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 41extern "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 "--VERS--" 127#define SQLITE_VERSION_NUMBER --VERSION-NUMBER-- 128#define SQLITE_SOURCE_ID "--SOURCE-ID--" 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*/ 162SQLITE_EXTERN const char sqlite3_version[]; 163const char *sqlite3_libversion(void); 164const char *sqlite3_sourceid(void); 165int 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 190int sqlite3_compileoption_used(const char *zOptName); 191const char *sqlite3_compileoption_get(int N); 192#endif 193 194/* 195** CAPI3REF: Test To See If The Library Is Threadsafe 196** 197** ^The sqlite3_threadsafe() function returns zero if and only if 198** SQLite was compiled with mutexing code omitted due to the 199** [SQLITE_THREADSAFE] compile-time option being set to 0. 200** 201** SQLite can be compiled with or without mutexes. When 202** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 203** are enabled and SQLite is threadsafe. When the 204** [SQLITE_THREADSAFE] macro is 0, 205** the mutexes are omitted. Without the mutexes, it is not safe 206** to use SQLite concurrently from more than one thread. 207** 208** Enabling mutexes incurs a measurable performance penalty. 209** So if speed is of utmost importance, it makes sense to disable 210** the mutexes. But for maximum safety, mutexes should be enabled. 211** ^The default behavior is for mutexes to be enabled. 212** 213** This interface can be used by an application to make sure that the 214** version of SQLite that it is linking against was compiled with 215** the desired setting of the [SQLITE_THREADSAFE] macro. 216** 217** This interface only reports on the compile-time mutex setting 218** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 219** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 220** can be fully or partially disabled using a call to [sqlite3_config()] 221** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 222** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 223** sqlite3_threadsafe() function shows only the compile-time setting of 224** thread safety, not any run-time changes to that setting made by 225** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 226** is unchanged by calls to sqlite3_config().)^ 227** 228** See the [threading mode] documentation for additional information. 229*/ 230int sqlite3_threadsafe(void); 231 232/* 233** CAPI3REF: Database Connection Handle 234** KEYWORDS: {database connection} {database connections} 235** 236** Each open SQLite database is represented by a pointer to an instance of 237** the opaque structure named "sqlite3". It is useful to think of an sqlite3 238** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 239** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 240** and [sqlite3_close_v2()] are its destructors. There are many other 241** interfaces (such as 242** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 243** [sqlite3_busy_timeout()] to name but three) that are methods on an 244** sqlite3 object. 245*/ 246typedef struct sqlite3 sqlite3; 247 248/* 249** CAPI3REF: 64-Bit Integer Types 250** KEYWORDS: sqlite_int64 sqlite_uint64 251** 252** Because there is no cross-platform way to specify 64-bit integer types 253** SQLite includes typedefs for 64-bit signed and unsigned integers. 254** 255** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 256** The sqlite_int64 and sqlite_uint64 types are supported for backwards 257** compatibility only. 258** 259** ^The sqlite3_int64 and sqlite_int64 types can store integer values 260** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 261** sqlite3_uint64 and sqlite_uint64 types can store integer values 262** between 0 and +18446744073709551615 inclusive. 263*/ 264#ifdef SQLITE_INT64_TYPE 265 typedef SQLITE_INT64_TYPE sqlite_int64; 266# ifdef SQLITE_UINT64_TYPE 267 typedef SQLITE_UINT64_TYPE sqlite_uint64; 268# else 269 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 270# endif 271#elif defined(_MSC_VER) || defined(__BORLANDC__) 272 typedef __int64 sqlite_int64; 273 typedef unsigned __int64 sqlite_uint64; 274#else 275 typedef long long int sqlