database schemas (the contents of the [sqlite_master] tables) 2279 ** are untainted by malicious content. 2280 ** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite 2281 ** takes additional defensive steps to protect the application from harm 2282 ** including: 2283 ** <ul> 2284 ** <li> Prohibit the use of SQL functions inside triggers, views, 2285 ** CHECK constraints, DEFAULT clauses, expression indexes, 2286 ** partial indexes, or generated columns 2287 ** unless those functions are tagged with [SQLITE_INNOCUOUS]. 2288 ** <li> Prohibit the use of virtual tables inside of triggers or views 2289 ** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS]. 2290 ** </ul> 2291 ** This setting defaults to "on" for legacy compatibility, however 2292 ** all applications are advised to turn it off if possible. This setting 2293 ** can also be controlled using the [PRAGMA trusted_schema] statement. 2294 ** </dd> 2295 ** 2296 ** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]] 2297 ** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</td> 2298 ** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates 2299 ** the legacy file format flag. When activated, this flag causes all newly 2300 ** created database file to have a schema format version number (the 4-byte 2301 ** integer found at offset 44 into the database header) of 1. This in turn 2302 ** means that the resulting database file will be readable and writable by 2303 ** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting, 2304 ** newly created databases are generally not understandable by SQLite versions 2305 ** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there 2306 ** is now scarcely any need to generated database files that are compatible 2307 ** all the way back to version 3.0.0, and so this setting is of little 2308 ** practical use, but is provided so that SQLite can continue to claim the 2309 ** ability to generate new database files that are compatible with version 2310 ** 3.0.0. 2311 ** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on, 2312 ** the [VACUUM] command will fail with an obscure error when attempting to 2313 ** process a table with generated columns and a descending index. This is 2314 ** not considered a bug since SQLite versions 3.3.0 and earlier do not support 2315 ** either generated columns or decending indexes. 2316 ** </dd> 2317 ** </dl> 2318 */ 2319 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2320 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2321 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2322 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2323 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2324 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2325 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2326 #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2327 #define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2328 #define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2329 #define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ 2330 #define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */ 2331 #define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */ 2332 #define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */ 2333 #define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */ 2334 #define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */ 2335 #define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */ 2336 #define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */ 2337 #define SQLITE_DBCONFIG_MAX 1017 /* Largest DBCONFIG */ 2338 2339 /* 2340 ** CAPI3REF: Enable Or Disable Extended Result Codes 2341 ** METHOD: sqlite3 2342 ** 2343 ** ^The sqlite3_extended_result_codes() routine enables or disables the 2344 ** [extended result codes] feature of SQLite. ^The extended result 2345 ** codes are disabled by default for historical compatibility. 2346 */ 2347 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 2348 2349 /* 2350 ** CAPI3REF: Last Insert Rowid 2351 ** METHOD: sqlite3 2352 ** 2353 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2354 ** has a unique 64-bit signed 2355 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2356 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2357 ** names are not also used by explicitly declared columns. ^If 2358 ** the table has a column of type [INTEGER PRIMARY KEY] then that column 2359 ** is another alias for the rowid. 2360 ** 2361 ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2362 ** the most recent successful [INSERT] into a rowid table or [virtual table] 2363 ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2364 ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2365 ** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2366 ** zero. 2367 ** 2368 ** As well as being set automatically as rows are inserted into database 2369 ** tables, the value returned by this function may be set explicitly by 2370 ** [sqlite3_set_last_insert_rowid()] 2371 ** 2372 ** Some virtual table implementations may INSERT rows into rowid tables as 2373 ** part of committing a transaction (e.g. to flush data accumulated in memory 2374 ** to disk). In this case subsequent calls to this function return the rowid 2375 ** associated with these internal INSERT operations, which leads to 2376 ** unintuitive results. Virtual table implementations that do write to rowid 2377 ** tables in this way can avoid this problem by restoring the original 2378 ** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2379 ** control to the user. 2380 ** 2381 ** ^(If an [INSERT] occurs within a trigger then this routine will 2382 ** return the [rowid] of the inserted row as long as the trigger is 2383 ** running. Once the trigger program ends, the value returned 2384 ** by this routine reverts to what it was before the trigger was fired.)^ 2385 ** 2386 ** ^An [INSERT] that fails due to a constraint violation is not a 2387 ** successful [INSERT] and does not change the value returned by this 2388 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2389 ** and INSERT OR ABORT make no changes to the return value of this 2390 ** routine when their insertion fails. ^(When INSERT OR REPLACE 2391 ** encounters a constraint violation, it does not fail. The 2392 ** INSERT continues to completion after deleting rows that caused 2393 ** the constraint problem so INSERT OR REPLACE will always change 2394 ** the return value of this interface.)^ 2395 ** 2396 ** ^For the purposes of this routine, an [INSERT] is considered to 2397 ** be successful even if it is subsequently rolled back. 2398 ** 2399 ** This function is accessible to SQL statements via the 2400 ** [last_insert_rowid() SQL function]. 2401 ** 2402 ** If a separate thread performs a new [INSERT] on the same 2403 ** database connection while the [sqlite3_last_insert_rowid()] 2404 ** function is running and thus changes the last insert [rowid], 2405 ** then the value returned by [sqlite3_last_insert_rowid()] is 2406 ** unpredictable and might not equal either the old or the new 2407 ** last insert [rowid]. 2408 */ 2409 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2410 2411 /* 2412 ** CAPI3REF: Set the Last Insert Rowid value. 2413 ** METHOD: sqlite3 2414 ** 2415 ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2416 ** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2417 ** without inserting a row into the database. 2418 */ 2419 SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2420 2421 /* 2422 ** CAPI3REF: Count The Number Of Rows Modified 2423 ** METHOD: sqlite3 2424 ** 2425 ** ^This function returns the number of rows modified, inserted or 2426 ** deleted by the most recently completed INSERT, UPDATE or DELETE 2427 ** statement on the database connection specified by the only parameter. 2428 ** ^Executing any other type of SQL statement does not modify the value 2429 ** returned by this function. 2430 ** 2431 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2432 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2433 ** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2434 ** 2435 ** Changes to a view that are intercepted by 2436 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2437 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2438 ** DELETE statement run on a view is always zero. Only changes made to real 2439 ** tables are counted. 2440 ** 2441 ** Things are more complicated if the sqlite3_changes() function is 2442 ** executed while a trigger program is running. This may happen if the 2443 ** program uses the [changes() SQL function], or if some other callback 2444 ** function invokes sqlite3_changes() directly. Essentially: 2445 ** 2446 ** <ul> 2447 ** <li> ^(Before entering a trigger program the value returned by 2448 ** sqlite3_changes() function is saved. After the trigger program 2449 ** has finished, the original value is restored.)^ 2450 ** 2451 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2452 ** statement sets the value returned by sqlite3_changes() 2453 ** upon completion as normal. Of course, this value will not include 2454 ** any changes performed by sub-triggers, as the sqlite3_changes() 2455 ** value will be saved and restored after each sub-trigger has run.)^ 2456 ** </ul> 2457 ** 2458 ** ^This means that if the changes() SQL function (or similar) is used 2459 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2460 ** returns the value as set when the calling statement began executing. 2461 ** ^If it is used by the second or subsequent such statement within a trigger 2462 ** program, the value returned reflects the number of rows modified by the 2463 ** previous INSERT, UPDATE or DELETE statement within the same trigger. 2464 ** 2465 ** If a separate thread makes changes on the same database connection 2466 ** while [sqlite3_changes()] is running then the value returned 2467 ** is unpredictable and not meaningful. 2468 ** 2469 ** See also: 2470 ** <ul> 2471 ** <li> the [sqlite3_total_changes()] interface 2472 ** <li> the [count_changes pragma] 2473 ** <li> the [changes() SQL function] 2474 ** <li> the [data_version pragma] 2475 ** </ul> 2476 */ 2477 SQLITE_API int sqlite3_changes(sqlite3*); 2478 2479 /* 2480 ** CAPI3REF: Total Number Of Rows Modified 2481 ** METHOD: sqlite3 2482 ** 2483 ** ^This function returns the total number of rows inserted, modified or 2484 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2485 ** since the database connection was opened, including those executed as 2486 ** part of trigger programs. ^Executing any other type of SQL statement 2487 ** does not affect the value returned by sqlite3_total_changes(). 2488 ** 2489 ** ^Changes made as part of [foreign key actions] are included in the 2490 ** count, but those made as part of REPLACE constraint resolution are 2491 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2492 ** are not counted. 2493 ** 2494 ** The [sqlite3_total_changes(D)] interface only reports the number 2495 ** of rows that changed due to SQL statement run against database 2496 ** connection D. Any changes by other database connections are ignored. 2497 ** To detect changes against a database file from other database 2498 ** connections use the [PRAGMA data_version] command or the 2499 ** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2500 ** 2501 ** If a separate thread makes changes on the same database connection 2502 ** while [sqlite3_total_changes()] is running then the value 2503 ** returned is unpredictable and not meaningful. 2504 ** 2505 ** See also: 2506 ** <ul> 2507 ** <li> the [sqlite3_changes()] interface 2508 ** <li> the [count_changes pragma] 2509 ** <li> the [changes() SQL function] 2510 ** <li> the [data_version pragma] 2511 ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2512 ** </ul> 2513 */ 2514 SQLITE_API int sqlite3_total_changes(sqlite3*); 2515 2516 /* 2517 ** CAPI3REF: Interrupt A Long-Running Query 2518 ** METHOD: sqlite3 2519 ** 2520 ** ^This function causes any pending database operation to abort and 2521 ** return at its earliest opportunity. This routine is typically 2522 ** called in response to a user action such as pressing "Cancel" 2523 ** or Ctrl-C where the user wants a long query operation to halt 2524 ** immediately. 2525 ** 2526 ** ^It is safe to call this routine from a thread different from the 2527 ** thread that is currently running the database operation. But it 2528 ** is not safe to call this routine with a [database connection] that 2529 ** is closed or might close before sqlite3_interrupt() returns. 2530 ** 2531 ** ^If an SQL operation is very nearly finished at the time when 2532 ** sqlite3_interrupt() is called, then it might not have an opportunity 2533 ** to be interrupted and might continue to completion. 2534 ** 2535 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2536 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2537 ** that is inside an explicit transaction, then the entire transaction 2538 ** will be rolled back automatically. 2539 ** 2540 ** ^The sqlite3_interrupt(D) call is in effect until all currently running 2541 ** SQL statements on [database connection] D complete. ^Any new SQL statements 2542 ** that are started after the sqlite3_interrupt() call and before the 2543 ** running statement count reaches zero are interrupted as if they had been 2544 ** running prior to the sqlite3_interrupt() call. ^New SQL statements 2545 ** that are started after the running statement count reaches zero are 2546 ** not effected by the sqlite3_interrupt(). 2547 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2548 ** SQL statements is a no-op and has no effect on SQL statements 2549 ** that are started after the sqlite3_interrupt() call returns. 2550 */ 2551 SQLITE_API void sqlite3_interrupt(sqlite3*); 2552 2553 /* 2554 ** CAPI3REF: Determine If An SQL Statement Is Complete 2555 ** 2556 ** These routines are useful during command-line input to determine if the 2557 ** currently entered text seems to form a complete SQL statement or 2558 ** if additional input is needed before sending the text into 2559 ** SQLite for parsing. ^These routines return 1 if the input string 2560 ** appears to be a complete SQL statement. ^A statement is judged to be 2561 ** complete if it ends with a semicolon token and is not a prefix of a 2562 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2563 ** string literals or quoted identifier names or comments are not 2564 ** independent tokens (they are part of the token in which they are 2565 ** embedded) and thus do not count as a statement terminator. ^Whitespace 2566 ** and comments that follow the final semicolon are ignored. 2567 ** 2568 ** ^These routines return 0 if the statement is incomplete. ^If a 2569 ** memory allocation fails, then SQLITE_NOMEM is returned. 2570 ** 2571 ** ^These routines do not parse the SQL statements thus 2572 ** will not detect syntactically incorrect SQL. 2573 ** 2574 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2575 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2576 ** automatically by sqlite3_complete16(). If that initialization fails, 2577 ** then the return value from sqlite3_complete16() will be non-zero 2578 ** regardless of whether or not the input SQL is complete.)^ 2579 ** 2580 ** The input to [sqlite3_complete()] must be a zero-terminated 2581 ** UTF-8 string. 2582 ** 2583 ** The input to [sqlite3_complete16()] must be a zero-terminated 2584 ** UTF-16 string in native byte order. 2585 */ 2586 SQLITE_API int sqlite3_complete(const char *sql); 2587 SQLITE_API int sqlite3_complete16(const void *sql); 2588 2589 /* 2590 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2591 ** KEYWORDS: {busy-handler callback} {busy handler} 2592 ** METHOD: sqlite3 2593 ** 2594 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2595 ** that might be invoked with argument P whenever 2596 ** an attempt is made to access a database table associated with 2597 ** [database connection] D when another thread 2598 ** or process has the table locked. 2599 ** The sqlite3_busy_handler() interface is used to implement 2600 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2601 ** 2602 ** ^If the busy callback is NULL, then [SQLITE_BUSY] 2603 ** is returned immediately upon encountering the lock. ^If the busy callback 2604 ** is not NULL, then the callback might be invoked with two arguments. 2605 ** 2606 ** ^The first argument to the busy handler is a copy of the void* pointer which 2607 ** is the third argument to sqlite3_busy_handler(). ^The second argument to 2608 ** the busy handler callback is the number of times that the busy handler has 2609 ** been invoked previously for the same locking event. ^If the 2610 ** busy callback returns 0, then no additional attempts are made to 2611 ** access the database and [SQLITE_BUSY] is returned 2612 ** to the application. 2613 ** ^If the callback returns non-zero, then another attempt 2614 ** is made to access the database and the cycle repeats. 2615 ** 2616 ** The presence of a busy handler does not guarantee that it will be invoked 2617 ** when there is lock contention. ^If SQLite determines that invoking the busy 2618 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2619 ** to the application instead of invoking the 2620 ** busy handler. 2621 ** Consider a scenario where one process is holding a read lock that 2622 ** it is trying to promote to a reserved lock and 2623 ** a second process is holding a reserved lock that it is trying 2624 ** to promote to an exclusive lock. The first process cannot proceed 2625 ** because it is blocked by the second and the second process cannot 2626 ** proceed because it is blocked by the first. If both processes 2627 ** invoke the busy handlers, neither will make any progress. Therefore, 2628 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2629 ** will induce the first process to release its read lock and allow 2630 ** the second process to proceed. 2631 ** 2632 ** ^The default busy callback is NULL. 2633 ** 2634 ** ^(There can only be a single busy handler defined for each 2635 ** [database connection]. Setting a new busy handler clears any 2636 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2637 ** or evaluating [PRAGMA busy_timeout=N] will change the 2638 ** busy handler and thus clear any previously set busy handler. 2639 ** 2640 ** The busy callback should not take any actions which modify the 2641 ** database connection that invoked the busy handler. In other words, 2642 ** the busy handler is not reentrant. Any such actions 2643 ** result in undefined behavior. 2644 ** 2645 ** A busy handler must not close the database connection 2646 ** or [prepared statement] that invoked the busy handler. 2647 */ 2648 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2649 2650 /* 2651 ** CAPI3REF: Set A Busy Timeout 2652 ** METHOD: sqlite3 2653 ** 2654 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2655 ** for a specified amount of time when a table is locked. ^The handler 2656 ** will sleep multiple times until at least "ms" milliseconds of sleeping 2657 ** have accumulated. ^After at least "ms" milliseconds of sleeping, 2658 ** the handler returns 0 which causes [sqlite3_step()] to return 2659 ** [SQLITE_BUSY]. 2660 ** 2661 ** ^Calling this routine with an argument less than or equal to zero 2662 ** turns off all busy handlers. 2663 ** 2664 ** ^(There can only be a single busy handler for a particular 2665 ** [database connection] at any given moment. If another busy handler 2666 ** was defined (using [sqlite3_busy_handler()]) prior to calling 2667 ** this routine, that other busy handler is cleared.)^ 2668 ** 2669 ** See also: [PRAGMA busy_timeout] 2670 */ 2671 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2672 2673 /* 2674 ** CAPI3REF: Convenience Routines For Running Queries 2675 ** METHOD: sqlite3 2676 ** 2677 ** This is a legacy interface that is preserved for backwards compatibility. 2678 ** Use of this interface is not recommended. 2679 ** 2680 ** Definition: A <b>result table</b> is memory data structure created by the 2681 ** [sqlite3_get_table()] interface. A result table records the 2682 ** complete query results from one or more queries. 2683 ** 2684 ** The table conceptually has a number of rows and columns. But 2685 ** these numbers are not part of the result table itself. These 2686 ** numbers are obtained separately. Let N be the number of rows 2687 ** and M be the number of columns. 2688 ** 2689 ** A result table is an array of pointers to zero-terminated UTF-8 strings. 2690 ** There are (N+1)*M elements in the array. The first M pointers point 2691 ** to zero-terminated strings that contain the names of the columns. 2692 ** The remaining entries all point to query results. NULL values result 2693 ** in NULL pointers. All other values are in their UTF-8 zero-terminated 2694 ** string representation as returned by [sqlite3_column_text()]. 2695 ** 2696 ** A result table might consist of one or more memory allocations. 2697 ** It is not safe to pass a result table directly to [sqlite3_free()]. 2698 ** A result table should be deallocated using [sqlite3_free_table()]. 2699 ** 2700 ** ^(As an example of the result table format, suppose a query result 2701 ** is as follows: 2702 ** 2703 ** <blockquote><pre> 2704 ** Name | Age 2705 ** ----------------------- 2706 ** Alice | 43 2707 ** Bob | 28 2708 ** Cindy | 21 2709 ** </pre></blockquote> 2710 ** 2711 ** There are two columns (M==2) and three rows (N==3). Thus the 2712 ** result table has 8 entries. Suppose the result table is stored 2713 ** in an array named azResult. Then azResult holds this content: 2714 ** 2715 ** <blockquote><pre> 2716 ** azResult[0] = "Name"; 2717 ** azResult[1] = "Age"; 2718 ** azResult[2] = "Alice"; 2719 ** azResult[3] = "43"; 2720 ** azResult[4] = "Bob"; 2721 ** azResult[5] = "28"; 2722 ** azResult[6] = "Cindy"; 2723 ** azResult[7] = "21"; 2724 ** </pre></blockquote>)^ 2725 ** 2726 ** ^The sqlite3_get_table() function evaluates one or more 2727 ** semicolon-separated SQL statements in the zero-terminated UTF-8 2728 ** string of its 2nd parameter and returns a result table to the 2729 ** pointer given in its 3rd parameter. 2730 ** 2731 ** After the application has finished with the result from sqlite3_get_table(), 2732 ** it must pass the result table pointer to sqlite3_free_table() in order to 2733 ** release the memory that was malloced. Because of the way the 2734 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2735 ** function must not try to call [sqlite3_free()] directly. Only 2736 ** [sqlite3_free_table()] is able to release the memory properly and safely. 2737 ** 2738 ** The sqlite3_get_table() interface is implemented as a wrapper around 2739 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2740 ** to any internal data structures of SQLite. It uses only the public 2741 ** interface defined here. As a consequence, errors that occur in the 2742 ** wrapper layer outside of the internal [sqlite3_exec()] call are not 2743 ** reflected in subsequent calls to [sqlite3_errcode()] or 2744 ** [sqlite3_errmsg()]. 2745 */ 2746 SQLITE_API int sqlite3_get_table( 2747 sqlite3 *db, /* An open database */ 2748 const char *zSql, /* SQL to be evaluated */ 2749 char ***pazResult, /* Results of the query */ 2750 int *pnRow, /* Number of result rows written here */ 2751 int *pnColumn, /* Number of result columns written here */ 2752 char **pzErrmsg /* Error msg written here */ 2753 ); 2754 SQLITE_API void sqlite3_free_table(char **result); 2755 2756 /* 2757 ** CAPI3REF: Formatted String Printing Functions 2758 ** 2759 ** These routines are work-alikes of the "printf()" family of functions 2760 ** from the standard C library. 2761 ** These routines understand most of the common formatting options from 2762 ** the standard library printf() 2763 ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2764 ** See the [built-in printf()] documentation for details. 2765 ** 2766 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2767 ** results into memory obtained from [sqlite3_malloc64()]. 2768 ** The strings returned by these two routines should be 2769 ** released by [sqlite3_free()]. ^Both routines return a 2770 ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2771 ** memory to hold the resulting string. 2772 ** 2773 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2774 ** the standard C library. The result is written into the 2775 ** buffer supplied as the second parameter whose size is given by 2776 ** the first parameter. Note that the order of the 2777 ** first two parameters is reversed from snprintf().)^ This is an 2778 ** historical accident that cannot be fixed without breaking 2779 ** backwards compatibility. ^(Note also that sqlite3_snprintf() 2780 ** returns a pointer to its buffer instead of the number of 2781 ** characters actually written into the buffer.)^ We admit that 2782 ** the number of characters written would be a more useful return 2783 ** value but we cannot change the implementation of sqlite3_snprintf() 2784 ** now without breaking compatibility. 2785 ** 2786 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2787 ** guarantees that the buffer is always zero-terminated. ^The first 2788 ** parameter "n" is the total size of the buffer, including space for 2789 ** the zero terminator. So the longest string that can be completely 2790 ** written will be n-1 characters. 2791 ** 2792 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2793 ** 2794 ** See also: [built-in printf()], [printf() SQL function] 2795 */ 2796 SQLITE_API char *sqlite3_mprintf(const char*,...); 2797 SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2798 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2799 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2800 2801 /* 2802 ** CAPI3REF: Memory Allocation Subsystem 2803 ** 2804 ** The SQLite core uses these three routines for all of its own 2805 ** internal memory allocation needs. "Core" in the previous sentence 2806 ** does not include operating-system specific [VFS] implementation. The 2807 ** Windows VFS uses native malloc() and free() for some operations. 2808 ** 2809 ** ^The sqlite3_malloc() routine returns a pointer to a block 2810 ** of memory at least N bytes in length, where N is the parameter. 2811 ** ^If sqlite3_malloc() is unable to obtain sufficient free 2812 ** memory, it returns a NULL pointer. ^If the parameter N to 2813 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2814 ** a NULL pointer. 2815 ** 2816 ** ^The sqlite3_malloc64(N) routine works just like 2817 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2818 ** of a signed 32-bit integer. 2819 ** 2820 ** ^Calling sqlite3_free() with a pointer previously returned 2821 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2822 ** that it might be reused. ^The sqlite3_free() routine is 2823 ** a no-op if is called with a NULL pointer. Passing a NULL pointer 2824 ** to sqlite3_free() is harmless. After being freed, memory 2825 ** should neither be read nor written. Even reading previously freed 2826 ** memory might result in a segmentation fault or other severe error. 2827 ** Memory corruption, a segmentation fault, or other severe error 2828 ** might result if sqlite3_free() is called with a non-NULL pointer that 2829 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2830 ** 2831 ** ^The sqlite3_realloc(X,N) interface attempts to resize a 2832 ** prior memory allocation X to be at least N bytes. 2833 ** ^If the X parameter to sqlite3_realloc(X,N) 2834 ** is a NULL pointer then its behavior is identical to calling 2835 ** sqlite3_malloc(N). 2836 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2837 ** negative then the behavior is exactly the same as calling 2838 ** sqlite3_free(X). 2839 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2840 ** of at least N bytes in size or NULL if insufficient memory is available. 2841 ** ^If M is the size of the prior allocation, then min(N,M) bytes 2842 ** of the prior allocation are copied into the beginning of buffer returned 2843 ** by sqlite3_realloc(X,N) and the prior allocation is freed. 2844 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2845 ** prior allocation is not freed. 2846 ** 2847 ** ^The sqlite3_realloc64(X,N) interfaces works the same as 2848 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2849 ** of a 32-bit signed integer. 2850 ** 2851 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2852 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2853 ** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2854 ** ^The value returned by sqlite3_msize(X) might be larger than the number 2855 ** of bytes requested when X was allocated. ^If X is a NULL pointer then 2856 ** sqlite3_msize(X) returns zero. If X points to something that is not 2857 ** the beginning of memory allocation, or if it points to a formerly 2858 ** valid memory allocation that has now been freed, then the behavior 2859 ** of sqlite3_msize(X) is undefined and possibly harmful. 2860 ** 2861 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2862 ** sqlite3_malloc64(), and sqlite3_realloc64() 2863 ** is always aligned to at least an 8 byte boundary, or to a 2864 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2865 ** option is used. 2866 ** 2867 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2868 ** must be either NULL or else pointers obtained from a prior 2869 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2870 ** not yet been released. 2871 ** 2872 ** The application must not read or write any part of 2873 ** a block of memory after it has been released using 2874 ** [sqlite3_free()] or [sqlite3_realloc()]. 2875 */ 2876 SQLITE_API void *sqlite3_malloc(int); 2877 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 2878 SQLITE_API void *sqlite3_realloc(void*, int); 2879 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 2880 SQLITE_API void sqlite3_free(void*); 2881 SQLITE_API sqlite3_uint64 sqlite3_msize(void*); 2882 2883 /* 2884 ** CAPI3REF: Memory Allocator Statistics 2885 ** 2886 ** SQLite provides these two interfaces for reporting on the status 2887 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2888 ** routines, which form the built-in memory allocation subsystem. 2889 ** 2890 ** ^The [sqlite3_memory_used()] routine returns the number of bytes 2891 ** of memory currently outstanding (malloced but not freed). 2892 ** ^The [sqlite3_memory_highwater()] routine returns the maximum 2893 ** value of [sqlite3_memory_used()] since the high-water mark 2894 ** was last reset. ^The values returned by [sqlite3_memory_used()] and 2895 ** [sqlite3_memory_highwater()] include any overhead 2896 ** added by SQLite in its implementation of [sqlite3_malloc()], 2897 ** but not overhead added by the any underlying system library 2898 ** routines that [sqlite3_malloc()] may call. 2899 ** 2900 ** ^The memory high-water mark is reset to the current value of 2901 ** [sqlite3_memory_used()] if and only if the parameter to 2902 ** [sqlite3_memory_highwater()] is true. ^The value returned 2903 ** by [sqlite3_memory_highwater(1)] is the high-water mark 2904 ** prior to the reset. 2905 */ 2906 SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 2907 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2908 2909 /* 2910 ** CAPI3REF: Pseudo-Random Number Generator 2911 ** 2912 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2913 ** select random [ROWID | ROWIDs] when inserting new records into a table that 2914 ** already uses the largest possible [ROWID]. The PRNG is also used for 2915 ** the built-in random() and randomblob() SQL functions. This interface allows 2916 ** applications to access the same PRNG for other purposes. 2917 ** 2918 ** ^A call to this routine stores N bytes of randomness into buffer P. 2919 ** ^The P parameter can be a NULL pointer. 2920 ** 2921 ** ^If this routine has not been previously called or if the previous 2922 ** call had N less than one or a NULL pointer for P, then the PRNG is 2923 ** seeded using randomness obtained from the xRandomness method of 2924 ** the default [sqlite3_vfs] object. 2925 ** ^If the previous call to this routine had an N of 1 or more and a 2926 ** non-NULL P then the pseudo-randomness is generated 2927 ** internally and without recourse to the [sqlite3_vfs] xRandomness 2928 ** method. 2929 */ 2930 SQLITE_API void sqlite3_randomness(int N, void *P); 2931 2932 /* 2933 ** CAPI3REF: Compile-Time Authorization Callbacks 2934 ** METHOD: sqlite3 2935 ** KEYWORDS: {authorizer callback} 2936 ** 2937 ** ^This routine registers an authorizer callback with a particular 2938 ** [database connection], supplied in the first argument. 2939 ** ^The authorizer callback is invoked as SQL statements are being compiled 2940 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2941 ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 2942 ** and [sqlite3_prepare16_v3()]. ^At various 2943 ** points during the compilation process, as logic is being created 2944 ** to perform various actions, the authorizer callback is invoked to 2945 ** see if those actions are allowed. ^The authorizer callback should 2946 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2947 ** specific action but allow the SQL statement to continue to be 2948 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2949 ** rejected with an error. ^If the authorizer callback returns 2950 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2951 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2952 ** the authorizer will fail with an error message. 2953 ** 2954 ** When the callback returns [SQLITE_OK], that means the operation 2955 ** requested is ok. ^When the callback returns [SQLITE_DENY], the 2956 ** [sqlite3_prepare_v2()] or equivalent call that triggered the 2957 ** authorizer will fail with an error message explaining that 2958 ** access is denied. 2959 ** 2960 ** ^The first parameter to the authorizer callback is a copy of the third 2961 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2962 ** to the callback is an integer [SQLITE_COPY | action code] that specifies 2963 ** the particular action to be authorized. ^The third through sixth parameters 2964 ** to the callback are either NULL pointers or zero-terminated strings 2965 ** that contain additional details about the action to be authorized. 2966 ** Applications must always be prepared to encounter a NULL pointer in any 2967 ** of the third through the sixth parameters of the authorization callback. 2968 ** 2969 ** ^If the action code is [SQLITE_READ] 2970 ** and the callback returns [SQLITE_IGNORE] then the 2971 ** [prepared statement] statement is constructed to substitute 2972 ** a NULL value in place of the table column that would have 2973 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2974 ** return can be used to deny an untrusted user access to individual 2975 ** columns of a table. 2976 ** ^When a table is referenced by a [SELECT] but no column values are 2977 ** extracted from that table (for example in a query like 2978 ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 2979 ** is invoked once for that table with a column name that is an empty string. 2980 ** ^If the action code is [SQLITE_DELETE] and the callback returns 2981 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2982 ** [truncate optimization] is disabled and all rows are deleted individually. 2983 ** 2984 ** An authorizer is used when [sqlite3_prepare | preparing] 2985 ** SQL statements from an untrusted source, to ensure that the SQL statements 2986 ** do not try to access data they are not allowed to see, or that they do not 2987 ** try to execute malicious statements that damage the database. For 2988 ** example, an application may allow a user to enter arbitrary 2989 ** SQL queries for evaluation by a database. But the application does 2990 ** not want the user to be able to make arbitrary changes to the 2991 ** database. An authorizer could then be put in place while the 2992 ** user-entered SQL is being [sqlite3_prepare | prepared] that 2993 ** disallows everything except [SELECT] statements. 2994 ** 2995 ** Applications that need to process SQL from untrusted sources 2996 ** might also consider lowering resource limits using [sqlite3_limit()] 2997 ** and limiting database size using the [max_page_count] [PRAGMA] 2998 ** in addition to using an authorizer. 2999 ** 3000 ** ^(Only a single authorizer can be in place on a database connection 3001 ** at a time. Each call to sqlite3_set_authorizer overrides the 3002 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 3003 ** The authorizer is disabled by default. 3004 ** 3005 ** The authorizer callback must not do anything that will modify 3006 ** the database connection that invoked the authorizer callback. 3007 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3008 ** database connections for the meaning of "modify" in this paragraph. 3009 ** 3010 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 3011 ** statement might be re-prepared during [sqlite3_step()] due to a 3012 ** schema change. Hence, the application should ensure that the 3013 ** correct authorizer callback remains in place during the [sqlite3_step()]. 3014 ** 3015 ** ^Note that the authorizer callback is invoked only during 3016 ** [sqlite3_prepare()] or its variants. Authorization is not 3017 ** performed during statement evaluation in [sqlite3_step()], unless 3018 ** as stated in the previous paragraph, sqlite3_step() invokes 3019 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 3020 */ 3021 SQLITE_API int sqlite3_set_authorizer( 3022 sqlite3*, 3023 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 3024 void *pUserData 3025 ); 3026 3027 /* 3028 ** CAPI3REF: Authorizer Return Codes 3029 ** 3030 ** The [sqlite3_set_authorizer | authorizer callback function] must 3031 ** return either [SQLITE_OK] or one of these two constants in order 3032 ** to signal SQLite whether or not the action is permitted. See the 3033 ** [sqlite3_set_authorizer | authorizer documentation] for additional 3034 ** information. 3035 ** 3036 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 3037 ** returned from the [sqlite3_vtab_on_conflict()] interface. 3038 */ 3039 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 3040 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 3041 3042 /* 3043 ** CAPI3REF: Authorizer Action Codes 3044 ** 3045 ** The [sqlite3_set_authorizer()] interface registers a callback function 3046 ** that is invoked to authorize certain SQL statement actions. The 3047 ** second parameter to the callback is an integer code that specifies 3048 ** what action is being authorized. These are the integer action codes that 3049 ** the authorizer callback may be passed. 3050 ** 3051 ** These action code values signify what kind of operation is to be 3052 ** authorized. The 3rd and 4th parameters to the authorization 3053 ** callback function will be parameters or NULL depending on which of these 3054 ** codes is used as the second parameter. ^(The 5th parameter to the 3055 ** authorizer callback is the name of the database ("main", "temp", 3056 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 3057 ** is the name of the inner-most trigger or view that is responsible for 3058 ** the access attempt or NULL if this access attempt is directly from 3059 ** top-level SQL code. 3060 */ 3061 /******************************************* 3rd ************ 4th ***********/ 3062 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 3063 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 3064 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 3065 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 3066 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 3067 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 3068 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 3069 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 3070 #define SQLITE_DELETE 9 /* Table Name NULL */ 3071 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 3072 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 3073 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 3074 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 3075 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 3076 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 3077 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 3078 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 3079 #define SQLITE_INSERT 18 /* Table Name NULL */ 3080 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 3081 #define SQLITE_READ 20 /* Table Name Column Name */ 3082 #define SQLITE_SELECT 21 /* NULL NULL */ 3083 #define SQLITE_TRANSACTION 22 /* Operation NULL */ 3084 #define SQLITE_UPDATE 23 /* Table Name Column Name */ 3085 #define SQLITE_ATTACH 24 /* Filename NULL */ 3086 #define SQLITE_DETACH 25 /* Database Name NULL */ 3087 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 3088 #define SQLITE_REINDEX 27 /* Index Name NULL */ 3089 #define SQLITE_ANALYZE 28 /* Table Name NULL */ 3090 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 3091 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 3092 #define SQLITE_FUNCTION 31 /* NULL Function Name */ 3093 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 3094 #define SQLITE_COPY 0 /* No longer used */ 3095 #define SQLITE_RECURSIVE 33 /* NULL NULL */ 3096 3097 /* 3098 ** CAPI3REF: Tracing And Profiling Functions 3099 ** METHOD: sqlite3 3100 ** 3101 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 3102 ** instead of the routines described here. 3103 ** 3104 ** These routines register callback functions that can be used for 3105 ** tracing and profiling the execution of SQL statements. 3106 ** 3107 ** ^The callback function registered by sqlite3_trace() is invoked at 3108 ** various times when an SQL statement is being run by [sqlite3_step()]. 3109 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 3110 ** SQL statement text as the statement first begins executing. 3111 ** ^(Additional sqlite3_trace() callbacks might occur 3112 ** as each triggered subprogram is entered. The callbacks for triggers 3113 ** contain a UTF-8 SQL comment that identifies the trigger.)^ 3114 ** 3115 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 3116 ** the length of [bound parameter] expansion in the output of sqlite3_trace(). 3117 ** 3118 ** ^The callback function registered by sqlite3_profile() is invoked 3119 ** as each SQL statement finishes. ^The profile callback contains 3120 ** the original statement text and an estimate of wall-clock time 3121 ** of how long that statement took to run. ^The profile callback 3122 ** time is in units of nanoseconds, however the current implementation 3123 ** is only capable of millisecond resolution so the six least significant 3124 ** digits in the time are meaningless. Future versions of SQLite 3125 ** might provide greater resolution on the profiler callback. Invoking 3126 ** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the 3127 ** profile callback. 3128 */ 3129 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 3130 void(*xTrace)(void*,const char*), void*); 3131 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 3132 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 3133 3134 /* 3135 ** CAPI3REF: SQL Trace Event Codes 3136 ** KEYWORDS: SQLITE_TRACE 3137 ** 3138 ** These constants identify classes of events that can be monitored 3139 ** using the [sqlite3_trace_v2()] tracing logic. The M argument 3140 ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 3141 ** the following constants. ^The first argument to the trace callback 3142 ** is one of the following constants. 3143 ** 3144 ** New tracing constants may be added in future releases. 3145 ** 3146 ** ^A trace callback has four arguments: xCallback(T,C,P,X). 3147 ** ^The T argument is one of the integer type codes above. 3148 ** ^The C argument is a copy of the context pointer passed in as the 3149 ** fourth argument to [sqlite3_trace_v2()]. 3150 ** The P and X arguments are pointers whose meanings depend on T. 3151 ** 3152 ** <dl> 3153 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3154 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3155 ** first begins running and possibly at other times during the 3156 ** execution of the prepared statement, such as at the start of each 3157 ** trigger subprogram. ^The P argument is a pointer to the 3158 ** [prepared statement]. ^The X argument is a pointer to a string which 3159 ** is the unexpanded SQL text of the prepared statement or an SQL comment 3160 ** that indicates the invocation of a trigger. ^The callback can compute 3161 ** the same text that would have been returned by the legacy [sqlite3_trace()] 3162 ** interface by using the X argument when X begins with "--" and invoking 3163 ** [sqlite3_expanded_sql(P)] otherwise. 3164 ** 3165 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3166 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3167 ** information as is provided by the [sqlite3_profile()] callback. 3168 ** ^The P argument is a pointer to the [prepared statement] and the 3169 ** X argument points to a 64-bit integer which is the estimated of 3170 ** the number of nanosecond that the prepared statement took to run. 3171 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3172 ** 3173 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3174 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3175 ** statement generates a single row of result. 3176 ** ^The P argument is a pointer to the [prepared statement] and the 3177 ** X argument is unused. 3178 ** 3179 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3180 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3181 ** connection closes. 3182 ** ^The P argument is a pointer to the [database connection] object 3183 ** and the X argument is unused. 3184 ** </dl> 3185 */ 3186 #define SQLITE_TRACE_STMT 0x01 3187 #define SQLITE_TRACE_PROFILE 0x02 3188 #define SQLITE_TRACE_ROW 0x04 3189 #define SQLITE_TRACE_CLOSE 0x08 3190 3191 /* 3192 ** CAPI3REF: SQL Trace Hook 3193 ** METHOD: sqlite3 3194 ** 3195 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3196 ** function X against [database connection] D, using property mask M 3197 ** and context pointer P. ^If the X callback is 3198 ** NULL or if the M mask is zero, then tracing is disabled. The 3199 ** M argument should be the bitwise OR-ed combination of 3200 ** zero or more [SQLITE_TRACE] constants. 3201 ** 3202 ** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3203 ** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3204 ** 3205 ** ^The X callback is invoked whenever any of the events identified by 3206 ** mask M occur. ^The integer return value from the callback is currently 3207 ** ignored, though this may change in future releases. Callback 3208 ** implementations should return zero to ensure future compatibility. 3209 ** 3210 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3211 ** ^The T argument is one of the [SQLITE_TRACE] 3212 ** constants to indicate why the callback was invoked. 3213 ** ^The C argument is a copy of the context pointer. 3214 ** The P and X arguments are pointers whose meanings depend on T. 3215 ** 3216 ** The sqlite3_trace_v2() interface is intended to replace the legacy 3217 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3218 ** are deprecated. 3219 */ 3220 SQLITE_API int sqlite3_trace_v2( 3221 sqlite3*, 3222 unsigned uMask, 3223 int(*xCallback)(unsigned,void*,void*,void*), 3224 void *pCtx 3225 ); 3226 3227 /* 3228 ** CAPI3REF: Query Progress Callbacks 3229 ** METHOD: sqlite3 3230 ** 3231 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3232 ** function X to be invoked periodically during long running calls to 3233 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3234 ** database connection D. An example use for this 3235 ** interface is to keep a GUI updated during a large query. 3236 ** 3237 ** ^The parameter P is passed through as the only parameter to the 3238 ** callback function X. ^The parameter N is the approximate number of 3239 ** [virtual machine instructions] that are evaluated between successive 3240 ** invocations of the callback X. ^If N is less than one then the progress 3241 ** handler is disabled. 3242 ** 3243 ** ^Only a single progress handler may be defined at one time per 3244 ** [database connection]; setting a new progress handler cancels the 3245 ** old one. ^Setting parameter X to NULL disables the progress handler. 3246 ** ^The progress handler is also disabled by setting N to a value less 3247 ** than 1. 3248 ** 3249 ** ^If the progress callback returns non-zero, the operation is 3250 ** interrupted. This feature can be used to implement a 3251 ** "Cancel" button on a GUI progress dialog box. 3252 ** 3253 ** The progress handler callback must not do anything that will modify 3254 ** the database connection that invoked the progress handler. 3255 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3256 ** database connections for the meaning of "modify" in this paragraph. 3257 ** 3258 */ 3259 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3260 3261 /* 3262 ** CAPI3REF: Opening A New Database Connection 3263 ** CONSTRUCTOR: sqlite3 3264 ** 3265 ** ^These routines open an SQLite database file as specified by the 3266 ** filename argument. ^The filename argument is interpreted as UTF-8 for 3267 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3268 ** order for sqlite3_open16(). ^(A [database connection] handle is usually 3269 ** returned in *ppDb, even if an error occurs. The only exception is that 3270 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3271 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3272 ** object.)^ ^(If the database is opened (and/or created) successfully, then 3273 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3274 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3275 ** an English language description of the error following a failure of any 3276 ** of the sqlite3_open() routines. 3277 ** 3278 ** ^The default encoding will be UTF-8 for databases created using 3279 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3280 ** created using sqlite3_open16() will be UTF-16 in the native byte order. 3281 ** 3282 ** Whether or not an error occurs when it is opened, resources 3283 ** associated with the [database connection] handle should be released by 3284 ** passing it to [sqlite3_close()] when it is no longer required. 3285 ** 3286 ** The sqlite3_open_v2() interface works like sqlite3_open() 3287 ** except that it accepts two additional parameters for additional control 3288 ** over the new database connection. ^(The flags parameter to 3289 ** sqlite3_open_v2() must include, at a minimum, one of the following 3290 ** three flag combinations:)^ 3291 ** 3292 ** <dl> 3293 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3294 ** <dd>The database is opened in read-only mode. If the database does not 3295 ** already exist, an error is returned.</dd>)^ 3296 ** 3297 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3298 ** <dd>The database is opened for reading and writing if possible, or reading 3299 ** only if the file is write protected by the operating system. In either 3300 ** case the database must already exist, otherwise an error is returned.</dd>)^ 3301 ** 3302 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3303 ** <dd>The database is opened for reading and writing, and is created if 3304 ** it does not already exist. This is the behavior that is always used for 3305 ** sqlite3_open() and sqlite3_open16().</dd>)^ 3306 ** </dl> 3307 ** 3308 ** In addition to the required flags, the following optional flags are 3309 ** also supported: 3310 ** 3311 ** <dl> 3312 ** ^(<dt>[SQLITE_OPEN_URI]</dt> 3313 ** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^ 3314 ** 3315 ** ^(<dt>[SQLITE_OPEN_MEMORY]</dt> 3316 ** <dd>The database will be opened as an in-memory database. The database 3317 ** is named by the "filename" argument for the purposes of cache-sharing, 3318 ** if shared cache mode is enabled, but the "filename" is otherwise ignored. 3319 ** </dd>)^ 3320 ** 3321 ** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt> 3322 ** <dd>The new database connection will use the "multi-thread" 3323 ** [threading mode].)^ This means that separate threads are allowed 3324 ** to use SQLite at the same time, as long as each thread is using 3325 ** a different [database connection]. 3326 ** 3327 ** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt> 3328 ** <dd>The new database connection will use the "serialized" 3329 ** [threading mode].)^ This means the multiple threads can safely 3330 ** attempt to use the same database connection at the same time. 3331 ** (Mutexes will block any actual concurrency, but in this mode 3332 ** there is no harm in trying.) 3333 ** 3334 ** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt> 3335 ** <dd>The database is opened [shared cache] enabled, overriding 3336 ** the default shared cache setting provided by 3337 ** [sqlite3_enable_shared_cache()].)^ 3338 ** 3339 ** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt> 3340 ** <dd>The database is opened [shared cache] disabled, overriding 3341 ** the default shared cache setting provided by 3342 ** [sqlite3_enable_shared_cache()].)^ 3343 ** 3344 ** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt> 3345 ** <dd>The database filename is not allowed to be a symbolic link</dd> 3346 ** </dl>)^ 3347 ** 3348 ** If the 3rd parameter to sqlite3_open_v2() is not one of the 3349 ** required combinations shown above optionally combined with other 3350 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3351 ** then the behavior is undefined. 3352 ** 3353 ** ^The fourth parameter to sqlite3_open_v2() is the name of the 3354 ** [sqlite3_vfs] object that defines the operating system interface that 3355 ** the new database connection should use. ^If the fourth parameter is 3356 ** a NULL pointer then the default [sqlite3_vfs] object is used. 3357 ** 3358 ** ^If the filename is ":memory:", then a private, temporary in-memory database 3359 ** is created for the connection. ^This in-memory database will vanish when 3360 ** the database connection is closed. Future versions of SQLite might 3361 ** make use of additional special filenames that begin with the ":" character. 3362 ** It is recommended that when a database filename actually does begin with 3363 ** a ":" character you should prefix the filename with a pathname such as 3364 ** "./" to avoid ambiguity. 3365 ** 3366 ** ^If the filename is an empty string, then a private, temporary 3367 ** on-disk database will be created. ^This private database will be 3368 ** automatically deleted as soon as the database connection is closed. 3369 ** 3370 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3371 ** 3372 ** ^If [URI filename] interpretation is enabled, and the filename argument 3373 ** begins with "file:", then the filename is interpreted as a URI. ^URI 3374 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3375 ** set in the third argument to sqlite3_open_v2(), or if it has 3376 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3377 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3378 ** URI filename interpretation is turned off 3379 ** by default, but future releases of SQLite might enable URI filename 3380 ** interpretation by default. See "[URI filenames]" for additional 3381 ** information. 3382 ** 3383 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3384 ** authority, then it must be either an empty string or the string 3385 ** "localhost". ^If the authority is not an empty string or "localhost", an 3386 ** error is returned to the caller. ^The fragment component of a URI, if 3387 ** present, is ignored. 3388 ** 3389 ** ^SQLite uses the path component of the URI as the name of the disk file 3390 ** which contains the database. ^If the path begins with a '/' character, 3391 ** then it is interpreted as an absolute path. ^If the path does not begin 3392 ** with a '/' (meaning that the authority section is omitted from the URI) 3393 ** then the path is interpreted as a relative path. 3394 ** ^(On windows, the first component of an absolute path 3395 ** is a drive specification (e.g. "C:").)^ 3396 ** 3397 ** [[core URI query parameters]] 3398 ** The query component of a URI may contain parameters that are interpreted 3399 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3400 ** SQLite and its built-in [VFSes] interpret the 3401 ** following query parameters: 3402 ** 3403 ** <ul> 3404 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3405 ** a VFS object that provides the operating system interface that should 3406 ** be used to access the database file on disk. ^If this option is set to 3407 ** an empty string the default VFS object is used. ^Specifying an unknown 3408 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3409 ** present, then the VFS specified by the option takes precedence over 3410 ** the value passed as the fourth parameter to sqlite3_open_v2(). 3411 ** 3412 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3413 ** "rwc", or "memory". Attempting to set it to any other value is 3414 ** an error)^. 3415 ** ^If "ro" is specified, then the database is opened for read-only 3416 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3417 ** third argument to sqlite3_open_v2(). ^If the mode option is set to 3418 ** "rw", then the database is opened for read-write (but not create) 3419 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3420 ** been set. ^Value "rwc" is equivalent to setting both 3421 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3422 ** set to "memory" then a pure [in-memory database] that never reads 3423 ** or writes from disk is used. ^It is an error to specify a value for 3424 ** the mode parameter that is less restrictive than that specified by 3425 ** the flags passed in the third parameter to sqlite3_open_v2(). 3426 ** 3427 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3428 ** "private". ^Setting it to "shared" is equivalent to setting the 3429 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3430 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3431 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3432 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3433 ** a URI filename, its value overrides any behavior requested by setting 3434 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3435 ** 3436 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3437 ** [powersafe overwrite] property does or does not apply to the 3438 ** storage media on which the database file resides. 3439 ** 3440 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3441 ** which if set disables file locking in rollback journal modes. This 3442 ** is useful for accessing a database on a filesystem that does not 3443 ** support locking. Caution: Database corruption might result if two 3444 ** or more processes write to the same database and any one of those 3445 ** processes uses nolock=1. 3446 ** 3447 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3448 ** parameter that indicates that the database file is stored on 3449 ** read-only media. ^When immutable is set, SQLite assumes that the 3450 ** database file cannot be changed, even by a process with higher 3451 ** privilege, and so the database is opened read-only and all locking 3452 ** and change detection is disabled. Caution: Setting the immutable 3453 ** property on a database file that does in fact change can result 3454 ** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3455 ** See also: [SQLITE_IOCAP_IMMUTABLE]. 3456 ** 3457 ** </ul> 3458 ** 3459 ** ^Specifying an unknown parameter in the query component of a URI is not an 3460 ** error. Future versions of SQLite might understand additional query 3461 ** parameters. See "[query parameters with special meaning to SQLite]" for 3462 ** additional information. 3463 ** 3464 ** [[URI filename examples]] <h3>URI filename examples</h3> 3465 ** 3466 ** <table border="1" align=center cellpadding=5> 3467 ** <tr><th> URI filenames <th> Results 3468 ** <tr><td> file:data.db <td> 3469 ** Open the file "data.db" in the current directory. 3470 ** <tr><td> file:/home/fred/data.db<br> 3471 ** file:///home/fred/data.db <br> 3472 ** file://localhost/home/fred/data.db <br> <td> 3473 ** Open the database file "/home/fred/data.db". 3474 ** <tr><td> file://darkstar/home/fred/data.db <td> 3475 ** An error. "darkstar" is not a recognized authority. 3476 ** <tr><td style="white-space:nowrap"> 3477 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3478 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3479 ** C:. Note that the %20 escaping in this example is not strictly 3480 ** necessary - space characters can be used literally 3481 ** in URI filenames. 3482 ** <tr><td> file:data.db?mode=ro&cache=private <td> 3483 ** Open file "data.db" in the current directory for read-only access. 3484 ** Regardless of whether or not shared-cache mode is enabled by 3485 ** default, use a private cache. 3486 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3487 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3488 ** that uses dot-files in place of posix advisory locking. 3489 ** <tr><td> file:data.db?mode=readonly <td> 3490 ** An error. "readonly" is not a valid option for the "mode" parameter. 3491 ** </table> 3492 ** 3493 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3494 ** query components of a URI. A hexadecimal escape sequence consists of a 3495 ** percent sign - "%" - followed by exactly two hexadecimal digits 3496 ** specifying an octet value. ^Before the path or query components of a 3497 ** URI filename are interpreted, they are encoded using UTF-8 and all 3498 ** hexadecimal escape sequences replaced by a single byte containing the 3499 ** corresponding octet. If this process generates an invalid UTF-8 encoding, 3500 ** the results are undefined. 3501 ** 3502 ** <b>Note to Windows users:</b> The encoding used for the filename argument 3503 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3504 ** codepage is currently defined. Filenames containing international 3505 ** characters must be converted to UTF-8 prior to passing them into 3506 ** sqlite3_open() or sqlite3_open_v2(). 3507 ** 3508 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3509 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3510 ** features that require the use of temporary files may fail. 3511 ** 3512 ** See also: [sqlite3_temp_directory] 3513 */ 3514 SQLITE_API int sqlite3_open( 3515 const char *filename, /* Database filename (UTF-8) */ 3516 sqlite3 **ppDb /* OUT: SQLite db handle */ 3517 ); 3518 SQLITE_API int sqlite3_open16( 3519 const void *filename, /* Database filename (UTF-16) */ 3520 sqlite3 **ppDb /* OUT: SQLite db handle */ 3521 ); 3522 SQLITE_API int sqlite3_open_v2( 3523 const char *filename, /* Database filename (UTF-8) */ 3524 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3525 int flags, /* Flags */ 3526 const char *zVfs /* Name of VFS module to use */ 3527 ); 3528 3529 /* 3530 ** CAPI3REF: Obtain Values For URI Parameters 3531 ** 3532 ** These are utility routines, useful to [VFS|custom VFS implementations], 3533 ** that check if a database file was a URI that contained a specific query 3534 ** parameter, and if so obtains the value of that query parameter. 3535 ** 3536 ** If F is the database filename pointer passed into the xOpen() method of 3537 ** a VFS implementation or it is the return value of [sqlite3_db_filename()] 3538 ** and if P is the name of the query parameter, then 3539 ** sqlite3_uri_parameter(F,P) returns the value of the P 3540 ** parameter if it exists or a NULL pointer if P does not appear as a 3541 ** query parameter on F. If P is a query parameter of F and it 3542 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3543 ** a pointer to an empty string. 3544 ** 3545 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3546 ** parameter and returns true (1) or false (0) according to the value 3547 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3548 ** value of query parameter P is one of "yes", "true", or "on" in any 3549 ** case or if the value begins with a non-zero number. The 3550 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3551 ** query parameter P is one of "no", "false", or "off" in any case or 3552 ** if the value begins with a numeric zero. If P is not a query 3553 ** parameter on F or if the value of P does not match any of the 3554 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3555 ** 3556 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3557 ** 64-bit signed integer and returns that integer, or D if P does not 3558 ** exist. If the value of P is something other than an integer, then 3559 ** zero is returned. 3560 ** 3561 ** The sqlite3_uri_key(F,N) returns a pointer to the name (not 3562 ** the value) of the N-th query parameter for filename F, or a NULL 3563 ** pointer if N is less than zero or greater than the number of query 3564 ** parameters minus 1. The N value is zero-based so N should be 0 to obtain 3565 ** the name of the first query parameter, 1 for the second parameter, and 3566 ** so forth. 3567 ** 3568 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3569 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3570 ** is not a database file pathname pointer that the SQLite core passed 3571 ** into the xOpen VFS method, then the behavior of this routine is undefined 3572 ** and probably undesirable. 3573 ** 3574 ** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F 3575 ** parameter can also be the name of a rollback journal file or WAL file 3576 ** in addition to the main database file. Prior to version 3.31.0, these 3577 ** routines would only work if F was the name of the main database file. 3578 ** When the F parameter is the name of the rollback journal or WAL file, 3579 ** it has access to all the same query parameters as were found on the 3580 ** main database file. 3581 ** 3582 ** See the [URI filename] documentation for additional information. 3583 */ 3584 SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3585 SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3586 SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3587 SQLITE_API const char *sqlite3_uri_key(const char *zFilename, int N); 3588 3589 /* 3590 ** CAPI3REF: Translate filenames 3591 ** 3592 ** These routines are available to [VFS|custom VFS implementations] for 3593 ** translating filenames between the main database file, the journal file, 3594 ** and the WAL file. 3595 ** 3596 ** If F is the name of an sqlite database file, journal file, or WAL file 3597 ** passed by the SQLite core into the VFS, then sqlite3_filename_database(F) 3598 ** returns the name of the corresponding database file. 3599 ** 3600 ** If F is the name of an sqlite database file, journal file, or WAL file 3601 ** passed by the SQLite core into the VFS, or if F is a database filename 3602 ** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F) 3603 ** returns the name of the corresponding rollback journal file. 3604 ** 3605 ** If F is the name of an sqlite database file, journal file, or WAL file 3606 ** that was passed by the SQLite core into the VFS, or if F is a database 3607 ** filename obtained from [sqlite3_db_filename()], then 3608 ** sqlite3_filename_wal(F) returns the name of the corresponding 3609 ** WAL file. 3610 ** 3611 ** In all of the above, if F is not the name of a database, journal or WAL 3612 ** filename passed into the VFS from the SQLite core and F is not the 3613 ** return value from [sqlite3_db_filename()], then the result is 3614 ** undefined and is likely a memory access violation. 3615 */ 3616 SQLITE_API const char *sqlite3_filename_database(const char*); 3617 SQLITE_API const char *sqlite3_filename_journal(const char*); 3618 SQLITE_API const char *sqlite3_filename_wal(const char*); 3619 3620 3621 /* 3622 ** CAPI3REF: Error Codes And Messages 3623 ** METHOD: sqlite3 3624 ** 3625 ** ^If the most recent sqlite3_* API call associated with 3626 ** [database connection] D failed, then the sqlite3_errcode(D) interface 3627 ** returns the numeric [result code] or [extended result code] for that 3628 ** API call. 3629 ** ^The sqlite3_extended_errcode() 3630 ** interface is the same except that it always returns the 3631 ** [extended result code] even when extended result codes are 3632 ** disabled. 3633 ** 3634 ** The values returned by sqlite3_errcode() and/or 3635 ** sqlite3_extended_errcode() might change with each API call. 3636 ** Except, there are some interfaces that are guaranteed to never 3637 ** change the value of the error code. The error-code preserving 3638 ** interfaces are: 3639 ** 3640 ** <ul> 3641 ** <li> sqlite3_errcode() 3642 ** <li> sqlite3_extended_errcode() 3643 ** <li> sqlite3_errmsg() 3644 ** <li> sqlite3_errmsg16() 3645 ** </ul> 3646 ** 3647 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3648 ** text that describes the error, as either UTF-8 or UTF-16 respectively. 3649 ** ^(Memory to hold the error message string is managed internally. 3650 ** The application does not need to worry about freeing the result. 3651 ** However, the error string might be overwritten or deallocated by 3652 ** subsequent calls to other SQLite interface functions.)^ 3653 ** 3654 ** ^The sqlite3_errstr() interface returns the English-language text 3655 ** that describes the [result code], as UTF-8. 3656 ** ^(Memory to hold the error message string is managed internally 3657 ** and must not be freed by the application)^. 3658 ** 3659 ** When the serialized [threading mode] is in use, it might be the 3660 ** case that a second error occurs on a separate thread in between 3661 ** the time of the first error and the call to these interfaces. 3662 ** When that happens, the second error will be reported since these 3663 ** interfaces always report the most recent result. To avoid 3664 ** this, each thread can obtain exclusive use of the [database connection] D 3665 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3666 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3667 ** all calls to the interfaces listed here are completed. 3668 ** 3669 ** If an interface fails with SQLITE_MISUSE, that means the interface 3670 ** was invoked incorrectly by the application. In that case, the 3671 ** error code and message may or may not be set. 3672 */ 3673 SQLITE_API int sqlite3_errcode(sqlite3 *db); 3674 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 3675 SQLITE_API const char *sqlite3_errmsg(sqlite3*); 3676 SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 3677 SQLITE_API const char *sqlite3_errstr(int); 3678 3679 /* 3680 ** CAPI3REF: Prepared Statement Object 3681 ** KEYWORDS: {prepared statement} {prepared statements} 3682 ** 3683 ** An instance of this object represents a single SQL statement that 3684 ** has been compiled into binary form and is ready to be evaluated. 3685 ** 3686 ** Think of each SQL statement as a separate computer program. The 3687 ** original SQL text is source code. A prepared statement object 3688 ** is the compiled object code. All SQL must be converted into a 3689 ** prepared statement before it can be run. 3690 ** 3691 ** The life-cycle of a prepared statement object usually goes like this: 3692 ** 3693 ** <ol> 3694 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3695 ** <li> Bind values to [parameters] using the sqlite3_bind_*() 3696 ** interfaces. 3697 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3698 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3699 ** to step 2. Do this zero or more times. 3700 ** <li> Destroy the object using [sqlite3_finalize()]. 3701 ** </ol> 3702 */ 3703 typedef struct sqlite3_stmt sqlite3_stmt; 3704 3705 /* 3706 ** CAPI3REF: Run-time Limits 3707 ** METHOD: sqlite3 3708 ** 3709 ** ^(This interface allows the size of various constructs to be limited 3710 ** on a connection by connection basis. The first parameter is the 3711 ** [database connection] whose limit is to be set or queried. The 3712 ** second parameter is one of the [limit categories] that define a 3713 ** class of constructs to be size limited. The third parameter is the 3714 ** new limit for that construct.)^ 3715 ** 3716 ** ^If the new limit is a negative number, the limit is unchanged. 3717 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3718 ** [limits | hard upper bound] 3719 ** set at compile-time by a C preprocessor macro called 3720 ** [limits | SQLITE_MAX_<i>NAME</i>]. 3721 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3722 ** ^Attempts to increase a limit above its hard upper bound are 3723 ** silently truncated to the hard upper bound. 3724 ** 3725 ** ^Regardless of whether or not the limit was changed, the 3726 ** [sqlite3_limit()] interface returns the prior value of the limit. 3727 ** ^Hence, to find the current value of a limit without changing it, 3728 ** simply invoke this interface with the third parameter set to -1. 3729 ** 3730 ** Run-time limits are intended for use in applications that manage 3731 ** both their own internal database and also databases that are controlled 3732 ** by untrusted external sources. An example application might be a 3733 ** web browser that has its own databases for storing history and 3734 ** separate databases controlled by JavaScript applications downloaded 3735 ** off the Internet. The internal databases can be given the 3736 ** large, default limits. Databases managed by external sources can 3737 ** be given much smaller limits designed to prevent a denial of service 3738 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3739 ** interface to further control untrusted SQL. The size of the database 3740 ** created by an untrusted script can be contained using the 3741 ** [max_page_count] [PRAGMA]. 3742 ** 3743 ** New run-time limit categories may be added in future releases. 3744 */ 3745 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 3746 3747 /* 3748 ** CAPI3REF: Run-Time Limit Categories 3749 ** KEYWORDS: {limit category} {*limit categories} 3750 ** 3751 ** These constants define various performance limits 3752 ** that can be lowered at run-time using [sqlite3_limit()]. 3753 ** The synopsis of the meanings of the various limits is shown below. 3754 ** Additional information is available at [limits | Limits in SQLite]. 3755 ** 3756 ** <dl> 3757 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3758 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3759 ** 3760 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3761 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3762 ** 3763 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3764 ** <dd>The maximum number of columns in a table definition or in the 3765 ** result set of a [SELECT] or the maximum number of columns in an index 3766 ** or in an ORDER BY or GROUP BY clause.</dd>)^ 3767 ** 3768 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3769 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3770 ** 3771 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3772 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3773 ** 3774 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3775 ** <dd>The maximum number of instructions in a virtual machine program 3776 ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 3777 ** the equivalent tries to allocate space for more than this many opcodes 3778 ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 3779 ** 3780 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3781 ** <dd>The maximum number of arguments on a function.</dd>)^ 3782 ** 3783 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3784 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3785 ** 3786 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3787 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3788 ** <dd>The maximum length of the pattern argument to the [LIKE] or 3789 ** [GLOB] operators.</dd>)^ 3790 ** 3791 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3792 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3793 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3794 ** 3795 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3796 ** <dd>The maximum depth of recursion for triggers.</dd>)^ 3797 ** 3798 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3799 ** <dd>The maximum number of auxiliary worker threads that a single 3800 ** [prepared statement] may start.</dd>)^ 3801 ** </dl> 3802 */ 3803 #define SQLITE_LIMIT_LENGTH 0 3804 #define SQLITE_LIMIT_SQL_LENGTH 1 3805 #define SQLITE_LIMIT_COLUMN 2 3806 #define SQLITE_LIMIT_EXPR_DEPTH 3 3807 #define SQLITE_LIMIT_COMPOUND_SELECT 4 3808 #define SQLITE_LIMIT_VDBE_OP 5 3809 #define SQLITE_LIMIT_FUNCTION_ARG 6 3810 #define SQLITE_LIMIT_ATTACHED 7 3811 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3812 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 3813 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 3814 #define SQLITE_LIMIT_WORKER_THREADS 11 3815 3816 /* 3817 ** CAPI3REF: Prepare Flags 3818 ** 3819 ** These constants define various flags that can be passed into 3820 ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 3821 ** [sqlite3_prepare16_v3()] interfaces. 3822 ** 3823 ** New flags may be added in future releases of SQLite. 3824 ** 3825 ** <dl> 3826 ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 3827 ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 3828 ** that the prepared statement will be retained for a long time and 3829 ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 3830 ** and [sqlite3_prepare16_v3()] assume that the prepared statement will 3831 ** be used just once or at most a few times and then destroyed using 3832 ** [sqlite3_finalize()] relatively soon. The current implementation acts 3833 ** on this hint by avoiding the use of [lookaside memory] so as not to 3834 ** deplete the limited store of lookaside memory. Future versions of 3835 ** SQLite may act on this hint differently. 3836 ** 3837 ** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt> 3838 ** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used 3839 ** to be required for any prepared statement that wanted to use the 3840 ** [sqlite3_normalized_sql()] interface. However, the 3841 ** [sqlite3_normalized_sql()] interface is now available to all 3842 ** prepared statements, regardless of whether or not they use this 3843 ** flag. 3844 ** 3845 ** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt> 3846 ** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler 3847 ** to return an error (error code SQLITE_ERROR) if the statement uses 3848 ** any virtual tables. 3849 ** </dl> 3850 */ 3851 #define SQLITE_PREPARE_PERSISTENT 0x01 3852 #define SQLITE_PREPARE_NORMALIZE 0x02 3853 #define SQLITE_PREPARE_NO_VTAB 0x04 3854 3855 /* 3856 ** CAPI3REF: Compiling An SQL Statement 3857 ** KEYWORDS: {SQL statement compiler} 3858 ** METHOD: sqlite3 3859 ** CONSTRUCTOR: sqlite3_stmt 3860 ** 3861 ** To execute an SQL statement, it must first be compiled into a byte-code 3862 ** program using one of these routines. Or, in other words, these routines 3863 ** are constructors for the [prepared statement] object. 3864 ** 3865 ** The preferred routine to use is [sqlite3_prepare_v2()]. The 3866 ** [sqlite3_prepare()] interface is legacy and should be avoided. 3867 ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 3868 ** for special purposes. 3869 ** 3870 ** The use of the UTF-8 interfaces is preferred, as SQLite currently 3871 ** does all parsing using UTF-8. The UTF-16 interfaces are provided 3872 ** as a convenience. The UTF-16 interfaces work by converting the 3873 ** input text into UTF-8, then invoking the corresponding UTF-8 interface. 3874 ** 3875 ** The first argument, "db", is a [database connection] obtained from a 3876 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3877 ** [sqlite3_open16()]. The database connection must not have been closed. 3878 ** 3879 ** The second argument, "zSql", is the statement to be compiled, encoded 3880 ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 3881 ** and sqlite3_prepare_v3() 3882 ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 3883 ** and sqlite3_prepare16_v3() use UTF-16. 3884 ** 3885 ** ^If the nByte argument is negative, then zSql is read up to the 3886 ** first zero terminator. ^If nByte is positive, then it is the 3887 ** number of bytes read from zSql. ^If nByte is zero, then no prepared 3888 ** statement is generated. 3889 ** If the caller knows that the supplied string is nul-terminated, then 3890 ** there is a small performance advantage to passing an nByte parameter that 3891 ** is the number of bytes in the input string <i>including</i> 3892 ** the nul-terminator. 3893 ** 3894 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3895 ** past the end of the first SQL statement in zSql. These routines only 3896 ** compile the first statement in zSql, so *pzTail is left pointing to 3897 ** what remains uncompiled. 3898 ** 3899 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3900 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3901 ** to NULL. ^If the input text contains no SQL (if the input is an empty 3902 ** string or a comment) then *ppStmt is set to NULL. 3903 ** The calling procedure is responsible for deleting the compiled 3904 ** SQL statement using [sqlite3_finalize()] after it has finished with it. 3905 ** ppStmt may not be NULL. 3906 ** 3907 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3908 ** otherwise an [error code] is returned. 3909 ** 3910 ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 3911 ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 3912 ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 3913 ** are retained for backwards compatibility, but their use is discouraged. 3914 ** ^In the "vX" interfaces, the prepared statement 3915 ** that is returned (the [sqlite3_stmt] object) contains a copy of the 3916 ** original SQL text. This causes the [sqlite3_step()] interface to 3917 ** behave differently in three ways: 3918 ** 3919 ** <ol> 3920 ** <li> 3921 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3922 ** always used to do, [sqlite3_step()] will automatically recompile the SQL 3923 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3924 ** retries will occur before sqlite3_step() gives up and returns an error. 3925 ** </li> 3926 ** 3927 ** <li> 3928 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3929 ** [error codes] or [extended error codes]. ^The legacy behavior was that 3930 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3931 ** and the application would have to make a second call to [sqlite3_reset()] 3932 ** in order to find the underlying cause of the problem. With the "v2" prepare 3933 ** interfaces, the underlying reason for the error is returned immediately. 3934 ** </li> 3935 ** 3936 ** <li> 3937 ** ^If the specific value bound to a [parameter | host parameter] in the 3938 ** WHERE clause might influence the choice of query plan for a statement, 3939 ** then the statement will be automatically recompiled, as if there had been 3940 ** a schema change, on the first [sqlite3_step()] call following any change 3941 ** to the [sqlite3_bind_text | bindings] of that [parameter]. 3942 ** ^The specific value of a WHERE-clause [parameter] might influence the 3943 ** choice of query plan if the parameter is the left-hand side of a [LIKE] 3944 ** or [GLOB] operator or if the parameter is compared to an indexed column 3945 ** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled. 3946 ** </li> 3947 ** </ol> 3948 ** 3949 ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 3950 ** the extra prepFlags parameter, which is a bit array consisting of zero or 3951 ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 3952 ** sqlite3_prepare_v2() interface works exactly the same as 3953 ** sqlite3_prepare_v3() with a zero prepFlags parameter. 3954 */ 3955 SQLITE_API int sqlite3_prepare( 3956 sqlite3 *db, /* Database handle */ 3957 const char *zSql, /* SQL statement, UTF-8 encoded */ 3958 int nByte, /* Maximum length of zSql in bytes. */ 3959 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3960 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3961 ); 3962 SQLITE_API int sqlite3_prepare_v2( 3963 sqlite3 *db, /* Database handle */ 3964 const char *zSql, /* SQL statement, UTF-8 encoded */ 3965 int nByte, /* Maximum length of zSql in bytes. */ 3966 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3967 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3968 ); 3969 SQLITE_API int sqlite3_prepare_v3( 3970 sqlite3 *db, /* Database handle */ 3971 const char *zSql, /* SQL statement, UTF-8 encoded */ 3972 int nByte, /* Maximum length of zSql in bytes. */ 3973 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3974 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3975 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3976 ); 3977 SQLITE_API int sqlite3_prepare16( 3978 sqlite3 *db, /* Database handle */ 3979 const void *zSql, /* SQL statement, UTF-16 encoded */ 3980 int nByte, /* Maximum length of zSql in bytes. */ 3981 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3982 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3983 ); 3984 SQLITE_API int sqlite3_prepare16_v2( 3985 sqlite3 *db, /* Database handle */ 3986 const void *zSql, /* SQL statement, UTF-16 encoded */ 3987 int nByte, /* Maximum length of zSql in bytes. */ 3988 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3989 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3990 ); 3991 SQLITE_API int sqlite3_prepare16_v3( 3992 sqlite3 *db, /* Database handle */ 3993 const void *zSql, /* SQL statement, UTF-16 encoded */ 3994 int nByte, /* Maximum length of zSql in bytes. */ 3995 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3996 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3997 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3998 ); 3999 4000 /* 4001 ** CAPI3REF: Retrieving Statement SQL 4002 ** METHOD: sqlite3_stmt 4003 ** 4004 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 4005 ** SQL text used to create [prepared statement] P if P was 4006 ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 4007 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4008 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 4009 ** string containing the SQL text of prepared statement P with 4010 ** [bound parameters] expanded. 4011 ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 4012 ** string containing the normalized SQL text of prepared statement P. The 4013 ** semantics used to normalize a SQL statement are unspecified and subject 4014 ** to change. At a minimum, literal values will be replaced with suitable 4015 ** placeholders. 4016 ** 4017 ** ^(For example, if a prepared statement is created using the SQL 4018 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 4019 ** and parameter :xyz is unbound, then sqlite3_sql() will return 4020 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 4021 ** will return "SELECT 2345,NULL".)^ 4022 ** 4023 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 4024 ** is available to hold the result, or if the result would exceed the 4025 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 4026 ** 4027 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 4028 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 4029 ** option causes sqlite3_expanded_sql() to always return NULL. 4030 ** 4031 ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) 4032 ** are managed by SQLite and are automatically freed when the prepared 4033 ** statement is finalized. 4034 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 4035 ** is obtained from [sqlite3_malloc()] and must be free by the application 4036 ** by passing it to [sqlite3_free()]. 4037 */ 4038 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 4039 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 4040 SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); 4041 4042 /* 4043 ** CAPI3REF: Determine If An SQL Statement Writes The Database 4044 ** METHOD: sqlite3_stmt 4045 ** 4046 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 4047 ** and only if the [prepared statement] X makes no direct changes to 4048 ** the content of the database file. 4049 ** 4050 ** Note that [application-defined SQL functions] or 4051 ** [virtual tables] might change the database indirectly as a side effect. 4052 ** ^(For example, if an application defines a function "eval()" that 4053 ** calls [sqlite3_exec()], then the following SQL statement would 4054 ** change the database file through side-effects: 4055 ** 4056 ** <blockquote><pre> 4057 ** SELECT eval('DELETE FROM t1') FROM t2; 4058 ** </pre></blockquote> 4059 ** 4060 ** But because the [SELECT] statement does not change the database file 4061 ** directly, sqlite3_stmt_readonly() would still return true.)^ 4062 ** 4063 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 4064 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 4065 ** since the statements themselves do not actually modify the database but 4066 ** rather they control the timing of when other statements modify the 4067 ** database. ^The [ATTACH] and [DETACH] statements also cause 4068 ** sqlite3_stmt_readonly() to return true since, while those statements 4069 ** change the configuration of a database connection, they do not make 4070 ** changes to the content of the database files on disk. 4071 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 4072 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 4073 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 4074 ** sqlite3_stmt_readonly() returns false for those commands. 4075 */ 4076 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 4077 4078 /* 4079 ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement 4080 ** METHOD: sqlite3_stmt 4081 ** 4082 ** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the 4083 ** prepared statement S is an EXPLAIN statement, or 2 if the 4084 ** statement S is an EXPLAIN QUERY PLAN. 4085 ** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is 4086 ** an ordinary statement or a NULL pointer. 4087 */ 4088 SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt); 4089 4090 /* 4091 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 4092 ** METHOD: sqlite3_stmt 4093 ** 4094 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 4095 ** [prepared statement] S has been stepped at least once using 4096 ** [sqlite3_step(S)] but has neither run to completion (returned 4097 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor 4098 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 4099 ** interface returns false if S is a NULL pointer. If S is not a 4100 ** NULL pointer and is not a pointer to a valid [prepared statement] 4101 ** object, then the behavior is undefined and probably undesirable. 4102 ** 4103 ** This interface can be used in combination [sqlite3_next_stmt()] 4104 ** to locate all prepared statements associated with a database 4105 ** connection that are in need of being reset. This can be used, 4106 ** for example, in diagnostic routines to search for prepared 4107 ** statements that are holding a transaction open. 4108 */ 4109 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 4110 4111 /* 4112 ** CAPI3REF: Dynamically Typed Value Object 4113 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 4114 ** 4115 ** SQLite uses the sqlite3_value object to represent all values 4116 ** that can be stored in a database table. SQLite uses dynamic typing 4117 ** for the values it stores. ^Values stored in sqlite3_value objects 4118 ** can be integers, floating point values, strings, BLOBs, or NULL. 4119 ** 4120 ** An sqlite3_value object may be either "protected" or "unprotected". 4121 ** Some interfaces require a protected sqlite3_value. Other interfaces 4122 ** will accept either a protected or an unprotected sqlite3_value. 4123 ** Every interface that accepts sqlite3_value arguments specifies 4124 ** whether or not it requires a protected sqlite3_value. The 4125 ** [sqlite3_value_dup()] interface can be used to construct a new 4126 ** protected sqlite3_value from an unprotected sqlite3_value. 4127 ** 4128 ** The terms "protected" and "unprotected" refer to whether or not 4129 ** a mutex is held. An internal mutex is held for a protected 4130 ** sqlite3_value object but no mutex is held for an unprotected 4131 ** sqlite3_value object. If SQLite is compiled to be single-threaded 4132 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 4133 ** or if SQLite is run in one of reduced mutex modes 4134 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 4135 ** then there is no distinction between protected and unprotected 4136 ** sqlite3_value objects and they can be used interchangeably. However, 4137 ** for maximum code portability it is recommended that applications 4138 ** still make the distinction between protected and unprotected 4139 ** sqlite3_value objects even when not strictly required. 4140 ** 4141 ** ^The sqlite3_value objects that are passed as parameters into the 4142 ** implementation of [application-defined SQL functions] are protected. 4143 ** ^The sqlite3_value object returned by 4144 ** [sqlite3_column_value()] is unprotected. 4145 ** Unprotected sqlite3_value objects may only be used as arguments 4146 ** to [sqlite3_result_value()], [sqlite3_bind_value()], and 4147 ** [sqlite3_value_dup()]. 4148 ** The [sqlite3_value_blob | sqlite3_value_type()] family of 4149 ** interfaces require protected sqlite3_value objects. 4150 */ 4151 typedef struct sqlite3_value sqlite3_value; 4152 4153 /* 4154 ** CAPI3REF: SQL Function Context Object 4155 ** 4156 ** The context in which an SQL function executes is stored in an 4157 ** sqlite3_context object. ^A pointer to an sqlite3_context object 4158 ** is always first parameter to [application-defined SQL functions]. 4159 ** The application-defined SQL function implementation will pass this 4160 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 4161 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 4162 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 4163 ** and/or [sqlite3_set_auxdata()]. 4164 */ 4165 typedef struct sqlite3_context sqlite3_context; 4166 4167 /* 4168 ** CAPI3REF: Binding Values To Prepared Statements 4169 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 4170 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 4171 ** METHOD: sqlite3_stmt 4172 ** 4173 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 4174 ** literals may be replaced by a [parameter] that matches one of following 4175 ** templates: 4176 ** 4177 ** <ul> 4178 ** <li> ? 4179 ** <li> ?NNN 4180 ** <li> :VVV 4181 ** <li> @VVV 4182 ** <li> $VVV 4183 ** </ul> 4184 ** 4185 ** In the templates above, NNN represents an integer literal, 4186 ** and VVV represents an alphanumeric identifier.)^ ^The values of these 4187 ** parameters (also called "host parameter names" or "SQL parameters") 4188 ** can be set using the sqlite3_bind_*() routines defined here. 4189 ** 4190 ** ^The first argument to the sqlite3_bind_*() routines is always 4191 ** a pointer to the [sqlite3_stmt] object returned from 4192 ** [sqlite3_prepare_v2()] or its variants. 4193 ** 4194 ** ^The second argument is the index of the SQL parameter to be set. 4195 ** ^The leftmost SQL parameter has an index of 1. ^When the same named 4196 ** SQL parameter is used more than once, second and subsequent 4197 ** occurrences have the same index as the first occurrence. 4198 ** ^The index for named parameters can be looked up using the 4199 ** [sqlite3_bind_parameter_index()] API if desired. ^The index 4200 ** for "?NNN" parameters is the value of NNN. 4201 ** ^The NNN value must be between 1 and the [sqlite3_limit()] 4202 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 4203 ** 4204 ** ^The third argument is the value to bind to the parameter. 4205 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4206 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 4207 ** is ignored and the end result is the same as sqlite3_bind_null(). 4208 ** 4209 ** ^(In those routines that have a fourth argument, its value is the 4210 ** number of bytes in the parameter. To be clear: the value is the 4211 ** number of <u>bytes</u> in the value, not the number of characters.)^ 4212 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4213 ** is negative, then the length of the string is 4214 ** the number of bytes up to the first zero terminator. 4215 ** If the fourth parameter to sqlite3_bind_blob() is negative, then 4216 ** the behavior is undefined. 4217 ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 4218 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then 4219 ** that parameter must be the byte offset 4220 ** where the NUL terminator would occur assuming the string were NUL 4221 ** terminated. If any NUL characters occur at byte offsets less than 4222 ** the value of the fourth parameter then the resulting string value will 4223 ** contain embedded NULs. The result of expressions involving strings 4224 ** with embedded NULs is undefined. 4225 ** 4226 ** ^The fifth argument to the BLOB and string binding interfaces 4227 ** is a destructor used to dispose of the BLOB or 4228 ** string after SQLite has finished with it. ^The destructor is called 4229 ** to dispose of the BLOB or string even if the call to the bind API fails, 4230 ** except the destructor is not called if the third parameter is a NULL 4231 ** pointer or the fourth parameter is negative. 4232 ** ^If the fifth argument is 4233 ** the special value [SQLITE_STATIC], then SQLite assumes that the 4234 ** information is in static, unmanaged space and does not need to be freed. 4235 ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 4236 ** SQLite makes its own private copy of the data immediately, before 4237 ** the sqlite3_bind_*() routine returns. 4238 ** 4239 ** ^The sixth argument to sqlite3_bind_text64() must be one of 4240 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 4241 ** to specify the encoding of the text in the third parameter. If 4242 ** the sixth argument to sqlite3_bind_text64() is not one of the 4243 ** allowed values shown above, or if the text encoding is different 4244 ** from the encoding specified by the sixth parameter, then the behavior 4245 ** is undefined. 4246 ** 4247 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 4248 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 4249 ** (just an integer to hold its size) while it is being processed. 4250 ** Zeroblobs are intended to serve as placeholders for BLOBs whose 4251 ** content is later written using 4252 ** [sqlite3_blob_open | incremental BLOB I/O] routines. 4253 ** ^A negative value for the zeroblob results in a zero-length BLOB. 4254 ** 4255 ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 4256 ** [prepared statement] S to have an SQL value of NULL, but to also be 4257 ** associated with the pointer P of type T. ^D is either a NULL pointer or 4258 ** a pointer to a destructor function for P. ^SQLite will invoke the 4259 ** destructor D with a single argument of P when it is finished using 4260 ** P. The T parameter should be a static string, preferably a string 4261 ** literal. The sqlite3_bind_pointer() routine is part of the 4262 ** [pointer passing interface] added for SQLite 3.20.0. 4263 ** 4264 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4265 ** for the [prepared statement] or with a prepared statement for which 4266 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4267 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4268 ** routine is passed a [prepared statement] that has been finalized, the 4269 ** result is undefined and probably harmful. 4270 ** 4271 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4272 ** ^Unbound parameters are interpreted as NULL. 4273 ** 4274 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4275 ** [error code] if anything goes wrong. 4276 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4277 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4278 ** [SQLITE_MAX_LENGTH]. 4279 ** ^[SQLITE_RANGE] is returned if the parameter 4280 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4281 ** 4282 ** See also: [sqlite3_bind_parameter_count()], 4283 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4284 */ 4285 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4286 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4287 void(*)(void*)); 4288 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 4289 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 4290 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4291 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 4292 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4293 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4294 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4295 void(*)(void*), unsigned char encoding); 4296 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4297 SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4298 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4299 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4300 4301 /* 4302 ** CAPI3REF: Number Of SQL Parameters 4303 ** METHOD: sqlite3_stmt 4304 ** 4305 ** ^This routine can be used to find the number of [SQL parameters] 4306 ** in a [prepared statement]. SQL parameters are tokens of the 4307 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4308 ** placeholders for values that are [sqlite3_bind_blob | bound] 4309 ** to the parameters at a later time. 4310 ** 4311 ** ^(This routine actually returns the index of the largest (rightmost) 4312 ** parameter. For all forms except ?NNN, this will correspond to the 4313 ** number of unique parameters. If parameters of the ?NNN form are used, 4314 ** there may be gaps in the list.)^ 4315 ** 4316 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4317 ** [sqlite3_bind_parameter_name()], and 4318 ** [sqlite3_bind_parameter_index()]. 4319 */ 4320 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 4321 4322 /* 4323 ** CAPI3REF: Name Of A Host Parameter 4324 ** METHOD: sqlite3_stmt 4325 ** 4326 ** ^The sqlite3_bind_parameter_name(P,N) interface returns 4327 ** the name of the N-th [SQL parameter] in the [prepared statement] P. 4328 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4329 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4330 ** respectively. 4331 ** In other words, the initial ":" or "$" or "@" or "?" 4332 ** is included as part of the name.)^ 4333 ** ^Parameters of the form "?" without a following integer have no name 4334 ** and are referred to as "nameless" or "anonymous parameters". 4335 ** 4336 ** ^The first host parameter has an index of 1, not 0. 4337 ** 4338 ** ^If the value N is out of range or if the N-th parameter is 4339 ** nameless, then NULL is returned. ^The returned string is 4340 ** always in UTF-8 encoding even if the named parameter was 4341 ** originally specified as UTF-16 in [sqlite3_prepare16()], 4342 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4343 ** 4344 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4345 ** [sqlite3_bind_parameter_count()], and 4346 ** [sqlite3_bind_parameter_index()]. 4347 */ 4348 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4349 4350 /* 4351 ** CAPI3REF: Index Of A Parameter With A Given Name 4352 ** METHOD: sqlite3_stmt 4353 ** 4354 ** ^Return the index of an SQL parameter given its name. ^The 4355 ** index value returned is suitable for use as the second 4356 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4357 ** is returned if no matching parameter is found. ^The parameter 4358 ** name must be given in UTF-8 even if the original statement 4359 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4360 ** [sqlite3_prepare16_v3()]. 4361 ** 4362 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4363 ** [sqlite3_bind_parameter_count()], and 4364 ** [sqlite3_bind_parameter_name()]. 4365 */ 4366 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4367 4368 /* 4369 ** CAPI3REF: Reset All Bindings On A Prepared Statement 4370 ** METHOD: sqlite3_stmt 4371 ** 4372 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4373 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4374 ** ^Use this routine to reset all host parameters to NULL. 4375 */ 4376 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 4377 4378 /* 4379 ** CAPI3REF: Number Of Columns In A Result Set 4380 ** METHOD: sqlite3_stmt 4381 ** 4382 ** ^Return the number of columns in the result set returned by the 4383 ** [prepared statement]. ^If this routine returns 0, that means the 4384 ** [prepared statement] returns no data (for example an [UPDATE]). 4385 ** ^However, just because this routine returns a positive number does not 4386 ** mean that one or more rows of data will be returned. ^A SELECT statement 4387 ** will always have a positive sqlite3_column_count() but depending on the 4388 ** WHERE clause constraints and the table content, it might return no rows. 4389 ** 4390 ** See also: [sqlite3_data_count()] 4391 */ 4392 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 4393 4394 /* 4395 ** CAPI3REF: Column Names In A Result Set 4396 ** METHOD: sqlite3_stmt 4397 ** 4398 ** ^These routines return the name assigned to a particular column 4399 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4400 ** interface returns a pointer to a zero-terminated UTF-8 string 4401 ** and sqlite3_column_name16() returns a pointer to a zero-terminated 4402 ** UTF-16 string. ^The first parameter is the [prepared statement] 4403 ** that implements the [SELECT] statement. ^The second parameter is the 4404 ** column number. ^The leftmost column is number 0. 4405 ** 4406 ** ^The returned string pointer is valid until either the [prepared statement] 4407 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4408 ** reprepared by the first call to [sqlite3_step()] for a particular run 4409 ** or until the next call to 4410 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4411 ** 4412 ** ^If sqlite3_malloc() fails during the processing of either routine 4413 ** (for example during a conversion from UTF-8 to UTF-16) then a 4414 ** NULL pointer is returned. 4415 ** 4416 ** ^The name of a result column is the value of the "AS" clause for 4417 ** that column, if there is an AS clause. If there is no AS clause 4418 ** then the name of the column is unspecified and may change from 4419 ** one release of SQLite to the next. 4420 */ 4421 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 4422 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4423 4424 /* 4425 ** CAPI3REF: Source Of Data In A Query Result 4426 ** METHOD: sqlite3_stmt 4427 ** 4428 ** ^These routines provide a means to determine the database, table, and 4429 ** table column that is the origin of a particular result column in 4430 ** [SELECT] statement. 4431 ** ^The name of the database or table or column can be returned as 4432 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4433 ** the database name, the _table_ routines return the table name, and 4434 ** the origin_ routines return the column name. 4435 ** ^The returned string is valid until the [prepared statement] is destroyed 4436 ** using [sqlite3_finalize()] or until the statement is automatically 4437 ** reprepared by the first call to [sqlite3_step()] for a particular run 4438 ** or until the same information is requested 4439 ** again in a different encoding. 4440 ** 4441 ** ^The names returned are the original un-aliased names of the 4442 ** database, table, and column. 4443 ** 4444 ** ^The first argument to these interfaces is a [prepared statement]. 4445 ** ^These functions return information about the Nth result column returned by 4446 ** the statement, where N is the second function argument. 4447 ** ^The left-most column is column 0 for these routines. 4448 ** 4449 ** ^If the Nth column returned by the statement is an expression or 4450 ** subquery and is not a column value, then all of these functions return 4451 ** NULL. ^These routines might also return NULL if a memory allocation error 4452 ** occurs. ^Otherwise, they return the name of the attached database, table, 4453 ** or column that query result column was extracted from. 4454 ** 4455 ** ^As with all other SQLite APIs, those whose names end with "16" return 4456 ** UTF-16 encoded strings and the other functions return UTF-8. 4457 ** 4458 ** ^These APIs are only available if the library was compiled with the 4459 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4460 ** 4461 ** If two or more threads call one or more 4462 ** [sqlite3_column_database_name | column metadata interfaces] 4463 ** for the same [prepared statement] and result column 4464 ** at the same time then the results are undefined. 4465 */ 4466 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4467 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4468 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4469 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4470 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4471 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4472 4473 /* 4474 ** CAPI3REF: Declared Datatype Of A Query Result 4475 ** METHOD: sqlite3_stmt 4476 ** 4477 ** ^(The first parameter is a [prepared statement]. 4478 ** If this statement is a [SELECT] statement and the Nth column of the 4479 ** returned result set of that [SELECT] is a table column (not an 4480 ** expression or subquery) then the declared type of the table 4481 ** column is returned.)^ ^If the Nth column of the result set is an 4482 ** expression or subquery, then a NULL pointer is returned. 4483 ** ^The returned string is always UTF-8 encoded. 4484 ** 4485 ** ^(For example, given the database schema: 4486 ** 4487 ** CREATE TABLE t1(c1 VARIANT); 4488 ** 4489 ** and the following statement to be compiled: 4490 ** 4491 ** SELECT c1 + 1, c1 FROM t1; 4492 ** 4493 ** this routine would return the string "VARIANT" for the second result 4494 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4495 ** 4496 ** ^SQLite uses dynamic run-time typing. ^So just because a column 4497 ** is declared to contain a particular type does not mean that the 4498 ** data stored in that column is of the declared type. SQLite is 4499 ** strongly typed, but the typing is dynamic not static. ^Type 4500 ** is associated with individual values, not with the containers 4501 ** used to hold those values. 4502 */ 4503 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4504 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4505 4506 /* 4507 ** CAPI3REF: Evaluate An SQL Statement 4508 ** METHOD: sqlite3_stmt 4509 ** 4510 ** After a [prepared statement] has been prepared using any of 4511 ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4512 ** or [sqlite3_prepare16_v3()] or one of the legacy 4513 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4514 ** must be called one or more times to evaluate the statement. 4515 ** 4516 ** The details of the behavior of the sqlite3_step() interface depend 4517 ** on whether the statement was prepared using the newer "vX" interfaces 4518 ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4519 ** [sqlite3_prepare16_v2()] or the older legacy 4520 ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4521 ** new "vX" interface is recommended for new applications but the legacy 4522 ** interface will continue to be supported. 4523 ** 4524 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4525 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4526 ** ^With the "v2" interface, any of the other [result codes] or 4527 ** [extended result codes] might be returned as well. 4528 ** 4529 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4530 ** database locks it needs to do its job. ^If the statement is a [COMMIT] 4531 ** or occurs outside of an explicit transaction, then you can retry the 4532 ** statement. If the statement is not a [COMMIT] and occurs within an 4533 ** explicit transaction then you should rollback the transaction before 4534 ** continuing. 4535 ** 4536 ** ^[SQLITE_DONE] means that the statement has finished executing 4537 ** successfully. sqlite3_step() should not be called again on this virtual 4538 ** machine without first calling [sqlite3_reset()] to reset the virtual 4539 ** machine back to its initial state. 4540 ** 4541 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4542 ** is returned each time a new row of data is ready for processing by the 4543 ** caller. The values may be accessed using the [column access functions]. 4544 ** sqlite3_step() is called again to retrieve the next row of data. 4545 ** 4546 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4547 ** violation) has occurred. sqlite3_step() should not be called again on 4548 ** the VM. More information may be found by calling [sqlite3_errmsg()]. 4549 ** ^With the legacy interface, a more specific error code (for example, 4550 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4551 ** can be obtained by calling [sqlite3_reset()] on the 4552 ** [prepared statement]. ^In the "v2" interface, 4553 ** the more specific error code is returned directly by sqlite3_step(). 4554 ** 4555 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4556 ** Perhaps it was called on a [prepared statement] that has 4557 ** already been [sqlite3_finalize | finalized] or on one that had 4558 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4559 ** be the case that the same database connection is being used by two or 4560 ** more threads at the same moment in time. 4561 ** 4562 ** For all versions of SQLite up to and including 3.6.23.1, a call to 4563 ** [sqlite3_reset()] was required after sqlite3_step() returned anything 4564 ** other than [SQLITE_ROW] before any subsequent invocation of 4565 ** sqlite3_step(). Failure to reset the prepared statement using 4566 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4567 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4568 ** sqlite3_step() began 4569 ** calling [sqlite3_reset()] automatically in this circumstance rather 4570 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4571 ** break because any application that ever receives an SQLITE_MISUSE error 4572 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4573 ** can be used to restore the legacy behavior. 4574 ** 4575 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4576 ** API always returns a generic error code, [SQLITE_ERROR], following any 4577 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4578 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4579 ** specific [error codes] that better describes the error. 4580 ** We admit that this is a goofy design. The problem has been fixed 4581 ** with the "v2" interface. If you prepare all of your SQL statements 4582 ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4583 ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4584 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4585 ** then the more specific [error codes] are returned directly 4586 ** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4587 */ 4588 SQLITE_API int sqlite3_step(sqlite3_stmt*); 4589 4590 /* 4591 ** CAPI3REF: Number of columns in a result set 4592 ** METHOD: sqlite3_stmt 4593 ** 4594 ** ^The sqlite3_data_count(P) interface returns the number of columns in the 4595 ** current row of the result set of [prepared statement] P. 4596 ** ^If prepared statement P does not have results ready to return 4597 ** (via calls to the [sqlite3_column_int | sqlite3_column()] family of 4598 ** interfaces) then sqlite3_data_count(P) returns 0. 4599 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4600 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4601 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4602 ** will return non-zero if previous call to [sqlite3_step](P) returned 4603 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4604 ** where it always returns zero since each step of that multi-step 4605 ** pragma returns 0 columns of data. 4606 ** 4607 ** See also: [sqlite3_column_count()] 4608 */ 4609 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 4610 4611 /* 4612 ** CAPI3REF: Fundamental Datatypes 4613 ** KEYWORDS: SQLITE_TEXT 4614 ** 4615 ** ^(Every value in SQLite has one of five fundamental datatypes: 4616 ** 4617 ** <ul> 4618 ** <li> 64-bit signed integer 4619 ** <li> 64-bit IEEE floating point number 4620 ** <li> string 4621 ** <li> BLOB 4622 ** <li> NULL 4623 ** </ul>)^ 4624 ** 4625 ** These constants are codes for each of those types. 4626 ** 4627 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4628 ** for a completely different meaning. Software that links against both 4629 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4630 ** SQLITE_TEXT. 4631 */ 4632 #define SQLITE_INTEGER 1 4633 #define SQLITE_FLOAT 2 4634 #define SQLITE_BLOB 4 4635 #define SQLITE_NULL 5 4636 #ifdef SQLITE_TEXT 4637 # undef SQLITE_TEXT 4638 #else 4639 # define SQLITE_TEXT 3 4640 #endif 4641 #define SQLITE3_TEXT 3 4642 4643 /* 4644 ** CAPI3REF: Result Values From A Query 4645 ** KEYWORDS: {column access functions} 4646 ** METHOD: sqlite3_stmt 4647 ** 4648 ** <b>Summary:</b> 4649 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4650 ** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 4651 ** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 4652 ** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 4653 ** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 4654 ** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 4655 ** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 4656 ** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 4657 ** [sqlite3_value|unprotected sqlite3_value] object. 4658 ** <tr><td> <td> <td> 4659 ** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 4660 ** or a UTF-8 TEXT result in bytes 4661 ** <tr><td><b>sqlite3_column_bytes16 </b> 4662 ** <td>→ <td>Size of UTF-16 4663 ** TEXT in bytes 4664 ** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 4665 ** datatype of the result 4666 ** </table></blockquote> 4667 ** 4668 ** <b>Details:</b> 4669 ** 4670 ** ^These routines return information about a single column of the current 4671 ** result row of a query. ^In every case the first argument is a pointer 4672 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4673 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4674 ** and the second argument is the index of the column for which information 4675 ** should be returned. ^The leftmost column of the result set has the index 0. 4676 ** ^The number of columns in the result can be determined using 4677 ** [sqlite3_column_count()]. 4678 ** 4679 ** If the SQL statement does not currently point to a valid row, or if the 4680 ** column index is out of range, the result is undefined. 4681 ** These routines may only be called when the most recent call to 4682 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4683 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4684 ** If any of these routines are called after [sqlite3_reset()] or 4685 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4686 ** something other than [SQLITE_ROW], the results are undefined. 4687 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4688 ** are called from a different thread while any of these routines 4689 ** are pending, then the results are undefined. 4690 ** 4691 ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 4692 ** each return the value of a result column in a specific data format. If 4693 ** the result column is not initially in the requested format (for example, 4694 ** if the query returns an integer but the sqlite3_column_text() interface 4695 ** is used to extract the value) then an automatic type conversion is performed. 4696 ** 4697 ** ^The sqlite3_column_type() routine returns the 4698 ** [SQLITE_INTEGER | datatype code] for the initial data type 4699 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4700 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 4701 ** The return value of sqlite3_column_type() can be used to decide which 4702 ** of the first six interface should be used to extract the column value. 4703 ** The value returned by sqlite3_column_type() is only meaningful if no 4704 ** automatic type conversions have occurred for the value in question. 4705 ** After a type conversion, the result of calling sqlite3_column_type() 4706 ** is undefined, though harmless. Future 4707 ** versions of SQLite may change the behavior of sqlite3_column_type() 4708 ** following a type conversion. 4709 ** 4710 ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 4711 ** or sqlite3_column_bytes16() interfaces can be used to determine the size 4712 ** of that BLOB or string. 4713 ** 4714 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4715 ** routine returns the number of bytes in that BLOB or string. 4716 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4717 ** the string to UTF-8 and then returns the number of bytes. 4718 ** ^If the result is a numeric value then sqlite3_column_bytes() uses 4719 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4720 ** the number of bytes in that string. 4721 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4722 ** 4723 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4724 ** routine returns the number of bytes in that BLOB or string. 4725 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4726 ** the string to UTF-16 and then returns the number of bytes. 4727 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4728 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4729 ** the number of bytes in that string. 4730 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4731 ** 4732 ** ^The values returned by [sqlite3_column_bytes()] and 4733 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4734 ** of the string. ^For clarity: the values returned by 4735 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4736 ** bytes in the string, not the number of characters. 4737 ** 4738 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4739 ** even empty strings, are always zero-terminated. ^The return 4740 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4741 ** 4742 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4743 ** [unprotected sqlite3_value] object. In a multithreaded environment, 4744 ** an unprotected sqlite3_value object may only be used safely with 4745 ** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4746 ** If the [unprotected sqlite3_value] object returned by 4747 ** [sqlite3_column_value()] is used in any other way, including calls 4748 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4749 ** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4750 ** Hence, the sqlite3_column_value() interface 4751 ** is normally only useful within the implementation of 4752 ** [application-defined SQL functions] or [virtual tables], not within 4753 ** top-level application code. 4754 ** 4755 ** The these routines may attempt to convert the datatype of the result. 4756 ** ^For example, if the internal representation is FLOAT and a text result 4757 ** is requested, [sqlite3_snprintf()] is used internally to perform the 4758 ** conversion automatically. ^(The following table details the conversions 4759 ** that are applied: 4760 ** 4761 ** <blockquote> 4762 ** <table border="1"> 4763 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4764 ** 4765 ** <tr><td> NULL <td> INTEGER <td> Result is 0 4766 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4767 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4768 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4769 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4770 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4771 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4772 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4773 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4774 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4775 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4776 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4777 ** <tr><td> TEXT <td> BLOB <td> No change 4778 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4779 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4780 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4781 ** </table> 4782 ** </blockquote>)^ 4783 ** 4784 ** Note that when type conversions occur, pointers returned by prior 4785 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4786 ** sqlite3_column_text16() may be invalidated. 4787 ** Type conversions and pointer invalidations might occur 4788 ** in the following cases: 4789 ** 4790 ** <ul> 4791 ** <li> The initial content is a BLOB and sqlite3_column_text() or 4792 ** sqlite3_column_text16() is called. A zero-terminator might 4793 ** need to be added to the string.</li> 4794 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4795 ** sqlite3_column_text16() is called. The content must be converted 4796 ** to UTF-16.</li> 4797 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4798 ** sqlite3_column_text() is called. The content must be converted 4799 ** to UTF-8.</li> 4800 ** </ul> 4801 ** 4802 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4803 ** not invalidate a prior pointer, though of course the content of the buffer 4804 ** that the prior pointer references will have been modified. Other kinds 4805 ** of conversion are done in place when it is possible, but sometimes they 4806 ** are not possible and in those cases prior pointers are invalidated. 4807 ** 4808 ** The safest policy is to invoke these routines 4809 ** in one of the following ways: 4810 ** 4811 ** <ul> 4812 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4813 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4814 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4815 ** </ul> 4816 ** 4817 ** In other words, you should call sqlite3_column_text(), 4818 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4819 ** into the desired format, then invoke sqlite3_column_bytes() or 4820 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4821 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4822 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4823 ** with calls to sqlite3_column_bytes(). 4824 ** 4825 ** ^The pointers returned are valid until a type conversion occurs as 4826 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4827 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4828 ** and BLOBs is freed automatically. Do not pass the pointers returned 4829 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4830 ** [sqlite3_free()]. 4831 ** 4832 ** As long as the input parameters are correct, these routines will only 4833 ** fail if an out-of-memory error occurs during a format conversion. 4834 ** Only the following subset of interfaces are subject to out-of-memory 4835 ** errors: 4836 ** 4837 ** <ul> 4838 ** <li> sqlite3_column_blob() 4839 ** <li> sqlite3_column_text() 4840 ** <li> sqlite3_column_text16() 4841 ** <li> sqlite3_column_bytes() 4842 ** <li> sqlite3_column_bytes16() 4843 ** </ul> 4844 ** 4845 ** If an out-of-memory error occurs, then the return value from these 4846 ** routines is the same as if the column had contained an SQL NULL value. 4847 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 4848 ** by invoking the [sqlite3_errcode()] immediately after the suspect 4849 ** return value is obtained and before any 4850 ** other SQLite interface is called on the same [database connection]. 4851 */ 4852 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4853 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 4854 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 4855 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4856 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4857 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4858 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4859 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4860 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4861 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 4862 4863 /* 4864 ** CAPI3REF: Destroy A Prepared Statement Object 4865 ** DESTRUCTOR: sqlite3_stmt 4866 ** 4867 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4868 ** ^If the most recent evaluation of the statement encountered no errors 4869 ** or if the statement is never been evaluated, then sqlite3_finalize() returns 4870 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4871 ** sqlite3_finalize(S) returns the appropriate [error code] or 4872 ** [extended error code]. 4873 ** 4874 ** ^The sqlite3_finalize(S) routine can be called at any point during 4875 ** the life cycle of [prepared statement] S: 4876 ** before statement S is ever evaluated, after 4877 ** one or more calls to [sqlite3_reset()], or after any call 4878 ** to [sqlite3_step()] regardless of whether or not the statement has 4879 ** completed execution. 4880 ** 4881 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4882 ** 4883 ** The application must finalize every [prepared statement] in order to avoid 4884 ** resource leaks. It is a grievous error for the application to try to use 4885 ** a prepared statement after it has been finalized. Any use of a prepared 4886 ** statement after it has been finalized can result in undefined and 4887 ** undesirable behavior such as segfaults and heap corruption. 4888 */ 4889 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 4890 4891 /* 4892 ** CAPI3REF: Reset A Prepared Statement Object 4893 ** METHOD: sqlite3_stmt 4894 ** 4895 ** The sqlite3_reset() function is called to reset a [prepared statement] 4896 ** object back to its initial state, ready to be re-executed. 4897 ** ^Any SQL statement variables that had values bound to them using 4898 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4899 ** Use [sqlite3_clear_bindings()] to reset the bindings. 4900 ** 4901 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4902 ** back to the beginning of its program. 4903 ** 4904 ** ^If the most recent call to [sqlite3_step(S)] for the 4905 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4906 ** or if [sqlite3_step(S)] has never before been called on S, 4907 ** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4908 ** 4909 ** ^If the most recent call to [sqlite3_step(S)] for the 4910 ** [prepared statement] S indicated an error, then 4911 ** [sqlite3_reset(S)] returns an appropriate [error code]. 4912 ** 4913 ** ^The [sqlite3_reset(S)] interface does not change the values 4914 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4915 */ 4916 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 4917 4918 /* 4919 ** CAPI3REF: Create Or Redefine SQL Functions 4920 ** KEYWORDS: {function creation routines} 4921 ** METHOD: sqlite3 4922 ** 4923 ** ^These functions (collectively known as "function creation routines") 4924 ** are used to add SQL functions or aggregates or to redefine the behavior 4925 ** of existing SQL functions or aggregates. The only differences between 4926 ** the three "sqlite3_create_function*" routines are the text encoding 4927 ** expected for the second parameter (the name of the function being 4928 ** created) and the presence or absence of a destructor callback for 4929 ** the application data pointer. Function sqlite3_create_window_function() 4930 ** is similar, but allows the user to supply the extra callback functions 4931 ** needed by [aggregate window functions]. 4932 ** 4933 ** ^The first parameter is the [database connection] to which the SQL 4934 ** function is to be added. ^If an application uses more than one database 4935 ** connection then application-defined SQL functions must be added 4936 ** to each database connection separately. 4937 ** 4938 ** ^The second parameter is the name of the SQL function to be created or 4939 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4940 ** representation, exclusive of the zero-terminator. ^Note that the name 4941 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4942 ** ^Any attempt to create a function with a longer name 4943 ** will result in [SQLITE_MISUSE] being returned. 4944 ** 4945 ** ^The third parameter (nArg) 4946 ** is the number of arguments that the SQL function or 4947 ** aggregate takes. ^If this parameter is -1, then the SQL function or 4948 ** aggregate may take any number of arguments between 0 and the limit 4949 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4950 ** parameter is less than -1 or greater than 127 then the behavior is 4951 ** undefined. 4952 ** 4953 ** ^The fourth parameter, eTextRep, specifies what 4954 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4955 ** its parameters. The application should set this parameter to 4956 ** [SQLITE_UTF16LE] if the function implementation invokes 4957 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4958 ** implementation invokes [sqlite3_value_text16be()] on an input, or 4959 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4960 ** otherwise. ^The same SQL function may be registered multiple times using 4961 ** different preferred text encodings, with different implementations for 4962 ** each encoding. 4963 ** ^When multiple implementations of the same function are available, SQLite 4964 ** will pick the one that involves the least amount of data conversion. 4965 ** 4966 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4967 ** to signal that the function will always return the same result given 4968 ** the same inputs within a single SQL statement. Most SQL functions are 4969 ** deterministic. The built-in [random()] SQL function is an example of a 4970 ** function that is not deterministic. The SQLite query planner is able to 4971 ** perform additional optimizations on deterministic functions, so use 4972 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4973 ** 4974 ** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY] 4975 ** flag, which if present prevents the function from being invoked from 4976 ** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions, 4977 ** index expressions, or the WHERE clause of partial indexes. 4978 ** 4979 ** <span style="background-color:#ffff90;"> 4980 ** For best security, the [SQLITE_DIRECTONLY] flag is recommended for 4981 ** all application-defined SQL functions that do not need to be 4982 ** used inside of triggers, view, CHECK constraints, or other elements of 4983 ** the database schema. This flags is especially recommended for SQL 4984 ** functions that have side effects or reveal internal application state. 4985 ** Without this flag, an attacker might be able to modify the schema of 4986 ** a database file to include invocations of the function with parameters 4987 ** chosen by the attacker, which the application will then execute when 4988 ** the database file is opened and read. 4989 ** </span> 4990 ** 4991 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4992 ** function can gain access to this pointer using [sqlite3_user_data()].)^ 4993 ** 4994 ** ^The sixth, seventh and eighth parameters passed to the three 4995 ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 4996 ** pointers to C-language functions that implement the SQL function or 4997 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4998 ** callback only; NULL pointers must be passed as the xStep and xFinal 4999 ** parameters. ^An aggregate SQL function requires an implementation of xStep 5000 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 5001 ** SQL function or aggregate, pass NULL pointers for all three function 5002 ** callbacks. 5003 ** 5004 ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 5005 ** and xInverse) passed to sqlite3_create_window_function are pointers to 5006 ** C-language callbacks that implement the new function. xStep and xFinal 5007 ** must both be non-NULL. xValue and xInverse may either both be NULL, in 5008 ** which case a regular aggregate function is created, or must both be 5009 ** non-NULL, in which case the new function may be used as either an aggregate 5010 ** or aggregate window function. More details regarding the implementation 5011 ** of aggregate window functions are 5012 ** [user-defined window functions|available here]. 5013 ** 5014 ** ^(If the final parameter to sqlite3_create_function_v2() or 5015 ** sqlite3_create_window_function() is not NULL, then it is destructor for 5016 ** the application data pointer. The destructor is invoked when the function 5017 ** is deleted, either by being overloaded or when the database connection 5018 ** closes.)^ ^The destructor is also invoked if the call to 5019 ** sqlite3_create_function_v2() fails. ^When the destructor callback is 5020 ** invoked, it is passed a single argument which is a copy of the application 5021 ** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 5022 ** 5023 ** ^It is permitted to register multiple implementations of the same 5024 ** functions with the same name but with either differing numbers of 5025 ** arguments or differing preferred text encodings. ^SQLite will use 5026 ** the implementation that most closely matches the way in which the 5027 ** SQL function is used. ^A function implementation with a non-negative 5028 ** nArg parameter is a better match than a function implementation with 5029 ** a negative nArg. ^A function where the preferred text encoding 5030 ** matches the database encoding is a better 5031 ** match than a function where the encoding is different. 5032 ** ^A function where the encoding difference is between UTF16le and UTF16be 5033 ** is a closer match than a function where the encoding difference is 5034 ** between UTF8 and UTF16. 5035 ** 5036 ** ^Built-in functions may be overloaded by new application-defined functions. 5037 ** 5038 ** ^An application-defined function is permitted to call other 5039 ** SQLite interfaces. However, such calls must not 5040 ** close the database connection nor finalize or reset the prepared 5041 ** statement in which the function is running. 5042 */ 5043 SQLITE_API int sqlite3_create_function( 5044 sqlite3 *db, 5045 const char *zFunctionName, 5046 int nArg, 5047 int eTextRep, 5048 void *pApp, 5049 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5050 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5051 void (*xFinal)(sqlite3_context*) 5052 ); 5053 SQLITE_API int sqlite3_create_function16( 5054 sqlite3 *db, 5055 const void *zFunctionName, 5056 int nArg, 5057 int eTextRep, 5058 void *pApp, 5059 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5060 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5061 void (*xFinal)(sqlite3_context*) 5062 ); 5063 SQLITE_API int sqlite3_create_function_v2( 5064 sqlite3 *db, 5065 const char *zFunctionName, 5066 int nArg, 5067 int eTextRep, 5068 void *pApp, 5069 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5070 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5071 void (*xFinal)(sqlite3_context*), 5072 void(*xDestroy)(void*) 5073 ); 5074 SQLITE_API int sqlite3_create_window_function( 5075 sqlite3 *db, 5076 const char *zFunctionName, 5077 int nArg, 5078 int eTextRep, 5079 void *pApp, 5080 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5081 void (*xFinal)(sqlite3_context*), 5082 void (*xValue)(sqlite3_context*), 5083 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 5084 void(*xDestroy)(void*) 5085 ); 5086 5087 /* 5088 ** CAPI3REF: Text Encodings 5089 ** 5090 ** These constant define integer codes that represent the various 5091 ** text encodings supported by SQLite. 5092 */ 5093 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 5094 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 5095 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 5096 #define SQLITE_UTF16 4 /* Use native byte order */ 5097 #define SQLITE_ANY 5 /* Deprecated */ 5098 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 5099 5100 /* 5101 ** CAPI3REF: Function Flags 5102 ** 5103 ** These constants may be ORed together with the 5104 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 5105 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 5106 ** [sqlite3_create_function_v2()]. 5107 ** 5108 ** <dl> 5109 ** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd> 5110 ** The SQLITE_DETERMINISTIC flag means that the new function always gives 5111 ** the same output when the input parameters are the same. 5112 ** The [abs|abs() function] is deterministic, for example, but 5113 ** [randomblob|randomblob()] is not. Functions must 5114 ** be deterministic in order to be used in certain contexts such as 5115 ** with the WHERE clause of [partial indexes] or in [generated columns]. 5116 ** SQLite might also optimize deterministic functions by factoring them 5117 ** out of inner loops. 5118 ** </dd> 5119 ** 5120 ** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd> 5121 ** The SQLITE_DIRECTONLY flag means that the function may only be invoked 5122 ** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in 5123 ** schema structures such as [CHECK constraints], [DEFAULT clauses], 5124 ** [expression indexes], [partial indexes], or [generated columns]. 5125 ** The SQLITE_DIRECTONLY flags is a security feature which is recommended 5126 ** for all [application-defined SQL functions], and especially for functions 5127 ** that have side-effects or that could potentially leak sensitive 5128 ** information. 5129 ** </dd> 5130 ** 5131 ** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd> 5132 ** The SQLITE_INNOCUOUS flag means that the function is unlikely 5133 ** to cause problems even if misused. An innocuous function should have 5134 ** no side effects and should not depend on any values other than its 5135 ** input parameters. The [abs|abs() function] is an example of an 5136 ** innocuous function. 5137 ** The [load_extension() SQL function] is not innocuous because of its 5138 ** side effects. 5139 ** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not 5140 ** exactly the same. The [random|random() function] is an example of a 5141 ** function that is innocuous but not deterministic. 5142 ** <p>Some heightened security settings 5143 ** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF]) 5144 ** disable the use of SQL functions inside views and triggers and in 5145 ** schema structures such as [CHECK constraints], [DEFAULT clauses], 5146 ** [expression indexes], [partial indexes], and [generated columns] unless 5147 ** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions 5148 ** are innocuous. Developers are advised to avoid using the 5149 ** SQLITE_INNOCUOUS flag for application-defined functions unless the 5150 ** function has been carefully audited and found to be free of potentially 5151 ** security-adverse side-effects and information-leaks. 5152 ** </dd> 5153 ** 5154 ** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd> 5155 ** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call 5156 ** [sqlite3_value_subtype()] to inspect the sub-types of its arguments. 5157 ** Specifying this flag makes no difference for scalar or aggregate user 5158 ** functions. However, if it is not specified for a user-defined window 5159 ** function, then any sub-types belonging to arguments passed to the window 5160 ** function may be discarded before the window function is called (i.e. 5161 ** sqlite3_value_subtype() will always return 0). 5162 ** </dd> 5163 ** </dl> 5164 */ 5165 #define SQLITE_DETERMINISTIC 0x000000800 5166 #define SQLITE_DIRECTONLY 0x000080000 5167 #define SQLITE_SUBTYPE 0x000100000 5168 #define SQLITE_INNOCUOUS 0x000200000 5169 5170 /* 5171 ** CAPI3REF: Deprecated Functions 5172 ** DEPRECATED 5173 ** 5174 ** These functions are [deprecated]. In order to maintain 5175 ** backwards compatibility with older code, these functions continue 5176 ** to be supported. However, new applications should avoid 5177 ** the use of these functions. To encourage programmers to avoid 5178 ** these functions, we will not explain what they do. 5179 */ 5180 #ifndef SQLITE_OMIT_DEPRECATED 5181 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 5182 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 5183 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 5184 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 5185 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 5186 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 5187 void*,sqlite3_int64); 5188 #endif 5189 5190 /* 5191 ** CAPI3REF: Obtaining SQL Values 5192 ** METHOD: sqlite3_value 5193 ** 5194 ** <b>Summary:</b> 5195 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5196 ** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 5197 ** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 5198 ** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 5199 ** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 5200 ** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 5201 ** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 5202 ** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 5203 ** the native byteorder 5204 ** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 5205 ** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 5206 ** <tr><td> <td> <td> 5207 ** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 5208 ** or a UTF-8 TEXT in bytes 5209 ** <tr><td><b>sqlite3_value_bytes16 </b> 5210 ** <td>→ <td>Size of UTF-16 5211 ** TEXT in bytes 5212 ** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 5213 ** datatype of the value 5214 ** <tr><td><b>sqlite3_value_numeric_type </b> 5215 ** <td>→ <td>Best numeric datatype of the value 5216 ** <tr><td><b>sqlite3_value_nochange </b> 5217 ** <td>→ <td>True if the column is unchanged in an UPDATE 5218 ** against a virtual table. 5219 ** <tr><td><b>sqlite3_value_frombind </b> 5220 ** <td>→ <td>True if value originated from a [bound parameter] 5221 ** </table></blockquote> 5222 ** 5223 ** <b>Details:</b> 5224 ** 5225 ** These routines extract type, size, and content information from 5226 ** [protected sqlite3_value] objects. Protected sqlite3_value objects 5227 ** are used to pass parameter information into the functions that 5228 ** implement [application-defined SQL functions] and [virtual tables]. 5229 ** 5230 ** These routines work only with [protected sqlite3_value] objects. 5231 ** Any attempt to use these routines on an [unprotected sqlite3_value] 5232 ** is not threadsafe. 5233 ** 5234 ** ^These routines work just like the corresponding [column access functions] 5235 ** except that these routines take a single [protected sqlite3_value] object 5236 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 5237 ** 5238 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 5239 ** in the native byte-order of the host machine. ^The 5240 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 5241 ** extract UTF-16 strings as big-endian and little-endian respectively. 5242 ** 5243 ** ^If [sqlite3_value] object V was initialized 5244 ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 5245 ** and if X and Y are strings that compare equal according to strcmp(X,Y), 5246 ** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 5247 ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 5248 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5249 ** 5250 ** ^(The sqlite3_value_type(V) interface returns the 5251 ** [SQLITE_INTEGER | datatype code] for the initial datatype of the 5252 ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 5253 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 5254 ** Other interfaces might change the datatype for an sqlite3_value object. 5255 ** For example, if the datatype is initially SQLITE_INTEGER and 5256 ** sqlite3_value_text(V) is called to extract a text value for that 5257 ** integer, then subsequent calls to sqlite3_value_type(V) might return 5258 ** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 5259 ** occurs is undefined and may change from one release of SQLite to the next. 5260 ** 5261 ** ^(The sqlite3_value_numeric_type() interface attempts to apply 5262 ** numeric affinity to the value. This means that an attempt is 5263 ** made to convert the value to an integer or floating point. If 5264 ** such a conversion is possible without loss of information (in other 5265 ** words, if the value is a string that looks like a number) 5266 ** then the conversion is performed. Otherwise no conversion occurs. 5267 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 5268 ** 5269 ** ^Within the [xUpdate] method of a [virtual table], the 5270 ** sqlite3_value_nochange(X) interface returns true if and only if 5271 ** the column corresponding to X is unchanged by the UPDATE operation 5272 ** that the xUpdate method call was invoked to implement and if 5273 ** and the prior [xColumn] method call that was invoked to extracted 5274 ** the value for that column returned without setting a result (probably 5275 ** because it queried [sqlite3_vtab_nochange()] and found that the column 5276 ** was unchanging). ^Within an [xUpdate] method, any value for which 5277 ** sqlite3_value_nochange(X) is true will in all other respects appear 5278 ** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 5279 ** than within an [xUpdate] method call for an UPDATE statement, then 5280 ** the return value is arbitrary and meaningless. 5281 ** 5282 ** ^The sqlite3_value_frombind(X) interface returns non-zero if the 5283 ** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()] 5284 ** interfaces. ^If X comes from an SQL literal value, or a table column, 5285 ** or an expression, then sqlite3_value_frombind(X) returns zero. 5286 ** 5287 ** Please pay particular attention to the fact that the pointer returned 5288 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 5289 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 5290 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 5291 ** or [sqlite3_value_text16()]. 5292 ** 5293 ** These routines must be called from the same thread as 5294 ** the SQL function that supplied the [sqlite3_value*] parameters. 5295 ** 5296 ** As long as the input parameter is correct, these routines can only 5297 ** fail if an out-of-memory error occurs during a format conversion. 5298 ** Only the following subset of interfaces are subject to out-of-memory 5299 ** errors: 5300 ** 5301 ** <ul> 5302 ** <li> sqlite3_value_blob() 5303 ** <li> sqlite3_value_text() 5304 ** <li> sqlite3_value_text16() 5305 ** <li> sqlite3_value_text16le() 5306 ** <li> sqlite3_value_text16be() 5307 ** <li> sqlite3_value_bytes() 5308 ** <li> sqlite3_value_bytes16() 5309 ** </ul> 5310 ** 5311 ** If an out-of-memory error occurs, then the return value from these 5312 ** routines is the same as if the column had contained an SQL NULL value. 5313 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 5314 ** by invoking the [sqlite3_errcode()] immediately after the suspect 5315 ** return value is obtained and before any 5316 ** other SQLite interface is called on the same [database connection]. 5317 */ 5318 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 5319 SQLITE_API double sqlite3_value_double(sqlite3_value*); 5320 SQLITE_API int sqlite3_value_int(sqlite3_value*); 5321 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 5322 SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*); 5323 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 5324 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 5325 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 5326 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 5327 SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 5328 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 5329 SQLITE_API int sqlite3_value_type(sqlite3_value*); 5330 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 5331 SQLITE_API int sqlite3_value_nochange(sqlite3_value*); 5332 SQLITE_API int sqlite3_value_frombind(sqlite3_value*); 5333 5334 /* 5335 ** CAPI3REF: Finding The Subtype Of SQL Values 5336 ** METHOD: sqlite3_value 5337 ** 5338 ** The sqlite3_value_subtype(V) function returns the subtype for 5339 ** an [application-defined SQL function] argument V. The subtype 5340 ** information can be used to pass a limited amount of context from 5341 ** one SQL function to another. Use the [sqlite3_result_subtype()] 5342 ** routine to set the subtype for the return value of an SQL function. 5343 */ 5344 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); 5345 5346 /* 5347 ** CAPI3REF: Copy And Free SQL Values 5348 ** METHOD: sqlite3_value 5349 ** 5350 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 5351 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 5352 ** is a [protected sqlite3_value] object even if the input is not. 5353 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 5354 ** memory allocation fails. 5355 ** 5356 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 5357 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 5358 ** then sqlite3_value_free(V) is a harmless no-op. 5359 */ 5360 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 5361 SQLITE_API void sqlite3_value_free(sqlite3_value*); 5362 5363 /* 5364 ** CAPI3REF: Obtain Aggregate Function Context 5365 ** METHOD: sqlite3_context 5366 ** 5367 ** Implementations of aggregate SQL functions use this 5368 ** routine to allocate memory for storing their state. 5369 ** 5370 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 5371 ** for a particular aggregate function, SQLite allocates 5372 ** N bytes of memory, zeroes out that memory, and returns a pointer 5373 ** to the new memory. ^On second and subsequent calls to 5374 ** sqlite3_aggregate_context() for the same aggregate function instance, 5375 ** the same buffer is returned. Sqlite3_aggregate_context() is normally 5376 ** called once for each invocation of the xStep callback and then one 5377 ** last time when the xFinal callback is invoked. ^(When no rows match 5378 ** an aggregate query, the xStep() callback of the aggregate function 5379 ** implementation is never called and xFinal() is called exactly once. 5380 ** In those cases, sqlite3_aggregate_context() might be called for the 5381 ** first time from within xFinal().)^ 5382 ** 5383 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5384 ** when first called if N is less than or equal to zero or if a memory 5385 ** allocate error occurs. 5386 ** 5387 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 5388 ** determined by the N parameter on first successful call. Changing the 5389 ** value of N in any subsequents call to sqlite3_aggregate_context() within 5390 ** the same aggregate function instance will not resize the memory 5391 ** allocation.)^ Within the xFinal callback, it is customary to set 5392 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5393 ** pointless memory allocations occur. 5394 ** 5395 ** ^SQLite automatically frees the memory allocated by 5396 ** sqlite3_aggregate_context() when the aggregate query concludes. 5397 ** 5398 ** The first parameter must be a copy of the 5399 ** [sqlite3_context | SQL function context] that is the first parameter 5400 ** to the xStep or xFinal callback routine that implements the aggregate 5401 ** function. 5402 ** 5403 ** This routine must be called from the same thread in which 5404 ** the aggregate SQL function is running. 5405 */ 5406 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 5407 5408 /* 5409 ** CAPI3REF: User Data For Functions 5410 ** METHOD: sqlite3_context 5411 ** 5412 ** ^The sqlite3_user_data() interface returns a copy of 5413 ** the pointer that was the pUserData parameter (the 5th parameter) 5414 ** of the [sqlite3_create_function()] 5415 ** and [sqlite3_create_function16()] routines that originally 5416 ** registered the application defined function. 5417 ** 5418 ** This routine must be called from the same thread in which 5419 ** the application-defined function is running. 5420 */ 5421 SQLITE_API void *sqlite3_user_data(sqlite3_context*); 5422 5423 /* 5424 ** CAPI3REF: Database Connection For Functions 5425 ** METHOD: sqlite3_context 5426 ** 5427 ** ^The sqlite3_context_db_handle() interface returns a copy of 5428 ** the pointer to the [database connection] (the 1st parameter) 5429 ** of the [sqlite3_create_function()] 5430 ** and [sqlite3_create_function16()] routines that originally 5431 ** registered the application defined function. 5432 */ 5433 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5434 5435 /* 5436 ** CAPI3REF: Function Auxiliary Data 5437 ** METHOD: sqlite3_context 5438 ** 5439 ** These functions may be used by (non-aggregate) SQL functions to 5440 ** associate metadata with argument values. If the same value is passed to 5441 ** multiple invocations of the same SQL function during query execution, under 5442 ** some circumstances the associated metadata may be preserved. An example 5443 ** of where this might be useful is in a regular-expression matching 5444 ** function. The compiled version of the regular expression can be stored as 5445 ** metadata associated with the pattern string. 5446 ** Then as long as the pattern string remains the same, 5447 ** the compiled regular expression can be reused on multiple 5448 ** invocations of the same function. 5449 ** 5450 ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 5451 ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5452 ** value to the application-defined function. ^N is zero for the left-most 5453 ** function argument. ^If there is no metadata 5454 ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5455 ** returns a NULL pointer. 5456 ** 5457 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 5458 ** argument of the application-defined function. ^Subsequent 5459 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5460 ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 5461 ** NULL if the metadata has been discarded. 5462 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5463 ** SQLite will invoke the destructor function X with parameter P exactly 5464 ** once, when the metadata is discarded. 5465 ** SQLite is free to discard the metadata at any time, including: <ul> 5466 ** <li> ^(when the corresponding function parameter changes)^, or 5467 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5468 ** SQL statement)^, or 5469 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5470 ** parameter)^, or 5471 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5472 ** allocation error occurs.)^ </ul> 5473 ** 5474 ** Note the last bullet in particular. The destructor X in 5475 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5476 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5477 ** should be called near the end of the function implementation and the 5478 ** function implementation should not make any use of P after 5479 ** sqlite3_set_auxdata() has been called. 5480 ** 5481 ** ^(In practice, metadata is preserved between function calls for 5482 ** function parameters that are compile-time constants, including literal 5483 ** values and [parameters] and expressions composed from the same.)^ 5484 ** 5485 ** The value of the N parameter to these interfaces should be non-negative. 5486 ** Future enhancements may make use of negative N values to define new 5487 ** kinds of function caching behavior. 5488 ** 5489 ** These routines must be called from the same thread in which 5490 ** the SQL function is running. 5491 */ 5492 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 5493 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5494 5495 5496 /* 5497 ** CAPI3REF: Constants Defining Special Destructor Behavior 5498 ** 5499 ** These are special values for the destructor that is passed in as the 5500 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5501 ** argument is SQLITE_STATIC, it means that the content pointer is constant 5502 ** and will never change. It does not need to be destroyed. ^The 5503 ** SQLITE_TRANSIENT value means that the content will likely change in 5504 ** the near future and that SQLite should make its own private copy of 5505 ** the content before returning. 5506 ** 5507 ** The typedef is necessary to work around problems in certain 5508 ** C++ compilers. 5509 */ 5510 typedef void (*sqlite3_destructor_type)(void*); 5511 #define SQLITE_STATIC ((sqlite3_destructor_type)0) 5512 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5513 5514 /* 5515 ** CAPI3REF: Setting The Result Of An SQL Function 5516 ** METHOD: sqlite3_context 5517 ** 5518 ** These routines are used by the xFunc or xFinal callbacks that 5519 ** implement SQL functions and aggregates. See 5520 ** [sqlite3_create_function()] and [sqlite3_create_function16()] 5521 ** for additional information. 5522 ** 5523 ** These functions work very much like the [parameter binding] family of 5524 ** functions used to bind values to host parameters in prepared statements. 5525 ** Refer to the [SQL parameter] documentation for additional information. 5526 ** 5527 ** ^The sqlite3_result_blob() interface sets the result from 5528 ** an application-defined function to be the BLOB whose content is pointed 5529 ** to by the second parameter and which is N bytes long where N is the 5530 ** third parameter. 5531 ** 5532 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5533 ** interfaces set the result of the application-defined function to be 5534 ** a BLOB containing all zero bytes and N bytes in size. 5535 ** 5536 ** ^The sqlite3_result_double() interface sets the result from 5537 ** an application-defined function to be a floating point value specified 5538 ** by its 2nd argument. 5539 ** 5540 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5541 ** cause the implemented SQL function to throw an exception. 5542 ** ^SQLite uses the string pointed to by the 5543 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5544 ** as the text of an error message. ^SQLite interprets the error 5545 ** message string from sqlite3_result_error() as UTF-8. ^SQLite 5546 ** interprets the string from sqlite3_result_error16() as UTF-16 in native 5547 ** byte order. ^If the third parameter to sqlite3_result_error() 5548 ** or sqlite3_result_error16() is negative then SQLite takes as the error 5549 ** message all text up through the first zero character. 5550 ** ^If the third parameter to sqlite3_result_error() or 5551 ** sqlite3_result_error16() is non-negative then SQLite takes that many 5552 ** bytes (not characters) from the 2nd parameter as the error message. 5553 ** ^The sqlite3_result_error() and sqlite3_result_error16() 5554 ** routines make a private copy of the error message text before 5555 ** they return. Hence, the calling function can deallocate or 5556 ** modify the text after they return without harm. 5557 ** ^The sqlite3_result_error_code() function changes the error code 5558 ** returned by SQLite as a result of an error in a function. ^By default, 5559 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5560 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5561 ** 5562 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5563 ** error indicating that a string or BLOB is too long to represent. 5564 ** 5565 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5566 ** error indicating that a memory allocation failed. 5567 ** 5568 ** ^The sqlite3_result_int() interface sets the return value 5569 ** of the application-defined function to be the 32-bit signed integer 5570 ** value given in the 2nd argument. 5571 ** ^The sqlite3_result_int64() interface sets the return value 5572 ** of the application-defined function to be the 64-bit signed integer 5573 ** value given in the 2nd argument. 5574 ** 5575 ** ^The sqlite3_result_null() interface sets the return value 5576 ** of the application-defined function to be NULL. 5577 ** 5578 ** ^The sqlite3_result_text(), sqlite3_result_text16(), 5579 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5580 ** set the return value of the application-defined function to be 5581 ** a text string which is represented as UTF-8, UTF-16 native byte order, 5582 ** UTF-16 little endian, or UTF-16 big endian, respectively. 5583 ** ^The sqlite3_result_text64() interface sets the return value of an 5584 ** application-defined function to be a text string in an encoding 5585 ** specified by the fifth (and last) parameter, which must be one 5586 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5587 ** ^SQLite takes the text result from the application from 5588 ** the 2nd parameter of the sqlite3_result_text* interfaces. 5589 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5590 ** is negative, then SQLite takes result text from the 2nd parameter 5591 ** through the first zero character. 5592 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5593 ** is non-negative, then as many bytes (not characters) of the text 5594 ** pointed to by the 2nd parameter are taken as the application-defined 5595 ** function result. If the 3rd parameter is non-negative, then it 5596 ** must be the byte offset into the string where the NUL terminator would 5597 ** appear if the string where NUL terminated. If any NUL characters occur 5598 ** in the string at a byte offset that is less than the value of the 3rd 5599 ** parameter, then the resulting string will contain embedded NULs and the 5600 ** result of expressions operating on strings with embedded NULs is undefined. 5601 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 5602 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5603 ** function as the destructor on the text or BLOB result when it has 5604 ** finished using that result. 5605 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5606 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 5607 ** assumes that the text or BLOB result is in constant space and does not 5608 ** copy the content of the parameter nor call a destructor on the content 5609 ** when it has finished using that result. 5610 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 5611 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 5612 ** then SQLite makes a copy of the result into space obtained 5613 ** from [sqlite3_malloc()] before it returns. 5614 ** 5615 ** ^The sqlite3_result_value() interface sets the result of 5616 ** the application-defined function to be a copy of the 5617 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 5618 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 5619 ** so that the [sqlite3_value] specified in the parameter may change or 5620 ** be deallocated after sqlite3_result_value() returns without harm. 5621 ** ^A [protected sqlite3_value] object may always be used where an 5622 ** [unprotected sqlite3_value] object is required, so either 5623 ** kind of [sqlite3_value] object can be used with this interface. 5624 ** 5625 ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 5626 ** SQL NULL value, just like [sqlite3_result_null(C)], except that it 5627 ** also associates the host-language pointer P or type T with that 5628 ** NULL value such that the pointer can be retrieved within an 5629 ** [application-defined SQL function] using [sqlite3_value_pointer()]. 5630 ** ^If the D parameter is not NULL, then it is a pointer to a destructor 5631 ** for the P parameter. ^SQLite invokes D with P as its only argument 5632 ** when SQLite is finished with P. The T parameter should be a static 5633 ** string and preferably a string literal. The sqlite3_result_pointer() 5634 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5635 ** 5636 ** If these routines are called from within the different thread 5637 ** than the one containing the application-defined function that received 5638 ** the [sqlite3_context] pointer, the results are undefined. 5639 */ 5640 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 5641 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 5642 sqlite3_uint64,void(*)(void*)); 5643 SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 5644 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 5645 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 5646 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 5647 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 5648 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 5649 SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 5650 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5651 SQLITE_API void sqlite3_result_null(sqlite3_context*); 5652 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5653 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5654 void(*)(void*), unsigned char encoding); 5655 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5656 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5657 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5658 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5659 SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 5660 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 5661 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 5662 5663 5664 /* 5665 ** CAPI3REF: Setting The Subtype Of An SQL Function 5666 ** METHOD: sqlite3_context 5667 ** 5668 ** The sqlite3_result_subtype(C,T) function causes the subtype of 5669 ** the result from the [application-defined SQL function] with 5670 ** [sqlite3_context] C to be the value T. Only the lower 8 bits 5671 ** of the subtype T are preserved in current versions of SQLite; 5672 ** higher order bits are discarded. 5673 ** The number of subtype bytes preserved by SQLite might increase 5674 ** in future releases of SQLite. 5675 */ 5676 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); 5677 5678 /* 5679 ** CAPI3REF: Define New Collating Sequences 5680 ** METHOD: sqlite3 5681 ** 5682 ** ^These functions add, remove, or modify a [collation] associated 5683 ** with the [database connection] specified as the first argument. 5684 ** 5685 ** ^The name of the collation is a UTF-8 string 5686 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 5687 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 5688 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 5689 ** considered to be the same name. 5690 ** 5691 ** ^(The third argument (eTextRep) must be one of the constants: 5692 ** <ul> 5693 ** <li> [SQLITE_UTF8], 5694 ** <li> [SQLITE_UTF16LE], 5695 ** <li> [SQLITE_UTF16BE], 5696 ** <li> [SQLITE_UTF16], or 5697 ** <li> [SQLITE_UTF16_ALIGNED]. 5698 ** </ul>)^ 5699 ** ^The eTextRep argument determines the encoding of strings passed 5700 ** to the collating function callback, xCompare. 5701 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 5702 ** force strings to be UTF16 with native byte order. 5703 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 5704 ** on an even byte address. 5705 ** 5706 ** ^The fourth argument, pArg, is an application data pointer that is passed 5707 ** through as the first argument to the collating function callback. 5708 ** 5709 ** ^The fifth argument, xCompare, is a pointer to the collating function. 5710 ** ^Multiple collating functions can be registered using the same name but 5711 ** with different eTextRep parameters and SQLite will use whichever 5712 ** function requires the least amount of data transformation. 5713 ** ^If the xCompare argument is NULL then the collating function is 5714 ** deleted. ^When all collating functions having the same name are deleted, 5715 ** that collation is no longer usable. 5716 ** 5717 ** ^The collating function callback is invoked with a copy of the pArg 5718 ** application data pointer and with two strings in the encoding specified 5719 ** by the eTextRep argument. The two integer parameters to the collating 5720 ** function callback are the length of the two strings, in bytes. The collating 5721 ** function must return an integer that is negative, zero, or positive 5722 ** if the first string is less than, equal to, or greater than the second, 5723 ** respectively. A collating function must always return the same answer 5724 ** given the same inputs. If two or more collating functions are registered 5725 ** to the same collation name (using different eTextRep values) then all 5726 ** must give an equivalent answer when invoked with equivalent strings. 5727 ** The collating function must obey the following properties for all 5728 ** strings A, B, and C: 5729 ** 5730 ** <ol> 5731 ** <li> If A==B then B==A. 5732 ** <li> If A==B and B==C then A==C. 5733 ** <li> If A<B THEN B>A. 5734 ** <li> If A<B and B<C then A<C. 5735 ** </ol> 5736 ** 5737 ** If a collating function fails any of the above constraints and that 5738 ** collating function is registered and used, then the behavior of SQLite 5739 ** is undefined. 5740 ** 5741 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 5742 ** with the addition that the xDestroy callback is invoked on pArg when 5743 ** the collating function is deleted. 5744 ** ^Collating functions are deleted when they are overridden by later 5745 ** calls to the collation creation functions or when the 5746 ** [database connection] is closed using [sqlite3_close()]. 5747 ** 5748 ** ^The xDestroy callback is <u>not</u> called if the 5749 ** sqlite3_create_collation_v2() function fails. Applications that invoke 5750 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5751 ** check the return code and dispose of the application data pointer 5752 ** themselves rather than expecting SQLite to deal with it for them. 5753 ** This is different from every other SQLite interface. The inconsistency 5754 ** is unfortunate but cannot be changed without breaking backwards 5755 ** compatibility. 5756 ** 5757 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5758 */ 5759 SQLITE_API int sqlite3_create_collation( 5760 sqlite3*, 5761 const char *zName, 5762 int eTextRep, 5763 void *pArg, 5764 int(*xCompare)(void*,int,const void*,int,const void*) 5765 ); 5766 SQLITE_API int sqlite3_create_collation_v2( 5767 sqlite3*, 5768 const char *zName, 5769 int eTextRep, 5770 void *pArg, 5771 int(*xCompare)(void*,int,const void*,int,const void*), 5772 void(*xDestroy)(void*) 5773 ); 5774 SQLITE_API int sqlite3_create_collation16( 5775 sqlite3*, 5776 const void *zName, 5777 int eTextRep, 5778 void *pArg, 5779 int(*xCompare)(void*,int,const void*,int,const void*) 5780 ); 5781 5782 /* 5783 ** CAPI3REF: Collation Needed Callbacks 5784 ** METHOD: sqlite3 5785 ** 5786 ** ^To avoid having to register all collation sequences before a database 5787 ** can be used, a single callback function may be registered with the 5788 ** [database connection] to be invoked whenever an undefined collation 5789 ** sequence is required. 5790 ** 5791 ** ^If the function is registered using the sqlite3_collation_needed() API, 5792 ** then it is passed the names of undefined collation sequences as strings 5793 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5794 ** the names are passed as UTF-16 in machine native byte order. 5795 ** ^A call to either function replaces the existing collation-needed callback. 5796 ** 5797 ** ^(When the callback is invoked, the first argument passed is a copy 5798 ** of the second argument to sqlite3_collation_needed() or 5799 ** sqlite3_collation_needed16(). The second argument is the database 5800 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5801 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5802 ** sequence function required. The fourth parameter is the name of the 5803 ** required collation sequence.)^ 5804 ** 5805 ** The callback function should register the desired collation using 5806 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5807 ** [sqlite3_create_collation_v2()]. 5808 */ 5809 SQLITE_API int sqlite3_collation_needed( 5810 sqlite3*, 5811 void*, 5812 void(*)(void*,sqlite3*,int eTextRep,const char*) 5813 ); 5814 SQLITE_API int sqlite3_collation_needed16( 5815 sqlite3*, 5816 void*, 5817 void(*)(void*,sqlite3*,int eTextRep,const void*) 5818 ); 5819 5820 #ifdef SQLITE_HAS_CODEC 5821 /* 5822 ** Specify the key for an encrypted database. This routine should be 5823 ** called right after sqlite3_open(). 5824 ** 5825 ** The code to implement this API is not available in the public release 5826 ** of SQLite. 5827 */ 5828 SQLITE_API int sqlite3_key( 5829 sqlite3 *db, /* Database to be rekeyed */ 5830 const void *pKey, int nKey /* The key */ 5831 ); 5832 SQLITE_API int sqlite3_key_v2( 5833 sqlite3 *db, /* Database to be rekeyed */ 5834 const char *zDbName, /* Name of the database */ 5835 const void *pKey, int nKey /* The key */ 5836 ); 5837 5838 /* 5839 ** Change the key on an open database. If the current database is not 5840 ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 5841 ** database is decrypted. 5842 ** 5843 ** The code to implement this API is not available in the public release 5844 ** of SQLite. 5845 */ 5846 SQLITE_API int sqlite3_rekey( 5847 sqlite3 *db, /* Database to be rekeyed */ 5848 const void *pKey, int nKey /* The new key */ 5849 ); 5850 SQLITE_API int sqlite3_rekey_v2( 5851 sqlite3 *db, /* Database to be rekeyed */ 5852 const char *zDbName, /* Name of the database */ 5853 const void *pKey, int nKey /* The new key */ 5854 ); 5855 5856 /* 5857 ** Specify the activation key for a SEE database. Unless 5858 ** activated, none of the SEE routines will work. 5859 */ 5860 SQLITE_API void sqlite3_activate_see( 5861 const char *zPassPhrase /* Activation phrase */ 5862 ); 5863 #endif 5864 5865 #ifdef SQLITE_ENABLE_CEROD 5866 /* 5867 ** Specify the activation key for a CEROD database. Unless 5868 ** activated, none of the CEROD routines will work. 5869 */ 5870 SQLITE_API void sqlite3_activate_cerod( 5871 const char *zPassPhrase /* Activation phrase */ 5872 ); 5873 #endif 5874 5875 /* 5876 ** CAPI3REF: Suspend Execution For A Short Time 5877 ** 5878 ** The sqlite3_sleep() function causes the current thread to suspend execution 5879 ** for at least a number of milliseconds specified in its parameter. 5880 ** 5881 ** If the operating system does not support sleep requests with 5882 ** millisecond time resolution, then the time will be rounded up to 5883 ** the nearest second. The number of milliseconds of sleep actually 5884 ** requested from the operating system is returned. 5885 ** 5886 ** ^SQLite implements this interface by calling the xSleep() 5887 ** method of the default [sqlite3_vfs] object. If the xSleep() method 5888 ** of the default VFS is not implemented correctly, or not implemented at 5889 ** all, then the behavior of sqlite3_sleep() may deviate from the description 5890 ** in the previous paragraphs. 5891 */ 5892 SQLITE_API int sqlite3_sleep(int); 5893 5894 /* 5895 ** CAPI3REF: Name Of The Folder Holding Temporary Files 5896 ** 5897 ** ^(If this global variable is made to point to a string which is 5898 ** the name of a folder (a.k.a. directory), then all temporary files 5899 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 5900 ** will be placed in that directory.)^ ^If this variable 5901 ** is a NULL pointer, then SQLite performs a search for an appropriate 5902 ** temporary file directory. 5903 ** 5904 ** Applications are strongly discouraged from using this global variable. 5905 ** It is required to set a temporary folder on Windows Runtime (WinRT). 5906 ** But for all other platforms, it is highly recommended that applications 5907 ** neither read nor write this variable. This global variable is a relic 5908 ** that exists for backwards compatibility of legacy applications and should 5909 ** be avoided in new projects. 5910 ** 5911 ** It is not safe to read or modify this variable in more than one 5912 ** thread at a time. It is not safe to read or modify this variable 5913 ** if a [database connection] is being used at the same time in a separate 5914 ** thread. 5915 ** It is intended that this variable be set once 5916 ** as part of process initialization and before any SQLite interface 5917 ** routines have been called and that this variable remain unchanged 5918 ** thereafter. 5919 ** 5920 ** ^The [temp_store_directory pragma] may modify this variable and cause 5921 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5922 ** the [temp_store_directory pragma] always assumes that any string 5923 ** that this variable points to is held in memory obtained from 5924 ** [sqlite3_malloc] and the pragma may attempt to free that memory 5925 ** using [sqlite3_free]. 5926 ** Hence, if this variable is modified directly, either it should be 5927 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 5928 ** or else the use of the [temp_store_directory pragma] should be avoided. 5929 ** Except when requested by the [temp_store_directory pragma], SQLite 5930 ** does not free the memory that sqlite3_temp_directory points to. If 5931 ** the application wants that memory to be freed, it must do 5932 ** so itself, taking care to only do so after all [database connection] 5933 ** objects have been destroyed. 5934 ** 5935 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 5936 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 5937 ** features that require the use of temporary files may fail. Here is an 5938 ** example of how to do this using C++ with the Windows Runtime: 5939 ** 5940 ** <blockquote><pre> 5941 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 5942 ** TemporaryFolder->Path->Data(); 5943 ** char zPathBuf[MAX_PATH + 1]; 5944 ** memset(zPathBuf, 0, sizeof(zPathBuf)); 5945 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 5946 ** NULL, NULL); 5947 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 5948 ** </pre></blockquote> 5949 */ 5950 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 5951 5952 /* 5953 ** CAPI3REF: Name Of The Folder Holding Database Files 5954 ** 5955 ** ^(If this global variable is made to point to a string which is 5956 ** the name of a folder (a.k.a. directory), then all database files 5957 ** specified with a relative pathname and created or accessed by 5958 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 5959 ** to be relative to that directory.)^ ^If this variable is a NULL 5960 ** pointer, then SQLite assumes that all database files specified 5961 ** with a relative pathname are relative to the current directory 5962 ** for the process. Only the windows VFS makes use of this global 5963 ** variable; it is ignored by the unix VFS. 5964 ** 5965 ** Changing the value of this variable while a database connection is 5966 ** open can result in a corrupt database. 5967 ** 5968 ** It is not safe to read or modify this variable in more than one 5969 ** thread at a time. It is not safe to read or modify this variable 5970 ** if a [database connection] is being used at the same time in a separate 5971 ** thread. 5972 ** It is intended that this variable be set once 5973 ** as part of process initialization and before any SQLite interface 5974 ** routines have been called and that this variable remain unchanged 5975 ** thereafter. 5976 ** 5977 ** ^The [data_store_directory pragma] may modify this variable and cause 5978 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5979 ** the [data_store_directory pragma] always assumes that any string 5980 ** that this variable points to is held in memory obtained from 5981 ** [sqlite3_malloc] and the pragma may attempt to free that memory 5982 ** using [sqlite3_free]. 5983 ** Hence, if this variable is modified directly, either it should be 5984 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 5985 ** or else the use of the [data_store_directory pragma] should be avoided. 5986 */ 5987 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 5988 5989 /* 5990 ** CAPI3REF: Win32 Specific Interface 5991 ** 5992 ** These interfaces are available only on Windows. The 5993 ** [sqlite3_win32_set_directory] interface is used to set the value associated 5994 ** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 5995 ** zValue, depending on the value of the type parameter. The zValue parameter 5996 ** should be NULL to cause the previous value to be freed via [sqlite3_free]; 5997 ** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 5998 ** prior to being used. The [sqlite3_win32_set_directory] interface returns 5999 ** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 6000 ** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 6001 ** [sqlite3_data_directory] variable is intended to act as a replacement for 6002 ** the current directory on the sub-platforms of Win32 where that concept is 6003 ** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 6004 ** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 6005 ** sqlite3_win32_set_directory interface except the string parameter must be 6006 ** UTF-8 or UTF-16, respectively. 6007 */ 6008 SQLITE_API int sqlite3_win32_set_directory( 6009 unsigned long type, /* Identifier for directory being set or reset */ 6010 void *zValue /* New value for directory being set or reset */ 6011 ); 6012 SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 6013 SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 6014 6015 /* 6016 ** CAPI3REF: Win32 Directory Types 6017 ** 6018 ** These macros are only available on Windows. They define the allowed values 6019 ** for the type argument to the [sqlite3_win32_set_directory] interface. 6020 */ 6021 #define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 6022 #define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 6023 6024 /* 6025 ** CAPI3REF: Test For Auto-Commit Mode 6026 ** KEYWORDS: {autocommit mode} 6027 ** METHOD: sqlite3 6028 ** 6029 ** ^The sqlite3_get_autocommit() interface returns non-zero or 6030 ** zero if the given database connection is or is not in autocommit mode, 6031 ** respectively. ^Autocommit mode is on by default. 6032 ** ^Autocommit mode is disabled by a [BEGIN] statement. 6033 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 6034 ** 6035 ** If certain kinds of errors occur on a statement within a multi-statement 6036 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 6037 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 6038 ** transaction might be rolled back automatically. The only way to 6039 ** find out whether SQLite automatically rolled back the transaction after 6040 ** an error is to use this function. 6041 ** 6042 ** If another thread changes the autocommit status of the database 6043 ** connection while this routine is running, then the return value 6044 ** is undefined. 6045 */ 6046 SQLITE_API int sqlite3_get_autocommit(sqlite3*); 6047 6048 /* 6049 ** CAPI3REF: Find The Database Handle Of A Prepared Statement 6050 ** METHOD: sqlite3_stmt 6051 ** 6052 ** ^The sqlite3_db_handle interface returns the [database connection] handle 6053 ** to which a [prepared statement] belongs. ^The [database connection] 6054 ** returned by sqlite3_db_handle is the same [database connection] 6055 ** that was the first argument 6056 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 6057 ** create the statement in the first place. 6058 */ 6059 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 6060 6061 /* 6062 ** CAPI3REF: Return The Filename For A Database Connection 6063 ** METHOD: sqlite3 6064 ** 6065 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename 6066 ** associated with database N of connection D. 6067 ** ^If there is no attached database N on the database 6068 ** connection D, or if database N is a temporary or in-memory database, then 6069 ** this function will return either a NULL pointer or an empty string. 6070 ** 6071 ** ^The string value returned by this routine is owned and managed by 6072 ** the database connection. ^The value will be valid until the database N 6073 ** is [DETACH]-ed or until the database connection closes. 6074 ** 6075 ** ^The filename returned by this function is the output of the 6076 ** xFullPathname method of the [VFS]. ^In other words, the filename 6077 ** will be an absolute pathname, even if the filename used 6078 ** to open the database originally was a URI or relative pathname. 6079 ** 6080 ** If the filename pointer returned by this routine is not NULL, then it 6081 ** can be used as the filename input parameter to these routines: 6082 ** <ul> 6083 ** <li> [sqlite3_uri_parameter()] 6084 ** <li> [sqlite3_uri_boolean()] 6085 ** <li> [sqlite3_uri_int64()] 6086 ** <li> [sqlite3_filename_database()] 6087 ** <li> [sqlite3_filename_journal()] 6088 ** <li> [sqlite3_filename_wal()] 6089 ** </ul> 6090 */ 6091 SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 6092 6093 /* 6094 ** CAPI3REF: Determine if a database is read-only 6095 ** METHOD: sqlite3 6096 ** 6097 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 6098 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not 6099 ** the name of a database on connection D. 6100 */ 6101 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 6102 6103 /* 6104 ** CAPI3REF: Find the next prepared statement 6105 ** METHOD: sqlite3 6106 ** 6107 ** ^This interface returns a pointer to the next [prepared statement] after 6108 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 6109 ** then this interface returns a pointer to the first prepared statement 6110 ** associated with the database connection pDb. ^If no prepared statement 6111 ** satisfies the conditions of this routine, it returns NULL. 6112 ** 6113 ** The [database connection] pointer D in a call to 6114 ** [sqlite3_next_stmt(D,S)] must refer to an open database 6115 ** connection and in particular must not be a NULL pointer. 6116 */ 6117 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 6118 6119 /* 6120 ** CAPI3REF: Commit And Rollback Notification Callbacks 6121 ** METHOD: sqlite3 6122 ** 6123 ** ^The sqlite3_commit_hook() interface registers a callback 6124 ** function to be invoked whenever a transaction is [COMMIT | committed]. 6125 ** ^Any callback set by a previous call to sqlite3_commit_hook() 6126 ** for the same database connection is overridden. 6127 ** ^The sqlite3_rollback_hook() interface registers a callback 6128 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 6129 ** ^Any callback set by a previous call to sqlite3_rollback_hook() 6130 ** for the same database connection is overridden. 6131 ** ^The pArg argument is passed through to the callback. 6132 ** ^If the callback on a commit hook function returns non-zero, 6133 ** then the commit is converted into a rollback. 6134 ** 6135 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 6136 ** return the P argument from the previous call of the same function 6137 ** on the same [database connection] D, or NULL for 6138 ** the first call for each function on D. 6139 ** 6140 ** The commit and rollback hook callbacks are not reentrant. 6141 ** The callback implementation must not do anything that will modify 6142 ** the database connection that invoked the callback. Any actions 6143 ** to modify the database connection must be deferred until after the 6144 ** completion of the [sqlite3_step()] call that triggered the commit 6145 ** or rollback hook in the first place. 6146 ** Note that running any other SQL statements, including SELECT statements, 6147 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 6148 ** the database connections for the meaning of "modify" in this paragraph. 6149 ** 6150 ** ^Registering a NULL function disables the callback. 6151 ** 6152 ** ^When the commit hook callback routine returns zero, the [COMMIT] 6153 ** operation is allowed to continue normally. ^If the commit hook 6154 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 6155 ** ^The rollback hook is invoked on a rollback that results from a commit 6156 ** hook returning non-zero, just as it would be with any other rollback. 6157 ** 6158 ** ^For the purposes of this API, a transaction is said to have been 6159 ** rolled back if an explicit "ROLLBACK" statement is executed, or 6160 ** an error or constraint causes an implicit rollback to occur. 6161 ** ^The rollback callback is not invoked if a transaction is 6162 ** automatically rolled back because the database connection is closed. 6163 ** 6164 ** See also the [sqlite3_update_hook()] interface. 6165 */ 6166 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 6167 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 6168 6169 /* 6170 ** CAPI3REF: Data Change Notification Callbacks 6171 ** METHOD: sqlite3 6172 ** 6173 ** ^The sqlite3_update_hook() interface registers a callback function 6174 ** with the [database connection] identified by the first argument 6175 ** to be invoked whenever a row is updated, inserted or deleted in 6176 ** a [rowid table]. 6177 ** ^Any callback set by a previous call to this function 6178 ** for the same database connection is overridden. 6179 ** 6180 ** ^The second argument is a pointer to the function to invoke when a 6181 ** row is updated, inserted or deleted in a rowid table. 6182 ** ^The first argument to the callback is a copy of the third argument 6183 ** to sqlite3_update_hook(). 6184 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 6185 ** or [SQLITE_UPDATE], depending on the operation that caused the callback 6186 ** to be invoked. 6187 ** ^The third and fourth arguments to the callback contain pointers to the 6188 ** database and table name containing the affected row. 6189 ** ^The final callback parameter is the [rowid] of the row. 6190 ** ^In the case of an update, this is the [rowid] after the update takes place. 6191 ** 6192 ** ^(The update hook is not invoked when internal system tables are 6193 ** modified (i.e. sqlite_master and sqlite_sequence).)^ 6194 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 6195 ** 6196 ** ^In the current implementation, the update hook 6197 ** is not invoked when conflicting rows are deleted because of an 6198 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 6199 ** invoked when rows are deleted using the [truncate optimization]. 6200 ** The exceptions defined in this paragraph might change in a future 6201 ** release of SQLite. 6202 ** 6203 ** The update hook implementation must not do anything that will modify 6204 ** the database connection that invoked the update hook. Any actions 6205 ** to modify the database connection must be deferred until after the 6206 ** completion of the [sqlite3_step()] call that triggered the update hook. 6207 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 6208 ** database connections for the meaning of "modify" in this paragraph. 6209 ** 6210 ** ^The sqlite3_update_hook(D,C,P) function 6211 ** returns the P argument from the previous call 6212 ** on the same [database connection] D, or NULL for 6213 ** the first call on D. 6214 ** 6215 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 6216 ** and [sqlite3_preupdate_hook()] interfaces. 6217 */ 6218 SQLITE_API void *sqlite3_update_hook( 6219 sqlite3*, 6220 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 6221 void* 6222 ); 6223 6224 /* 6225 ** CAPI3REF: Enable Or Disable Shared Pager Cache 6226 ** 6227 ** ^(This routine enables or disables the sharing of the database cache 6228 ** and schema data structures between [database connection | connections] 6229 ** to the same database. Sharing is enabled if the argument is true 6230 ** and disabled if the argument is false.)^ 6231 ** 6232 ** ^Cache sharing is enabled and disabled for an entire process. 6233 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 6234 ** In prior versions of SQLite, 6235 ** sharing was enabled or disabled for each thread separately. 6236 ** 6237 ** ^(The cache sharing mode set by this interface effects all subsequent 6238 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 6239 ** Existing database connections continue to use the sharing mode 6240 ** that was in effect at the time they were opened.)^ 6241 ** 6242 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 6243 ** successfully. An [error code] is returned otherwise.)^ 6244 ** 6245 ** ^Shared cache is disabled by default. It is recommended that it stay 6246 ** that way. In other words, do not use this routine. This interface 6247 ** continues to be provided for historical compatibility, but its use is 6248 ** discouraged. Any use of shared cache is discouraged. If shared cache 6249 ** must be used, it is recommended that shared cache only be enabled for 6250 ** individual database connections using the [sqlite3_open_v2()] interface 6251 ** with the [SQLITE_OPEN_SHAREDCACHE] flag. 6252 ** 6253 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 6254 ** and will always return SQLITE_MISUSE. On those systems, 6255 ** shared cache mode should be enabled per-database connection via 6256 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 6257 ** 6258 ** This interface is threadsafe on processors where writing a 6259 ** 32-bit integer is atomic. 6260 ** 6261 ** See Also: [SQLite Shared-Cache Mode] 6262 */ 6263 SQLITE_API int sqlite3_enable_shared_cache(int); 6264 6265 /* 6266 ** CAPI3REF: Attempt To Free Heap Memory 6267 ** 6268 ** ^The sqlite3_release_memory() interface attempts to free N bytes 6269 ** of heap memory by deallocating non-essential memory allocations 6270 ** held by the database library. Memory used to cache database 6271 ** pages to improve performance is an example of non-essential memory. 6272 ** ^sqlite3_release_memory() returns the number of bytes actually freed, 6273 ** which might be more or less than the amount requested. 6274 ** ^The sqlite3_release_memory() routine is a no-op returning zero 6275 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 6276 ** 6277 ** See also: [sqlite3_db_release_memory()] 6278 */ 6279 SQLITE_API int sqlite3_release_memory(int); 6280 6281 /* 6282 ** CAPI3REF: Free Memory Used By A Database Connection 6283 ** METHOD: sqlite3 6284 ** 6285 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 6286 ** memory as possible from database connection D. Unlike the 6287 ** [sqlite3_release_memory()] interface, this interface is in effect even 6288 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 6289 ** omitted. 6290 ** 6291 ** See also: [sqlite3_release_memory()] 6292 */ 6293 SQLITE_API int sqlite3_db_release_memory(sqlite3*); 6294 6295 /* 6296 ** CAPI3REF: Impose A Limit On Heap Size 6297 ** 6298 ** These interfaces impose limits on the amount of heap memory that will be 6299 ** by all database connections within a single process. 6300 ** 6301 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 6302 ** soft limit on the amount of heap memory that may be allocated by SQLite. 6303 ** ^SQLite strives to keep heap memory utilization below the soft heap 6304 ** limit by reducing the number of pages held in the page cache 6305 ** as heap memory usages approaches the limit. 6306 ** ^The soft heap limit is "soft" because even though SQLite strives to stay 6307 ** below the limit, it will exceed the limit rather than generate 6308 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 6309 ** is advisory only. 6310 ** 6311 ** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of 6312 ** N bytes on the amount of memory that will be allocated. ^The 6313 ** sqlite3_hard_heap_limit64(N) interface is similar to 6314 ** sqlite3_soft_heap_limit64(N) except that memory allocations will fail 6315 ** when the hard heap limit is reached. 6316 ** 6317 ** ^The return value from both sqlite3_soft_heap_limit64() and 6318 ** sqlite3_hard_heap_limit64() is the size of 6319 ** the heap limit prior to the call, or negative in the case of an 6320 ** error. ^If the argument N is negative 6321 ** then no change is made to the heap limit. Hence, the current 6322 ** size of heap limits can be determined by invoking 6323 ** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1). 6324 ** 6325 ** ^Setting the heap limits to zero disables the heap limiter mechanism. 6326 ** 6327 ** ^The soft heap limit may not be greater than the hard heap limit. 6328 ** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N) 6329 ** is invoked with a value of N that is greater than the hard heap limit, 6330 ** the the soft heap limit is set to the value of the hard heap limit. 6331 ** ^The soft heap limit is automatically enabled whenever the hard heap 6332 ** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and 6333 ** the soft heap limit is outside the range of 1..N, then the soft heap 6334 ** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the 6335 ** hard heap limit is enabled makes the soft heap limit equal to the 6336 ** hard heap limit. 6337 ** 6338 ** The memory allocation limits can also be adjusted using 6339 ** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit]. 6340 ** 6341 ** ^(The heap limits are not enforced in the current implementation 6342 ** if one or more of following conditions are true: 6343 ** 6344 ** <ul> 6345 ** <li> The limit value is set to zero. 6346 ** <li> Memory accounting is disabled using a combination of the 6347 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 6348 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 6349 ** <li> An alternative page cache implementation is specified using 6350 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 6351 ** <li> The page cache allocates from its own memory pool supplied 6352 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 6353 ** from the heap. 6354 ** </ul>)^ 6355 ** 6356 ** The circumstances under which SQLite will enforce the heap limits may 6357 ** changes in future releases of SQLite. 6358 */ 6359 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 6360 SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N); 6361 6362 /* 6363 ** CAPI3REF: Deprecated Soft Heap Limit Interface 6364 ** DEPRECATED 6365 ** 6366 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 6367 ** interface. This routine is provided for historical compatibility 6368 ** only. All new applications should use the 6369 ** [sqlite3_soft_heap_limit64()] interface rather than this one. 6370 */ 6371 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 6372 6373 6374 /* 6375 ** CAPI3REF: Extract Metadata About A Column Of A Table 6376 ** METHOD: sqlite3 6377 ** 6378 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 6379 ** information about column C of table T in database D 6380 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 6381 ** interface returns SQLITE_OK and fills in the non-NULL pointers in 6382 ** the final five arguments with appropriate values if the specified 6383 ** column exists. ^The sqlite3_table_column_metadata() interface returns 6384 ** SQLITE_ERROR if the specified column does not exist. 6385 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a 6386 ** NULL pointer, then this routine simply checks for the existence of the 6387 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 6388 ** does not. If the table name parameter T in a call to 6389 ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 6390 ** undefined behavior. 6391 ** 6392 ** ^The column is identified by the second, third and fourth parameters to 6393 ** this function. ^(The second parameter is either the name of the database 6394 ** (i.e. "main", "temp", or an attached database) containing the specified 6395 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched 6396 ** for the table using the same algorithm used by the database engine to 6397 ** resolve unqualified table references. 6398 ** 6399 ** ^The third and fourth parameters to this function are the table and column 6400 ** name of the desired column, respectively. 6401 ** 6402 ** ^Metadata is returned by writing to the memory locations passed as the 5th 6403 ** and subsequent parameters to this function. ^Any of these arguments may be 6404 ** NULL, in which case the corresponding element of metadata is omitted. 6405 ** 6406 ** ^(<blockquote> 6407 ** <table border="1"> 6408 ** <tr><th> Parameter <th> Output<br>Type <th> Description 6409 ** 6410 ** <tr><td> 5th <td> const char* <td> Data type 6411 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 6412 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 6413 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 6414 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 6415 ** </table> 6416 ** </blockquote>)^ 6417 ** 6418 ** ^The memory pointed to by the character pointers returned for the 6419 ** declaration type and collation sequence is valid until the next 6420 ** call to any SQLite API function. 6421 ** 6422 ** ^If the specified table is actually a view, an [error code] is returned. 6423 ** 6424 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 6425 ** is not a [WITHOUT ROWID] table and an 6426 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 6427 ** parameters are set for the explicitly declared column. ^(If there is no 6428 ** [INTEGER PRIMARY KEY] column, then the outputs 6429 ** for the [rowid] are set as follows: 6430 ** 6431 ** <pre> 6432 ** data type: "INTEGER" 6433 ** collation sequence: "BINARY" 6434 ** not null: 0 6435 ** primary key: 1 6436 ** auto increment: 0 6437 ** </pre>)^ 6438 ** 6439 ** ^This function causes all database schemas to be read from disk and 6440 ** parsed, if that has not already been done, and returns an error if 6441 ** any errors are encountered while loading the schema. 6442 */ 6443 SQLITE_API int sqlite3_table_column_metadata( 6444 sqlite3 *db, /* Connection handle */ 6445 const char *zDbName, /* Database name or NULL */ 6446 const char *zTableName, /* Table name */ 6447 const char *zColumnName, /* Column name */ 6448 char const **pzDataType, /* OUTPUT: Declared data type */ 6449 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 6450 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 6451 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 6452 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 6453 ); 6454 6455 /* 6456 ** CAPI3REF: Load An Extension 6457 ** METHOD: sqlite3 6458 ** 6459 ** ^This interface loads an SQLite extension library from the named file. 6460 ** 6461 ** ^The sqlite3_load_extension() interface attempts to load an 6462 ** [SQLite extension] library contained in the file zFile. If 6463 ** the file cannot be loaded directly, attempts are made to load 6464 ** with various operating-system specific extensions added. 6465 ** So for example, if "samplelib" cannot be loaded, then names like 6466 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 6467 ** be tried also. 6468 ** 6469 ** ^The entry point is zProc. 6470 ** ^(zProc may be 0, in which case SQLite will try to come up with an 6471 ** entry point name on its own. It first tries "sqlite3_extension_init". 6472 ** If that does not work, it constructs a name "sqlite3_X_init" where the 6473 ** X is consists of the lower-case equivalent of all ASCII alphabetic 6474 ** characters in the filename from the last "/" to the first following 6475 ** "." and omitting any initial "lib".)^ 6476 ** ^The sqlite3_load_extension() interface returns 6477 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 6478 ** ^If an error occurs and pzErrMsg is not 0, then the 6479 ** [sqlite3_load_extension()] interface shall attempt to 6480 ** fill *pzErrMsg with error message text stored in memory 6481 ** obtained from [sqlite3_malloc()]. The calling function 6482 ** should free this memory by calling [sqlite3_free()]. 6483 ** 6484 ** ^Extension loading must be enabled using 6485 ** [sqlite3_enable_load_extension()] or 6486 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 6487 ** prior to calling this API, 6488 ** otherwise an error will be returned. 6489 ** 6490 ** <b>Security warning:</b> It is recommended that the 6491 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 6492 ** interface. The use of the [sqlite3_enable_load_extension()] interface 6493 ** should be avoided. This will keep the SQL function [load_extension()] 6494 ** disabled and prevent SQL injections from giving attackers 6495 ** access to extension loading capabilities. 6496 ** 6497 ** See also the [load_extension() SQL function]. 6498 */ 6499 SQLITE_API int sqlite3_load_extension( 6500 sqlite3 *db, /* Load the extension into this database connection */ 6501 const char *zFile, /* Name of the shared library containing extension */ 6502 const char *zProc, /* Entry point. Derived from zFile if 0 */ 6503 char **pzErrMsg /* Put error message here if not 0 */ 6504 ); 6505 6506 /* 6507 ** CAPI3REF: Enable Or Disable Extension Loading 6508 ** METHOD: sqlite3 6509 ** 6510 ** ^So as not to open security holes in older applications that are 6511 ** unprepared to deal with [extension loading], and as a means of disabling 6512 ** [extension loading] while evaluating user-entered SQL, the following API 6513 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 6514 ** 6515 ** ^Extension loading is off by default. 6516 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 6517 ** to turn extension loading on and call it with onoff==0 to turn 6518 ** it back off again. 6519 ** 6520 ** ^This interface enables or disables both the C-API 6521 ** [sqlite3_load_extension()] and the SQL function [load_extension()]. 6522 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 6523 ** to enable or disable only the C-API.)^ 6524 ** 6525 ** <b>Security warning:</b> It is recommended that extension loading 6526 ** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 6527 ** rather than this interface, so the [load_extension()] SQL function 6528 ** remains disabled. This will prevent SQL injections from giving attackers 6529 ** access to extension loading capabilities. 6530 */ 6531 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 6532 6533 /* 6534 ** CAPI3REF: Automatically Load Statically Linked Extensions 6535 ** 6536 ** ^This interface causes the xEntryPoint() function to be invoked for 6537 ** each new [database connection] that is created. The idea here is that 6538 ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 6539 ** that is to be automatically loaded into all new database connections. 6540 ** 6541 ** ^(Even though the function prototype shows that xEntryPoint() takes 6542 ** no arguments and returns void, SQLite invokes xEntryPoint() with three 6543 ** arguments and expects an integer result as if the signature of the 6544 ** entry point where as follows: 6545 ** 6546 ** <blockquote><pre> 6547 ** int xEntryPoint( 6548 ** sqlite3 *db, 6549 ** const char **pzErrMsg, 6550 ** const struct sqlite3_api_routines *pThunk 6551 ** ); 6552 ** </pre></blockquote>)^ 6553 ** 6554 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 6555 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 6556 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 6557 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 6558 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 6559 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 6560 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 6561 ** 6562 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 6563 ** on the list of automatic extensions is a harmless no-op. ^No entry point 6564 ** will be called more than once for each database connection that is opened. 6565 ** 6566 ** See also: [sqlite3_reset_auto_extension()] 6567 ** and [sqlite3_cancel_auto_extension()] 6568 */ 6569 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void)); 6570 6571 /* 6572 ** CAPI3REF: Cancel Automatic Extension Loading 6573 ** 6574 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 6575 ** initialization routine X that was registered using a prior call to 6576 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 6577 ** routine returns 1 if initialization routine X was successfully 6578 ** unregistered and it returns 0 if X was not on the list of initialization 6579 ** routines. 6580 */ 6581 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 6582 6583 /* 6584 ** CAPI3REF: Reset Automatic Extension Loading 6585 ** 6586 ** ^This interface disables all automatic extensions previously 6587 ** registered using [sqlite3_auto_extension()]. 6588 */ 6589 SQLITE_API void sqlite3_reset_auto_extension(void); 6590 6591 /* 6592 ** The interface to the virtual-table mechanism is currently considered 6593 ** to be experimental. The interface might change in incompatible ways. 6594 ** If this is a problem for you, do not use the interface at this time. 6595 ** 6596 ** When the virtual-table mechanism stabilizes, we will declare the 6597 ** interface fixed, support it indefinitely, and remove this comment. 6598 */ 6599 6600 /* 6601 ** Structures used by the virtual table interface 6602 */ 6603 typedef struct sqlite3_vtab sqlite3_vtab; 6604 typedef struct sqlite3_index_info sqlite3_index_info; 6605 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 6606 typedef struct sqlite3_module sqlite3_module; 6607 6608 /* 6609 ** CAPI3REF: Virtual Table Object 6610 ** KEYWORDS: sqlite3_module {virtual table module} 6611 ** 6612 ** This structure, sometimes called a "virtual table module", 6613 ** defines the implementation of a [virtual table]. 6614 ** This structure consists mostly of methods for the module. 6615 ** 6616 ** ^A virtual table module is created by filling in a persistent 6617 ** instance of this structure and passing a pointer to that instance 6618 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 6619 ** ^The registration remains valid until it is replaced by a different 6620 ** module or until the [database connection] closes. The content 6621 ** of this structure must not change while it is registered with 6622 ** any database connection. 6623 */ 6624 struct sqlite3_module { 6625 int iVersion; 6626 int (*xCreate)(sqlite3*, void *pAux, 6627 int argc, const char *const*argv, 6628 sqlite3_vtab **ppVTab, char**); 6629 int (*xConnect)(sqlite3*, void *pAux, 6630 int argc, const char *const*argv, 6631 sqlite3_vtab **ppVTab, char**); 6632 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 6633 int (*xDisconnect)(sqlite3_vtab *pVTab); 6634 int (*xDestroy)(sqlite3_vtab *pVTab); 6635 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 6636 int (*xClose)(sqlite3_vtab_cursor*); 6637 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 6638 int argc, sqlite3_value **argv); 6639 int (*xNext)(sqlite3_vtab_cursor*); 6640 int (*xEof)(sqlite3_vtab_cursor*); 6641 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 6642 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 6643 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 6644 int (*xBegin)(sqlite3_vtab *pVTab); 6645 int (*xSync)(sqlite3_vtab *pVTab); 6646 int (*xCommit)(sqlite3_vtab *pVTab); 6647 int (*xRollback)(sqlite3_vtab *pVTab); 6648 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 6649 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 6650 void **ppArg); 6651 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 6652 /* The methods above are in version 1 of the sqlite_module object. Those 6653 ** below are for version 2 and greater. */ 6654 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 6655 int (*xRelease)(sqlite3_vtab *pVTab, int); 6656 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 6657 /* The methods above are in versions 1 and 2 of the sqlite_module object. 6658 ** Those below are for version 3 and greater. */ 6659 int (*xShadowName)(const char*); 6660 }; 6661 6662 /* 6663 ** CAPI3REF: Virtual Table Indexing Information 6664 ** KEYWORDS: sqlite3_index_info 6665 ** 6666 ** The sqlite3_index_info structure and its substructures is used as part 6667 ** of the [virtual table] interface to 6668 ** pass information into and receive the reply from the [xBestIndex] 6669 ** method of a [virtual table module]. The fields under **Inputs** are the 6670 ** inputs to xBestIndex and are read-only. xBestIndex inserts its 6671 ** results into the **Outputs** fields. 6672 ** 6673 ** ^(The aConstraint[] array records WHERE clause constraints of the form: 6674 ** 6675 ** <blockquote>column OP expr</blockquote> 6676 ** 6677 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 6678 ** stored in aConstraint[].op using one of the 6679 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 6680 ** ^(The index of the column is stored in 6681 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 6682 ** expr on the right-hand side can be evaluated (and thus the constraint 6683 ** is usable) and false if it cannot.)^ 6684 ** 6685 ** ^The optimizer automatically inverts terms of the form "expr OP column" 6686 ** and makes other simplifications to the WHERE clause in an attempt to 6687 ** get as many WHERE clause terms into the form shown above as possible. 6688 ** ^The aConstraint[] array only reports WHERE clause terms that are 6689 ** relevant to the particular virtual table being queried. 6690 ** 6691 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 6692 ** ^Each term of aOrderBy records a column of the ORDER BY clause. 6693 ** 6694 ** The colUsed field indicates which columns of the virtual table may be 6695 ** required by the current scan. Virtual table columns are numbered from 6696 ** zero in the order in which they appear within the CREATE TABLE statement 6697 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 6698 ** the corresponding bit is set within the colUsed mask if the column may be 6699 ** required by SQLite. If the table has at least 64 columns and any column 6700 ** to the right of the first 63 is required, then bit 63 of colUsed is also 6701 ** set. In other words, column iCol may be required if the expression 6702 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 6703 ** non-zero. 6704 ** 6705 ** The [xBestIndex] method must fill aConstraintUsage[] with information 6706 ** about what parameters to pass to xFilter. ^If argvIndex>0 then 6707 ** the right-hand side of the corresponding aConstraint[] is evaluated 6708 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 6709 ** is true, then the constraint is assumed to be fully handled by the 6710 ** virtual table and might not be checked again by the byte code.)^ ^(The 6711 ** aConstraintUsage[].omit flag is an optimization hint. When the omit flag 6712 ** is left in its default setting of false, the constraint will always be 6713 ** checked separately in byte code. If the omit flag is change to true, then 6714 ** the constraint may or may not be checked in byte code. In other words, 6715 ** when the omit flag is true there is no guarantee that the constraint will 6716 ** not be checked again using byte code.)^ 6717 ** 6718 ** ^The idxNum and idxPtr values are recorded and passed into the 6719 ** [xFilter] method. 6720 ** ^[sqlite3_free()] is used to free idxPtr if and only if 6721 ** needToFreeIdxPtr is true. 6722 ** 6723 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 6724 ** the correct order to satisfy the ORDER BY clause so that no separate 6725 ** sorting step is required. 6726 ** 6727 ** ^The estimatedCost value is an estimate of the cost of a particular 6728 ** strategy. A cost of N indicates that the cost of the strategy is similar 6729 ** to a linear scan of an SQLite table with N rows. A cost of log(N) 6730 ** indicates that the expense of the operation is similar to that of a 6731 ** binary search on a unique indexed field of an SQLite table with N rows. 6732 ** 6733 ** ^The estimatedRows value is an estimate of the number of rows that 6734 ** will be returned by the strategy. 6735 ** 6736 ** The xBestIndex method may optionally populate the idxFlags field with a 6737 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 6738 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 6739 ** assumes that the strategy may visit at most one row. 6740 ** 6741 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 6742 ** SQLite also assumes that if a call to the xUpdate() method is made as 6743 ** part of the same statement to delete or update a virtual table row and the 6744 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 6745 ** any database changes. In other words, if the xUpdate() returns 6746 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were 6747 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 6748 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 6749 ** the xUpdate method are automatically rolled back by SQLite. 6750 ** 6751 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 6752 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 6753 ** If a virtual table extension is 6754 ** used with an SQLite version earlier than 3.8.2, the results of attempting 6755 ** to read or write the estimatedRows field are undefined (but are likely 6756 ** to include crashing the application). The estimatedRows field should 6757 ** therefore only be used if [sqlite3_libversion_number()] returns a 6758 ** value greater than or equal to 3008002. Similarly, the idxFlags field 6759 ** was added for [version 3.9.0] ([dateof:3.9.0]). 6760 ** It may therefore only be used if 6761 ** sqlite3_libversion_number() returns a value greater than or equal to 6762 ** 3009000. 6763 */ 6764 struct sqlite3_index_info { 6765 /* Inputs */ 6766 int nConstraint; /* Number of entries in aConstraint */ 6767 struct sqlite3_index_constraint { 6768 int iColumn; /* Column constrained. -1 for ROWID */ 6769 unsigned char op; /* Constraint operator */ 6770 unsigned char usable; /* True if this constraint is usable */ 6771 int iTermOffset; /* Used internally - xBestIndex should ignore */ 6772 } *aConstraint; /* Table of WHERE clause constraints */ 6773 int nOrderBy; /* Number of terms in the ORDER BY clause */ 6774 struct sqlite3_index_orderby { 6775 int iColumn; /* Column number */ 6776 unsigned char desc; /* True for DESC. False for ASC. */ 6777 } *aOrderBy; /* The ORDER BY clause */ 6778 /* Outputs */ 6779 struct sqlite3_index_constraint_usage { 6780 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 6781 unsigned char omit; /* Do not code a test for this constraint */ 6782 } *aConstraintUsage; 6783 int idxNum; /* Number used to identify the index */ 6784 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 6785 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 6786 int orderByConsumed; /* True if output is already ordered */ 6787 double estimatedCost; /* Estimated cost of using this index */ 6788 /* Fields below are only available in SQLite 3.8.2 and later */ 6789 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 6790 /* Fields below are only available in SQLite 3.9.0 and later */ 6791 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 6792 /* Fields below are only available in SQLite 3.10.0 and later */ 6793 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 6794 }; 6795 6796 /* 6797 ** CAPI3REF: Virtual Table Scan Flags 6798 ** 6799 ** Virtual table implementations are allowed to set the 6800 ** [sqlite3_index_info].idxFlags field to some combination of 6801 ** these bits. 6802 */ 6803 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 6804 6805 /* 6806 ** CAPI3REF: Virtual Table Constraint Operator Codes 6807 ** 6808 ** These macros define the allowed values for the 6809 ** [sqlite3_index_info].aConstraint[].op field. Each value represents 6810 ** an operator that is part of a constraint term in the wHERE clause of 6811 ** a query that uses a [virtual table]. 6812 */ 6813 #define SQLITE_INDEX_CONSTRAINT_EQ 2 6814 #define SQLITE_INDEX_CONSTRAINT_GT 4 6815 #define SQLITE_INDEX_CONSTRAINT_LE 8 6816 #define SQLITE_INDEX_CONSTRAINT_LT 16 6817 #define SQLITE_INDEX_CONSTRAINT_GE 32 6818 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 6819 #define SQLITE_INDEX_CONSTRAINT_LIKE 65 6820 #define SQLITE_INDEX_CONSTRAINT_GLOB 66 6821 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67 6822 #define SQLITE_INDEX_CONSTRAINT_NE 68 6823 #define SQLITE_INDEX_CONSTRAINT_ISNOT 69 6824 #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 6825 #define SQLITE_INDEX_CONSTRAINT_ISNULL 71 6826 #define SQLITE_INDEX_CONSTRAINT_IS 72 6827 #define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 6828 6829 /* 6830 ** CAPI3REF: Register A Virtual Table Implementation 6831 ** METHOD: sqlite3 6832 ** 6833 ** ^These routines are used to register a new [virtual table module] name. 6834 ** ^Module names must be registered before 6835 ** creating a new [virtual table] using the module and before using a 6836 ** preexisting [virtual table] for the module. 6837 ** 6838 ** ^The module name is registered on the [database connection] specified 6839 ** by the first parameter. ^The name of the module is given by the 6840 ** second parameter. ^The third parameter is a pointer to 6841 ** the implementation of the [virtual table module]. ^The fourth 6842 ** parameter is an arbitrary client data pointer that is passed through 6843 ** into the [xCreate] and [xConnect] methods of the virtual table module 6844 ** when a new virtual table is be being created or reinitialized. 6845 ** 6846 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 6847 ** is a pointer to a destructor for the pClientData. ^SQLite will 6848 ** invoke the destructor function (if it is not NULL) when SQLite 6849 ** no longer needs the pClientData pointer. ^The destructor will also 6850 ** be invoked if the call to sqlite3_create_module_v2() fails. 6851 ** ^The sqlite3_create_module() 6852 ** interface is equivalent to sqlite3_create_module_v2() with a NULL 6853 ** destructor. 6854 ** 6855 ** ^If the third parameter (the pointer to the sqlite3_module object) is 6856 ** NULL then no new module is create and any existing modules with the 6857 ** same name are dropped. 6858 ** 6859 ** See also: [sqlite3_drop_modules()] 6860 */ 6861 SQLITE_API int sqlite3_create_module( 6862 sqlite3 *db, /* SQLite connection to register module with */ 6863 const char *zName, /* Name of the module */ 6864 const sqlite3_module *p, /* Methods for the module */ 6865 void *pClientData /* Client data for xCreate/xConnect */ 6866 ); 6867 SQLITE_API int sqlite3_create_module_v2( 6868 sqlite3 *db, /* SQLite connection to register module with */ 6869 const char *zName, /* Name of the module */ 6870 const sqlite3_module *p, /* Methods for the module */ 6871 void *pClientData, /* Client data for xCreate/xConnect */ 6872 void(*xDestroy)(void*) /* Module destructor function */ 6873 ); 6874 6875 /* 6876 ** CAPI3REF: Remove Unnecessary Virtual Table Implementations 6877 ** METHOD: sqlite3 6878 ** 6879 ** ^The sqlite3_drop_modules(D,L) interface removes all virtual 6880 ** table modules from database connection D except those named on list L. 6881 ** The L parameter must be either NULL or a pointer to an array of pointers 6882 ** to strings where the array is terminated by a single NULL pointer. 6883 ** ^If the L parameter is NULL, then all virtual table modules are removed. 6884 ** 6885 ** See also: [sqlite3_create_module()] 6886 */ 6887 SQLITE_API int sqlite3_drop_modules( 6888 sqlite3 *db, /* Remove modules from this connection */ 6889 const char **azKeep /* Except, do not remove the ones named here */ 6890 ); 6891 6892 /* 6893 ** CAPI3REF: Virtual Table Instance Object 6894 ** KEYWORDS: sqlite3_vtab 6895 ** 6896 ** Every [virtual table module] implementation uses a subclass 6897 ** of this object to describe a particular instance 6898 ** of the [virtual table]. Each subclass will 6899 ** be tailored to the specific needs of the module implementation. 6900 ** The purpose of this superclass is to define certain fields that are 6901 ** common to all module implementations. 6902 ** 6903 ** ^Virtual tables methods can set an error message by assigning a 6904 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 6905 ** take care that any prior string is freed by a call to [sqlite3_free()] 6906 ** prior to assigning a new string to zErrMsg. ^After the error message 6907 ** is delivered up to the client application, the string will be automatically 6908 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 6909 */ 6910 struct sqlite3_vtab { 6911 const sqlite3_module *pModule; /* The module for this virtual table */ 6912 int nRef; /* Number of open cursors */ 6913 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 6914 /* Virtual table implementations will typically add additional fields */ 6915 }; 6916 6917 /* 6918 ** CAPI3REF: Virtual Table Cursor Object 6919 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 6920 ** 6921 ** Every [virtual table module] implementation uses a subclass of the 6922 ** following structure to describe cursors that point into the 6923 ** [virtual table] and are used 6924 ** to loop through the virtual table. Cursors are created using the 6925 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 6926 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 6927 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 6928 ** of the module. Each module implementation will define 6929 ** the content of a cursor structure to suit its own needs. 6930 ** 6931 ** This superclass exists in order to define fields of the cursor that 6932 ** are common to all implementations. 6933 */ 6934 struct sqlite3_vtab_cursor { 6935 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 6936 /* Virtual table implementations will typically add additional fields */ 6937 }; 6938 6939 /* 6940 ** CAPI3REF: Declare The Schema Of A Virtual Table 6941 ** 6942 ** ^The [xCreate] and [xConnect] methods of a 6943 ** [virtual table module] call this interface 6944 ** to declare the format (the names and datatypes of the columns) of 6945 ** the virtual tables they implement. 6946 */ 6947 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 6948 6949 /* 6950 ** CAPI3REF: Overload A Function For A Virtual Table 6951 ** METHOD: sqlite3 6952 ** 6953 ** ^(Virtual tables can provide alternative implementations of functions 6954 ** using the [xFindFunction] method of the [virtual table module]. 6955 ** But global versions of those functions 6956 ** must exist in order to be overloaded.)^ 6957 ** 6958 ** ^(This API makes sure a global version of a function with a particular 6959 ** name and number of parameters exists. If no such function exists 6960 ** before this API is called, a new function is created.)^ ^The implementation 6961 ** of the new function always causes an exception to be thrown. So 6962 ** the new function is not good for anything by itself. Its only 6963 ** purpose is to be a placeholder function that can be overloaded 6964 ** by a [virtual table]. 6965 */ 6966 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 6967 6968 /* 6969 ** The interface to the virtual-table mechanism defined above (back up 6970 ** to a comment remarkably similar to this one) is currently considered 6971 ** to be experimental. The interface might change in incompatible ways. 6972 ** If this is a problem for you, do not use the interface at this time. 6973 ** 6974 ** When the virtual-table mechanism stabilizes, we will declare the 6975 ** interface fixed, support it indefinitely, and remove this comment. 6976 */ 6977 6978 /* 6979 ** CAPI3REF: A Handle To An Open BLOB 6980 ** KEYWORDS: {BLOB handle} {BLOB handles} 6981 ** 6982 ** An instance of this object represents an open BLOB on which 6983 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 6984 ** ^Objects of this type are created by [sqlite3_blob_open()] 6985 ** and destroyed by [sqlite3_blob_close()]. 6986 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 6987 ** can be used to read or write small subsections of the BLOB. 6988 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 6989 */ 6990 typedef struct sqlite3_blob sqlite3_blob; 6991 6992 /* 6993 ** CAPI3REF: Open A BLOB For Incremental I/O 6994 ** METHOD: sqlite3 6995 ** CONSTRUCTOR: sqlite3_blob 6996 ** 6997 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 6998 ** in row iRow, column zColumn, table zTable in database zDb; 6999 ** in other words, the same BLOB that would be selected by: 7000 ** 7001 ** <pre> 7002 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 7003 ** </pre>)^ 7004 ** 7005 ** ^(Parameter zDb is not the filename that contains the database, but 7006 ** rather the symbolic name of the database. For attached databases, this is 7007 ** the name that appears after the AS keyword in the [ATTACH] statement. 7008 ** For the main database file, the database name is "main". For TEMP 7009 ** tables, the database name is "temp".)^ 7010 ** 7011 ** ^If the flags parameter is non-zero, then the BLOB is opened for read 7012 ** and write access. ^If the flags parameter is zero, the BLOB is opened for 7013 ** read-only access. 7014 ** 7015 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 7016 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error 7017 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 7018 ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 7019 ** on *ppBlob after this function it returns. 7020 ** 7021 ** This function fails with SQLITE_ERROR if any of the following are true: 7022 ** <ul> 7023 ** <li> ^(Database zDb does not exist)^, 7024 ** <li> ^(Table zTable does not exist within database zDb)^, 7025 ** <li> ^(Table zTable is a WITHOUT ROWID table)^, 7026 ** <li> ^(Column zColumn does not exist)^, 7027 ** <li> ^(Row iRow is not present in the table)^, 7028 ** <li> ^(The specified column of row iRow contains a value that is not 7029 ** a TEXT or BLOB value)^, 7030 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 7031 ** constraint and the blob is being opened for read/write access)^, 7032 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 7033 ** column zColumn is part of a [child key] definition and the blob is 7034 ** being opened for read/write access)^. 7035 ** </ul> 7036 ** 7037 ** ^Unless it returns SQLITE_MISUSE, this function sets the 7038 ** [database connection] error code and message accessible via 7039 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7040 ** 7041 ** A BLOB referenced by sqlite3_blob_open() may be read using the 7042 ** [sqlite3_blob_read()] interface and modified by using 7043 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 7044 ** different row of the same table using the [sqlite3_blob_reopen()] 7045 ** interface. However, the column, table, or database of a [BLOB handle] 7046 ** cannot be changed after the [BLOB handle] is opened. 7047 ** 7048 ** ^(If the row that a BLOB handle points to is modified by an 7049 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 7050 ** then the BLOB handle is marked as "expired". 7051 ** This is true if any column of the row is changed, even a column 7052 ** other than the one the BLOB handle is open on.)^ 7053 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 7054 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 7055 ** ^(Changes written into a BLOB prior to the BLOB expiring are not 7056 ** rolled back by the expiration of the BLOB. Such changes will eventually 7057 ** commit if the transaction continues to completion.)^ 7058 ** 7059 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 7060 ** the opened blob. ^The size of a blob may not be changed by this 7061 ** interface. Use the [UPDATE] SQL command to change the size of a 7062 ** blob. 7063 ** 7064 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 7065 ** and the built-in [zeroblob] SQL function may be used to create a 7066 ** zero-filled blob to read or write using the incremental-blob interface. 7067 ** 7068 ** To avoid a resource leak, every open [BLOB handle] should eventually 7069 ** be released by a call to [sqlite3_blob_close()]. 7070 ** 7071 ** See also: [sqlite3_blob_close()], 7072 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 7073 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 7074 */ 7075 SQLITE_API int sqlite3_blob_open( 7076 sqlite3*, 7077 const char *zDb, 7078 const char *zTable, 7079 const char *zColumn, 7080 sqlite3_int64 iRow, 7081 int flags, 7082 sqlite3_blob **ppBlob 7083 ); 7084 7085 /* 7086 ** CAPI3REF: Move a BLOB Handle to a New Row 7087 ** METHOD: sqlite3_blob 7088 ** 7089 ** ^This function is used to move an existing [BLOB handle] so that it points 7090 ** to a different row of the same database table. ^The new row is identified 7091 ** by the rowid value passed as the second argument. Only the row can be 7092 ** changed. ^The database, table and column on which the blob handle is open 7093 ** remain the same. Moving an existing [BLOB handle] to a new row is 7094 ** faster than closing the existing handle and opening a new one. 7095 ** 7096 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 7097 ** it must exist and there must be either a blob or text value stored in 7098 ** the nominated column.)^ ^If the new row is not present in the table, or if 7099 ** it does not contain a blob or text value, or if another error occurs, an 7100 ** SQLite error code is returned and the blob handle is considered aborted. 7101 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 7102 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 7103 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 7104 ** always returns zero. 7105 ** 7106 ** ^This function sets the database handle error code and message. 7107 */ 7108 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 7109 7110 /* 7111 ** CAPI3REF: Close A BLOB Handle 7112 ** DESTRUCTOR: sqlite3_blob 7113 ** 7114 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 7115 ** unconditionally. Even if this routine returns an error code, the 7116 ** handle is still closed.)^ 7117 ** 7118 ** ^If the blob handle being closed was opened for read-write access, and if 7119 ** the database is in auto-commit mode and there are no other open read-write 7120 ** blob handles or active write statements, the current transaction is 7121 ** committed. ^If an error occurs while committing the transaction, an error 7122 ** code is returned and the transaction rolled back. 7123 ** 7124 ** Calling this function with an argument that is not a NULL pointer or an 7125 ** open blob handle results in undefined behaviour. ^Calling this routine 7126 ** with a null pointer (such as would be returned by a failed call to 7127 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 7128 ** is passed a valid open blob handle, the values returned by the 7129 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 7130 */ 7131 SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 7132 7133 /* 7134 ** CAPI3REF: Return The Size Of An Open BLOB 7135 ** METHOD: sqlite3_blob 7136 ** 7137 ** ^Returns the size in bytes of the BLOB accessible via the 7138 ** successfully opened [BLOB handle] in its only argument. ^The 7139 ** incremental blob I/O routines can only read or overwriting existing 7140 ** blob content; they cannot change the size of a blob. 7141 ** 7142 ** This routine only works on a [BLOB handle] which has been created 7143 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7144 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7145 ** to this routine results in undefined and probably undesirable behavior. 7146 */ 7147 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 7148 7149 /* 7150 ** CAPI3REF: Read Data From A BLOB Incrementally 7151 ** METHOD: sqlite3_blob 7152 ** 7153 ** ^(This function is used to read data from an open [BLOB handle] into a 7154 ** caller-supplied buffer. N bytes of data are copied into buffer Z 7155 ** from the open BLOB, starting at offset iOffset.)^ 7156 ** 7157 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 7158 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 7159 ** less than zero, [SQLITE_ERROR] is returned and no data is read. 7160 ** ^The size of the blob (and hence the maximum value of N+iOffset) 7161 ** can be determined using the [sqlite3_blob_bytes()] interface. 7162 ** 7163 ** ^An attempt to read from an expired [BLOB handle] fails with an 7164 ** error code of [SQLITE_ABORT]. 7165 ** 7166 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 7167 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 7168 ** 7169 ** This routine only works on a [BLOB handle] which has been created 7170 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7171 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7172 ** to this routine results in undefined and probably undesirable behavior. 7173 ** 7174 ** See also: [sqlite3_blob_write()]. 7175 */ 7176 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 7177 7178 /* 7179 ** CAPI3REF: Write Data Into A BLOB Incrementally 7180 ** METHOD: sqlite3_blob 7181 ** 7182 ** ^(This function is used to write data into an open [BLOB handle] from a 7183 ** caller-supplied buffer. N bytes of data are copied from the buffer Z 7184 ** into the open BLOB, starting at offset iOffset.)^ 7185 ** 7186 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 7187 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 7188 ** ^Unless SQLITE_MISUSE is returned, this function sets the 7189 ** [database connection] error code and message accessible via 7190 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7191 ** 7192 ** ^If the [BLOB handle] passed as the first argument was not opened for 7193 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 7194 ** this function returns [SQLITE_READONLY]. 7195 ** 7196 ** This function may only modify the contents of the BLOB; it is 7197 ** not possible to increase the size of a BLOB using this API. 7198 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 7199 ** [SQLITE_ERROR] is returned and no data is written. The size of the 7200 ** BLOB (and hence the maximum value of N+iOffset) can be determined 7201 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 7202 ** than zero [SQLITE_ERROR] is returned and no data is written. 7203 ** 7204 ** ^An attempt to write to an expired [BLOB handle] fails with an 7205 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 7206 ** before the [BLOB handle] expired are not rolled back by the 7207 ** expiration of the handle, though of course those changes might 7208 ** have been overwritten by the statement that expired the BLOB handle 7209 ** or by other independent statements. 7210 ** 7211 ** This routine only works on a [BLOB handle] which has been created 7212 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7213 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7214 ** to this routine results in undefined and probably undesirable behavior. 7215 ** 7216 ** See also: [sqlite3_blob_read()]. 7217 */ 7218 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 7219 7220 /* 7221 ** CAPI3REF: Virtual File System Objects 7222 ** 7223 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 7224 ** that SQLite uses to interact 7225 ** with the underlying operating system. Most SQLite builds come with a 7226 ** single default VFS that is appropriate for the host computer. 7227 ** New VFSes can be registered and existing VFSes can be unregistered. 7228 ** The following interfaces are provided. 7229 ** 7230 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 7231 ** ^Names are case sensitive. 7232 ** ^Names are zero-terminated UTF-8 strings. 7233 ** ^If there is no match, a NULL pointer is returned. 7234 ** ^If zVfsName is NULL then the default VFS is returned. 7235 ** 7236 ** ^New VFSes are registered with sqlite3_vfs_register(). 7237 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 7238 ** ^The same VFS can be registered multiple times without injury. 7239 ** ^To make an existing VFS into the default VFS, register it again 7240 ** with the makeDflt flag set. If two different VFSes with the 7241 ** same name are registered, the behavior is undefined. If a 7242 ** VFS is registered with a name that is NULL or an empty string, 7243 ** then the behavior is undefined. 7244 ** 7245 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 7246 ** ^(If the default VFS is unregistered, another VFS is chosen as 7247 ** the default. The choice for the new VFS is arbitrary.)^ 7248 */ 7249 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 7250 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 7251 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 7252 7253 /* 7254 ** CAPI3REF: Mutexes 7255 ** 7256 ** The SQLite core uses these routines for thread 7257 ** synchronization. Though they are intended for internal 7258 ** use by SQLite, code that links against SQLite is 7259 ** permitted to use any of these routines. 7260 ** 7261 ** The SQLite source code contains multiple implementations 7262 ** of these mutex routines. An appropriate implementation 7263 ** is selected automatically at compile-time. The following 7264 ** implementations are available in the SQLite core: 7265 ** 7266 ** <ul> 7267 ** <li> SQLITE_MUTEX_PTHREADS 7268 ** <li> SQLITE_MUTEX_W32 7269 ** <li> SQLITE_MUTEX_NOOP 7270 ** </ul> 7271 ** 7272 ** The SQLITE_MUTEX_NOOP implementation is a set of routines 7273 ** that does no real locking and is appropriate for use in 7274 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 7275 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 7276 ** and Windows. 7277 ** 7278 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 7279 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 7280 ** implementation is included with the library. In this case the 7281 ** application must supply a custom mutex implementation using the 7282 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 7283 ** before calling sqlite3_initialize() or any other public sqlite3_ 7284 ** function that calls sqlite3_initialize(). 7285 ** 7286 ** ^The sqlite3_mutex_alloc() routine allocates a new 7287 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 7288 ** routine returns NULL if it is unable to allocate the requested 7289 ** mutex. The argument to sqlite3_mutex_alloc() must one of these 7290 ** integer constants: 7291 ** 7292 ** <ul> 7293 ** <li> SQLITE_MUTEX_FAST 7294 ** <li> SQLITE_MUTEX_RECURSIVE 7295 ** <li> SQLITE_MUTEX_STATIC_MASTER 7296 ** <li> SQLITE_MUTEX_STATIC_MEM 7297 ** <li> SQLITE_MUTEX_STATIC_OPEN 7298 ** <li> SQLITE_MUTEX_STATIC_PRNG 7299 ** <li> SQLITE_MUTEX_STATIC_LRU 7300 ** <li> SQLITE_MUTEX_STATIC_PMEM 7301 ** <li> SQLITE_MUTEX_STATIC_APP1 7302 ** <li> SQLITE_MUTEX_STATIC_APP2 7303 ** <li> SQLITE_MUTEX_STATIC_APP3 7304 ** <li> SQLITE_MUTEX_STATIC_VFS1 7305 ** <li> SQLITE_MUTEX_STATIC_VFS2 7306 ** <li> SQLITE_MUTEX_STATIC_VFS3 7307 ** </ul> 7308 ** 7309 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 7310 ** cause sqlite3_mutex_alloc() to create 7311 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 7312 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 7313 ** The mutex implementation does not need to make a distinction 7314 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 7315 ** not want to. SQLite will only request a recursive mutex in 7316 ** cases where it really needs one. If a faster non-recursive mutex 7317 ** implementation is available on the host platform, the mutex subsystem 7318 ** might return such a mutex in response to SQLITE_MUTEX_FAST. 7319 ** 7320 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 7321 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 7322 ** a pointer to a static preexisting mutex. ^Nine static mutexes are 7323 ** used by the current version of SQLite. Future versions of SQLite 7324 ** may add additional static mutexes. Static mutexes are for internal 7325 ** use by SQLite only. Applications that use SQLite mutexes should 7326 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 7327 ** SQLITE_MUTEX_RECURSIVE. 7328 ** 7329 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 7330 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 7331 ** returns a different mutex on every call. ^For the static 7332 ** mutex types, the same mutex is returned on every call that has 7333 ** the same type number. 7334 ** 7335 ** ^The sqlite3_mutex_free() routine deallocates a previously 7336 ** allocated dynamic mutex. Attempting to deallocate a static 7337 ** mutex results in undefined behavior. 7338 ** 7339 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 7340 ** to enter a mutex. ^If another thread is already within the mutex, 7341 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 7342 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 7343 ** upon successful entry. ^(Mutexes created using 7344 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 7345 ** In such cases, the 7346 ** mutex must be exited an equal number of times before another thread 7347 ** can enter.)^ If the same thread tries to enter any mutex other 7348 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 7349 ** 7350 ** ^(Some systems (for example, Windows 95) do not support the operation 7351 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 7352 ** will always return SQLITE_BUSY. The SQLite core only ever uses 7353 ** sqlite3_mutex_try() as an optimization so this is acceptable 7354 ** behavior.)^ 7355 ** 7356 ** ^The sqlite3_mutex_leave() routine exits a mutex that was 7357 ** previously entered by the same thread. The behavior 7358 ** is undefined if the mutex is not currently entered by the 7359 ** calling thread or is not currently allocated. 7360 ** 7361 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 7362 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines 7363 ** behave as no-ops. 7364 ** 7365 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 7366 */ 7367 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 7368 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 7369 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 7370 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 7371 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 7372 7373 /* 7374 ** CAPI3REF: Mutex Methods Object 7375 ** 7376 ** An instance of this structure defines the low-level routines 7377 ** used to allocate and use mutexes. 7378 ** 7379 ** Usually, the default mutex implementations provided by SQLite are 7380 ** sufficient, however the application has the option of substituting a custom 7381 ** implementation for specialized deployments or systems for which SQLite 7382 ** does not provide a suitable implementation. In this case, the application 7383 ** creates and populates an instance of this structure to pass 7384 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 7385 ** Additionally, an instance of this structure can be used as an 7386 ** output variable when querying the system for the current mutex 7387 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 7388 ** 7389 ** ^The xMutexInit method defined by this structure is invoked as 7390 ** part of system initialization by the sqlite3_initialize() function. 7391 ** ^The xMutexInit routine is called by SQLite exactly once for each 7392 ** effective call to [sqlite3_initialize()]. 7393 ** 7394 ** ^The xMutexEnd method defined by this structure is invoked as 7395 ** part of system shutdown by the sqlite3_shutdown() function. The 7396 ** implementation of this method is expected to release all outstanding 7397 ** resources obtained by the mutex methods implementation, especially 7398 ** those obtained by the xMutexInit method. ^The xMutexEnd() 7399 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 7400 ** 7401 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 7402 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 7403 ** xMutexNotheld) implement the following interfaces (respectively): 7404 ** 7405 ** <ul> 7406 ** <li> [sqlite3_mutex_alloc()] </li> 7407 ** <li> [sqlite3_mutex_free()] </li> 7408 ** <li> [sqlite3_mutex_enter()] </li> 7409 ** <li> [sqlite3_mutex_try()] </li> 7410 ** <li> [sqlite3_mutex_leave()] </li> 7411 ** <li> [sqlite3_mutex_held()] </li> 7412 ** <li> [sqlite3_mutex_notheld()] </li> 7413 ** </ul>)^ 7414 ** 7415 ** The only difference is that the public sqlite3_XXX functions enumerated 7416 ** above silently ignore any invocations that pass a NULL pointer instead 7417 ** of a valid mutex handle. The implementations of the methods defined 7418 ** by this structure are not required to handle this case. The results 7419 ** of passing a NULL pointer instead of a valid mutex handle are undefined 7420 ** (i.e. it is acceptable to provide an implementation that segfaults if 7421 ** it is passed a NULL pointer). 7422 ** 7423 ** The xMutexInit() method must be threadsafe. It must be harmless to 7424 ** invoke xMutexInit() multiple times within the same process and without 7425 ** intervening calls to xMutexEnd(). Second and subsequent calls to 7426 ** xMutexInit() must be no-ops. 7427 ** 7428 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 7429 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 7430 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 7431 ** memory allocation for a fast or recursive mutex. 7432 ** 7433 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 7434 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 7435 ** If xMutexInit fails in any way, it is expected to clean up after itself 7436 ** prior to returning. 7437 */ 7438 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 7439 struct sqlite3_mutex_methods { 7440 int (*xMutexInit)(void); 7441 int (*xMutexEnd)(void); 7442 sqlite3_mutex *(*xMutexAlloc)(int); 7443 void (*xMutexFree)(sqlite3_mutex *); 7444 void (*xMutexEnter)(sqlite3_mutex *); 7445 int (*xMutexTry)(sqlite3_mutex *); 7446 void (*xMutexLeave)(sqlite3_mutex *); 7447 int (*xMutexHeld)(sqlite3_mutex *); 7448 int (*xMutexNotheld)(sqlite3_mutex *); 7449 }; 7450 7451 /* 7452 ** CAPI3REF: Mutex Verification Routines 7453 ** 7454 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 7455 ** are intended for use inside assert() statements. The SQLite core 7456 ** never uses these routines except inside an assert() and applications 7457 ** are advised to follow the lead of the core. The SQLite core only 7458 ** provides implementations for these routines when it is compiled 7459 ** with the SQLITE_DEBUG flag. External mutex implementations 7460 ** are only required to provide these routines if SQLITE_DEBUG is 7461 ** defined and if NDEBUG is not defined. 7462 ** 7463 ** These routines should return true if the mutex in their argument 7464 ** is held or not held, respectively, by the calling thread. 7465 ** 7466 ** The implementation is not required to provide versions of these 7467 ** routines that actually work. If the implementation does not provide working 7468 ** versions of these routines, it should at least provide stubs that always 7469 ** return true so that one does not get spurious assertion failures. 7470 ** 7471 ** If the argument to sqlite3_mutex_held() is a NULL pointer then 7472 ** the routine should return 1. This seems counter-intuitive since 7473 ** clearly the mutex cannot be held if it does not exist. But 7474 ** the reason the mutex does not exist is because the build is not 7475 ** using mutexes. And we do not want the assert() containing the 7476 ** call to sqlite3_mutex_held() to fail, so a non-zero return is 7477 ** the appropriate thing to do. The sqlite3_mutex_notheld() 7478 ** interface should also return 1 when given a NULL pointer. 7479 */ 7480 #ifndef NDEBUG 7481 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 7482 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 7483 #endif 7484 7485 /* 7486 ** CAPI3REF: Mutex Types 7487 ** 7488 ** The [sqlite3_mutex_alloc()] interface takes a single argument 7489 ** which is one of these integer constants. 7490 ** 7491 ** The set of static mutexes may change from one SQLite release to the 7492 ** next. Applications that override the built-in mutex logic must be 7493 ** prepared to accommodate additional static mutexes. 7494 */ 7495 #define SQLITE_MUTEX_FAST 0 7496 #define SQLITE_MUTEX_RECURSIVE 1 7497 #define SQLITE_MUTEX_STATIC_MASTER 2 7498 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 7499 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 7500 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 7501 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 7502 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 7503 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 7504 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 7505 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 7506 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 7507 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 7508 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 7509 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 7510 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 7511 7512 /* 7513 ** CAPI3REF: Retrieve the mutex for a database connection 7514 ** METHOD: sqlite3 7515 ** 7516 ** ^This interface returns a pointer the [sqlite3_mutex] object that 7517 ** serializes access to the [database connection] given in the argument 7518 ** when the [threading mode] is Serialized. 7519 ** ^If the [threading mode] is Single-thread or Multi-thread then this 7520 ** routine returns a NULL pointer. 7521 */ 7522 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 7523 7524 /* 7525 ** CAPI3REF: Low-Level Control Of Database Files 7526 ** METHOD: sqlite3 7527 ** KEYWORDS: {file control} 7528 ** 7529 ** ^The [sqlite3_file_control()] interface makes a direct call to the 7530 ** xFileControl method for the [sqlite3_io_methods] object associated 7531 ** with a particular database identified by the second argument. ^The 7532 ** name of the database is "main" for the main database or "temp" for the 7533 ** TEMP database, or the name that appears after the AS keyword for 7534 ** databases that are added using the [ATTACH] SQL command. 7535 ** ^A NULL pointer can be used in place of "main" to refer to the 7536 ** main database file. 7537 ** ^The third and fourth parameters to this routine 7538 ** are passed directly through to the second and third parameters of 7539 ** the xFileControl method. ^The return value of the xFileControl 7540 ** method becomes the return value of this routine. 7541 ** 7542 ** A few opcodes for [sqlite3_file_control()] are handled directly 7543 ** by the SQLite core and never invoke the 7544 ** sqlite3_io_methods.xFileControl method. 7545 ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 7546 ** a pointer to the underlying [sqlite3_file] object to be written into 7547 ** the space pointed to by the 4th parameter. The 7548 ** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 7549 ** the [sqlite3_file] object associated with the journal file instead of 7550 ** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 7551 ** a pointer to the underlying [sqlite3_vfs] object for the file. 7552 ** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 7553 ** from the pager. 7554 ** 7555 ** ^If the second parameter (zDbName) does not match the name of any 7556 ** open database file, then SQLITE_ERROR is returned. ^This error 7557 ** code is not remembered and will not be recalled by [sqlite3_errcode()] 7558 ** or [sqlite3_errmsg()]. The underlying xFileControl method might 7559 ** also return SQLITE_ERROR. There is no way to distinguish between 7560 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 7561 ** xFileControl method. 7562 ** 7563 ** See also: [file control opcodes] 7564 */ 7565 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 7566 7567 /* 7568 ** CAPI3REF: Testing Interface 7569 ** 7570 ** ^The sqlite3_test_control() interface is used to read out internal 7571 ** state of SQLite and to inject faults into SQLite for testing 7572 ** purposes. ^The first parameter is an operation code that determines 7573 ** the number, meaning, and operation of all subsequent parameters. 7574 ** 7575 ** This interface is not for use by applications. It exists solely 7576 ** for verifying the correct operation of the SQLite library. Depending 7577 ** on how the SQLite library is compiled, this interface might not exist. 7578 ** 7579 ** The details of the operation codes, their meanings, the parameters 7580 ** they take, and what they do are all subject to change without notice. 7581 ** Unlike most of the SQLite API, this function is not guaranteed to 7582 ** operate consistently from one release to the next. 7583 */ 7584 SQLITE_API int sqlite3_test_control(int op, ...); 7585 7586 /* 7587 ** CAPI3REF: Testing Interface Operation Codes 7588 ** 7589 ** These constants are the valid operation code parameters used 7590 ** as the first argument to [sqlite3_test_control()]. 7591 ** 7592 ** These parameters and their meanings are subject to change 7593 ** without notice. These values are for testing purposes only. 7594 ** Applications should not use any of these parameters or the 7595 ** [sqlite3_test_control()] interface. 7596 */ 7597 #define SQLITE_TESTCTRL_FIRST 5 7598 #define SQLITE_TESTCTRL_PRNG_SAVE 5 7599 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 7600 #define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */ 7601 #define SQLITE_TESTCTRL_BITVEC_TEST 8 7602 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 7603 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 7604 #define SQLITE_TESTCTRL_PENDING_BYTE 11 7605 #define SQLITE_TESTCTRL_ASSERT 12 7606 #define SQLITE_TESTCTRL_ALWAYS 13 7607 #define SQLITE_TESTCTRL_RESERVE 14 7608 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 7609 #define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 7610 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 7611 #define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 7612 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 7613 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 7614 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 7615 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 7616 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 7617 #define SQLITE_TESTCTRL_BYTEORDER 22 7618 #define SQLITE_TESTCTRL_ISINIT 23 7619 #define SQLITE_TESTCTRL_SORTER_MMAP 24 7620 #define SQLITE_TESTCTRL_IMPOSTER 25 7621 #define SQLITE_TESTCTRL_PARSER_COVERAGE 26 7622 #define SQLITE_TESTCTRL_RESULT_INTREAL 27 7623 #define SQLITE_TESTCTRL_PRNG_SEED 28 7624 #define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29 7625 #define SQLITE_TESTCTRL_LAST 29 /* Largest TESTCTRL */ 7626 7627 /* 7628 ** CAPI3REF: SQL Keyword Checking 7629 ** 7630 ** These routines provide access to the set of SQL language keywords 7631 ** recognized by SQLite. Applications can uses these routines to determine 7632 ** whether or not a specific identifier needs to be escaped (for example, 7633 ** by enclosing in double-quotes) so as not to confuse the parser. 7634 ** 7635 ** The sqlite3_keyword_count() interface returns the number of distinct 7636 ** keywords understood by SQLite. 7637 ** 7638 ** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 7639 ** makes *Z point to that keyword expressed as UTF8 and writes the number 7640 ** of bytes in the keyword into *L. The string that *Z points to is not 7641 ** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 7642 ** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 7643 ** or L are NULL or invalid pointers then calls to 7644 ** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 7645 ** 7646 ** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 7647 ** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 7648 ** if it is and zero if not. 7649 ** 7650 ** The parser used by SQLite is forgiving. It is often possible to use 7651 ** a keyword as an identifier as long as such use does not result in a 7652 ** parsing ambiguity. For example, the statement 7653 ** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 7654 ** creates a new table named "BEGIN" with three columns named 7655 ** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 7656 ** using keywords as identifiers. Common techniques used to avoid keyword 7657 ** name collisions include: 7658 ** <ul> 7659 ** <li> Put all identifier names inside double-quotes. This is the official 7660 ** SQL way to escape identifier names. 7661 ** <li> Put identifier names inside [...]. This is not standard SQL, 7662 ** but it is what SQL Server does and so lots of programmers use this 7663 ** technique. 7664 ** <li> Begin every identifier with the letter "Z" as no SQL keywords start 7665 ** with "Z". 7666 ** <li> Include a digit somewhere in every identifier name. 7667 ** </ul> 7668 ** 7669 ** Note that the number of keywords understood by SQLite can depend on 7670 ** compile-time options. For example, "VACUUM" is not a keyword if 7671 ** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 7672 ** new keywords may be added to future releases of SQLite. 7673 */ 7674 SQLITE_API int sqlite3_keyword_count(void); 7675 SQLITE_API int sqlite3_keyword_name(int,const char**,int*); 7676 SQLITE_API int sqlite3_keyword_check(const char*,int); 7677 7678 /* 7679 ** CAPI3REF: Dynamic String Object 7680 ** KEYWORDS: {dynamic string} 7681 ** 7682 ** An instance of the sqlite3_str object contains a dynamically-sized 7683 ** string under construction. 7684 ** 7685 ** The lifecycle of an sqlite3_str object is as follows: 7686 ** <ol> 7687 ** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 7688 ** <li> ^Text is appended to the sqlite3_str object using various 7689 ** methods, such as [sqlite3_str_appendf()]. 7690 ** <li> ^The sqlite3_str object is destroyed and the string it created 7691 ** is returned using the [sqlite3_str_finish()] interface. 7692 ** </ol> 7693 */ 7694 typedef struct sqlite3_str sqlite3_str; 7695 7696 /* 7697 ** CAPI3REF: Create A New Dynamic String Object 7698 ** CONSTRUCTOR: sqlite3_str 7699 ** 7700 ** ^The [sqlite3_str_new(D)] interface allocates and initializes 7701 ** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 7702 ** [sqlite3_str_new()] must be freed by a subsequent call to 7703 ** [sqlite3_str_finish(X)]. 7704 ** 7705 ** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 7706 ** valid [sqlite3_str] object, though in the event of an out-of-memory 7707 ** error the returned object might be a special singleton that will 7708 ** silently reject new text, always return SQLITE_NOMEM from 7709 ** [sqlite3_str_errcode()], always return 0 for 7710 ** [sqlite3_str_length()], and always return NULL from 7711 ** [sqlite3_str_finish(X)]. It is always safe to use the value 7712 ** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 7713 ** to any of the other [sqlite3_str] methods. 7714 ** 7715 ** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 7716 ** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 7717 ** length of the string contained in the [sqlite3_str] object will be 7718 ** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 7719 ** of [SQLITE_MAX_LENGTH]. 7720 */ 7721 SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*); 7722 7723 /* 7724 ** CAPI3REF: Finalize A Dynamic String 7725 ** DESTRUCTOR: sqlite3_str 7726 ** 7727 ** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 7728 ** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 7729 ** that contains the constructed string. The calling application should 7730 ** pass the returned value to [sqlite3_free()] to avoid a memory leak. 7731 ** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 7732 ** errors were encountered during construction of the string. ^The 7733 ** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 7734 ** string in [sqlite3_str] object X is zero bytes long. 7735 */ 7736 SQLITE_API char *sqlite3_str_finish(sqlite3_str*); 7737 7738 /* 7739 ** CAPI3REF: Add Content To A Dynamic String 7740 ** METHOD: sqlite3_str 7741 ** 7742 ** These interfaces add content to an sqlite3_str object previously obtained 7743 ** from [sqlite3_str_new()]. 7744 ** 7745 ** ^The [sqlite3_str_appendf(X,F,...)] and 7746 ** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 7747 ** functionality of SQLite to append formatted text onto the end of 7748 ** [sqlite3_str] object X. 7749 ** 7750 ** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 7751 ** onto the end of the [sqlite3_str] object X. N must be non-negative. 7752 ** S must contain at least N non-zero bytes of content. To append a 7753 ** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 7754 ** method instead. 7755 ** 7756 ** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 7757 ** zero-terminated string S onto the end of [sqlite3_str] object X. 7758 ** 7759 ** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 7760 ** single-byte character C onto the end of [sqlite3_str] object X. 7761 ** ^This method can be used, for example, to add whitespace indentation. 7762 ** 7763 ** ^The [sqlite3_str_reset(X)] method resets the string under construction 7764 ** inside [sqlite3_str] object X back to zero bytes in length. 7765 ** 7766 ** These methods do not return a result code. ^If an error occurs, that fact 7767 ** is recorded in the [sqlite3_str] object and can be recovered by a 7768 ** subsequent call to [sqlite3_str_errcode(X)]. 7769 */ 7770 SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 7771 SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 7772 SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 7773 SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 7774 SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 7775 SQLITE_API void sqlite3_str_reset(sqlite3_str*); 7776 7777 /* 7778 ** CAPI3REF: Status Of A Dynamic String 7779 ** METHOD: sqlite3_str 7780 ** 7781 ** These interfaces return the current status of an [sqlite3_str] object. 7782 ** 7783 ** ^If any prior errors have occurred while constructing the dynamic string 7784 ** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 7785 ** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 7786 ** [SQLITE_NOMEM] following any out-of-memory error, or 7787 ** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 7788 ** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 7789 ** 7790 ** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 7791 ** of the dynamic string under construction in [sqlite3_str] object X. 7792 ** ^The length returned by [sqlite3_str_length(X)] does not include the 7793 ** zero-termination byte. 7794 ** 7795 ** ^The [sqlite3_str_value(X)] method returns a pointer to the current 7796 ** content of the dynamic string under construction in X. The value 7797 ** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 7798 ** and might be freed or altered by any subsequent method on the same 7799 ** [sqlite3_str] object. Applications must not used the pointer returned 7800 ** [sqlite3_str_value(X)] after any subsequent method call on the same 7801 ** object. ^Applications may change the content of the string returned 7802 ** by [sqlite3_str_value(X)] as long as they do not write into any bytes 7803 ** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 7804 ** write any byte after any subsequent sqlite3_str method call. 7805 */ 7806 SQLITE_API int sqlite3_str_errcode(sqlite3_str*); 7807 SQLITE_API int sqlite3_str_length(sqlite3_str*); 7808 SQLITE_API char *sqlite3_str_value(sqlite3_str*); 7809 7810 /* 7811 ** CAPI3REF: SQLite Runtime Status 7812 ** 7813 ** ^These interfaces are used to retrieve runtime status information 7814 ** about the performance of SQLite, and optionally to reset various 7815 ** highwater marks. ^The first argument is an integer code for 7816 ** the specific parameter to measure. ^(Recognized integer codes 7817 ** are of the form [status parameters | SQLITE_STATUS_...].)^ 7818 ** ^The current value of the parameter is returned into *pCurrent. 7819 ** ^The highest recorded value is returned in *pHighwater. ^If the 7820 ** resetFlag is true, then the highest record value is reset after 7821 ** *pHighwater is written. ^(Some parameters do not record the highest 7822 ** value. For those parameters 7823 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 7824 ** ^(Other parameters record only the highwater mark and not the current 7825 ** value. For these latter parameters nothing is written into *pCurrent.)^ 7826 ** 7827 ** ^The sqlite3_status() and sqlite3_status64() routines return 7828 ** SQLITE_OK on success and a non-zero [error code] on failure. 7829 ** 7830 ** If either the current value or the highwater mark is too large to 7831 ** be represented by a 32-bit integer, then the values returned by 7832 ** sqlite3_status() are undefined. 7833 ** 7834 ** See also: [sqlite3_db_status()] 7835 */ 7836 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 7837 SQLITE_API int sqlite3_status64( 7838 int op, 7839 sqlite3_int64 *pCurrent, 7840 sqlite3_int64 *pHighwater, 7841 int resetFlag 7842 ); 7843 7844 7845 /* 7846 ** CAPI3REF: Status Parameters 7847 ** KEYWORDS: {status parameters} 7848 ** 7849 ** These integer constants designate various run-time status parameters 7850 ** that can be returned by [sqlite3_status()]. 7851 ** 7852 ** <dl> 7853 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 7854 ** <dd>This parameter is the current amount of memory checked out 7855 ** using [sqlite3_malloc()], either directly or indirectly. The 7856 ** figure includes calls made to [sqlite3_malloc()] by the application 7857 ** and internal memory usage by the SQLite library. Auxiliary page-cache 7858 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 7859 ** this parameter. The amount returned is the sum of the allocation 7860 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 7861 ** 7862 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 7863 ** <dd>This parameter records the largest memory allocation request 7864 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 7865 ** internal equivalents). Only the value returned in the 7866 ** *pHighwater parameter to [sqlite3_status()] is of interest. 7867 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 7868 ** 7869 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 7870 ** <dd>This parameter records the number of separate memory allocations 7871 ** currently checked out.</dd>)^ 7872 ** 7873 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 7874 ** <dd>This parameter returns the number of pages used out of the 7875 ** [pagecache memory allocator] that was configured using 7876 ** [SQLITE_CONFIG_PAGECACHE]. The 7877 ** value returned is in pages, not in bytes.</dd>)^ 7878 ** 7879 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 7880 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 7881 ** <dd>This parameter returns the number of bytes of page cache 7882 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 7883 ** buffer and where forced to overflow to [sqlite3_malloc()]. The 7884 ** returned value includes allocations that overflowed because they 7885 ** where too large (they were larger than the "sz" parameter to 7886 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 7887 ** no space was left in the page cache.</dd>)^ 7888 ** 7889 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 7890 ** <dd>This parameter records the largest memory allocation request 7891 ** handed to the [pagecache memory allocator]. Only the value returned in the 7892 ** *pHighwater parameter to [sqlite3_status()] is of interest. 7893 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 7894 ** 7895 ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 7896 ** <dd>No longer used.</dd> 7897 ** 7898 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 7899 ** <dd>No longer used.</dd> 7900 ** 7901 ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 7902 ** <dd>No longer used.</dd> 7903 ** 7904 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 7905 ** <dd>The *pHighwater parameter records the deepest parser stack. 7906 ** The *pCurrent value is undefined. The *pHighwater value is only 7907 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 7908 ** </dl> 7909 ** 7910 ** New status parameters may be added from time to time. 7911 */ 7912 #define SQLITE_STATUS_MEMORY_USED 0 7913 #define SQLITE_STATUS_PAGECACHE_USED 1 7914 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 7915 #define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 7916 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 7917 #define SQLITE_STATUS_MALLOC_SIZE 5 7918 #define SQLITE_STATUS_PARSER_STACK 6 7919 #define SQLITE_STATUS_PAGECACHE_SIZE 7 7920 #define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 7921 #define SQLITE_STATUS_MALLOC_COUNT 9 7922 7923 /* 7924 ** CAPI3REF: Database Connection Status 7925 ** METHOD: sqlite3 7926 ** 7927 ** ^This interface is used to retrieve runtime status information 7928 ** about a single [database connection]. ^The first argument is the 7929 ** database connection object to be interrogated. ^The second argument 7930 ** is an integer constant, taken from the set of 7931 ** [SQLITE_DBSTATUS options], that 7932 ** determines the parameter to interrogate. The set of 7933 ** [SQLITE_DBSTATUS options] is likely 7934 ** to grow in future releases of SQLite. 7935 ** 7936 ** ^The current value of the requested parameter is written into *pCur 7937 ** and the highest instantaneous value is written into *pHiwtr. ^If 7938 ** the resetFlg is true, then the highest instantaneous value is 7939 ** reset back down to the current value. 7940 ** 7941 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 7942 ** non-zero [error code] on failure. 7943 ** 7944 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 7945 */ 7946 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 7947 7948 /* 7949 ** CAPI3REF: Status Parameters for database connections 7950 ** KEYWORDS: {SQLITE_DBSTATUS options} 7951 ** 7952 ** These constants are the available integer "verbs" that can be passed as 7953 ** the second argument to the [sqlite3_db_status()] interface. 7954 ** 7955 ** New verbs may be added in future releases of SQLite. Existing verbs 7956 ** might be discontinued. Applications should check the return code from 7957 ** [sqlite3_db_status()] to make sure that the call worked. 7958 ** The [sqlite3_db_status()] interface will return a non-zero error code 7959 ** if a discontinued or unsupported verb is invoked. 7960 ** 7961 ** <dl> 7962 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 7963 ** <dd>This parameter returns the number of lookaside memory slots currently 7964 ** checked out.</dd>)^ 7965 ** 7966 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 7967 ** <dd>This parameter returns the number of malloc attempts that were 7968 ** satisfied using lookaside memory. Only the high-water value is meaningful; 7969 ** the current value is always zero.)^ 7970 ** 7971 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 7972 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 7973 ** <dd>This parameter returns the number malloc attempts that might have 7974 ** been satisfied using lookaside memory but failed due to the amount of 7975 ** memory requested being larger than the lookaside slot size. 7976 ** Only the high-water value is meaningful; 7977 ** the current value is always zero.)^ 7978 ** 7979 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 7980 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 7981 ** <dd>This parameter returns the number malloc attempts that might have 7982 ** been satisfied using lookaside memory but failed due to all lookaside 7983 ** memory already being in use. 7984 ** Only the high-water value is meaningful; 7985 ** the current value is always zero.)^ 7986 ** 7987 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 7988 ** <dd>This parameter returns the approximate number of bytes of heap 7989 ** memory used by all pager caches associated with the database connection.)^ 7990 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 7991 ** 7992 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 7993 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 7994 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 7995 ** pager cache is shared between two or more connections the bytes of heap 7996 ** memory used by that pager cache is divided evenly between the attached 7997 ** connections.)^ In other words, if none of the pager caches associated 7998 ** with the database connection are shared, this request returns the same 7999 ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 8000 ** shared, the value returned by this call will be smaller than that returned 8001 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 8002 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 8003 ** 8004 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 8005 ** <dd>This parameter returns the approximate number of bytes of heap 8006 ** memory used to store the schema for all databases associated 8007 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 8008 ** ^The full amount of memory used by the schemas is reported, even if the 8009 ** schema memory is shared with other database connections due to 8010 ** [shared cache mode] being enabled. 8011 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 8012 ** 8013 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 8014 ** <dd>This parameter returns the approximate number of bytes of heap 8015 ** and lookaside memory used by all prepared statements associated with 8016 ** the database connection.)^ 8017 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 8018 ** </dd> 8019 ** 8020 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 8021 ** <dd>This parameter returns the number of pager cache hits that have 8022 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 8023 ** is always 0. 8024 ** </dd> 8025 ** 8026 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 8027 ** <dd>This parameter returns the number of pager cache misses that have 8028 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 8029 ** is always 0. 8030 ** </dd> 8031 ** 8032 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 8033 ** <dd>This parameter returns the number of dirty cache entries that have 8034 ** been written to disk. Specifically, the number of pages written to the 8035 ** wal file in wal mode databases, or the number of pages written to the 8036 ** database file in rollback mode databases. Any pages written as part of 8037 ** transaction rollback or database recovery operations are not included. 8038 ** If an IO or other error occurs while writing a page to disk, the effect 8039 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 8040 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 8041 ** </dd> 8042 ** 8043 ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 8044 ** <dd>This parameter returns the number of dirty cache entries that have 8045 ** been written to disk in the middle of a transaction due to the page 8046 ** cache overflowing. Transactions are more efficient if they are written 8047 ** to disk all at once. When pages spill mid-transaction, that introduces 8048 ** additional overhead. This parameter can be used help identify 8049 ** inefficiencies that can be resolved by increasing the cache size. 8050 ** </dd> 8051 ** 8052 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 8053 ** <dd>This parameter returns zero for the current value if and only if 8054 ** all foreign key constraints (deferred or immediate) have been 8055 ** resolved.)^ ^The highwater mark is always 0. 8056 ** </dd> 8057 ** </dl> 8058 */ 8059 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 8060 #define SQLITE_DBSTATUS_CACHE_USED 1 8061 #define SQLITE_DBSTATUS_SCHEMA_USED 2 8062 #define SQLITE_DBSTATUS_STMT_USED 3 8063 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 8064 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 8065 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 8066 #define SQLITE_DBSTATUS_CACHE_HIT 7 8067 #define SQLITE_DBSTATUS_CACHE_MISS 8 8068 #define SQLITE_DBSTATUS_CACHE_WRITE 9 8069 #define SQLITE_DBSTATUS_DEFERRED_FKS 10 8070 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 8071 #define SQLITE_DBSTATUS_CACHE_SPILL 12 8072 #define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 8073 8074 8075 /* 8076 ** CAPI3REF: Prepared Statement Status 8077 ** METHOD: sqlite3_stmt 8078 ** 8079 ** ^(Each prepared statement maintains various 8080 ** [SQLITE_STMTSTATUS counters] that measure the number 8081 ** of times it has performed specific operations.)^ These counters can 8082 ** be used to monitor the performance characteristics of the prepared 8083 ** statements. For example, if the number of table steps greatly exceeds 8084 ** the number of table searches or result rows, that would tend to indicate 8085 ** that the prepared statement is using a full table scan rather than 8086 ** an index. 8087 ** 8088 ** ^(This interface is used to retrieve and reset counter values from 8089 ** a [prepared statement]. The first argument is the prepared statement 8090 ** object to be interrogated. The second argument 8091 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 8092 ** to be interrogated.)^ 8093 ** ^The current value of the requested counter is returned. 8094 ** ^If the resetFlg is true, then the counter is reset to zero after this 8095 ** interface call returns. 8096 ** 8097 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 8098 */ 8099 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 8100 8101 /* 8102 ** CAPI3REF: Status Parameters for prepared statements 8103 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 8104 ** 8105 ** These preprocessor macros define integer codes that name counter 8106 ** values associated with the [sqlite3_stmt_status()] interface. 8107 ** The meanings of the various counters are as follows: 8108 ** 8109 ** <dl> 8110 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 8111 ** <dd>^This is the number of times that SQLite has stepped forward in 8112 ** a table as part of a full table scan. Large numbers for this counter 8113 ** may indicate opportunities for performance improvement through 8114 ** careful use of indices.</dd> 8115 ** 8116 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 8117 ** <dd>^This is the number of sort operations that have occurred. 8118 ** A non-zero value in this counter may indicate an opportunity to 8119 ** improvement performance through careful use of indices.</dd> 8120 ** 8121 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 8122 ** <dd>^This is the number of rows inserted into transient indices that 8123 ** were created automatically in order to help joins run faster. 8124 ** A non-zero value in this counter may indicate an opportunity to 8125 ** improvement performance by adding permanent indices that do not 8126 ** need to be reinitialized each time the statement is run.</dd> 8127 ** 8128 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 8129 ** <dd>^This is the number of virtual machine operations executed 8130 ** by the prepared statement if that number is less than or equal 8131 ** to 2147483647. The number of virtual machine operations can be 8132 ** used as a proxy for the total work done by the prepared statement. 8133 ** If the number of virtual machine operations exceeds 2147483647 8134 ** then the value returned by this statement status code is undefined. 8135 ** 8136 ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 8137 ** <dd>^This is the number of times that the prepare statement has been 8138 ** automatically regenerated due to schema changes or changes to 8139 ** [bound parameters] that might affect the query plan. 8140 ** 8141 ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 8142 ** <dd>^This is the number of times that the prepared statement has 8143 ** been run. A single "run" for the purposes of this counter is one 8144 ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 8145 ** The counter is incremented on the first [sqlite3_step()] call of each 8146 ** cycle. 8147 ** 8148 ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 8149 ** <dd>^This is the approximate number of bytes of heap memory 8150 ** used to store the prepared statement. ^This value is not actually 8151 ** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 8152 ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 8153 ** </dd> 8154 ** </dl> 8155 */ 8156 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 8157 #define SQLITE_STMTSTATUS_SORT 2 8158 #define SQLITE_STMTSTATUS_AUTOINDEX 3 8159 #define SQLITE_STMTSTATUS_VM_STEP 4 8160 #define SQLITE_STMTSTATUS_REPREPARE 5 8161 #define SQLITE_STMTSTATUS_RUN 6 8162 #define SQLITE_STMTSTATUS_MEMUSED 99 8163 8164 /* 8165 ** CAPI3REF: Custom Page Cache Object 8166 ** 8167 ** The sqlite3_pcache type is opaque. It is implemented by 8168 ** the pluggable module. The SQLite core has no knowledge of 8169 ** its size or internal structure and never deals with the 8170 ** sqlite3_pcache object except by holding and passing pointers 8171 ** to the object. 8172 ** 8173 ** See [sqlite3_pcache_methods2] for additional information. 8174 */ 8175 typedef struct sqlite3_pcache sqlite3_pcache; 8176 8177 /* 8178 ** CAPI3REF: Custom Page Cache Object 8179 ** 8180 ** The sqlite3_pcache_page object represents a single page in the 8181 ** page cache. The page cache will allocate instances of this 8182 ** object. Various methods of the page cache use pointers to instances 8183 ** of this object as parameters or as their return value. 8184 ** 8185 ** See [sqlite3_pcache_methods2] for additional information. 8186 */ 8187 typedef struct sqlite3_pcache_page sqlite3_pcache_page; 8188 struct sqlite3_pcache_page { 8189 void *pBuf; /* The content of the page */ 8190 void *pExtra; /* Extra information associated with the page */ 8191 }; 8192 8193 /* 8194 ** CAPI3REF: Application Defined Page Cache. 8195 ** KEYWORDS: {page cache} 8196 ** 8197 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 8198 ** register an alternative page cache implementation by passing in an 8199 ** instance of the sqlite3_pcache_methods2 structure.)^ 8200 ** In many applications, most of the heap memory allocated by 8201 ** SQLite is used for the page cache. 8202 ** By implementing a 8203 ** custom page cache using this API, an application can better control 8204 ** the amount of memory consumed by SQLite, the way in which 8205 ** that memory is allocated and released, and the policies used to 8206 ** determine exactly which parts of a database file are cached and for 8207 ** how long. 8208 ** 8209 ** The alternative page cache mechanism is an 8210 ** extreme measure that is only needed by the most demanding applications. 8211 ** The built-in page cache is recommended for most uses. 8212 ** 8213 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 8214 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 8215 ** the application may discard the parameter after the call to 8216 ** [sqlite3_config()] returns.)^ 8217 ** 8218 ** [[the xInit() page cache method]] 8219 ** ^(The xInit() method is called once for each effective 8220 ** call to [sqlite3_initialize()])^ 8221 ** (usually only once during the lifetime of the process). ^(The xInit() 8222 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 8223 ** The intent of the xInit() method is to set up global data structures 8224 ** required by the custom page cache implementation. 8225 ** ^(If the xInit() method is NULL, then the 8226 ** built-in default page cache is used instead of the application defined 8227 ** page cache.)^ 8228 ** 8229 ** [[the xShutdown() page cache method]] 8230 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 8231 ** It can be used to clean up 8232 ** any outstanding resources before process shutdown, if required. 8233 ** ^The xShutdown() method may be NULL. 8234 ** 8235 ** ^SQLite automatically serializes calls to the xInit method, 8236 ** so the xInit method need not be threadsafe. ^The 8237 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 8238 ** not need to be threadsafe either. All other methods must be threadsafe 8239 ** in multithreaded applications. 8240 ** 8241 ** ^SQLite will never invoke xInit() more than once without an intervening 8242 ** call to xShutdown(). 8243 ** 8244 ** [[the xCreate() page cache methods]] 8245 ** ^SQLite invokes the xCreate() method to construct a new cache instance. 8246 ** SQLite will typically create one cache instance for each open database file, 8247 ** though this is not guaranteed. ^The 8248 ** first parameter, szPage, is the size in bytes of the pages that must 8249 ** be allocated by the cache. ^szPage will always a power of two. ^The 8250 ** second parameter szExtra is a number of bytes of extra storage 8251 ** associated with each page cache entry. ^The szExtra parameter will 8252 ** a number less than 250. SQLite will use the 8253 ** extra szExtra bytes on each page to store metadata about the underlying 8254 ** database page on disk. The value passed into szExtra depends 8255 ** on the SQLite version, the target platform, and how SQLite was compiled. 8256 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 8257 ** created will be used to cache database pages of a file stored on disk, or 8258 ** false if it is used for an in-memory database. The cache implementation 8259 ** does not have to do anything special based with the value of bPurgeable; 8260 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 8261 ** never invoke xUnpin() except to deliberately delete a page. 8262 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 8263 ** false will always have the "discard" flag set to true. 8264 ** ^Hence, a cache created with bPurgeable false will 8265 ** never contain any unpinned pages. 8266 ** 8267 ** [[the xCachesize() page cache method]] 8268 ** ^(The xCachesize() method may be called at any time by SQLite to set the 8269 ** suggested maximum cache-size (number of pages stored by) the cache 8270 ** instance passed as the first argument. This is the value configured using 8271 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 8272 ** parameter, the implementation is not required to do anything with this 8273 ** value; it is advisory only. 8274 ** 8275 ** [[the xPagecount() page cache methods]] 8276 ** The xPagecount() method must return the number of pages currently 8277 ** stored in the cache, both pinned and unpinned. 8278 ** 8279 ** [[the xFetch() page cache methods]] 8280 ** The xFetch() method locates a page in the cache and returns a pointer to 8281 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 8282 ** The pBuf element of the returned sqlite3_pcache_page object will be a 8283 ** pointer to a buffer of szPage bytes used to store the content of a 8284 ** single database page. The pExtra element of sqlite3_pcache_page will be 8285 ** a pointer to the szExtra bytes of extra storage that SQLite has requested 8286 ** for each entry in the page cache. 8287 ** 8288 ** The page to be fetched is determined by the key. ^The minimum key value 8289 ** is 1. After it has been retrieved using xFetch, the page is considered 8290 ** to be "pinned". 8291 ** 8292 ** If the requested page is already in the page cache, then the page cache 8293 ** implementation must return a pointer to the page buffer with its content 8294 ** intact. If the requested page is not already in the cache, then the 8295 ** cache implementation should use the value of the createFlag 8296 ** parameter to help it determined what action to take: 8297 ** 8298 ** <table border=1 width=85% align=center> 8299 ** <tr><th> createFlag <th> Behavior when page is not already in cache 8300 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 8301 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 8302 ** Otherwise return NULL. 8303 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 8304 ** NULL if allocating a new page is effectively impossible. 8305 ** </table> 8306 ** 8307 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 8308 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 8309 ** failed.)^ In between the xFetch() calls, SQLite may 8310 ** attempt to unpin one or more cache pages by spilling the content of 8311 ** pinned pages to disk and synching the operating system disk cache. 8312 ** 8313 ** [[the xUnpin() page cache method]] 8314 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 8315 ** as its second argument. If the third parameter, discard, is non-zero, 8316 ** then the page must be evicted from the cache. 8317 ** ^If the discard parameter is 8318 ** zero, then the page may be discarded or retained at the discretion of 8319 ** page cache implementation. ^The page cache implementation 8320 ** may choose to evict unpinned pages at any time. 8321 ** 8322 ** The cache must not perform any reference counting. A single 8323 ** call to xUnpin() unpins the page regardless of the number of prior calls 8324 ** to xFetch(). 8325 ** 8326 ** [[the xRekey() page cache methods]] 8327 ** The xRekey() method is used to change the key value associated with the 8328 ** page passed as the second argument. If the cache 8329 ** previously contains an entry associated with newKey, it must be 8330 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 8331 ** to be pinned. 8332 ** 8333 ** When SQLite calls the xTruncate() method, the cache must discard all 8334 ** existing cache entries with page numbers (keys) greater than or equal 8335 ** to the value of the iLimit parameter passed to xTruncate(). If any 8336 ** of these pages are pinned, they are implicitly unpinned, meaning that 8337 ** they can be safely discarded. 8338 ** 8339 ** [[the xDestroy() page cache method]] 8340 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 8341 ** All resources associated with the specified cache should be freed. ^After 8342 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 8343 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 8344 ** functions. 8345 ** 8346 ** [[the xShrink() page cache method]] 8347 ** ^SQLite invokes the xShrink() method when it wants the page cache to 8348 ** free up as much of heap memory as possible. The page cache implementation 8349 ** is not obligated to free any memory, but well-behaved implementations should 8350 ** do their best. 8351 */ 8352 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 8353 struct sqlite3_pcache_methods2 { 8354 int iVersion; 8355 void *pArg; 8356 int (*xInit)(void*); 8357 void (*xShutdown)(void*); 8358 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 8359 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8360 int (*xPagecount)(sqlite3_pcache*); 8361 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8362 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 8363 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 8364 unsigned oldKey, unsigned newKey); 8365 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8366 void (*xDestroy)(sqlite3_pcache*); 8367 void (*xShrink)(sqlite3_pcache*); 8368 }; 8369 8370 /* 8371 ** This is the obsolete pcache_methods object that has now been replaced 8372 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 8373 ** retained in the header file for backwards compatibility only. 8374 */ 8375 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 8376 struct sqlite3_pcache_methods { 8377 void *pArg; 8378 int (*xInit)(void*); 8379 void (*xShutdown)(void*); 8380 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 8381 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8382 int (*xPagecount)(sqlite3_pcache*); 8383 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8384 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 8385 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 8386 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8387 void (*xDestroy)(sqlite3_pcache*); 8388 }; 8389 8390 8391 /* 8392 ** CAPI3REF: Online Backup Object 8393 ** 8394 ** The sqlite3_backup object records state information about an ongoing 8395 ** online backup operation. ^The sqlite3_backup object is created by 8396 ** a call to [sqlite3_backup_init()] and is destroyed by a call to 8397 ** [sqlite3_backup_finish()]. 8398 ** 8399 ** See Also: [Using the SQLite Online Backup API] 8400 */ 8401 typedef struct sqlite3_backup sqlite3_backup; 8402 8403 /* 8404 ** CAPI3REF: Online Backup API. 8405 ** 8406 ** The backup API copies the content of one database into another. 8407 ** It is useful either for creating backups of databases or 8408 ** for copying in-memory databases to or from persistent files. 8409 ** 8410 ** See Also: [Using the SQLite Online Backup API] 8411 ** 8412 ** ^SQLite holds a write transaction open on the destination database file 8413 ** for the duration of the backup operation. 8414 ** ^The source database is read-locked only while it is being read; 8415 ** it is not locked continuously for the entire backup operation. 8416 ** ^Thus, the backup may be performed on a live source database without 8417 ** preventing other database connections from 8418 ** reading or writing to the source database while the backup is underway. 8419 ** 8420 ** ^(To perform a backup operation: 8421 ** <ol> 8422 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 8423 ** backup, 8424 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 8425 ** the data between the two databases, and finally 8426 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 8427 ** associated with the backup operation. 8428 ** </ol>)^ 8429 ** There should be exactly one call to sqlite3_backup_finish() for each 8430 ** successful call to sqlite3_backup_init(). 8431 ** 8432 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 8433 ** 8434 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 8435 ** [database connection] associated with the destination database 8436 ** and the database name, respectively. 8437 ** ^The database name is "main" for the main database, "temp" for the 8438 ** temporary database, or the name specified after the AS keyword in 8439 ** an [ATTACH] statement for an attached database. 8440 ** ^The S and M arguments passed to 8441 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 8442 ** and database name of the source database, respectively. 8443 ** ^The source and destination [database connections] (parameters S and D) 8444 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 8445 ** an error. 8446 ** 8447 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if 8448 ** there is already a read or read-write transaction open on the 8449 ** destination database. 8450 ** 8451 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 8452 ** returned and an error code and error message are stored in the 8453 ** destination [database connection] D. 8454 ** ^The error code and message for the failed call to sqlite3_backup_init() 8455 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 8456 ** [sqlite3_errmsg16()] functions. 8457 ** ^A successful call to sqlite3_backup_init() returns a pointer to an 8458 ** [sqlite3_backup] object. 8459 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 8460 ** sqlite3_backup_finish() functions to perform the specified backup 8461 ** operation. 8462 ** 8463 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 8464 ** 8465 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 8466 ** the source and destination databases specified by [sqlite3_backup] object B. 8467 ** ^If N is negative, all remaining source pages are copied. 8468 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 8469 ** are still more pages to be copied, then the function returns [SQLITE_OK]. 8470 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 8471 ** from source to destination, then it returns [SQLITE_DONE]. 8472 ** ^If an error occurs while running sqlite3_backup_step(B,N), 8473 ** then an [error code] is returned. ^As well as [SQLITE_OK] and 8474 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 8475 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 8476 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 8477 ** 8478 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 8479 ** <ol> 8480 ** <li> the destination database was opened read-only, or 8481 ** <li> the destination database is using write-ahead-log journaling 8482 ** and the destination and source page sizes differ, or 8483 ** <li> the destination database is an in-memory database and the 8484 ** destination and source page sizes differ. 8485 ** </ol>)^ 8486 ** 8487 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 8488 ** the [sqlite3_busy_handler | busy-handler function] 8489 ** is invoked (if one is specified). ^If the 8490 ** busy-handler returns non-zero before the lock is available, then 8491 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 8492 ** sqlite3_backup_step() can be retried later. ^If the source 8493 ** [database connection] 8494 ** is being used to write to the source database when sqlite3_backup_step() 8495 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 8496 ** case the call to sqlite3_backup_step() can be retried later on. ^(If 8497 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 8498 ** [SQLITE_READONLY] is returned, then 8499 ** there is no point in retrying the call to sqlite3_backup_step(). These 8500 ** errors are considered fatal.)^ The application must accept 8501 ** that the backup operation has failed and pass the backup operation handle 8502 ** to the sqlite3_backup_finish() to release associated resources. 8503 ** 8504 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 8505 ** on the destination file. ^The exclusive lock is not released until either 8506 ** sqlite3_backup_finish() is called or the backup operation is complete 8507 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 8508 ** sqlite3_backup_step() obtains a [shared lock] on the source database that 8509 ** lasts for the duration of the sqlite3_backup_step() call. 8510 ** ^Because the source database is not locked between calls to 8511 ** sqlite3_backup_step(), the source database may be modified mid-way 8512 ** through the backup process. ^If the source database is modified by an 8513 ** external process or via a database connection other than the one being 8514 ** used by the backup operation, then the backup will be automatically 8515 ** restarted by the next call to sqlite3_backup_step(). ^If the source 8516 ** database is modified by the using the same database connection as is used 8517 ** by the backup operation, then the backup database is automatically 8518 ** updated at the same time. 8519 ** 8520 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 8521 ** 8522 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 8523 ** application wishes to abandon the backup operation, the application 8524 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 8525 ** ^The sqlite3_backup_finish() interfaces releases all 8526 ** resources associated with the [sqlite3_backup] object. 8527 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 8528 ** active write-transaction on the destination database is rolled back. 8529 ** The [sqlite3_backup] object is invalid 8530 ** and may not be used following a call to sqlite3_backup_finish(). 8531 ** 8532 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 8533 ** sqlite3_backup_step() errors occurred, regardless or whether or not 8534 ** sqlite3_backup_step() completed. 8535 ** ^If an out-of-memory condition or IO error occurred during any prior 8536 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 8537 ** sqlite3_backup_finish() returns the corresponding [error code]. 8538 ** 8539 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 8540 ** is not a permanent error and does not affect the return value of 8541 ** sqlite3_backup_finish(). 8542 ** 8543 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 8544 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 8545 ** 8546 ** ^The sqlite3_backup_remaining() routine returns the number of pages still 8547 ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 8548 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages 8549 ** in the source database at the conclusion of the most recent 8550 ** sqlite3_backup_step(). 8551 ** ^(The values returned by these functions are only updated by 8552 ** sqlite3_backup_step(). If the source database is modified in a way that 8553 ** changes the size of the source database or the number of pages remaining, 8554 ** those changes are not reflected in the output of sqlite3_backup_pagecount() 8555 ** and sqlite3_backup_remaining() until after the next 8556 ** sqlite3_backup_step().)^ 8557 ** 8558 ** <b>Concurrent Usage of Database Handles</b> 8559 ** 8560 ** ^The source [database connection] may be used by the application for other 8561 ** purposes while a backup operation is underway or being initialized. 8562 ** ^If SQLite is compiled and configured to support threadsafe database 8563 ** connections, then the source database connection may be used concurrently 8564 ** from within other threads. 8565 ** 8566 ** However, the application must guarantee that the destination 8567 ** [database connection] is not passed to any other API (by any thread) after 8568 ** sqlite3_backup_init() is called and before the corresponding call to 8569 ** sqlite3_backup_finish(). SQLite does not currently check to see 8570 ** if the application incorrectly accesses the destination [database connection] 8571 ** and so no error code is reported, but the operations may malfunction 8572 ** nevertheless. Use of the destination database connection while a 8573 ** backup is in progress might also also cause a mutex deadlock. 8574 ** 8575 ** If running in [shared cache mode], the application must 8576 ** guarantee that the shared cache used by the destination database 8577 ** is not accessed while the backup is running. In practice this means 8578 ** that the application must guarantee that the disk file being 8579 ** backed up to is not accessed by any connection within the process, 8580 ** not just the specific connection that was passed to sqlite3_backup_init(). 8581 ** 8582 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 8583 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 8584 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 8585 ** APIs are not strictly speaking threadsafe. If they are invoked at the 8586 ** same time as another thread is invoking sqlite3_backup_step() it is 8587 ** possible that they return invalid values. 8588 */ 8589 SQLITE_API sqlite3_backup *sqlite3_backup_init( 8590 sqlite3 *pDest, /* Destination database handle */ 8591 const char *zDestName, /* Destination database name */ 8592 sqlite3 *pSource, /* Source database handle */ 8593 const char *zSourceName /* Source database name */ 8594 ); 8595 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 8596 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 8597 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 8598 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 8599 8600 /* 8601 ** CAPI3REF: Unlock Notification 8602 ** METHOD: sqlite3 8603 ** 8604 ** ^When running in shared-cache mode, a database operation may fail with 8605 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 8606 ** individual tables within the shared-cache cannot be obtained. See 8607 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 8608 ** ^This API may be used to register a callback that SQLite will invoke 8609 ** when the connection currently holding the required lock relinquishes it. 8610 ** ^This API is only available if the library was compiled with the 8611 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 8612 ** 8613 ** See Also: [Using the SQLite Unlock Notification Feature]. 8614 ** 8615 ** ^Shared-cache locks are released when a database connection concludes 8616 ** its current transaction, either by committing it or rolling it back. 8617 ** 8618 ** ^When a connection (known as the blocked connection) fails to obtain a 8619 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 8620 ** identity of the database connection (the blocking connection) that 8621 ** has locked the required resource is stored internally. ^After an 8622 ** application receives an SQLITE_LOCKED error, it may call the 8623 ** sqlite3_unlock_notify() method with the blocked connection handle as 8624 ** the first argument to register for a callback that will be invoked 8625 ** when the blocking connections current transaction is concluded. ^The 8626 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 8627 ** call that concludes the blocking connection's transaction. 8628 ** 8629 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 8630 ** there is a chance that the blocking connection will have already 8631 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 8632 ** If this happens, then the specified callback is invoked immediately, 8633 ** from within the call to sqlite3_unlock_notify().)^ 8634 ** 8635 ** ^If the blocked connection is attempting to obtain a write-lock on a 8636 ** shared-cache table, and more than one other connection currently holds 8637 ** a read-lock on the same table, then SQLite arbitrarily selects one of 8638 ** the other connections to use as the blocking connection. 8639 ** 8640 ** ^(There may be at most one unlock-notify callback registered by a 8641 ** blocked connection. If sqlite3_unlock_notify() is called when the 8642 ** blocked connection already has a registered unlock-notify callback, 8643 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 8644 ** called with a NULL pointer as its second argument, then any existing 8645 ** unlock-notify callback is canceled. ^The blocked connections 8646 ** unlock-notify callback may also be canceled by closing the blocked 8647 ** connection using [sqlite3_close()]. 8648 ** 8649 ** The unlock-notify callback is not reentrant. If an application invokes 8650 ** any sqlite3_xxx API functions from within an unlock-notify callback, a 8651 ** crash or deadlock may be the result. 8652 ** 8653 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 8654 ** returns SQLITE_OK. 8655 ** 8656 ** <b>Callback Invocation Details</b> 8657 ** 8658 ** When an unlock-notify callback is registered, the application provides a 8659 ** single void* pointer that is passed to the callback when it is invoked. 8660 ** However, the signature of the callback function allows SQLite to pass 8661 ** it an array of void* context pointers. The first argument passed to 8662 ** an unlock-notify callback is a pointer to an array of void* pointers, 8663 ** and the second is the number of entries in the array. 8664 ** 8665 ** When a blocking connection's transaction is concluded, there may be 8666 ** more than one blocked connection that has registered for an unlock-notify 8667 ** callback. ^If two or more such blocked connections have specified the 8668 ** same callback function, then instead of invoking the callback function 8669 ** multiple times, it is invoked once with the set of void* context pointers 8670 ** specified by the blocked connections bundled together into an array. 8671 ** This gives the application an opportunity to prioritize any actions 8672 ** related to the set of unblocked database connections. 8673 ** 8674 ** <b>Deadlock Detection</b> 8675 ** 8676 ** Assuming that after registering for an unlock-notify callback a 8677 ** database waits for the callback to be issued before taking any further 8678 ** action (a reasonable assumption), then using this API may cause the 8679 ** application to deadlock. For example, if connection X is waiting for 8680 ** connection Y's transaction to be concluded, and similarly connection 8681 ** Y is waiting on connection X's transaction, then neither connection 8682 ** will proceed and the system may remain deadlocked indefinitely. 8683 ** 8684 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 8685 ** detection. ^If a given call to sqlite3_unlock_notify() would put the 8686 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 8687 ** unlock-notify callback is registered. The system is said to be in 8688 ** a deadlocked state if connection A has registered for an unlock-notify 8689 ** callback on the conclusion of connection B's transaction, and connection 8690 ** B has itself registered for an unlock-notify callback when connection 8691 ** A's transaction is concluded. ^Indirect deadlock is also detected, so 8692 ** the system is also considered to be deadlocked if connection B has 8693 ** registered for an unlock-notify callback on the conclusion of connection 8694 ** C's transaction, where connection C is waiting on connection A. ^Any 8695 ** number of levels of indirection are allowed. 8696 ** 8697 ** <b>The "DROP TABLE" Exception</b> 8698 ** 8699 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 8700 ** always appropriate to call sqlite3_unlock_notify(). There is however, 8701 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 8702 ** SQLite checks if there are any currently executing SELECT statements 8703 ** that belong to the same connection. If there are, SQLITE_LOCKED is 8704 ** returned. In this case there is no "blocking connection", so invoking 8705 ** sqlite3_unlock_notify() results in the unlock-notify callback being 8706 ** invoked immediately. If the application then re-attempts the "DROP TABLE" 8707 ** or "DROP INDEX" query, an infinite loop might be the result. 8708 ** 8709 ** One way around this problem is to check the extended error code returned 8710 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 8711 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 8712 ** the special "DROP TABLE/INDEX" case, the extended error code is just 8713 ** SQLITE_LOCKED.)^ 8714 */ 8715 SQLITE_API int sqlite3_unlock_notify( 8716 sqlite3 *pBlocked, /* Waiting connection */ 8717 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 8718 void *pNotifyArg /* Argument to pass to xNotify */ 8719 ); 8720 8721 8722 /* 8723 ** CAPI3REF: String Comparison 8724 ** 8725 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 8726 ** and extensions to compare the contents of two buffers containing UTF-8 8727 ** strings in a case-independent fashion, using the same definition of "case 8728 ** independence" that SQLite uses internally when comparing identifiers. 8729 */ 8730 SQLITE_API int sqlite3_stricmp(const char *, const char *); 8731 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 8732 8733 /* 8734 ** CAPI3REF: String Globbing 8735 * 8736 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 8737 ** string X matches the [GLOB] pattern P. 8738 ** ^The definition of [GLOB] pattern matching used in 8739 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 8740 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 8741 ** is case sensitive. 8742 ** 8743 ** Note that this routine returns zero on a match and non-zero if the strings 8744 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8745 ** 8746 ** See also: [sqlite3_strlike()]. 8747 */ 8748 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 8749 8750 /* 8751 ** CAPI3REF: String LIKE Matching 8752 * 8753 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 8754 ** string X matches the [LIKE] pattern P with escape character E. 8755 ** ^The definition of [LIKE] pattern matching used in 8756 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 8757 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 8758 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 8759 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 8760 ** insensitive - equivalent upper and lower case ASCII characters match 8761 ** one another. 8762 ** 8763 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 8764 ** only ASCII characters are case folded. 8765 ** 8766 ** Note that this routine returns zero on a match and non-zero if the strings 8767 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8768 ** 8769 ** See also: [sqlite3_strglob()]. 8770 */ 8771 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 8772 8773 /* 8774 ** CAPI3REF: Error Logging Interface 8775 ** 8776 ** ^The [sqlite3_log()] interface writes a message into the [error log] 8777 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 8778 ** ^If logging is enabled, the zFormat string and subsequent arguments are 8779 ** used with [sqlite3_snprintf()] to generate the final output string. 8780 ** 8781 ** The sqlite3_log() interface is intended for use by extensions such as 8782 ** virtual tables, collating functions, and SQL functions. While there is 8783 ** nothing to prevent an application from calling sqlite3_log(), doing so 8784 ** is considered bad form. 8785 ** 8786 ** The zFormat string must not be NULL. 8787 ** 8788 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 8789 ** will not use dynamically allocated memory. The log message is stored in 8790 ** a fixed-length buffer on the stack. If the log message is longer than 8791 ** a few hundred characters, it will be truncated to the length of the 8792 ** buffer. 8793 */ 8794 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 8795 8796 /* 8797 ** CAPI3REF: Write-Ahead Log Commit Hook 8798 ** METHOD: sqlite3 8799 ** 8800 ** ^The [sqlite3_wal_hook()] function is used to register a callback that 8801 ** is invoked each time data is committed to a database in wal mode. 8802 ** 8803 ** ^(The callback is invoked by SQLite after the commit has taken place and 8804 ** the associated write-lock on the database released)^, so the implementation 8805 ** may read, write or [checkpoint] the database as required. 8806 ** 8807 ** ^The first parameter passed to the callback function when it is invoked 8808 ** is a copy of the third parameter passed to sqlite3_wal_hook() when 8809 ** registering the callback. ^The second is a copy of the database handle. 8810 ** ^The third parameter is the name of the database that was written to - 8811 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 8812 ** is the number of pages currently in the write-ahead log file, 8813 ** including those that were just committed. 8814 ** 8815 ** The callback function should normally return [SQLITE_OK]. ^If an error 8816 ** code is returned, that error will propagate back up through the 8817 ** SQLite code base to cause the statement that provoked the callback 8818 ** to report an error, though the commit will have still occurred. If the 8819 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 8820 ** that does not correspond to any valid SQLite error code, the results 8821 ** are undefined. 8822 ** 8823 ** A single database handle may have at most a single write-ahead log callback 8824 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 8825 ** previously registered write-ahead log callback. ^Note that the 8826 ** [sqlite3_wal_autocheckpoint()] interface and the 8827 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 8828 ** overwrite any prior [sqlite3_wal_hook()] settings. 8829 */ 8830 SQLITE_API void *sqlite3_wal_hook( 8831 sqlite3*, 8832 int(*)(void *,sqlite3*,const char*,int), 8833 void* 8834 ); 8835 8836 /* 8837 ** CAPI3REF: Configure an auto-checkpoint 8838 ** METHOD: sqlite3 8839 ** 8840 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 8841 ** [sqlite3_wal_hook()] that causes any database on [database connection] D 8842 ** to automatically [checkpoint] 8843 ** after committing a transaction if there are N or 8844 ** more frames in the [write-ahead log] file. ^Passing zero or 8845 ** a negative value as the nFrame parameter disables automatic 8846 ** checkpoints entirely. 8847 ** 8848 ** ^The callback registered by this function replaces any existing callback 8849 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 8850 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 8851 ** configured by this function. 8852 ** 8853 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 8854 ** from SQL. 8855 ** 8856 ** ^Checkpoints initiated by this mechanism are 8857 ** [sqlite3_wal_checkpoint_v2|PASSIVE]. 8858 ** 8859 ** ^Every new [database connection] defaults to having the auto-checkpoint 8860 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 8861 ** pages. The use of this interface 8862 ** is only necessary if the default setting is found to be suboptimal 8863 ** for a particular application. 8864 */ 8865 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 8866 8867 /* 8868 ** CAPI3REF: Checkpoint a database 8869 ** METHOD: sqlite3 8870 ** 8871 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 8872 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 8873 ** 8874 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 8875 ** [write-ahead log] for database X on [database connection] D to be 8876 ** transferred into the database file and for the write-ahead log to 8877 ** be reset. See the [checkpointing] documentation for addition 8878 ** information. 8879 ** 8880 ** This interface used to be the only way to cause a checkpoint to 8881 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 8882 ** interface was added. This interface is retained for backwards 8883 ** compatibility and as a convenience for applications that need to manually 8884 ** start a callback but which do not need the full power (and corresponding 8885 ** complication) of [sqlite3_wal_checkpoint_v2()]. 8886 */ 8887 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 8888 8889 /* 8890 ** CAPI3REF: Checkpoint a database 8891 ** METHOD: sqlite3 8892 ** 8893 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 8894 ** operation on database X of [database connection] D in mode M. Status 8895 ** information is written back into integers pointed to by L and C.)^ 8896 ** ^(The M parameter must be a valid [checkpoint mode]:)^ 8897 ** 8898 ** <dl> 8899 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 8900 ** ^Checkpoint as many frames as possible without waiting for any database 8901 ** readers or writers to finish, then sync the database file if all frames 8902 ** in the log were checkpointed. ^The [busy-handler callback] 8903 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 8904 ** ^On the other hand, passive mode might leave the checkpoint unfinished 8905 ** if there are concurrent readers or writers. 8906 ** 8907 ** <dt>SQLITE_CHECKPOINT_FULL<dd> 8908 ** ^This mode blocks (it invokes the 8909 ** [sqlite3_busy_handler|busy-handler callback]) until there is no 8910 ** database writer and all readers are reading from the most recent database 8911 ** snapshot. ^It then checkpoints all frames in the log file and syncs the 8912 ** database file. ^This mode blocks new database writers while it is pending, 8913 ** but new database readers are allowed to continue unimpeded. 8914 ** 8915 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 8916 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 8917 ** that after checkpointing the log file it blocks (calls the 8918 ** [busy-handler callback]) 8919 ** until all readers are reading from the database file only. ^This ensures 8920 ** that the next writer will restart the log file from the beginning. 8921 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 8922 ** database writer attempts while it is pending, but does not impede readers. 8923 ** 8924 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 8925 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 8926 ** addition that it also truncates the log file to zero bytes just prior 8927 ** to a successful return. 8928 ** </dl> 8929 ** 8930 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 8931 ** the log file or to -1 if the checkpoint could not run because 8932 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 8933 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 8934 ** log file (including any that were already checkpointed before the function 8935 ** was called) or to -1 if the checkpoint could not run due to an error or 8936 ** because the database is not in WAL mode. ^Note that upon successful 8937 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 8938 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 8939 ** 8940 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 8941 ** any other process is running a checkpoint operation at the same time, the 8942 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 8943 ** busy-handler configured, it will not be invoked in this case. 8944 ** 8945 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 8946 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be 8947 ** obtained immediately, and a busy-handler is configured, it is invoked and 8948 ** the writer lock retried until either the busy-handler returns 0 or the lock 8949 ** is successfully obtained. ^The busy-handler is also invoked while waiting for 8950 ** database readers as described above. ^If the busy-handler returns 0 before 8951 ** the writer lock is obtained or while waiting for database readers, the 8952 ** checkpoint operation proceeds from that point in the same way as 8953 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 8954 ** without blocking any further. ^SQLITE_BUSY is returned in this case. 8955 ** 8956 ** ^If parameter zDb is NULL or points to a zero length string, then the 8957 ** specified operation is attempted on all WAL databases [attached] to 8958 ** [database connection] db. In this case the 8959 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 8960 ** an SQLITE_BUSY error is encountered when processing one or more of the 8961 ** attached WAL databases, the operation is still attempted on any remaining 8962 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other 8963 ** error occurs while processing an attached database, processing is abandoned 8964 ** and the error code is returned to the caller immediately. ^If no error 8965 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 8966 ** databases, SQLITE_OK is returned. 8967 ** 8968 ** ^If database zDb is the name of an attached database that is not in WAL 8969 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 8970 ** zDb is not NULL (or a zero length string) and is not the name of any 8971 ** attached database, SQLITE_ERROR is returned to the caller. 8972 ** 8973 ** ^Unless it returns SQLITE_MISUSE, 8974 ** the sqlite3_wal_checkpoint_v2() interface 8975 ** sets the error information that is queried by 8976 ** [sqlite3_errcode()] and [sqlite3_errmsg()]. 8977 ** 8978 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 8979 ** from SQL. 8980 */ 8981 SQLITE_API int sqlite3_wal_checkpoint_v2( 8982 sqlite3 *db, /* Database handle */ 8983 const char *zDb, /* Name of attached database (or NULL) */ 8984 int eMode, /* SQLITE_CHECKPOINT_* value */ 8985 int *pnLog, /* OUT: Size of WAL log in frames */ 8986 int *pnCkpt /* OUT: Total number of frames checkpointed */ 8987 ); 8988 8989 /* 8990 ** CAPI3REF: Checkpoint Mode Values 8991 ** KEYWORDS: {checkpoint mode} 8992 ** 8993 ** These constants define all valid values for the "checkpoint mode" passed 8994 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 8995 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 8996 ** meaning of each of these checkpoint modes. 8997 */ 8998 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 8999 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 9000 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 9001 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 9002 9003 /* 9004 ** CAPI3REF: Virtual Table Interface Configuration 9005 ** 9006 ** This function may be called by either the [xConnect] or [xCreate] method 9007 ** of a [virtual table] implementation to configure 9008 ** various facets of the virtual table interface. 9009 ** 9010 ** If this interface is invoked outside the context of an xConnect or 9011 ** xCreate virtual table method then the behavior is undefined. 9012 ** 9013 ** In the call sqlite3_vtab_config(D,C,...) the D parameter is the 9014 ** [database connection] in which the virtual table is being created and 9015 ** which is passed in as the first argument to the [xConnect] or [xCreate] 9016 ** method that is invoking sqlite3_vtab_config(). The C parameter is one 9017 ** of the [virtual table configuration options]. The presence and meaning 9018 ** of parameters after C depend on which [virtual table configuration option] 9019 ** is used. 9020 */ 9021 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 9022 9023 /* 9024 ** CAPI3REF: Virtual Table Configuration Options 9025 ** KEYWORDS: {virtual table configuration options} 9026 ** KEYWORDS: {virtual table configuration option} 9027 ** 9028 ** These macros define the various options to the 9029 ** [sqlite3_vtab_config()] interface that [virtual table] implementations 9030 ** can use to customize and optimize their behavior. 9031 ** 9032 ** <dl> 9033 ** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] 9034 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt> 9035 ** <dd>Calls of the form 9036 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 9037 ** where X is an integer. If X is zero, then the [virtual table] whose 9038 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 9039 ** support constraints. In this configuration (which is the default) if 9040 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 9041 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 9042 ** specified as part of the users SQL statement, regardless of the actual 9043 ** ON CONFLICT mode specified. 9044 ** 9045 ** If X is non-zero, then the virtual table implementation guarantees 9046 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 9047 ** any modifications to internal or persistent data structures have been made. 9048 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 9049 ** is able to roll back a statement or database transaction, and abandon 9050 ** or continue processing the current SQL statement as appropriate. 9051 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 9052 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 9053 ** had been ABORT. 9054 ** 9055 ** Virtual table implementations that are required to handle OR REPLACE 9056 ** must do so within the [xUpdate] method. If a call to the 9057 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 9058 ** CONFLICT policy is REPLACE, the virtual table implementation should 9059 ** silently replace the appropriate rows within the xUpdate callback and 9060 ** return SQLITE_OK. Or, if this is not possible, it may return 9061 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 9062 ** constraint handling. 9063 ** </dd> 9064 ** 9065 ** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt> 9066 ** <dd>Calls of the form 9067 ** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the 9068 ** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9069 ** prohibits that virtual table from being used from within triggers and 9070 ** views. 9071 ** </dd> 9072 ** 9073 ** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt> 9074 ** <dd>Calls of the form 9075 ** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the 9076 ** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9077 ** identify that virtual table as being safe to use from within triggers 9078 ** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the 9079 ** virtual table can do no serious harm even if it is controlled by a 9080 ** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS 9081 ** flag unless absolutely necessary. 9082 ** </dd> 9083 ** </dl> 9084 */ 9085 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 9086 #define SQLITE_VTAB_INNOCUOUS 2 9087 #define SQLITE_VTAB_DIRECTONLY 3 9088 9089 /* 9090 ** CAPI3REF: Determine The Virtual Table Conflict Policy 9091 ** 9092 ** This function may only be called from within a call to the [xUpdate] method 9093 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 9094 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 9095 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 9096 ** of the SQL statement that triggered the call to the [xUpdate] method of the 9097 ** [virtual table]. 9098 */ 9099 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 9100 9101 /* 9102 ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 9103 ** 9104 ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 9105 ** method of a [virtual table], then it returns true if and only if the 9106 ** column is being fetched as part of an UPDATE operation during which the 9107 ** column value will not change. Applications might use this to substitute 9108 ** a return value that is less expensive to compute and that the corresponding 9109 ** [xUpdate] method understands as a "no-change" value. 9110 ** 9111 ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 9112 ** the column is not changed by the UPDATE statement, then the xColumn 9113 ** method can optionally return without setting a result, without calling 9114 ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 9115 ** In that case, [sqlite3_value_nochange(X)] will return true for the 9116 ** same column in the [xUpdate] method. 9117 */ 9118 SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*); 9119 9120 /* 9121 ** CAPI3REF: Determine The Collation For a Virtual Table Constraint 9122 ** 9123 ** This function may only be called from within a call to the [xBestIndex] 9124 ** method of a [virtual table]. 9125 ** 9126 ** The first argument must be the sqlite3_index_info object that is the 9127 ** first parameter to the xBestIndex() method. The second argument must be 9128 ** an index into the aConstraint[] array belonging to the sqlite3_index_info 9129 ** structure passed to xBestIndex. This function returns a pointer to a buffer 9130 ** containing the name of the collation sequence for the corresponding 9131 ** constraint. 9132 */ 9133 SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 9134 9135 /* 9136 ** CAPI3REF: Conflict resolution modes 9137 ** KEYWORDS: {conflict resolution mode} 9138 ** 9139 ** These constants are returned by [sqlite3_vtab_on_conflict()] to 9140 ** inform a [virtual table] implementation what the [ON CONFLICT] mode 9141 ** is for the SQL statement being evaluated. 9142 ** 9143 ** Note that the [SQLITE_IGNORE] constant is also used as a potential 9144 ** return value from the [sqlite3_set_authorizer()] callback and that 9145 ** [SQLITE_ABORT] is also a [result code]. 9146 */ 9147 #define SQLITE_ROLLBACK 1 9148 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 9149 #define SQLITE_FAIL 3 9150 /* #define SQLITE_ABORT 4 // Also an error code */ 9151 #define SQLITE_REPLACE 5 9152 9153 /* 9154 ** CAPI3REF: Prepared Statement Scan Status Opcodes 9155 ** KEYWORDS: {scanstatus options} 9156 ** 9157 ** The following constants can be used for the T parameter to the 9158 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 9159 ** different metric for sqlite3_stmt_scanstatus() to return. 9160 ** 9161 ** When the value returned to V is a string, space to hold that string is 9162 ** managed by the prepared statement S and will be automatically freed when 9163 ** S is finalized. 9164 ** 9165 ** <dl> 9166 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 9167 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be 9168 ** set to the total number of times that the X-th loop has run.</dd> 9169 ** 9170 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 9171 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set 9172 ** to the total number of rows examined by all iterations of the X-th loop.</dd> 9173 ** 9174 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 9175 ** <dd>^The "double" variable pointed to by the V parameter will be set to the 9176 ** query planner's estimate for the average number of rows output from each 9177 ** iteration of the X-th loop. If the query planner's estimates was accurate, 9178 ** then this value will approximate the quotient NVISIT/NLOOP and the 9179 ** product of this value for all prior loops with the same SELECTID will 9180 ** be the NLOOP value for the current loop. 9181 ** 9182 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 9183 ** <dd>^The "const char *" variable pointed to by the V parameter will be set 9184 ** to a zero-terminated UTF-8 string containing the name of the index or table 9185 ** used for the X-th loop. 9186 ** 9187 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 9188 ** <dd>^The "const char *" variable pointed to by the V parameter will be set 9189 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 9190 ** description for the X-th loop. 9191 ** 9192 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 9193 ** <dd>^The "int" variable pointed to by the V parameter will be set to the 9194 ** "select-id" for the X-th loop. The select-id identifies which query or 9195 ** subquery the loop is part of. The main query has a select-id of zero. 9196 ** The select-id is the same value as is output in the first column 9197 ** of an [EXPLAIN QUERY PLAN] query. 9198 ** </dl> 9199 */ 9200 #define SQLITE_SCANSTAT_NLOOP 0 9201 #define SQLITE_SCANSTAT_NVISIT 1 9202 #define SQLITE_SCANSTAT_EST 2 9203 #define SQLITE_SCANSTAT_NAME 3 9204 #define SQLITE_SCANSTAT_EXPLAIN 4 9205 #define SQLITE_SCANSTAT_SELECTID 5 9206 9207 /* 9208 ** CAPI3REF: Prepared Statement Scan Status 9209 ** METHOD: sqlite3_stmt 9210 ** 9211 ** This interface returns information about the predicted and measured 9212 ** performance for pStmt. Advanced applications can use this 9213 ** interface to compare the predicted and the measured performance and 9214 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 9215 ** 9216 ** Since this interface is expected to be rarely used, it is only 9217 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 9218 ** compile-time option. 9219 ** 9220 ** The "iScanStatusOp" parameter determines which status information to return. 9221 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 9222 ** of this interface is undefined. 9223 ** ^The requested measurement is written into a variable pointed to by 9224 ** the "pOut" parameter. 9225 ** Parameter "idx" identifies the specific loop to retrieve statistics for. 9226 ** Loops are numbered starting from zero. ^If idx is out of range - less than 9227 ** zero or greater than or equal to the total number of loops used to implement 9228 ** the statement - a non-zero value is returned and the variable that pOut 9229 ** points to is unchanged. 9230 ** 9231 ** ^Statistics might not be available for all loops in all statements. ^In cases 9232 ** where there exist loops with no available statistics, this function behaves 9233 ** as if the loop did not exist - it returns non-zero and leave the variable 9234 ** that pOut points to unchanged. 9235 ** 9236 ** See also: [sqlite3_stmt_scanstatus_reset()] 9237 */ 9238 SQLITE_API int sqlite3_stmt_scanstatus( 9239 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 9240 int idx, /* Index of loop to report on */ 9241 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 9242 void *pOut /* Result written here */ 9243 ); 9244 9245 /* 9246 ** CAPI3REF: Zero Scan-Status Counters 9247 ** METHOD: sqlite3_stmt 9248 ** 9249 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 9250 ** 9251 ** This API is only available if the library is built with pre-processor 9252 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 9253 */ 9254 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 9255 9256 /* 9257 ** CAPI3REF: Flush caches to disk mid-transaction 9258 ** 9259 ** ^If a write-transaction is open on [database connection] D when the 9260 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 9261 ** pages in the pager-cache that are not currently in use are written out 9262 ** to disk. A dirty page may be in use if a database cursor created by an 9263 ** active SQL statement is reading from it, or if it is page 1 of a database 9264 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 9265 ** interface flushes caches for all schemas - "main", "temp", and 9266 ** any [attached] databases. 9267 ** 9268 ** ^If this function needs to obtain extra database locks before dirty pages 9269 ** can be flushed to disk, it does so. ^If those locks cannot be obtained 9270 ** immediately and there is a busy-handler callback configured, it is invoked 9271 ** in the usual manner. ^If the required lock still cannot be obtained, then 9272 ** the database is skipped and an attempt made to flush any dirty pages 9273 ** belonging to the next (if any) database. ^If any databases are skipped 9274 ** because locks cannot be obtained, but no other error occurs, this 9275 ** function returns SQLITE_BUSY. 9276 ** 9277 ** ^If any other error occurs while flushing dirty pages to disk (for 9278 ** example an IO error or out-of-memory condition), then processing is 9279 ** abandoned and an SQLite [error code] is returned to the caller immediately. 9280 ** 9281 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 9282 ** 9283 ** ^This function does not set the database handle error code or message 9284 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 9285 */ 9286 SQLITE_API int sqlite3_db_cacheflush(sqlite3*); 9287 9288 /* 9289 ** CAPI3REF: The pre-update hook. 9290 ** 9291 ** ^These interfaces are only available if SQLite is compiled using the 9292 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 9293 ** 9294 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function 9295 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 9296 ** on a database table. 9297 ** ^At most one preupdate hook may be registered at a time on a single 9298 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 9299 ** the previous setting. 9300 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 9301 ** with a NULL pointer as the second parameter. 9302 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 9303 ** the first parameter to callbacks. 9304 ** 9305 ** ^The preupdate hook only fires for changes to real database tables; the 9306 ** preupdate hook is not invoked for changes to [virtual tables] or to 9307 ** system tables like sqlite_master or sqlite_stat1. 9308 ** 9309 ** ^The second parameter to the preupdate callback is a pointer to 9310 ** the [database connection] that registered the preupdate hook. 9311 ** ^The third parameter to the preupdate callback is one of the constants 9312 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 9313 ** kind of update operation that is about to occur. 9314 ** ^(The fourth parameter to the preupdate callback is the name of the 9315 ** database within the database connection that is being modified. This 9316 ** will be "main" for the main database or "temp" for TEMP tables or 9317 ** the name given after the AS keyword in the [ATTACH] statement for attached 9318 ** databases.)^ 9319 ** ^The fifth parameter to the preupdate callback is the name of the 9320 ** table that is being modified. 9321 ** 9322 ** For an UPDATE or DELETE operation on a [rowid table], the sixth 9323 ** parameter passed to the preupdate callback is the initial [rowid] of the 9324 ** row being modified or deleted. For an INSERT operation on a rowid table, 9325 ** or any operation on a WITHOUT ROWID table, the value of the sixth 9326 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the 9327 ** seventh parameter is the final rowid value of the row being inserted 9328 ** or updated. The value of the seventh parameter passed to the callback 9329 ** function is not defined for operations on WITHOUT ROWID tables, or for 9330 ** INSERT operations on rowid tables. 9331 ** 9332 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 9333 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 9334 ** provide additional information about a preupdate event. These routines 9335 ** may only be called from within a preupdate callback. Invoking any of 9336 ** these routines from outside of a preupdate callback or with a 9337 ** [database connection] pointer that is different from the one supplied 9338 ** to the preupdate callback results in undefined and probably undesirable 9339 ** behavior. 9340 ** 9341 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 9342 ** in the row that is being inserted, updated, or deleted. 9343 ** 9344 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 9345 ** a [protected sqlite3_value] that contains the value of the Nth column of 9346 ** the table row before it is updated. The N parameter must be between 0 9347 ** and one less than the number of columns or the behavior will be 9348 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 9349 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 9350 ** behavior is undefined. The [sqlite3_value] that P points to 9351 ** will be destroyed when the preupdate callback returns. 9352 ** 9353 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 9354 ** a [protected sqlite3_value] that contains the value of the Nth column of 9355 ** the table row after it is updated. The N parameter must be between 0 9356 ** and one less than the number of columns or the behavior will be 9357 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 9358 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 9359 ** behavior is undefined. The [sqlite3_value] that P points to 9360 ** will be destroyed when the preupdate callback returns. 9361 ** 9362 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 9363 ** callback was invoked as a result of a direct insert, update, or delete 9364 ** operation; or 1 for inserts, updates, or deletes invoked by top-level 9365 ** triggers; or 2 for changes resulting from triggers called by top-level 9366 ** triggers; and so forth. 9367 ** 9368 ** See also: [sqlite3_update_hook()] 9369 */ 9370 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 9371 SQLITE_API void *sqlite3_preupdate_hook( 9372 sqlite3 *db, 9373 void(*xPreUpdate)( 9374 void *pCtx, /* Copy of third arg to preupdate_hook() */ 9375 sqlite3 *db, /* Database handle */ 9376 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 9377 char const *zDb, /* Database name */ 9378 char const *zName, /* Table name */ 9379 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 9380 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 9381 ), 9382 void* 9383 ); 9384 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 9385 SQLITE_API int sqlite3_preupdate_count(sqlite3 *); 9386 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *); 9387 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 9388 #endif 9389 9390 /* 9391 ** CAPI3REF: Low-level system error code 9392 ** 9393 ** ^Attempt to return the underlying operating system error code or error 9394 ** number that caused the most recent I/O error or failure to open a file. 9395 ** The return value is OS-dependent. For example, on unix systems, after 9396 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 9397 ** called to get back the underlying "errno" that caused the problem, such 9398 ** as ENOSPC, EAUTH, EISDIR, and so forth. 9399 */ 9400 SQLITE_API int sqlite3_system_errno(sqlite3*); 9401 9402 /* 9403 ** CAPI3REF: Database Snapshot 9404 ** KEYWORDS: {snapshot} {sqlite3_snapshot} 9405 ** 9406 ** An instance of the snapshot object records the state of a [WAL mode] 9407 ** database for some specific point in history. 9408 ** 9409 ** In [WAL mode], multiple [database connections] that are open on the 9410 ** same database file can each be reading a different historical version 9411 ** of the database file. When a [database connection] begins a read 9412 ** transaction, that connection sees an unchanging copy of the database 9413 ** as it existed for the point in time when the transaction first started. 9414 ** Subsequent changes to the database from other connections are not seen 9415 ** by the reader until a new read transaction is started. 9416 ** 9417 ** The sqlite3_snapshot object records state information about an historical 9418 ** version of the database file so that it is possible to later open a new read 9419 ** transaction that sees that historical version of the database rather than 9420 ** the most recent version. 9421 */ 9422 typedef struct sqlite3_snapshot { 9423 unsigned char hidden[48]; 9424 } sqlite3_snapshot; 9425 9426 /* 9427 ** CAPI3REF: Record A Database Snapshot 9428 ** CONSTRUCTOR: sqlite3_snapshot 9429 ** 9430 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 9431 ** new [sqlite3_snapshot] object that records the current state of 9432 ** schema S in database connection D. ^On success, the 9433 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 9434 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 9435 ** If there is not already a read-transaction open on schema S when 9436 ** this function is called, one is opened automatically. 9437 ** 9438 ** The following must be true for this function to succeed. If any of 9439 ** the following statements are false when sqlite3_snapshot_get() is 9440 ** called, SQLITE_ERROR is returned. The final value of *P is undefined 9441 ** in this case. 9442 ** 9443 ** <ul> 9444 ** <li> The database handle must not be in [autocommit mode]. 9445 ** 9446 ** <li> Schema S of [database connection] D must be a [WAL mode] database. 9447 ** 9448 ** <li> There must not be a write transaction open on schema S of database 9449 ** connection D. 9450 ** 9451 ** <li> One or more transactions must have been written to the current wal 9452 ** file since it was created on disk (by any connection). This means 9453 ** that a snapshot cannot be taken on a wal mode database with no wal 9454 ** file immediately after it is first opened. At least one transaction 9455 ** must be written to it first. 9456 ** </ul> 9457 ** 9458 ** This function may also return SQLITE_NOMEM. If it is called with the 9459 ** database handle in autocommit mode but fails for some other reason, 9460 ** whether or not a read transaction is opened on schema S is undefined. 9461 ** 9462 ** The [sqlite3_snapshot] object returned from a successful call to 9463 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 9464 ** to avoid a memory leak. 9465 ** 9466 ** The [sqlite3_snapshot_get()] interface is only available when the 9467 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9468 */ 9469 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 9470 sqlite3 *db, 9471 const char *zSchema, 9472 sqlite3_snapshot **ppSnapshot 9473 ); 9474 9475 /* 9476 ** CAPI3REF: Start a read transaction on an historical snapshot 9477 ** METHOD: sqlite3_snapshot 9478 ** 9479 ** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 9480 ** transaction or upgrades an existing one for schema S of 9481 ** [database connection] D such that the read transaction refers to 9482 ** historical [snapshot] P, rather than the most recent change to the 9483 ** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 9484 ** on success or an appropriate [error code] if it fails. 9485 ** 9486 ** ^In order to succeed, the database connection must not be in 9487 ** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 9488 ** is already a read transaction open on schema S, then the database handle 9489 ** must have no active statements (SELECT statements that have been passed 9490 ** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 9491 ** SQLITE_ERROR is returned if either of these conditions is violated, or 9492 ** if schema S does not exist, or if the snapshot object is invalid. 9493 ** 9494 ** ^A call to sqlite3_snapshot_open() will fail to open if the specified 9495 ** snapshot has been overwritten by a [checkpoint]. In this case 9496 ** SQLITE_ERROR_SNAPSHOT is returned. 9497 ** 9498 ** If there is already a read transaction open when this function is 9499 ** invoked, then the same read transaction remains open (on the same 9500 ** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 9501 ** is returned. If another error code - for example SQLITE_PROTOCOL or an 9502 ** SQLITE_IOERR error code - is returned, then the final state of the 9503 ** read transaction is undefined. If SQLITE_OK is returned, then the 9504 ** read transaction is now open on database snapshot P. 9505 ** 9506 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 9507 ** database connection D does not know that the database file for 9508 ** schema S is in [WAL mode]. A database connection might not know 9509 ** that the database file is in [WAL mode] if there has been no prior 9510 ** I/O on that database connection, or if the database entered [WAL mode] 9511 ** after the most recent I/O on the database connection.)^ 9512 ** (Hint: Run "[PRAGMA application_id]" against a newly opened 9513 ** database connection in order to make it ready to use snapshots.) 9514 ** 9515 ** The [sqlite3_snapshot_open()] interface is only available when the 9516 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9517 */ 9518 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 9519 sqlite3 *db, 9520 const char *zSchema, 9521 sqlite3_snapshot *pSnapshot 9522 ); 9523 9524 /* 9525 ** CAPI3REF: Destroy a snapshot 9526 ** DESTRUCTOR: sqlite3_snapshot 9527 ** 9528 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 9529 ** The application must eventually free every [sqlite3_snapshot] object 9530 ** using this routine to avoid a memory leak. 9531 ** 9532 ** The [sqlite3_snapshot_free()] interface is only available when the 9533 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9534 */ 9535 SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 9536 9537 /* 9538 ** CAPI3REF: Compare the ages of two snapshot handles. 9539 ** METHOD: sqlite3_snapshot 9540 ** 9541 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 9542 ** of two valid snapshot handles. 9543 ** 9544 ** If the two snapshot handles are not associated with the same database 9545 ** file, the result of the comparison is undefined. 9546 ** 9547 ** Additionally, the result of the comparison is only valid if both of the 9548 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 9549 ** last time the wal file was deleted. The wal file is deleted when the 9550 ** database is changed back to rollback mode or when the number of database 9551 ** clients drops to zero. If either snapshot handle was obtained before the 9552 ** wal file was last deleted, the value returned by this function 9553 ** is undefined. 9554 ** 9555 ** Otherwise, this API returns a negative value if P1 refers to an older 9556 ** snapshot than P2, zero if the two handles refer to the same database 9557 ** snapshot, and a positive value if P1 is a newer snapshot than P2. 9558 ** 9559 ** This interface is only available if SQLite is compiled with the 9560 ** [SQLITE_ENABLE_SNAPSHOT] option. 9561 */ 9562 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 9563 sqlite3_snapshot *p1, 9564 sqlite3_snapshot *p2 9565 ); 9566 9567 /* 9568 ** CAPI3REF: Recover snapshots from a wal file 9569 ** METHOD: sqlite3_snapshot 9570 ** 9571 ** If a [WAL file] remains on disk after all database connections close 9572 ** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 9573 ** or because the last process to have the database opened exited without 9574 ** calling [sqlite3_close()]) and a new connection is subsequently opened 9575 ** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 9576 ** will only be able to open the last transaction added to the WAL file 9577 ** even though the WAL file contains other valid transactions. 9578 ** 9579 ** This function attempts to scan the WAL file associated with database zDb 9580 ** of database handle db and make all valid snapshots available to 9581 ** sqlite3_snapshot_open(). It is an error if there is already a read 9582 ** transaction open on the database, or if the database is not a WAL mode 9583 ** database. 9584 ** 9585 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 9586 ** 9587 ** This interface is only available if SQLite is compiled with the 9588 ** [SQLITE_ENABLE_SNAPSHOT] option. 9589 */ 9590 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 9591 9592 /* 9593 ** CAPI3REF: Serialize a database 9594 ** 9595 ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 9596 ** that is a serialization of the S database on [database connection] D. 9597 ** If P is not a NULL pointer, then the size of the database in bytes 9598 ** is written into *P. 9599 ** 9600 ** For an ordinary on-disk database file, the serialization is just a 9601 ** copy of the disk file. For an in-memory database or a "TEMP" database, 9602 ** the serialization is the same sequence of bytes which would be written 9603 ** to disk if that database where backed up to disk. 9604 ** 9605 ** The usual case is that sqlite3_serialize() copies the serialization of 9606 ** the database into memory obtained from [sqlite3_malloc64()] and returns 9607 ** a pointer to that memory. The caller is responsible for freeing the 9608 ** returned value to avoid a memory leak. However, if the F argument 9609 ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 9610 ** are made, and the sqlite3_serialize() function will return a pointer 9611 ** to the contiguous memory representation of the database that SQLite 9612 ** is currently using for that database, or NULL if the no such contiguous 9613 ** memory representation of the database exists. A contiguous memory 9614 ** representation of the database will usually only exist if there has 9615 ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 9616 ** values of D and S. 9617 ** The size of the database is written into *P even if the 9618 ** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 9619 ** of the database exists. 9620 ** 9621 ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 9622 ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 9623 ** allocation error occurs. 9624 ** 9625 ** This interface is only available if SQLite is compiled with the 9626 ** [SQLITE_ENABLE_DESERIALIZE] option. 9627 */ 9628 SQLITE_API unsigned char *sqlite3_serialize( 9629 sqlite3 *db, /* The database connection */ 9630 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 9631 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 9632 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 9633 ); 9634 9635 /* 9636 ** CAPI3REF: Flags for sqlite3_serialize 9637 ** 9638 ** Zero or more of the following constants can be OR-ed together for 9639 ** the F argument to [sqlite3_serialize(D,S,P,F)]. 9640 ** 9641 ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 9642 ** a pointer to contiguous in-memory database that it is currently using, 9643 ** without making a copy of the database. If SQLite is not currently using 9644 ** a contiguous in-memory database, then this option causes 9645 ** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 9646 ** using a contiguous in-memory database if it has been initialized by a 9647 ** prior call to [sqlite3_deserialize()]. 9648 */ 9649 #define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 9650 9651 /* 9652 ** CAPI3REF: Deserialize a database 9653 ** 9654 ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 9655 ** [database connection] D to disconnect from database S and then 9656 ** reopen S as an in-memory database based on the serialization contained 9657 ** in P. The serialized database P is N bytes in size. M is the size of 9658 ** the buffer P, which might be larger than N. If M is larger than N, and 9659 ** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 9660 ** permitted to add content to the in-memory database as long as the total 9661 ** size does not exceed M bytes. 9662 ** 9663 ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 9664 ** invoke sqlite3_free() on the serialization buffer when the database 9665 ** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 9666 ** SQLite will try to increase the buffer size using sqlite3_realloc64() 9667 ** if writes on the database cause it to grow larger than M bytes. 9668 ** 9669 ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 9670 ** database is currently in a read transaction or is involved in a backup 9671 ** operation. 9672 ** 9673 ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 9674 ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 9675 ** [sqlite3_free()] is invoked on argument P prior to returning. 9676 ** 9677 ** This interface is only available if SQLite is compiled with the 9678 ** [SQLITE_ENABLE_DESERIALIZE] option. 9679 */ 9680 SQLITE_API int sqlite3_deserialize( 9681 sqlite3 *db, /* The database connection */ 9682 const char *zSchema, /* Which DB to reopen with the deserialization */ 9683 unsigned char *pData, /* The serialized database content */ 9684 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 9685 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 9686 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 9687 ); 9688 9689 /* 9690 ** CAPI3REF: Flags for sqlite3_deserialize() 9691 ** 9692 ** The following are allowed values for 6th argument (the F argument) to 9693 ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 9694 ** 9695 ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 9696 ** in the P argument is held in memory obtained from [sqlite3_malloc64()] 9697 ** and that SQLite should take ownership of this memory and automatically 9698 ** free it when it has finished using it. Without this flag, the caller 9699 ** is responsible for freeing any dynamically allocated memory. 9700 ** 9701 ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 9702 ** grow the size of the database using calls to [sqlite3_realloc64()]. This 9703 ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 9704 ** Without this flag, the deserialized database cannot increase in size beyond 9705 ** the number of bytes specified by the M parameter. 9706 ** 9707 ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 9708 ** should be treated as read-only. 9709 */ 9710 #define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 9711 #define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 9712 #define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 9713 9714 /* 9715 ** Undo the hack that converts floating point types to integer for 9716 ** builds on processors without floating point support. 9717 */ 9718 #ifdef SQLITE_OMIT_FLOATING_POINT 9719 # undef double 9720 #endif 9721 9722 #ifdef __cplusplus 9723 } /* End of the 'extern "C"' block */ 9724 #endif 9725 #endif /* SQLITE3_H */ 9726 9727 /******** Begin file sqlite3rtree.h *********/ 9728 /* 9729 ** 2010 August 30 9730 ** 9731 ** The author disclaims copyright to this source code. In place of 9732 ** a legal notice, here is a blessing: 9733 ** 9734 ** May you do good and not evil. 9735 ** May you find forgiveness for yourself and forgive others. 9736 ** May you share freely, never taking more than you give. 9737 ** 9738 ************************************************************************* 9739 */ 9740 9741 #ifndef _SQLITE3RTREE_H_ 9742 #define _SQLITE3RTREE_H_ 9743 9744 9745 #ifdef __cplusplus 9746 extern "C" { 9747 #endif 9748 9749 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 9750 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 9751 9752 /* The double-precision datatype used by RTree depends on the 9753 ** SQLITE_RTREE_INT_ONLY compile-time option. 9754 */ 9755 #ifdef SQLITE_RTREE_INT_ONLY 9756 typedef sqlite3_int64 sqlite3_rtree_dbl; 9757 #else 9758 typedef double sqlite3_rtree_dbl; 9759 #endif 9760 9761 /* 9762 ** Register a geometry callback named zGeom that can be used as part of an 9763 ** R-Tree geometry query as follows: 9764 ** 9765 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 9766 */ 9767 SQLITE_API int sqlite3_rtree_geometry_callback( 9768 sqlite3 *db, 9769 const char *zGeom, 9770 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 9771 void *pContext 9772 ); 9773 9774 9775 /* 9776 ** A pointer to a structure of the following type is passed as the first 9777 ** argument to callbacks registered using rtree_geometry_callback(). 9778 */ 9779 struct sqlite3_rtree_geometry { 9780 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 9781 int nParam; /* Size of array aParam[] */ 9782 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 9783 void *pUser; /* Callback implementation user data */ 9784 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 9785 }; 9786 9787 /* 9788 ** Register a 2nd-generation geometry callback named zScore that can be 9789 ** used as part of an R-Tree geometry query as follows: 9790 ** 9791 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 9792 */ 9793 SQLITE_API int sqlite3_rtree_query_callback( 9794 sqlite3 *db, 9795 const char *zQueryFunc, 9796 int (*xQueryFunc)(sqlite3_rtree_query_info*), 9797 void *pContext, 9798 void (*xDestructor)(void*) 9799 ); 9800 9801 9802 /* 9803 ** A pointer to a structure of the following type is passed as the 9804 ** argument to scored geometry callback registered using 9805 ** sqlite3_rtree_query_callback(). 9806 ** 9807 ** Note that the first 5 fields of this structure are identical to 9808 ** sqlite3_rtree_geometry. This structure is a subclass of 9809 ** sqlite3_rtree_geometry. 9810 */ 9811 struct sqlite3_rtree_query_info { 9812 void *pContext; /* pContext from when function registered */ 9813 int nParam; /* Number of function parameters */ 9814 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 9815 void *pUser; /* callback can use this, if desired */ 9816 void (*xDelUser)(void*); /* function to free pUser */ 9817 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 9818 unsigned int *anQueue; /* Number of pending entries in the queue */ 9819 int nCoord; /* Number of coordinates */ 9820 int iLevel; /* Level of current node or entry */ 9821 int mxLevel; /* The largest iLevel value in the tree */ 9822 sqlite3_int64 iRowid; /* Rowid for current entry */ 9823 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 9824 int eParentWithin; /* Visibility of parent node */ 9825 int eWithin; /* OUT: Visibility */ 9826 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 9827 /* The following fields are only available in 3.8.11 and later */ 9828 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 9829 }; 9830 9831 /* 9832 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 9833 */ 9834 #define NOT_WITHIN 0 /* Object completely outside of query region */ 9835 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 9836 #define FULLY_WITHIN 2 /* Object fully contained within query region */ 9837 9838 9839 #ifdef __cplusplus 9840 } /* end of the 'extern "C"' block */ 9841 #endif 9842 9843 #endif /* ifndef _SQLITE3RTREE_H_ */ 9844 9845 /******** End of sqlite3rtree.h *********/ 9846 /******** Begin file sqlite3session.h *********/ 9847 9848 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 9849 #define __SQLITESESSION_H_ 1 9850 9851 /* 9852 ** Make sure we can call this stuff from C++. 9853 */ 9854 #ifdef __cplusplus 9855 extern "C" { 9856 #endif 9857 9858 9859 /* 9860 ** CAPI3REF: Session Object Handle 9861 ** 9862 ** An instance of this object is a [session] that can be used to 9863 ** record changes to a database. 9864 */ 9865 typedef struct sqlite3_session sqlite3_session; 9866 9867 /* 9868 ** CAPI3REF: Changeset Iterator Handle 9869 ** 9870 ** An instance of this object acts as a cursor for iterating 9871 ** over the elements of a [changeset] or [patchset]. 9872 */ 9873 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 9874 9875 /* 9876 ** CAPI3REF: Create A New Session Object 9877 ** CONSTRUCTOR: sqlite3_session 9878 ** 9879 ** Create a new session object attached to database handle db. If successful, 9880 ** a pointer to the new object is written to *ppSession and SQLITE_OK is 9881 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite 9882 ** error code (e.g. SQLITE_NOMEM) is returned. 9883 ** 9884 ** It is possible to create multiple session objects attached to a single 9885 ** database handle. 9886 ** 9887 ** Session objects created using this function should be deleted using the 9888 ** [sqlite3session_delete()] function before the database handle that they 9889 ** are attached to is itself closed. If the database handle is closed before 9890 ** the session object is deleted, then the results of calling any session 9891 ** module function, including [sqlite3session_delete()] on the session object 9892 ** are undefined. 9893 ** 9894 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it 9895 ** is not possible for an application to register a pre-update hook on a 9896 ** database handle that has one or more session objects attached. Nor is 9897 ** it possible to create a session object attached to a database handle for 9898 ** which a pre-update hook is already defined. The results of attempting 9899 ** either of these things are undefined. 9900 ** 9901 ** The session object will be used to create changesets for tables in 9902 ** database zDb, where zDb is either "main", or "temp", or the name of an 9903 ** attached database. It is not an error if database zDb is not attached 9904 ** to the database when the session object is created. 9905 */ 9906 SQLITE_API int sqlite3session_create( 9907 sqlite3 *db, /* Database handle */ 9908 const char *zDb, /* Name of db (e.g. "main") */ 9909 sqlite3_session **ppSession /* OUT: New session object */ 9910 ); 9911 9912 /* 9913 ** CAPI3REF: Delete A Session Object 9914 ** DESTRUCTOR: sqlite3_session 9915 ** 9916 ** Delete a session object previously allocated using 9917 ** [sqlite3session_create()]. Once a session object has been deleted, the 9918 ** results of attempting to use pSession with any other session module 9919 ** function are undefined. 9920 ** 9921 ** Session objects must be deleted before the database handle to which they 9922 ** are attached is closed. Refer to the documentation for 9923 ** [sqlite3session_create()] for details. 9924 */ 9925 SQLITE_API void sqlite3session_delete(sqlite3_session *pSession); 9926 9927 9928 /* 9929 ** CAPI3REF: Enable Or Disable A Session Object 9930 ** METHOD: sqlite3_session 9931 ** 9932 ** Enable or disable the recording of changes by a session object. When 9933 ** enabled, a session object records changes made to the database. When 9934 ** disabled - it does not. A newly created session object is enabled. 9935 ** Refer to the documentation for [sqlite3session_changeset()] for further 9936 ** details regarding how enabling and disabling a session object affects 9937 ** the eventual changesets. 9938 ** 9939 ** Passing zero to this function disables the session. Passing a value 9940 ** greater than zero enables it. Passing a value less than zero is a 9941 ** no-op, and may be used to query the current state of the session. 9942 ** 9943 ** The return value indicates the final state of the session object: 0 if 9944 ** the session is disabled, or 1 if it is enabled. 9945 */ 9946 SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 9947 9948 /* 9949 ** CAPI3REF: Set Or Clear the Indirect Change Flag 9950 ** METHOD: sqlite3_session 9951 ** 9952 ** Each change recorded by a session object is marked as either direct or 9953 ** indirect. A change is marked as indirect if either: 9954 ** 9955 ** <ul> 9956 ** <li> The session object "indirect" flag is set when the change is 9957 ** made, or 9958 ** <li> The change is made by an SQL trigger or foreign key action 9959 ** instead of directly as a result of a users SQL statement. 9960 ** </ul> 9961 ** 9962 ** If a single row is affected by more than one operation within a session, 9963 ** then the change is considered indirect if all operations meet the criteria 9964 ** for an indirect change above, or direct otherwise. 9965 ** 9966 ** This function is used to set, clear or query the session object indirect 9967 ** flag. If the second argument passed to this function is zero, then the 9968 ** indirect flag is cleared. If it is greater than zero, the indirect flag 9969 ** is set. Passing a value less than zero does not modify the current value 9970 ** of the indirect flag, and may be used to query the current state of the 9971 ** indirect flag for the specified session object. 9972 ** 9973 ** The return value indicates the final state of the indirect flag: 0 if 9974 ** it is clear, or 1 if it is set. 9975 */ 9976 SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 9977 9978 /* 9979 ** CAPI3REF: Attach A Table To A Session Object 9980 ** METHOD: sqlite3_session 9981 ** 9982 ** If argument zTab is not NULL, then it is the name of a table to attach 9983 ** to the session object passed as the first argument. All subsequent changes 9984 ** made to the table while the session object is enabled will be recorded. See 9985 ** documentation for [sqlite3session_changeset()] for further details. 9986 ** 9987 ** Or, if argument zTab is NULL, then changes are recorded for all tables 9988 ** in the database. If additional tables are added to the database (by 9989 ** executing "CREATE TABLE" statements) after this call is made, changes for 9990 ** the new tables are also recorded. 9991 ** 9992 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 9993 ** defined as part of their CREATE TABLE statement. It does not matter if the 9994 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 9995 ** KEY may consist of a single column, or may be a composite key. 9996 ** 9997 ** It is not an error if the named table does not exist in the database. Nor 9998 ** is it an error if the named table does not have a PRIMARY KEY. However, 9999 ** no changes will be recorded in either of these scenarios. 10000 ** 10001 ** Changes are not recorded for individual rows that have NULL values stored 10002 ** in one or more of their PRIMARY KEY columns. 10003 ** 10004 ** SQLITE_OK is returned if the call completes without error. Or, if an error 10005 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 10006 ** 10007 ** <h3>Special sqlite_stat1 Handling</h3> 10008 ** 10009 ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to 10010 ** some of the rules above. In SQLite, the schema of sqlite_stat1 is: 10011 ** <pre> 10012 ** CREATE TABLE sqlite_stat1(tbl,idx,stat) 10013 ** </pre> 10014 ** 10015 ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are 10016 ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes 10017 ** are recorded for rows for which (idx IS NULL) is true. However, for such 10018 ** rows a zero-length blob (SQL value X'') is stored in the changeset or 10019 ** patchset instead of a NULL value. This allows such changesets to be 10020 ** manipulated by legacy implementations of sqlite3changeset_invert(), 10021 ** concat() and similar. 10022 ** 10023 ** The sqlite3changeset_apply() function automatically converts the 10024 ** zero-length blob back to a NULL value when updating the sqlite_stat1 10025 ** table. However, if the application calls sqlite3changeset_new(), 10026 ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset 10027 ** iterator directly (including on a changeset iterator passed to a 10028 ** conflict-handler callback) then the X'' value is returned. The application 10029 ** must translate X'' to NULL itself if required. 10030 ** 10031 ** Legacy (older than 3.22.0) versions of the sessions module cannot capture 10032 ** changes made to the sqlite_stat1 table. Legacy versions of the 10033 ** sqlite3changeset_apply() function silently ignore any modifications to the 10034 ** sqlite_stat1 table that are part of a changeset or patchset. 10035 */ 10036 SQLITE_API int sqlite3session_attach( 10037 sqlite3_session *pSession, /* Session object */ 10038 const char *zTab /* Table name */ 10039 ); 10040 10041 /* 10042 ** CAPI3REF: Set a table filter on a Session Object. 10043 ** METHOD: sqlite3_session 10044 ** 10045 ** The second argument (xFilter) is the "filter callback". For changes to rows 10046 ** in tables that are not attached to the Session object, the filter is called 10047 ** to determine whether changes to the table's rows should be tracked or not. 10048 ** If xFilter returns 0, changes are not tracked. Note that once a table is 10049 ** attached, xFilter will not be called again. 10050 */ 10051 SQLITE_API void sqlite3session_table_filter( 10052 sqlite3_session *pSession, /* Session object */ 10053 int(*xFilter)( 10054 void *pCtx, /* Copy of third arg to _filter_table() */ 10055 const char *zTab /* Table name */ 10056 ), 10057 void *pCtx /* First argument passed to xFilter */ 10058 ); 10059 10060 /* 10061 ** CAPI3REF: Generate A Changeset From A Session Object 10062 ** METHOD: sqlite3_session 10063 ** 10064 ** Obtain a changeset containing changes to the tables attached to the 10065 ** session object passed as the first argument. If successful, 10066 ** set *ppChangeset to point to a buffer containing the changeset 10067 ** and *pnChangeset to the size of the changeset in bytes before returning 10068 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 10069 ** zero and return an SQLite error code. 10070 ** 10071 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 10072 ** each representing a change to a single row of an attached table. An INSERT 10073 ** change contains the values of each field of a new database row. A DELETE 10074 ** contains the original values of each field of a deleted database row. An 10075 ** UPDATE change contains the original values of each field of an updated 10076 ** database row along with the updated values for each updated non-primary-key 10077 ** column. It is not possible for an UPDATE change to represent a change that 10078 ** modifies the values of primary key columns. If such a change is made, it 10079 ** is represented in a changeset as a DELETE followed by an INSERT. 10080 ** 10081 ** Changes are not recorded for rows that have NULL values stored in one or 10082 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 10083 ** no corresponding change is present in the changesets returned by this 10084 ** function. If an existing row with one or more NULL values stored in 10085 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 10086 ** only an INSERT is appears in the changeset. Similarly, if an existing row 10087 ** with non-NULL PRIMARY KEY values is updated so that one or more of its 10088 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 10089 ** DELETE change only. 10090 ** 10091 ** The contents of a changeset may be traversed using an iterator created 10092 ** using the [sqlite3changeset_start()] API. A changeset may be applied to 10093 ** a database with a compatible schema using the [sqlite3changeset_apply()] 10094 ** API. 10095 ** 10096 ** Within a changeset generated by this function, all changes related to a 10097 ** single table are grouped together. In other words, when iterating through 10098 ** a changeset or when applying a changeset to a database, all changes related 10099 ** to a single table are processed before moving on to the next table. Tables 10100 ** are sorted in the same order in which they were attached (or auto-attached) 10101 ** to the sqlite3_session object. The order in which the changes related to 10102 ** a single table are stored is undefined. 10103 ** 10104 ** Following a successful call to this function, it is the responsibility of 10105 ** the caller to eventually free the buffer that *ppChangeset points to using 10106 ** [sqlite3_free()]. 10107 ** 10108 ** <h3>Changeset Generation</h3> 10109 ** 10110 ** Once a table has been attached to a session object, the session object 10111 ** records the primary key values of all new rows inserted into the table. 10112 ** It also records the original primary key and other column values of any 10113 ** deleted or updated rows. For each unique primary key value, data is only 10114 ** recorded once - the first time a row with said primary key is inserted, 10115 ** updated or deleted in the lifetime of the session. 10116 ** 10117 ** There is one exception to the previous paragraph: when a row is inserted, 10118 ** updated or deleted, if one or more of its primary key columns contain a 10119 ** NULL value, no record of the change is made. 10120 ** 10121 ** The session object therefore accumulates two types of records - those 10122 ** that consist of primary key values only (created when the user inserts 10123 ** a new record) and those that consist of the primary key values and the 10124 ** original values of other table columns (created when the users deletes 10125 ** or updates a record). 10126 ** 10127 ** When this function is called, the requested changeset is created using 10128 ** both the accumulated records and the current contents of the database 10129 ** file. Specifically: 10130 ** 10131 ** <ul> 10132 ** <li> For each record generated by an insert, the database is queried 10133 ** for a row with a matching primary key. If one is found, an INSERT 10134 ** change is added to the changeset. If no such row is found, no change 10135 ** is added to the changeset. 10136 ** 10137 ** <li> For each record generated by an update or delete, the database is 10138 ** queried for a row with a matching primary key. If such a row is 10139 ** found and one or more of the non-primary key fields have been 10140 ** modified from their original values, an UPDATE change is added to 10141 ** the changeset. Or, if no such row is found in the table, a DELETE 10142 ** change is added to the changeset. If there is a row with a matching 10143 ** primary key in the database, but all fields contain their original 10144 ** values, no change is added to the changeset. 10145 ** </ul> 10146 ** 10147 ** This means, amongst other things, that if a row is inserted and then later 10148 ** deleted while a session object is active, neither the insert nor the delete 10149 ** will be present in the changeset. Or if a row is deleted and then later a 10150 ** row with the same primary key values inserted while a session object is 10151 ** active, the resulting changeset will contain an UPDATE change instead of 10152 ** a DELETE and an INSERT. 10153 ** 10154 ** When a session object is disabled (see the [sqlite3session_enable()] API), 10155 ** it does not accumulate records when rows are inserted, updated or deleted. 10156 ** This may appear to have some counter-intuitive effects if a single row 10157 ** is written to more than once during a session. For example, if a row 10158 ** is inserted while a session object is enabled, then later deleted while 10159 ** the same session object is disabled, no INSERT record will appear in the 10160 ** changeset, even though the delete took place while the session was disabled. 10161 ** Or, if one field of a row is updated while a session is disabled, and 10162 ** another field of the same row is updated while the session is enabled, the 10163 ** resulting changeset will contain an UPDATE change that updates both fields. 10164 */ 10165 SQLITE_API int sqlite3session_changeset( 10166 sqlite3_session *pSession, /* Session object */ 10167 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 10168 void **ppChangeset /* OUT: Buffer containing changeset */ 10169 ); 10170 10171 /* 10172 ** CAPI3REF: Load The Difference Between Tables Into A Session 10173 ** METHOD: sqlite3_session 10174 ** 10175 ** If it is not already attached to the session object passed as the first 10176 ** argument, this function attaches table zTbl in the same manner as the 10177 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it 10178 ** does not have a primary key, this function is a no-op (but does not return 10179 ** an error). 10180 ** 10181 ** Argument zFromDb must be the name of a database ("main", "temp" etc.) 10182 ** attached to the same database handle as the session object that contains 10183 ** a table compatible with the table attached to the session by this function. 10184 ** A table is considered compatible if it: 10185 ** 10186 ** <ul> 10187 ** <li> Has the same name, 10188 ** <li> Has the same set of columns declared in the same order, and 10189 ** <li> Has the same PRIMARY KEY definition. 10190 ** </ul> 10191 ** 10192 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 10193 ** are compatible but do not have any PRIMARY KEY columns, it is not an error 10194 ** but no changes are added to the session object. As with other session 10195 ** APIs, tables without PRIMARY KEYs are simply ignored. 10196 ** 10197 ** This function adds a set of changes to the session object that could be 10198 ** used to update the table in database zFrom (call this the "from-table") 10199 ** so that its content is the same as the table attached to the session 10200 ** object (call this the "to-table"). Specifically: 10201 ** 10202 ** <ul> 10203 ** <li> For each row (primary key) that exists in the to-table but not in 10204 ** the from-table, an INSERT record is added to the session object. 10205 ** 10206 ** <li> For each row (primary key) that exists in the to-table but not in 10207 ** the from-table, a DELETE record is added to the session object. 10208 ** 10209 ** <li> For each row (primary key) that exists in both tables, but features 10210 ** different non-PK values in each, an UPDATE record is added to the 10211 ** session. 10212 ** </ul> 10213 ** 10214 ** To clarify, if this function is called and then a changeset constructed 10215 ** using [sqlite3session_changeset()], then after applying that changeset to 10216 ** database zFrom the contents of the two compatible tables would be 10217 ** identical. 10218 ** 10219 ** It an error if database zFrom does not exist or does not contain the 10220 ** required compatible table. 10221 ** 10222 ** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite 10223 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 10224 ** may be set to point to a buffer containing an English language error 10225 ** message. It is the responsibility of the caller to free this buffer using 10226 ** sqlite3_free(). 10227 */ 10228 SQLITE_API int sqlite3session_diff( 10229 sqlite3_session *pSession, 10230 const char *zFromDb, 10231 const char *zTbl, 10232 char **pzErrMsg 10233 ); 10234 10235 10236 /* 10237 ** CAPI3REF: Generate A Patchset From A Session Object 10238 ** METHOD: sqlite3_session 10239 ** 10240 ** The differences between a patchset and a changeset are that: 10241 ** 10242 ** <ul> 10243 ** <li> DELETE records consist of the primary key fields only. The 10244 ** original values of other fields are omitted. 10245 ** <li> The original values of any modified fields are omitted from 10246 ** UPDATE records. 10247 ** </ul> 10248 ** 10249 ** A patchset blob may be used with up to date versions of all 10250 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 10251 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 10252 ** attempting to use a patchset blob with old versions of the 10253 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 10254 ** 10255 ** Because the non-primary key "old.*" fields are omitted, no 10256 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 10257 ** is passed to the sqlite3changeset_apply() API. Other conflict types work 10258 ** in the same way as for changesets. 10259 ** 10260 ** Changes within a patchset are ordered in the same way as for changesets 10261 ** generated by the sqlite3session_changeset() function (i.e. all changes for 10262 ** a single table are grouped together, tables appear in the order in which 10263 ** they were attached to the session object). 10264 */ 10265 SQLITE_API int sqlite3session_patchset( 10266 sqlite3_session *pSession, /* Session object */ 10267 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */ 10268 void **ppPatchset /* OUT: Buffer containing patchset */ 10269 ); 10270 10271 /* 10272 ** CAPI3REF: Test if a changeset has recorded any changes. 10273 ** 10274 ** Return non-zero if no changes to attached tables have been recorded by 10275 ** the session object passed as the first argument. Otherwise, if one or 10276 ** more changes have been recorded, return zero. 10277 ** 10278 ** Even if this function returns zero, it is possible that calling 10279 ** [sqlite3session_changeset()] on the session handle may still return a 10280 ** changeset that contains no changes. This can happen when a row in 10281 ** an attached table is modified and then later on the original values 10282 ** are restored. However, if this function returns non-zero, then it is 10283 ** guaranteed that a call to sqlite3session_changeset() will return a 10284 ** changeset containing zero changes. 10285 */ 10286 SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession); 10287 10288 /* 10289 ** CAPI3REF: Create An Iterator To Traverse A Changeset 10290 ** CONSTRUCTOR: sqlite3_changeset_iter 10291 ** 10292 ** Create an iterator used to iterate through the contents of a changeset. 10293 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK 10294 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an 10295 ** SQLite error code is returned. 10296 ** 10297 ** The following functions can be used to advance and query a changeset 10298 ** iterator created by this function: 10299 ** 10300 ** <ul> 10301 ** <li> [sqlite3changeset_next()] 10302 ** <li> [sqlite3changeset_op()] 10303 ** <li> [sqlite3changeset_new()] 10304 ** <li> [sqlite3changeset_old()] 10305 ** </ul> 10306 ** 10307 ** It is the responsibility of the caller to eventually destroy the iterator 10308 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 10309 ** changeset (pChangeset) must remain valid until after the iterator is 10310 ** destroyed. 10311 ** 10312 ** Assuming the changeset blob was created by one of the 10313 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 10314 ** [sqlite3changeset_invert()] functions, all changes within the changeset 10315 ** that apply to a single table are grouped together. This means that when 10316 ** an application iterates through a changeset using an iterator created by 10317 ** this function, all changes that relate to a single table are visited 10318 ** consecutively. There is no chance that the iterator will visit a change 10319 ** the applies to table X, then one for table Y, and then later on visit 10320 ** another change for table X. 10321 ** 10322 ** The behavior of sqlite3changeset_start_v2() and its streaming equivalent 10323 ** may be modified by passing a combination of 10324 ** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter. 10325 ** 10326 ** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b> 10327 ** and therefore subject to change. 10328 */ 10329 SQLITE_API int sqlite3changeset_start( 10330 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 10331 int nChangeset, /* Size of changeset blob in bytes */ 10332 void *pChangeset /* Pointer to blob containing changeset */ 10333 ); 10334 SQLITE_API int sqlite3changeset_start_v2( 10335 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 10336 int nChangeset, /* Size of changeset blob in bytes */ 10337 void *pChangeset, /* Pointer to blob containing changeset */ 10338 int flags /* SESSION_CHANGESETSTART_* flags */ 10339 ); 10340 10341 /* 10342 ** CAPI3REF: Flags for sqlite3changeset_start_v2 10343 ** 10344 ** The following flags may passed via the 4th parameter to 10345 ** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]: 10346 ** 10347 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 10348 ** Invert the changeset while iterating through it. This is equivalent to 10349 ** inverting a changeset using sqlite3changeset_invert() before applying it. 10350 ** It is an error to specify this flag with a patchset. 10351 */ 10352 #define SQLITE_CHANGESETSTART_INVERT 0x0002 10353 10354 10355 /* 10356 ** CAPI3REF: Advance A Changeset Iterator 10357 ** METHOD: sqlite3_changeset_iter 10358 ** 10359 ** This function may only be used with iterators created by the function 10360 ** [sqlite3changeset_start()]. If it is called on an iterator passed to 10361 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 10362 ** is returned and the call has no effect. 10363 ** 10364 ** Immediately after an iterator is created by sqlite3changeset_start(), it 10365 ** does not point to any change in the changeset. Assuming the changeset 10366 ** is not empty, the first call to this function advances the iterator to 10367 ** point to the first change in the changeset. Each subsequent call advances 10368 ** the iterator to point to the next change in the changeset (if any). If 10369 ** no error occurs and the iterator points to a valid change after a call 10370 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 10371 ** Otherwise, if all changes in the changeset have already been visited, 10372 ** SQLITE_DONE is returned. 10373 ** 10374 ** If an error occurs, an SQLite error code is returned. Possible error 10375 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 10376 ** SQLITE_NOMEM. 10377 */ 10378 SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 10379 10380 /* 10381 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 10382 ** METHOD: sqlite3_changeset_iter 10383 ** 10384 ** The pIter argument passed to this function may either be an iterator 10385 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10386 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 10387 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 10388 ** is not the case, this function returns [SQLITE_MISUSE]. 10389 ** 10390 ** If argument pzTab is not NULL, then *pzTab is set to point to a 10391 ** nul-terminated utf-8 encoded string containing the name of the table 10392 ** affected by the current change. The buffer remains valid until either 10393 ** sqlite3changeset_next() is called on the iterator or until the 10394 ** conflict-handler function returns. If pnCol is not NULL, then *pnCol is 10395 ** set to the number of columns in the table affected by the change. If 10396 ** pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change 10397 ** is an indirect change, or false (0) otherwise. See the documentation for 10398 ** [sqlite3session_indirect()] for a description of direct and indirect 10399 ** changes. Finally, if pOp is not NULL, then *pOp is set to one of 10400 ** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the 10401 ** type of change that the iterator currently points to. 10402 ** 10403 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an 10404 ** SQLite error code is returned. The values of the output variables may not 10405 ** be trusted in this case. 10406 */ 10407 SQLITE_API int sqlite3changeset_op( 10408 sqlite3_changeset_iter *pIter, /* Iterator object */ 10409 const char **pzTab, /* OUT: Pointer to table name */ 10410 int *pnCol, /* OUT: Number of columns in table */ 10411 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 10412 int *pbIndirect /* OUT: True for an 'indirect' change */ 10413 ); 10414 10415 /* 10416 ** CAPI3REF: Obtain The Primary Key Definition Of A Table 10417 ** METHOD: sqlite3_changeset_iter 10418 ** 10419 ** For each modified table, a changeset includes the following: 10420 ** 10421 ** <ul> 10422 ** <li> The number of columns in the table, and 10423 ** <li> Which of those columns make up the tables PRIMARY KEY. 10424 ** </ul> 10425 ** 10426 ** This function is used to find which columns comprise the PRIMARY KEY of 10427 ** the table modified by the change that iterator pIter currently points to. 10428 ** If successful, *pabPK is set to point to an array of nCol entries, where 10429 ** nCol is the number of columns in the table. Elements of *pabPK are set to 10430 ** 0x01 if the corresponding column is part of the tables primary key, or 10431 ** 0x00 if it is not. 10432 ** 10433 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns 10434 ** in the table. 10435 ** 10436 ** If this function is called when the iterator does not point to a valid 10437 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 10438 ** SQLITE_OK is returned and the output variables populated as described 10439 ** above. 10440 */ 10441 SQLITE_API int sqlite3changeset_pk( 10442 sqlite3_changeset_iter *pIter, /* Iterator object */ 10443 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 10444 int *pnCol /* OUT: Number of entries in output array */ 10445 ); 10446 10447 /* 10448 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator 10449 ** METHOD: sqlite3_changeset_iter 10450 ** 10451 ** The pIter argument passed to this function may either be an iterator 10452 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10453 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 10454 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 10455 ** Furthermore, it may only be called if the type of change that the iterator 10456 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 10457 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 10458 ** 10459 ** Argument iVal must be greater than or equal to 0, and less than the number 10460 ** of columns in the table affected by the current change. Otherwise, 10461 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10462 ** 10463 ** If successful, this function sets *ppValue to point to a protected 10464 ** sqlite3_value object containing the iVal'th value from the vector of 10465 ** original row values stored as part of the UPDATE or DELETE change and 10466 ** returns SQLITE_OK. The name of the function comes from the fact that this 10467 ** is similar to the "old.*" columns available to update or delete triggers. 10468 ** 10469 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 10470 ** is returned and *ppValue is set to NULL. 10471 */ 10472 SQLITE_API int sqlite3changeset_old( 10473 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10474 int iVal, /* Column number */ 10475 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 10476 ); 10477 10478 /* 10479 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator 10480 ** METHOD: sqlite3_changeset_iter 10481 ** 10482 ** The pIter argument passed to this function may either be an iterator 10483 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10484 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 10485 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 10486 ** Furthermore, it may only be called if the type of change that the iterator 10487 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 10488 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 10489 ** 10490 ** Argument iVal must be greater than or equal to 0, and less than the number 10491 ** of columns in the table affected by the current change. Otherwise, 10492 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10493 ** 10494 ** If successful, this function sets *ppValue to point to a protected 10495 ** sqlite3_value object containing the iVal'th value from the vector of 10496 ** new row values stored as part of the UPDATE or INSERT change and 10497 ** returns SQLITE_OK. If the change is an UPDATE and does not include 10498 ** a new value for the requested column, *ppValue is set to NULL and 10499 ** SQLITE_OK returned. The name of the function comes from the fact that 10500 ** this is similar to the "new.*" columns available to update or delete 10501 ** triggers. 10502 ** 10503 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 10504 ** is returned and *ppValue is set to NULL. 10505 */ 10506 SQLITE_API int sqlite3changeset_new( 10507 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10508 int iVal, /* Column number */ 10509 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 10510 ); 10511 10512 /* 10513 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 10514 ** METHOD: sqlite3_changeset_iter 10515 ** 10516 ** This function should only be used with iterator objects passed to a 10517 ** conflict-handler callback by [sqlite3changeset_apply()] with either 10518 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 10519 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 10520 ** is set to NULL. 10521 ** 10522 ** Argument iVal must be greater than or equal to 0, and less than the number 10523 ** of columns in the table affected by the current change. Otherwise, 10524 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10525 ** 10526 ** If successful, this function sets *ppValue to point to a protected 10527 ** sqlite3_value object containing the iVal'th value from the 10528 ** "conflicting row" associated with the current conflict-handler callback 10529 ** and returns SQLITE_OK. 10530 ** 10531 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 10532 ** is returned and *ppValue is set to NULL. 10533 */ 10534 SQLITE_API int sqlite3changeset_conflict( 10535 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10536 int iVal, /* Column number */ 10537 sqlite3_value **ppValue /* OUT: Value from conflicting row */ 10538 ); 10539 10540 /* 10541 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 10542 ** METHOD: sqlite3_changeset_iter 10543 ** 10544 ** This function may only be called with an iterator passed to an 10545 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 10546 ** it sets the output variable to the total number of known foreign key 10547 ** violations in the destination database and returns SQLITE_OK. 10548 ** 10549 ** In all other cases this function returns SQLITE_MISUSE. 10550 */ 10551 SQLITE_API int sqlite3changeset_fk_conflicts( 10552 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10553 int *pnOut /* OUT: Number of FK violations */ 10554 ); 10555 10556 10557 /* 10558 ** CAPI3REF: Finalize A Changeset Iterator 10559 ** METHOD: sqlite3_changeset_iter 10560 ** 10561 ** This function is used to finalize an iterator allocated with 10562 ** [sqlite3changeset_start()]. 10563 ** 10564 ** This function should only be called on iterators created using the 10565 ** [sqlite3changeset_start()] function. If an application calls this 10566 ** function with an iterator passed to a conflict-handler by 10567 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 10568 ** call has no effect. 10569 ** 10570 ** If an error was encountered within a call to an sqlite3changeset_xxx() 10571 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 10572 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 10573 ** to that error is returned by this function. Otherwise, SQLITE_OK is 10574 ** returned. This is to allow the following pattern (pseudo-code): 10575 ** 10576 ** <pre> 10577 ** sqlite3changeset_start(); 10578 ** while( SQLITE_ROW==sqlite3changeset_next() ){ 10579 ** // Do something with change. 10580 ** } 10581 ** rc = sqlite3changeset_finalize(); 10582 ** if( rc!=SQLITE_OK ){ 10583 ** // An error has occurred 10584 ** } 10585 ** </pre> 10586 */ 10587 SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 10588 10589 /* 10590 ** CAPI3REF: Invert A Changeset 10591 ** 10592 ** This function is used to "invert" a changeset object. Applying an inverted 10593 ** changeset to a database reverses the effects of applying the uninverted 10594 ** changeset. Specifically: 10595 ** 10596 ** <ul> 10597 ** <li> Each DELETE change is changed to an INSERT, and 10598 ** <li> Each INSERT change is changed to a DELETE, and 10599 ** <li> For each UPDATE change, the old.* and new.* values are exchanged. 10600 ** </ul> 10601 ** 10602 ** This function does not change the order in which changes appear within 10603 ** the changeset. It merely reverses the sense of each individual change. 10604 ** 10605 ** If successful, a pointer to a buffer containing the inverted changeset 10606 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 10607 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 10608 ** zeroed and an SQLite error code returned. 10609 ** 10610 ** It is the responsibility of the caller to eventually call sqlite3_free() 10611 ** on the *ppOut pointer to free the buffer allocation following a successful 10612 ** call to this function. 10613 ** 10614 ** WARNING/TODO: This function currently assumes that the input is a valid 10615 ** changeset. If it is not, the results are undefined. 10616 */ 10617 SQLITE_API int sqlite3changeset_invert( 10618 int nIn, const void *pIn, /* Input changeset */ 10619 int *pnOut, void **ppOut /* OUT: Inverse of input */ 10620 ); 10621 10622 /* 10623 ** CAPI3REF: Concatenate Two Changeset Objects 10624 ** 10625 ** This function is used to concatenate two changesets, A and B, into a 10626 ** single changeset. The result is a changeset equivalent to applying 10627 ** changeset A followed by changeset B. 10628 ** 10629 ** This function combines the two input changesets using an 10630 ** sqlite3_changegroup object. Calling it produces similar results as the 10631 ** following code fragment: 10632 ** 10633 ** <pre> 10634 ** sqlite3_changegroup *pGrp; 10635 ** rc = sqlite3_changegroup_new(&pGrp); 10636 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 10637 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 10638 ** if( rc==SQLITE_OK ){ 10639 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 10640 ** }else{ 10641 ** *ppOut = 0; 10642 ** *pnOut = 0; 10643 ** } 10644 ** </pre> 10645 ** 10646 ** Refer to the sqlite3_changegroup documentation below for details. 10647 */ 10648 SQLITE_API int sqlite3changeset_concat( 10649 int nA, /* Number of bytes in buffer pA */ 10650 void *pA, /* Pointer to buffer containing changeset A */ 10651 int nB, /* Number of bytes in buffer pB */ 10652 void *pB, /* Pointer to buffer containing changeset B */ 10653 int *pnOut, /* OUT: Number of bytes in output changeset */ 10654 void **ppOut /* OUT: Buffer containing output changeset */ 10655 ); 10656 10657 10658 /* 10659 ** CAPI3REF: Changegroup Handle 10660 ** 10661 ** A changegroup is an object used to combine two or more 10662 ** [changesets] or [patchsets] 10663 */ 10664 typedef struct sqlite3_changegroup sqlite3_changegroup; 10665 10666 /* 10667 ** CAPI3REF: Create A New Changegroup Object 10668 ** CONSTRUCTOR: sqlite3_changegroup 10669 ** 10670 ** An sqlite3_changegroup object is used to combine two or more changesets 10671 ** (or patchsets) into a single changeset (or patchset). A single changegroup 10672 ** object may combine changesets or patchsets, but not both. The output is 10673 ** always in the same format as the input. 10674 ** 10675 ** If successful, this function returns SQLITE_OK and populates (*pp) with 10676 ** a pointer to a new sqlite3_changegroup object before returning. The caller 10677 ** should eventually free the returned object using a call to 10678 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 10679 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 10680 ** 10681 ** The usual usage pattern for an sqlite3_changegroup object is as follows: 10682 ** 10683 ** <ul> 10684 ** <li> It is created using a call to sqlite3changegroup_new(). 10685 ** 10686 ** <li> Zero or more changesets (or patchsets) are added to the object 10687 ** by calling sqlite3changegroup_add(). 10688 ** 10689 ** <li> The result of combining all input changesets together is obtained 10690 ** by the application via a call to sqlite3changegroup_output(). 10691 ** 10692 ** <li> The object is deleted using a call to sqlite3changegroup_delete(). 10693 ** </ul> 10694 ** 10695 ** Any number of calls to add() and output() may be made between the calls to 10696 ** new() and delete(), and in any order. 10697 ** 10698 ** As well as the regular sqlite3changegroup_add() and 10699 ** sqlite3changegroup_output() functions, also available are the streaming 10700 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 10701 */ 10702 SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp); 10703 10704 /* 10705 ** CAPI3REF: Add A Changeset To A Changegroup 10706 ** METHOD: sqlite3_changegroup 10707 ** 10708 ** Add all changes within the changeset (or patchset) in buffer pData (size 10709 ** nData bytes) to the changegroup. 10710 ** 10711 ** If the buffer contains a patchset, then all prior calls to this function 10712 ** on the same changegroup object must also have specified patchsets. Or, if 10713 ** the buffer contains a changeset, so must have the earlier calls to this 10714 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added 10715 ** to the changegroup. 10716 ** 10717 ** Rows within the changeset and changegroup are identified by the values in 10718 ** their PRIMARY KEY columns. A change in the changeset is considered to 10719 ** apply to the same row as a change already present in the changegroup if 10720 ** the two rows have the same primary key. 10721 ** 10722 ** Changes to rows that do not already appear in the changegroup are 10723 ** simply copied into it. Or, if both the new changeset and the changegroup 10724 ** contain changes that apply to a single row, the final contents of the 10725 ** changegroup depends on the type of each change, as follows: 10726 ** 10727 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 10728 ** <tr><th style="white-space:pre">Existing Change </th> 10729 ** <th style="white-space:pre">New Change </th> 10730 ** <th>Output Change 10731 ** <tr><td>INSERT <td>INSERT <td> 10732 ** The new change is ignored. This case does not occur if the new 10733 ** changeset was recorded immediately after the changesets already 10734 ** added to the changegroup. 10735 ** <tr><td>INSERT <td>UPDATE <td> 10736 ** The INSERT change remains in the changegroup. The values in the 10737 ** INSERT change are modified as if the row was inserted by the 10738 ** existing change and then updated according to the new change. 10739 ** <tr><td>INSERT <td>DELETE <td> 10740 ** The existing INSERT is removed from the changegroup. The DELETE is 10741 ** not added. 10742 ** <tr><td>UPDATE <td>INSERT <td> 10743 ** The new change is ignored. This case does not occur if the new 10744 ** changeset was recorded immediately after the changesets already 10745 ** added to the changegroup. 10746 ** <tr><td>UPDATE <td>UPDATE <td> 10747 ** The existing UPDATE remains within the changegroup. It is amended 10748 ** so that the accompanying values are as if the row was updated once 10749 ** by the existing change and then again by the new change. 10750 ** <tr><td>UPDATE <td>DELETE <td> 10751 ** The existing UPDATE is replaced by the new DELETE within the 10752 ** changegroup. 10753 ** <tr><td>DELETE <td>INSERT <td> 10754 ** If one or more of the column values in the row inserted by the 10755 ** new change differ from those in the row deleted by the existing 10756 ** change, the existing DELETE is replaced by an UPDATE within the 10757 ** changegroup. Otherwise, if the inserted row is exactly the same 10758 ** as the deleted row, the existing DELETE is simply discarded. 10759 ** <tr><td>DELETE <td>UPDATE <td> 10760 ** The new change is ignored. This case does not occur if the new 10761 ** changeset was recorded immediately after the changesets already 10762 ** added to the changegroup. 10763 ** <tr><td>DELETE <td>DELETE <td> 10764 ** The new change is ignored. This case does not occur if the new 10765 ** changeset was recorded immediately after the changesets already 10766 ** added to the changegroup. 10767 ** </table> 10768 ** 10769 ** If the new changeset contains changes to a table that is already present 10770 ** in the changegroup, then the number of columns and the position of the 10771 ** primary key columns for the table must be consistent. If this is not the 10772 ** case, this function fails with SQLITE_SCHEMA. If the input changeset 10773 ** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is 10774 ** returned. Or, if an out-of-memory condition occurs during processing, this 10775 ** function returns SQLITE_NOMEM. In all cases, if an error occurs the state 10776 ** of the final contents of the changegroup is undefined. 10777 ** 10778 ** If no error occurs, SQLITE_OK is returned. 10779 */ 10780 SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 10781 10782 /* 10783 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup 10784 ** METHOD: sqlite3_changegroup 10785 ** 10786 ** Obtain a buffer containing a changeset (or patchset) representing the 10787 ** current contents of the changegroup. If the inputs to the changegroup 10788 ** were themselves changesets, the output is a changeset. Or, if the 10789 ** inputs were patchsets, the output is also a patchset. 10790 ** 10791 ** As with the output of the sqlite3session_changeset() and 10792 ** sqlite3session_patchset() functions, all changes related to a single 10793 ** table are grouped together in the output of this function. Tables appear 10794 ** in the same order as for the very first changeset added to the changegroup. 10795 ** If the second or subsequent changesets added to the changegroup contain 10796 ** changes for tables that do not appear in the first changeset, they are 10797 ** appended onto the end of the output changeset, again in the order in 10798 ** which they are first encountered. 10799 ** 10800 ** If an error occurs, an SQLite error code is returned and the output 10801 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 10802 ** is returned and the output variables are set to the size of and a 10803 ** pointer to the output buffer, respectively. In this case it is the 10804 ** responsibility of the caller to eventually free the buffer using a 10805 ** call to sqlite3_free(). 10806 */ 10807 SQLITE_API int sqlite3changegroup_output( 10808 sqlite3_changegroup*, 10809 int *pnData, /* OUT: Size of output buffer in bytes */ 10810 void **ppData /* OUT: Pointer to output buffer */ 10811 ); 10812 10813 /* 10814 ** CAPI3REF: Delete A Changegroup Object 10815 ** DESTRUCTOR: sqlite3_changegroup 10816 */ 10817 SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*); 10818 10819 /* 10820 ** CAPI3REF: Apply A Changeset To A Database 10821 ** 10822 ** Apply a changeset or patchset to a database. These functions attempt to 10823 ** update the "main" database attached to handle db with the changes found in 10824 ** the changeset passed via the second and third arguments. 10825 ** 10826 ** The fourth argument (xFilter) passed to these functions is the "filter 10827 ** callback". If it is not NULL, then for each table affected by at least one 10828 ** change in the changeset, the filter callback is invoked with 10829 ** the table name as the second argument, and a copy of the context pointer 10830 ** passed as the sixth argument as the first. If the "filter callback" 10831 ** returns zero, then no attempt is made to apply any changes to the table. 10832 ** Otherwise, if the return value is non-zero or the xFilter argument to 10833 ** is NULL, all changes related to the table are attempted. 10834 ** 10835 ** For each table that is not excluded by the filter callback, this function 10836 ** tests that the target database contains a compatible table. A table is 10837 ** considered compatible if all of the following are true: 10838 ** 10839 ** <ul> 10840 ** <li> The table has the same name as the name recorded in the 10841 ** changeset, and 10842 ** <li> The table has at least as many columns as recorded in the 10843 ** changeset, and 10844 ** <li> The table has primary key columns in the same position as 10845 ** recorded in the changeset. 10846 ** </ul> 10847 ** 10848 ** If there is no compatible table, it is not an error, but none of the 10849 ** changes associated with the table are applied. A warning message is issued 10850 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 10851 ** one such warning is issued for each table in the changeset. 10852 ** 10853 ** For each change for which there is a compatible table, an attempt is made 10854 ** to modify the table contents according to the UPDATE, INSERT or DELETE 10855 ** change. If a change cannot be applied cleanly, the conflict handler 10856 ** function passed as the fifth argument to sqlite3changeset_apply() may be 10857 ** invoked. A description of exactly when the conflict handler is invoked for 10858 ** each type of change is below. 10859 ** 10860 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results 10861 ** of passing anything other than a valid function pointer as the xConflict 10862 ** argument are undefined. 10863 ** 10864 ** Each time the conflict handler function is invoked, it must return one 10865 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 10866 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 10867 ** if the second argument passed to the conflict handler is either 10868 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 10869 ** returns an illegal value, any changes already made are rolled back and 10870 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 10871 ** actions are taken by sqlite3changeset_apply() depending on the value 10872 ** returned by each invocation of the conflict-handler function. Refer to 10873 ** the documentation for the three 10874 ** [SQLITE_CHANGESET_OMIT|available return values] for details. 10875 ** 10876 ** <dl> 10877 ** <dt>DELETE Changes<dd> 10878 ** For each DELETE change, the function checks if the target database 10879 ** contains a row with the same primary key value (or values) as the 10880 ** original row values stored in the changeset. If it does, and the values 10881 ** stored in all non-primary key columns also match the values stored in 10882 ** the changeset the row is deleted from the target database. 10883 ** 10884 ** If a row with matching primary key values is found, but one or more of 10885 ** the non-primary key fields contains a value different from the original 10886 ** row value stored in the changeset, the conflict-handler function is 10887 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the 10888 ** database table has more columns than are recorded in the changeset, 10889 ** only the values of those non-primary key fields are compared against 10890 ** the current database contents - any trailing database table columns 10891 ** are ignored. 10892 ** 10893 ** If no row with matching primary key values is found in the database, 10894 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 10895 ** passed as the second argument. 10896 ** 10897 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 10898 ** (which can only happen if a foreign key constraint is violated), the 10899 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 10900 ** passed as the second argument. This includes the case where the DELETE 10901 ** operation is attempted because an earlier call to the conflict handler 10902 ** function returned [SQLITE_CHANGESET_REPLACE]. 10903 ** 10904 ** <dt>INSERT Changes<dd> 10905 ** For each INSERT change, an attempt is made to insert the new row into 10906 ** the database. If the changeset row contains fewer fields than the 10907 ** database table, the trailing fields are populated with their default 10908 ** values. 10909 ** 10910 ** If the attempt to insert the row fails because the database already 10911 ** contains a row with the same primary key values, the conflict handler 10912 ** function is invoked with the second argument set to 10913 ** [SQLITE_CHANGESET_CONFLICT]. 10914 ** 10915 ** If the attempt to insert the row fails because of some other constraint 10916 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 10917 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 10918 ** This includes the case where the INSERT operation is re-attempted because 10919 ** an earlier call to the conflict handler function returned 10920 ** [SQLITE_CHANGESET_REPLACE]. 10921 ** 10922 ** <dt>UPDATE Changes<dd> 10923 ** For each UPDATE change, the function checks if the target database 10924 ** contains a row with the same primary key value (or values) as the 10925 ** original row values stored in the changeset. If it does, and the values 10926 ** stored in all modified non-primary key columns also match the values 10927 ** stored in the changeset the row is updated within the target database. 10928 ** 10929 ** If a row with matching primary key values is found, but one or more of 10930 ** the modified non-primary key fields contains a value different from an 10931 ** original row value stored in the changeset, the conflict-handler function 10932 ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 10933 ** UPDATE changes only contain values for non-primary key fields that are 10934 ** to be modified, only those fields need to match the original values to 10935 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 10936 ** 10937 ** If no row with matching primary key values is found in the database, 10938 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 10939 ** passed as the second argument. 10940 ** 10941 ** If the UPDATE operation is attempted, but SQLite returns 10942 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 10943 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 10944 ** This includes the case where the UPDATE operation is attempted after 10945 ** an earlier call to the conflict handler function returned 10946 ** [SQLITE_CHANGESET_REPLACE]. 10947 ** </dl> 10948 ** 10949 ** It is safe to execute SQL statements, including those that write to the 10950 ** table that the callback related to, from within the xConflict callback. 10951 ** This can be used to further customize the application's conflict 10952 ** resolution strategy. 10953 ** 10954 ** All changes made by these functions are enclosed in a savepoint transaction. 10955 ** If any other error (aside from a constraint failure when attempting to 10956 ** write to the target database) occurs, then the savepoint transaction is 10957 ** rolled back, restoring the target database to its original state, and an 10958 ** SQLite error code returned. 10959 ** 10960 ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and 10961 ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2() 10962 ** may set (*ppRebase) to point to a "rebase" that may be used with the 10963 ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase) 10964 ** is set to the size of the buffer in bytes. It is the responsibility of the 10965 ** caller to eventually free any such buffer using sqlite3_free(). The buffer 10966 ** is only allocated and populated if one or more conflicts were encountered 10967 ** while applying the patchset. See comments surrounding the sqlite3_rebaser 10968 ** APIs for further details. 10969 ** 10970 ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent 10971 ** may be modified by passing a combination of 10972 ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter. 10973 ** 10974 ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b> 10975 ** and therefore subject to change. 10976 */ 10977 SQLITE_API int sqlite3changeset_apply( 10978 sqlite3 *db, /* Apply change to "main" db of this handle */ 10979 int nChangeset, /* Size of changeset in bytes */ 10980 void *pChangeset, /* Changeset blob */ 10981 int(*xFilter)( 10982 void *pCtx, /* Copy of sixth arg to _apply() */ 10983 const char *zTab /* Table name */ 10984 ), 10985 int(*xConflict)( 10986 void *pCtx, /* Copy of sixth arg to _apply() */ 10987 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 10988 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 10989 ), 10990 void *pCtx /* First argument passed to xConflict */ 10991 ); 10992 SQLITE_API int sqlite3changeset_apply_v2( 10993 sqlite3 *db, /* Apply change to "main" db of this handle */ 10994 int nChangeset, /* Size of changeset in bytes */ 10995 void *pChangeset, /* Changeset blob */ 10996 int(*xFilter)( 10997 void *pCtx, /* Copy of sixth arg to _apply() */ 10998 const char *zTab /* Table name */ 10999 ), 11000 int(*xConflict)( 11001 void *pCtx, /* Copy of sixth arg to _apply() */ 11002 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11003 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11004 ), 11005 void *pCtx, /* First argument passed to xConflict */ 11006 void **ppRebase, int *pnRebase, /* OUT: Rebase data */ 11007 int flags /* SESSION_CHANGESETAPPLY_* flags */ 11008 ); 11009 11010 /* 11011 ** CAPI3REF: Flags for sqlite3changeset_apply_v2 11012 ** 11013 ** The following flags may passed via the 9th parameter to 11014 ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]: 11015 ** 11016 ** <dl> 11017 ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd> 11018 ** Usually, the sessions module encloses all operations performed by 11019 ** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The 11020 ** SAVEPOINT is committed if the changeset or patchset is successfully 11021 ** applied, or rolled back if an error occurs. Specifying this flag 11022 ** causes the sessions module to omit this savepoint. In this case, if the 11023 ** caller has an open transaction or savepoint when apply_v2() is called, 11024 ** it may revert the partially applied changeset by rolling it back. 11025 ** 11026 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 11027 ** Invert the changeset before applying it. This is equivalent to inverting 11028 ** a changeset using sqlite3changeset_invert() before applying it. It is 11029 ** an error to specify this flag with a patchset. 11030 */ 11031 #define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001 11032 #define SQLITE_CHANGESETAPPLY_INVERT 0x0002 11033 11034 /* 11035 ** CAPI3REF: Constants Passed To The Conflict Handler 11036 ** 11037 ** Values that may be passed as the second argument to a conflict-handler. 11038 ** 11039 ** <dl> 11040 ** <dt>SQLITE_CHANGESET_DATA<dd> 11041 ** The conflict handler is invoked with CHANGESET_DATA as the second argument 11042 ** when processing a DELETE or UPDATE change if a row with the required 11043 ** PRIMARY KEY fields is present in the database, but one or more other 11044 ** (non primary-key) fields modified by the update do not contain the 11045 ** expected "before" values. 11046 ** 11047 ** The conflicting row, in this case, is the database row with the matching 11048 ** primary key. 11049 ** 11050 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 11051 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 11052 ** argument when processing a DELETE or UPDATE change if a row with the 11053 ** required PRIMARY KEY fields is not present in the database. 11054 ** 11055 ** There is no conflicting row in this case. The results of invoking the 11056 ** sqlite3changeset_conflict() API are undefined. 11057 ** 11058 ** <dt>SQLITE_CHANGESET_CONFLICT<dd> 11059 ** CHANGESET_CONFLICT is passed as the second argument to the conflict 11060 ** handler while processing an INSERT change if the operation would result 11061 ** in duplicate primary key values. 11062 ** 11063 ** The conflicting row in this case is the database row with the matching 11064 ** primary key. 11065 ** 11066 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 11067 ** If foreign key handling is enabled, and applying a changeset leaves the 11068 ** database in a state containing foreign key violations, the conflict 11069 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 11070 ** exactly once before the changeset is committed. If the conflict handler 11071 ** returns CHANGESET_OMIT, the changes, including those that caused the 11072 ** foreign key constraint violation, are committed. Or, if it returns 11073 ** CHANGESET_ABORT, the changeset is rolled back. 11074 ** 11075 ** No current or conflicting row information is provided. The only function 11076 ** it is possible to call on the supplied sqlite3_changeset_iter handle 11077 ** is sqlite3changeset_fk_conflicts(). 11078 ** 11079 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 11080 ** If any other constraint violation occurs while applying a change (i.e. 11081 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 11082 ** invoked with CHANGESET_CONSTRAINT as the second argument. 11083 ** 11084 ** There is no conflicting row in this case. The results of invoking the 11085 ** sqlite3changeset_conflict() API are undefined. 11086 ** 11087 ** </dl> 11088 */ 11089 #define SQLITE_CHANGESET_DATA 1 11090 #define SQLITE_CHANGESET_NOTFOUND 2 11091 #define SQLITE_CHANGESET_CONFLICT 3 11092 #define SQLITE_CHANGESET_CONSTRAINT 4 11093 #define SQLITE_CHANGESET_FOREIGN_KEY 5 11094 11095 /* 11096 ** CAPI3REF: Constants Returned By The Conflict Handler 11097 ** 11098 ** A conflict handler callback must return one of the following three values. 11099 ** 11100 ** <dl> 11101 ** <dt>SQLITE_CHANGESET_OMIT<dd> 11102 ** If a conflict handler returns this value no special action is taken. The 11103 ** change that caused the conflict is not applied. The session module 11104 ** continues to the next change in the changeset. 11105 ** 11106 ** <dt>SQLITE_CHANGESET_REPLACE<dd> 11107 ** This value may only be returned if the second argument to the conflict 11108 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 11109 ** is not the case, any changes applied so far are rolled back and the 11110 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 11111 ** 11112 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 11113 ** handler, then the conflicting row is either updated or deleted, depending 11114 ** on the type of change. 11115 ** 11116 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 11117 ** handler, then the conflicting row is removed from the database and a 11118 ** second attempt to apply the change is made. If this second attempt fails, 11119 ** the original row is restored to the database before continuing. 11120 ** 11121 ** <dt>SQLITE_CHANGESET_ABORT<dd> 11122 ** If this value is returned, any changes applied so far are rolled back 11123 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 11124 ** </dl> 11125 */ 11126 #define SQLITE_CHANGESET_OMIT 0 11127 #define SQLITE_CHANGESET_REPLACE 1 11128 #define SQLITE_CHANGESET_ABORT 2 11129 11130 /* 11131 ** CAPI3REF: Rebasing changesets 11132 ** EXPERIMENTAL 11133 ** 11134 ** Suppose there is a site hosting a database in state S0. And that 11135 ** modifications are made that move that database to state S1 and a 11136 ** changeset recorded (the "local" changeset). Then, a changeset based 11137 ** on S0 is received from another site (the "remote" changeset) and 11138 ** applied to the database. The database is then in state 11139 ** (S1+"remote"), where the exact state depends on any conflict 11140 ** resolution decisions (OMIT or REPLACE) made while applying "remote". 11141 ** Rebasing a changeset is to update it to take those conflict 11142 ** resolution decisions into account, so that the same conflicts 11143 ** do not have to be resolved elsewhere in the network. 11144 ** 11145 ** For example, if both the local and remote changesets contain an 11146 ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)": 11147 ** 11148 ** local: INSERT INTO t1 VALUES(1, 'v1'); 11149 ** remote: INSERT INTO t1 VALUES(1, 'v2'); 11150 ** 11151 ** and the conflict resolution is REPLACE, then the INSERT change is 11152 ** removed from the local changeset (it was overridden). Or, if the 11153 ** conflict resolution was "OMIT", then the local changeset is modified 11154 ** to instead contain: 11155 ** 11156 ** UPDATE t1 SET b = 'v2' WHERE a=1; 11157 ** 11158 ** Changes within the local changeset are rebased as follows: 11159 ** 11160 ** <dl> 11161 ** <dt>Local INSERT<dd> 11162 ** This may only conflict with a remote INSERT. If the conflict 11163 ** resolution was OMIT, then add an UPDATE change to the rebased 11164 ** changeset. Or, if the conflict resolution was REPLACE, add 11165 ** nothing to the rebased changeset. 11166 ** 11167 ** <dt>Local DELETE<dd> 11168 ** This may conflict with a remote UPDATE or DELETE. In both cases the 11169 ** only possible resolution is OMIT. If the remote operation was a 11170 ** DELETE, then add no change to the rebased changeset. If the remote 11171 ** operation was an UPDATE, then the old.* fields of change are updated 11172 ** to reflect the new.* values in the UPDATE. 11173 ** 11174 ** <dt>Local UPDATE<dd> 11175 ** This may conflict with a remote UPDATE or DELETE. If it conflicts 11176 ** with a DELETE, and the conflict resolution was OMIT, then the update 11177 ** is changed into an INSERT. Any undefined values in the new.* record 11178 ** from the update change are filled in using the old.* values from 11179 ** the conflicting DELETE. Or, if the conflict resolution was REPLACE, 11180 ** the UPDATE change is simply omitted from the rebased changeset. 11181 ** 11182 ** If conflict is with a remote UPDATE and the resolution is OMIT, then 11183 ** the old.* values are rebased using the new.* values in the remote 11184 ** change. Or, if the resolution is REPLACE, then the change is copied 11185 ** into the rebased changeset with updates to columns also updated by 11186 ** the conflicting remote UPDATE removed. If this means no columns would 11187 ** be updated, the change is omitted. 11188 ** </dl> 11189 ** 11190 ** A local change may be rebased against multiple remote changes 11191 ** simultaneously. If a single key is modified by multiple remote 11192 ** changesets, they are combined as follows before the local changeset 11193 ** is rebased: 11194 ** 11195 ** <ul> 11196 ** <li> If there has been one or more REPLACE resolutions on a 11197 ** key, it is rebased according to a REPLACE. 11198 ** 11199 ** <li> If there have been no REPLACE resolutions on a key, then 11200 ** the local changeset is rebased according to the most recent 11201 ** of the OMIT resolutions. 11202 ** </ul> 11203 ** 11204 ** Note that conflict resolutions from multiple remote changesets are 11205 ** combined on a per-field basis, not per-row. This means that in the 11206 ** case of multiple remote UPDATE operations, some fields of a single 11207 ** local change may be rebased for REPLACE while others are rebased for 11208 ** OMIT. 11209 ** 11210 ** In order to rebase a local changeset, the remote changeset must first 11211 ** be applied to the local database using sqlite3changeset_apply_v2() and 11212 ** the buffer of rebase information captured. Then: 11213 ** 11214 ** <ol> 11215 ** <li> An sqlite3_rebaser object is created by calling 11216 ** sqlite3rebaser_create(). 11217 ** <li> The new object is configured with the rebase buffer obtained from 11218 ** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure(). 11219 ** If the local changeset is to be rebased against multiple remote 11220 ** changesets, then sqlite3rebaser_configure() should be called 11221 ** multiple times, in the same order that the multiple 11222 ** sqlite3changeset_apply_v2() calls were made. 11223 ** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase(). 11224 ** <li> The sqlite3_rebaser object is deleted by calling 11225 ** sqlite3rebaser_delete(). 11226 ** </ol> 11227 */ 11228 typedef struct sqlite3_rebaser sqlite3_rebaser; 11229 11230 /* 11231 ** CAPI3REF: Create a changeset rebaser object. 11232 ** EXPERIMENTAL 11233 ** 11234 ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to 11235 ** point to the new object and return SQLITE_OK. Otherwise, if an error 11236 ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew) 11237 ** to NULL. 11238 */ 11239 SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew); 11240 11241 /* 11242 ** CAPI3REF: Configure a changeset rebaser object. 11243 ** EXPERIMENTAL 11244 ** 11245 ** Configure the changeset rebaser object to rebase changesets according 11246 ** to the conflict resolutions described by buffer pRebase (size nRebase 11247 ** bytes), which must have been obtained from a previous call to 11248 ** sqlite3changeset_apply_v2(). 11249 */ 11250 SQLITE_API int sqlite3rebaser_configure( 11251 sqlite3_rebaser*, 11252 int nRebase, const void *pRebase 11253 ); 11254 11255 /* 11256 ** CAPI3REF: Rebase a changeset 11257 ** EXPERIMENTAL 11258 ** 11259 ** Argument pIn must point to a buffer containing a changeset nIn bytes 11260 ** in size. This function allocates and populates a buffer with a copy 11261 ** of the changeset rebased according to the configuration of the 11262 ** rebaser object passed as the first argument. If successful, (*ppOut) 11263 ** is set to point to the new buffer containing the rebased changeset and 11264 ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the 11265 ** responsibility of the caller to eventually free the new buffer using 11266 ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut) 11267 ** are set to zero and an SQLite error code returned. 11268 */ 11269 SQLITE_API int sqlite3rebaser_rebase( 11270 sqlite3_rebaser*, 11271 int nIn, const void *pIn, 11272 int *pnOut, void **ppOut 11273 ); 11274 11275 /* 11276 ** CAPI3REF: Delete a changeset rebaser object. 11277 ** EXPERIMENTAL 11278 ** 11279 ** Delete the changeset rebaser object and all associated resources. There 11280 ** should be one call to this function for each successful invocation 11281 ** of sqlite3rebaser_create(). 11282 */ 11283 SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p); 11284 11285 /* 11286 ** CAPI3REF: Streaming Versions of API functions. 11287 ** 11288 ** The six streaming API xxx_strm() functions serve similar purposes to the 11289 ** corresponding non-streaming API functions: 11290 ** 11291 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 11292 ** <tr><th>Streaming function<th>Non-streaming equivalent</th> 11293 ** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply] 11294 ** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2] 11295 ** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat] 11296 ** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert] 11297 ** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start] 11298 ** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset] 11299 ** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset] 11300 ** </table> 11301 ** 11302 ** Non-streaming functions that accept changesets (or patchsets) as input 11303 ** require that the entire changeset be stored in a single buffer in memory. 11304 ** Similarly, those that return a changeset or patchset do so by returning 11305 ** a pointer to a single large buffer allocated using sqlite3_malloc(). 11306 ** Normally this is convenient. However, if an application running in a 11307 ** low-memory environment is required to handle very large changesets, the 11308 ** large contiguous memory allocations required can become onerous. 11309 ** 11310 ** In order to avoid this problem, instead of a single large buffer, input 11311 ** is passed to a streaming API functions by way of a callback function that 11312 ** the sessions module invokes to incrementally request input data as it is 11313 ** required. In all cases, a pair of API function parameters such as 11314 ** 11315 ** <pre> 11316 ** int nChangeset, 11317 ** void *pChangeset, 11318 ** </pre> 11319 ** 11320 ** Is replaced by: 11321 ** 11322 ** <pre> 11323 ** int (*xInput)(void *pIn, void *pData, int *pnData), 11324 ** void *pIn, 11325 ** </pre> 11326 ** 11327 ** Each time the xInput callback is invoked by the sessions module, the first 11328 ** argument passed is a copy of the supplied pIn context pointer. The second 11329 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 11330 ** error occurs the xInput method should copy up to (*pnData) bytes of data 11331 ** into the buffer and set (*pnData) to the actual number of bytes copied 11332 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 11333 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite 11334 ** error code should be returned. In all cases, if an xInput callback returns 11335 ** an error, all processing is abandoned and the streaming API function 11336 ** returns a copy of the error code to the caller. 11337 ** 11338 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be 11339 ** invoked by the sessions module at any point during the lifetime of the 11340 ** iterator. If such an xInput callback returns an error, the iterator enters 11341 ** an error state, whereby all subsequent calls to iterator functions 11342 ** immediately fail with the same error code as returned by xInput. 11343 ** 11344 ** Similarly, streaming API functions that return changesets (or patchsets) 11345 ** return them in chunks by way of a callback function instead of via a 11346 ** pointer to a single large buffer. In this case, a pair of parameters such 11347 ** as: 11348 ** 11349 ** <pre> 11350 ** int *pnChangeset, 11351 ** void **ppChangeset, 11352 ** </pre> 11353 ** 11354 ** Is replaced by: 11355 ** 11356 ** <pre> 11357 ** int (*xOutput)(void *pOut, const void *pData, int nData), 11358 ** void *pOut 11359 ** </pre> 11360 ** 11361 ** The xOutput callback is invoked zero or more times to return data to 11362 ** the application. The first parameter passed to each call is a copy of the 11363 ** pOut pointer supplied by the application. The second parameter, pData, 11364 ** points to a buffer nData bytes in size containing the chunk of output 11365 ** data being returned. If the xOutput callback successfully processes the 11366 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 11367 ** it should return some other SQLite error code. In this case processing 11368 ** is immediately abandoned and the streaming API function returns a copy 11369 ** of the xOutput error code to the application. 11370 ** 11371 ** The sessions module never invokes an xOutput callback with the third 11372 ** parameter set to a value less than or equal to zero. Other than this, 11373 ** no guarantees are made as to the size of the chunks of data returned. 11374 */ 11375 SQLITE_API int sqlite3changeset_apply_strm( 11376 sqlite3 *db, /* Apply change to "main" db of this handle */ 11377 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 11378 void *pIn, /* First arg for xInput */ 11379 int(*xFilter)( 11380 void *pCtx, /* Copy of sixth arg to _apply() */ 11381 const char *zTab /* Table name */ 11382 ), 11383 int(*xConflict)( 11384 void *pCtx, /* Copy of sixth arg to _apply() */ 11385 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11386 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11387 ), 11388 void *pCtx /* First argument passed to xConflict */ 11389 ); 11390 SQLITE_API int sqlite3changeset_apply_v2_strm( 11391 sqlite3 *db, /* Apply change to "main" db of this handle */ 11392 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 11393 void *pIn, /* First arg for xInput */ 11394 int(*xFilter)( 11395 void *pCtx, /* Copy of sixth arg to _apply() */ 11396 const char *zTab /* Table name */ 11397 ), 11398 int(*xConflict)( 11399 void *pCtx, /* Copy of sixth arg to _apply() */ 11400 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11401 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11402 ), 11403 void *pCtx, /* First argument passed to xConflict */ 11404 void **ppRebase, int *pnRebase, 11405 int flags 11406 ); 11407 SQLITE_API int sqlite3changeset_concat_strm( 11408 int (*xInputA)(void *pIn, void *pData, int *pnData), 11409 void *pInA, 11410 int (*xInputB)(void *pIn, void *pData, int *pnData), 11411 void *pInB, 11412 int (*xOutput)(void *pOut, const void *pData, int nData), 11413 void *pOut 11414 ); 11415 SQLITE_API int sqlite3changeset_invert_strm( 11416 int (*xInput)(void *pIn, void *pData, int *pnData), 11417 void *pIn, 11418 int (*xOutput)(void *pOut, const void *pData, int nData), 11419 void *pOut 11420 ); 11421 SQLITE_API int sqlite3changeset_start_strm( 11422 sqlite3_changeset_iter **pp, 11423 int (*xInput)(void *pIn, void *pData, int *pnData), 11424 void *pIn 11425 ); 11426 SQLITE_API int sqlite3changeset_start_v2_strm( 11427 sqlite3_changeset_iter **pp, 11428 int (*xInput)(void *pIn, void *pData, int *pnData), 11429 void *pIn, 11430 int flags 11431 ); 11432 SQLITE_API int sqlite3session_changeset_strm( 11433 sqlite3_session *pSession, 11434 int (*xOutput)(void *pOut, const void *pData, int nData), 11435 void *pOut 11436 ); 11437 SQLITE_API int sqlite3session_patchset_strm( 11438 sqlite3_session *pSession, 11439 int (*xOutput)(void *pOut, const void *pData, int nData), 11440 void *pOut 11441 ); 11442 SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*, 11443 int (*xInput)(void *pIn, void *pData, int *pnData), 11444 void *pIn 11445 ); 11446 SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*, 11447 int (*xOutput)(void *pOut, const void *pData, int nData), 11448 void *pOut 11449 ); 11450 SQLITE_API int sqlite3rebaser_rebase_strm( 11451 sqlite3_rebaser *pRebaser, 11452 int (*xInput)(void *pIn, void *pData, int *pnData), 11453 void *pIn, 11454 int (*xOutput)(void *pOut, const void *pData, int nData), 11455 void *pOut 11456 ); 11457 11458 /* 11459 ** CAPI3REF: Configure global parameters 11460 ** 11461 ** The sqlite3session_config() interface is used to make global configuration 11462 ** changes to the sessions module in order to tune it to the specific needs 11463 ** of the application. 11464 ** 11465 ** The sqlite3session_config() interface is not threadsafe. If it is invoked 11466 ** while any other thread is inside any other sessions method then the 11467 ** results are undefined. Furthermore, if it is invoked after any sessions 11468 ** related objects have been created, the results are also undefined. 11469 ** 11470 ** The first argument to the sqlite3session_config() function must be one 11471 ** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The 11472 ** interpretation of the (void*) value passed as the second parameter and 11473 ** the effect of calling this function depends on the value of the first 11474 ** parameter. 11475 ** 11476 ** <dl> 11477 ** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd> 11478 ** By default, the sessions module streaming interfaces attempt to input 11479 ** and output data in approximately 1 KiB chunks. This operand may be used 11480 ** to set and query the value of this configuration setting. The pointer 11481 ** passed as the second argument must point to a value of type (int). 11482 ** If this value is greater than 0, it is used as the new streaming data 11483 ** chunk size for both input and output. Before returning, the (int) value 11484 ** pointed to by pArg is set to the final value of the streaming interface 11485 ** chunk size. 11486 ** </dl> 11487 ** 11488 ** This function returns SQLITE_OK if successful, or an SQLite error code 11489 ** otherwise. 11490 */ 11491 SQLITE_API int sqlite3session_config(int op, void *pArg); 11492 11493 /* 11494 ** CAPI3REF: Values for sqlite3session_config(). 11495 */ 11496 #define SQLITE_SESSION_CONFIG_STRMSIZE 1 11497 11498 /* 11499 ** Make sure we can call this stuff from C++. 11500 */ 11501 #ifdef __cplusplus 11502 } 11503 #endif 11504 11505 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 11506 11507 /******** End of sqlite3session.h *********/ 11508 /******** Begin file fts5.h *********/ 11509 /* 11510 ** 2014 May 31 11511 ** 11512 ** The author disclaims copyright to this source code. In place of 11513 ** a legal notice, here is a blessing: 11514 ** 11515 ** May you do good and not evil. 11516 ** May you find forgiveness for yourself and forgive others. 11517 ** May you share freely, never taking more than you give. 11518 ** 11519 ****************************************************************************** 11520 ** 11521 ** Interfaces to extend FTS5. Using the interfaces defined in this file, 11522 ** FTS5 may be extended with: 11523 ** 11524 ** * custom tokenizers, and 11525 ** * custom auxiliary functions. 11526 */ 11527 11528 11529 #ifndef _FTS5_H 11530 #define _FTS5_H 11531 11532 11533 #ifdef __cplusplus 11534 extern "C" { 11535 #endif 11536 11537 /************************************************************************* 11538 ** CUSTOM AUXILIARY FUNCTIONS 11539 ** 11540 ** Virtual table implementations may overload SQL functions by implementing 11541 ** the sqlite3_module.xFindFunction() method. 11542 */ 11543 11544 typedef struct Fts5ExtensionApi Fts5ExtensionApi; 11545 typedef struct Fts5Context Fts5Context; 11546 typedef struct Fts5PhraseIter Fts5PhraseIter; 11547 11548 typedef void (*fts5_extension_function)( 11549 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 11550 Fts5Context *pFts, /* First arg to pass to pApi functions */ 11551 sqlite3_context *pCtx, /* Context for returning result/error */ 11552 int nVal, /* Number of values in apVal[] array */ 11553 sqlite3_value **apVal /* Array of trailing arguments */ 11554 ); 11555 11556 struct Fts5PhraseIter { 11557 const unsigned char *a; 11558 const unsigned char *b; 11559 }; 11560 11561 /* 11562 ** EXTENSION API FUNCTIONS 11563 ** 11564 ** xUserData(pFts): 11565 ** Return a copy of the context pointer the extension function was 11566 ** registered with. 11567 ** 11568 ** xColumnTotalSize(pFts, iCol, pnToken): 11569 ** If parameter iCol is less than zero, set output variable *pnToken 11570 ** to the total number of tokens in the FTS5 table. Or, if iCol is 11571 ** non-negative but less than the number of columns in the table, return 11572 ** the total number of tokens in column iCol, considering all rows in 11573 ** the FTS5 table. 11574 ** 11575 ** If parameter iCol is greater than or equal to the number of columns 11576 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 11577 ** an OOM condition or IO error), an appropriate SQLite error code is 11578 ** returned. 11579 ** 11580 ** xColumnCount(pFts): 11581 ** Return the number of columns in the table. 11582 ** 11583 ** xColumnSize(pFts, iCol, pnToken): 11584 ** If parameter iCol is less than zero, set output variable *pnToken 11585 ** to the total number of tokens in the current row. Or, if iCol is 11586 ** non-negative but less than the number of columns in the table, set 11587 ** *pnToken to the number of tokens in column iCol of the current row. 11588 ** 11589 ** If parameter iCol is greater than or equal to the number of columns 11590 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 11591 ** an OOM condition or IO error), an appropriate SQLite error code is 11592 ** returned. 11593 ** 11594 ** This function may be quite inefficient if used with an FTS5 table 11595 ** created with the "columnsize=0" option. 11596 ** 11597 ** xColumnText: 11598 ** This function attempts to retrieve the text of column iCol of the 11599 ** current document. If successful, (*pz) is set to point to a buffer 11600 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 11601 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 11602 ** if an error occurs, an SQLite error code is returned and the final values 11603 ** of (*pz) and (*pn) are undefined. 11604 ** 11605 ** xPhraseCount: 11606 ** Returns the number of phrases in the current query expression. 11607 ** 11608 ** xPhraseSize: 11609 ** Returns the number of tokens in phrase iPhrase of the query. Phrases 11610 ** are numbered starting from zero. 11611 ** 11612 ** xInstCount: 11613 ** Set *pnInst to the total number of occurrences of all phrases within 11614 ** the query within the current row. Return SQLITE_OK if successful, or 11615 ** an error code (i.e. SQLITE_NOMEM) if an error occurs. 11616 ** 11617 ** This API can be quite slow if used with an FTS5 table created with the 11618 ** "detail=none" or "detail=column" option. If the FTS5 table is created 11619 ** with either "detail=none" or "detail=column" and "content=" option 11620 ** (i.e. if it is a contentless table), then this API always returns 0. 11621 ** 11622 ** xInst: 11623 ** Query for the details of phrase match iIdx within the current row. 11624 ** Phrase matches are numbered starting from zero, so the iIdx argument 11625 ** should be greater than or equal to zero and smaller than the value 11626 ** output by xInstCount(). 11627 ** 11628 ** Usually, output parameter *piPhrase is set to the phrase number, *piCol 11629 ** to the column in which it occurs and *piOff the token offset of the 11630 ** first token of the phrase. Returns SQLITE_OK if successful, or an error 11631 ** code (i.e. SQLITE_NOMEM) if an error occurs. 11632 ** 11633 ** This API can be quite slow if used with an FTS5 table created with the 11634 ** "detail=none" or "detail=column" option. 11635 ** 11636 ** xRowid: 11637 ** Returns the rowid of the current row. 11638 ** 11639 ** xTokenize: 11640 ** Tokenize text using the tokenizer belonging to the FTS5 table. 11641 ** 11642 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 11643 ** This API function is used to query the FTS table for phrase iPhrase 11644 ** of the current query. Specifically, a query equivalent to: 11645 ** 11646 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 11647 ** 11648 ** with $p set to a phrase equivalent to the phrase iPhrase of the 11649 ** current query is executed. Any column filter that applies to 11650 ** phrase iPhrase of the current query is included in $p. For each 11651 ** row visited, the callback function passed as the fourth argument 11652 ** is invoked. The context and API objects passed to the callback 11653 ** function may be used to access the properties of each matched row. 11654 ** Invoking Api.xUserData() returns a copy of the pointer passed as 11655 ** the third argument to pUserData. 11656 ** 11657 ** If the callback function returns any value other than SQLITE_OK, the 11658 ** query is abandoned and the xQueryPhrase function returns immediately. 11659 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 11660 ** Otherwise, the error code is propagated upwards. 11661 ** 11662 ** If the query runs to completion without incident, SQLITE_OK is returned. 11663 ** Or, if some error occurs before the query completes or is aborted by 11664 ** the callback, an SQLite error code is returned. 11665 ** 11666 ** 11667 ** xSetAuxdata(pFts5, pAux, xDelete) 11668 ** 11669 ** Save the pointer passed as the second argument as the extension function's 11670 ** "auxiliary data". The pointer may then be retrieved by the current or any 11671 ** future invocation of the same fts5 extension function made as part of 11672 ** the same MATCH query using the xGetAuxdata() API. 11673 ** 11674 ** Each extension function is allocated a single auxiliary data slot for 11675 ** each FTS query (MATCH expression). If the extension function is invoked 11676 ** more than once for a single FTS query, then all invocations share a 11677 ** single auxiliary data context. 11678 ** 11679 ** If there is already an auxiliary data pointer when this function is 11680 ** invoked, then it is replaced by the new pointer. If an xDelete callback 11681 ** was specified along with the original pointer, it is invoked at this 11682 ** point. 11683 ** 11684 ** The xDelete callback, if one is specified, is also invoked on the 11685 ** auxiliary data pointer after the FTS5 query has finished. 11686 ** 11687 ** If an error (e.g. an OOM condition) occurs within this function, 11688 ** the auxiliary data is set to NULL and an error code returned. If the 11689 ** xDelete parameter was not NULL, it is invoked on the auxiliary data 11690 ** pointer before returning. 11691 ** 11692 ** 11693 ** xGetAuxdata(pFts5, bClear) 11694 ** 11695 ** Returns the current auxiliary data pointer for the fts5 extension 11696 ** function. See the xSetAuxdata() method for details. 11697 ** 11698 ** If the bClear argument is non-zero, then the auxiliary data is cleared 11699 ** (set to NULL) before this function returns. In this case the xDelete, 11700 ** if any, is not invoked. 11701 ** 11702 ** 11703 ** xRowCount(pFts5, pnRow) 11704 ** 11705 ** This function is used to retrieve the total number of rows in the table. 11706 ** In other words, the same value that would be returned by: 11707 ** 11708 ** SELECT count(*) FROM ftstable; 11709 ** 11710 ** xPhraseFirst() 11711 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext 11712 ** method, to iterate through all instances of a single query phrase within 11713 ** the current row. This is the same information as is accessible via the 11714 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 11715 ** to use, this API may be faster under some circumstances. To iterate 11716 ** through instances of phrase iPhrase, use the following code: 11717 ** 11718 ** Fts5PhraseIter iter; 11719 ** int iCol, iOff; 11720 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 11721 ** iCol>=0; 11722 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 11723 ** ){ 11724 ** // An instance of phrase iPhrase at offset iOff of column iCol 11725 ** } 11726 ** 11727 ** The Fts5PhraseIter structure is defined above. Applications should not 11728 ** modify this structure directly - it should only be used as shown above 11729 ** with the xPhraseFirst() and xPhraseNext() API methods (and by 11730 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 11731 ** 11732 ** This API can be quite slow if used with an FTS5 table created with the 11733 ** "detail=none" or "detail=column" option. If the FTS5 table is created 11734 ** with either "detail=none" or "detail=column" and "content=" option 11735 ** (i.e. if it is a contentless table), then this API always iterates 11736 ** through an empty set (all calls to xPhraseFirst() set iCol to -1). 11737 ** 11738 ** xPhraseNext() 11739 ** See xPhraseFirst above. 11740 ** 11741 ** xPhraseFirstColumn() 11742 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 11743 ** and xPhraseNext() APIs described above. The difference is that instead 11744 ** of iterating through all instances of a phrase in the current row, these 11745 ** APIs are used to iterate through the set of columns in the current row 11746 ** that contain one or more instances of a specified phrase. For example: 11747 ** 11748 ** Fts5PhraseIter iter; 11749 ** int iCol; 11750 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 11751 ** iCol>=0; 11752 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 11753 ** ){ 11754 ** // Column iCol contains at least one instance of phrase iPhrase 11755 ** } 11756 ** 11757 ** This API can be quite slow if used with an FTS5 table created with the 11758 ** "detail=none" option. If the FTS5 table is created with either 11759 ** "detail=none" "content=" option (i.e. if it is a contentless table), 11760 ** then this API always iterates through an empty set (all calls to 11761 ** xPhraseFirstColumn() set iCol to -1). 11762 ** 11763 ** The information accessed using this API and its companion 11764 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 11765 ** (or xInst/xInstCount). The chief advantage of this API is that it is 11766 ** significantly more efficient than those alternatives when used with 11767 ** "detail=column" tables. 11768 ** 11769 ** xPhraseNextColumn() 11770 ** See xPhraseFirstColumn above. 11771 */ 11772 struct Fts5ExtensionApi { 11773 int iVersion; /* Currently always set to 3 */ 11774 11775 void *(*xUserData)(Fts5Context*); 11776 11777 int (*xColumnCount)(Fts5Context*); 11778 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 11779 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 11780 11781 int (*xTokenize)(Fts5Context*, 11782 const char *pText, int nText, /* Text to tokenize */ 11783 void *pCtx, /* Context passed to xToken() */ 11784 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 11785 ); 11786 11787 int (*xPhraseCount)(Fts5Context*); 11788 int (*xPhraseSize)(Fts5Context*, int iPhrase); 11789 11790 int (*xInstCount)(Fts5Context*, int *pnInst); 11791 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 11792 11793 sqlite3_int64 (*xRowid)(Fts5Context*); 11794 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 11795 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 11796 11797 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 11798 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 11799 ); 11800 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 11801 void *(*xGetAuxdata)(Fts5Context*, int bClear); 11802 11803 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 11804 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 11805 11806 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 11807 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 11808 }; 11809 11810 /* 11811 ** CUSTOM AUXILIARY FUNCTIONS 11812 *************************************************************************/ 11813 11814 /************************************************************************* 11815 ** CUSTOM TOKENIZERS 11816 ** 11817 ** Applications may also register custom tokenizer types. A tokenizer 11818 ** is registered by providing fts5 with a populated instance of the 11819 ** following structure. All structure methods must be defined, setting 11820 ** any member of the fts5_tokenizer struct to NULL leads to undefined 11821 ** behaviour. The structure methods are expected to function as follows: 11822 ** 11823 ** xCreate: 11824 ** This function is used to allocate and initialize a tokenizer instance. 11825 ** A tokenizer instance is required to actually tokenize text. 11826 ** 11827 ** The first argument passed to this function is a copy of the (void*) 11828 ** pointer provided by the application when the fts5_tokenizer object 11829 ** was registered with FTS5 (the third argument to xCreateTokenizer()). 11830 ** The second and third arguments are an array of nul-terminated strings 11831 ** containing the tokenizer arguments, if any, specified following the 11832 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 11833 ** to create the FTS5 table. 11834 ** 11835 ** The final argument is an output variable. If successful, (*ppOut) 11836 ** should be set to point to the new tokenizer handle and SQLITE_OK 11837 ** returned. If an error occurs, some value other than SQLITE_OK should 11838 ** be returned. In this case, fts5 assumes that the final value of *ppOut 11839 ** is undefined. 11840 ** 11841 ** xDelete: 11842 ** This function is invoked to delete a tokenizer handle previously 11843 ** allocated using xCreate(). Fts5 guarantees that this function will 11844 ** be invoked exactly once for each successful call to xCreate(). 11845 ** 11846 ** xTokenize: 11847 ** This function is expected to tokenize the nText byte string indicated 11848 ** by argument pText. pText may or may not be nul-terminated. The first 11849 ** argument passed to this function is a pointer to an Fts5Tokenizer object 11850 ** returned by an earlier call to xCreate(). 11851 ** 11852 ** The second argument indicates the reason that FTS5 is requesting 11853 ** tokenization of the supplied text. This is always one of the following 11854 ** four values: 11855 ** 11856 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 11857 ** or removed from the FTS table. The tokenizer is being invoked to 11858 ** determine the set of tokens to add to (or delete from) the 11859 ** FTS index. 11860 ** 11861 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 11862 ** against the FTS index. The tokenizer is being called to tokenize 11863 ** a bareword or quoted string specified as part of the query. 11864 ** 11865 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 11866 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 11867 ** followed by a "*" character, indicating that the last token 11868 ** returned by the tokenizer will be treated as a token prefix. 11869 ** 11870 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 11871 ** satisfy an fts5_api.xTokenize() request made by an auxiliary 11872 ** function. Or an fts5_api.xColumnSize() request made by the same 11873 ** on a columnsize=0 database. 11874 ** </ul> 11875 ** 11876 ** For each token in the input string, the supplied callback xToken() must 11877 ** be invoked. The first argument to it should be a copy of the pointer 11878 ** passed as the second argument to xTokenize(). The third and fourth 11879 ** arguments are a pointer to a buffer containing the token text, and the 11880 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets 11881 ** of the first byte of and first byte immediately following the text from 11882 ** which the token is derived within the input. 11883 ** 11884 ** The second argument passed to the xToken() callback ("tflags") should 11885 ** normally be set to 0. The exception is if the tokenizer supports 11886 ** synonyms. In this case see the discussion below for details. 11887 ** 11888 ** FTS5 assumes the xToken() callback is invoked for each token in the 11889 ** order that they occur within the input text. 11890 ** 11891 ** If an xToken() callback returns any value other than SQLITE_OK, then 11892 ** the tokenization should be abandoned and the xTokenize() method should 11893 ** immediately return a copy of the xToken() return value. Or, if the 11894 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 11895 ** if an error occurs with the xTokenize() implementation itself, it 11896 ** may abandon the tokenization and return any error code other than 11897 ** SQLITE_OK or SQLITE_DONE. 11898 ** 11899 ** SYNONYM SUPPORT 11900 ** 11901 ** Custom tokenizers may also support synonyms. Consider a case in which a 11902 ** user wishes to query for a phrase such as "first place". Using the 11903 ** built-in tokenizers, the FTS5 query 'first + place' will match instances 11904 ** of "first place" within the document set, but not alternative forms 11905 ** such as "1st place". In some applications, it would be better to match 11906 ** all instances of "first place" or "1st place" regardless of which form 11907 ** the user specified in the MATCH query text. 11908 ** 11909 ** There are several ways to approach this in FTS5: 11910 ** 11911 ** <ol><li> By mapping all synonyms to a single token. In this case, using 11912 ** the above example, this means that the tokenizer returns the 11913 ** same token for inputs "first" and "1st". Say that token is in 11914 ** fact "first", so that when the user inserts the document "I won 11915 ** 1st place" entries are added to the index for tokens "i", "won", 11916 ** "first" and "place". If the user then queries for '1st + place', 11917 ** the tokenizer substitutes "first" for "1st" and the query works 11918 ** as expected. 11919 ** 11920 ** <li> By querying the index for all synonyms of each query term 11921 ** separately. In this case, when tokenizing query text, the 11922 ** tokenizer may provide multiple synonyms for a single term 11923 ** within the document. FTS5 then queries the index for each 11924 ** synonym individually. For example, faced with the query: 11925 ** 11926 ** <codeblock> 11927 ** ... MATCH 'first place'</codeblock> 11928 ** 11929 ** the tokenizer offers both "1st" and "first" as synonyms for the 11930 ** first token in the MATCH query and FTS5 effectively runs a query 11931 ** similar to: 11932 ** 11933 ** <codeblock> 11934 ** ... MATCH '(first OR 1st) place'</codeblock> 11935 ** 11936 ** except that, for the purposes of auxiliary functions, the query 11937 ** still appears to contain just two phrases - "(first OR 1st)" 11938 ** being treated as a single phrase. 11939 ** 11940 ** <li> By adding multiple synonyms for a single term to the FTS index. 11941 ** Using this method, when tokenizing document text, the tokenizer 11942 ** provides multiple synonyms for each token. So that when a 11943 ** document such as "I won first place" is tokenized, entries are 11944 ** added to the FTS index for "i", "won", "first", "1st" and 11945 ** "place". 11946 ** 11947 ** This way, even if the tokenizer does not provide synonyms 11948 ** when tokenizing query text (it should not - to do so would be 11949 ** inefficient), it doesn't matter if the user queries for 11950 ** 'first + place' or '1st + place', as there are entries in the 11951 ** FTS index corresponding to both forms of the first token. 11952 ** </ol> 11953 ** 11954 ** Whether it is parsing document or query text, any call to xToken that 11955 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 11956 ** is considered to supply a synonym for the previous token. For example, 11957 ** when parsing the document "I won first place", a tokenizer that supports 11958 ** synonyms would call xToken() 5 times, as follows: 11959 ** 11960 ** <codeblock> 11961 ** xToken(pCtx, 0, "i", 1, 0, 1); 11962 ** xToken(pCtx, 0, "won", 3, 2, 5); 11963 ** xToken(pCtx, 0, "first", 5, 6, 11); 11964 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 11965 ** xToken(pCtx, 0, "place", 5, 12, 17); 11966 **</codeblock> 11967 ** 11968 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 11969 ** xToken() is called. Multiple synonyms may be specified for a single token 11970 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 11971 ** There is no limit to the number of synonyms that may be provided for a 11972 ** single token. 11973 ** 11974 ** In many cases, method (1) above is the best approach. It does not add 11975 ** extra data to the FTS index or require FTS5 to query for multiple terms, 11976 ** so it is efficient in terms of disk space and query speed. However, it 11977 ** does not support prefix queries very well. If, as suggested above, the 11978 ** token "first" is substituted for "1st" by the tokenizer, then the query: 11979 ** 11980 ** <codeblock> 11981 ** ... MATCH '1s*'</codeblock> 11982 ** 11983 ** will not match documents that contain the token "1st" (as the tokenizer 11984 ** will probably not map "1s" to any prefix of "first"). 11985 ** 11986 ** For full prefix support, method (3) may be preferred. In this case, 11987 ** because the index contains entries for both "first" and "1st", prefix 11988 ** queries such as 'fi*' or '1s*' will match correctly. However, because 11989 ** extra entries are added to the FTS index, this method uses more space 11990 ** within the database. 11991 ** 11992 ** Method (2) offers a midpoint between (1) and (3). Using this method, 11993 ** a query such as '1s*' will match documents that contain the literal 11994 ** token "1st", but not "first" (assuming the tokenizer is not able to 11995 ** provide synonyms for prefixes). However, a non-prefix query like '1st' 11996 ** will match against "1st" and "first". This method does not require 11997 ** extra disk space, as no extra entries are added to the FTS index. 11998 ** On the other hand, it may require more CPU cycles to run MATCH queries, 11999 ** as separate queries of the FTS index are required for each synonym. 12000 ** 12001 ** When using methods (2) or (3), it is important that the tokenizer only 12002 ** provide synonyms when tokenizing document text (method (2)) or query 12003 ** text (method (3)), not both. Doing so will not cause any errors, but is 12004 ** inefficient. 12005 */ 12006 typedef struct Fts5Tokenizer Fts5Tokenizer; 12007 typedef struct fts5_tokenizer fts5_tokenizer; 12008 struct fts5_tokenizer { 12009 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 12010 void (*xDelete)(Fts5Tokenizer*); 12011 int (*xTokenize)(Fts5Tokenizer*, 12012 void *pCtx, 12013 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 12014 const char *pText, int nText, 12015 int (*xToken)( 12016 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 12017 int tflags, /* Mask of FTS5_TOKEN_* flags */ 12018 const char *pToken, /* Pointer to buffer containing token */ 12019 int nToken, /* Size of token in bytes */ 12020 int iStart, /* Byte offset of token within input text */ 12021 int iEnd /* Byte offset of end of token within input text */ 12022 ) 12023 ); 12024 }; 12025 12026 /* Flags that may be passed as the third argument to xTokenize() */ 12027 #define FTS5_TOKENIZE_QUERY 0x0001 12028 #define FTS5_TOKENIZE_PREFIX 0x0002 12029 #define FTS5_TOKENIZE_DOCUMENT 0x0004 12030 #define FTS5_TOKENIZE_AUX 0x0008 12031 12032 /* Flags that may be passed by the tokenizer implementation back to FTS5 12033 ** as the third argument to the supplied xToken callback. */ 12034 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 12035 12036 /* 12037 ** END OF CUSTOM TOKENIZERS 12038 *************************************************************************/ 12039 12040 /************************************************************************* 12041 ** FTS5 EXTENSION REGISTRATION API 12042 */ 12043 typedef struct fts5_api fts5_api; 12044 struct fts5_api { 12045 int iVersion; /* Currently always set to 2 */ 12046 12047 /* Create a new tokenizer */ 12048 int (*xCreateTokenizer)( 12049 fts5_api *pApi, 12050 const char *zName, 12051 void *pContext, 12052 fts5_tokenizer *pTokenizer, 12053 void (*xDestroy)(void*) 12054 ); 12055 12056 /* Find an existing tokenizer */ 12057 int (*xFindTokenizer)( 12058 fts5_api *pApi, 12059 const char *zName, 12060 void **ppContext, 12061 fts5_tokenizer *pTokenizer 12062 ); 12063 12064 /* Create a new auxiliary function */ 12065 int (*xCreateFunction)( 12066 fts5_api *pApi, 12067 const char *zName, 12068 void *pContext, 12069 fts5_extension_function xFunction, 12070 void (*xDestroy)(void*) 12071 ); 12072 }; 12073 12074 /* 12075 ** END OF REGISTRATION API 12076 *************************************************************************/ 12077 12078 #ifdef __cplusplus 12079 } /* end of the 'extern "C"' block */ 12080 #endif 12081 12082 #endif /* _FTS5_H */ 12083 12084 /******** End of fts5.h *********/ 12085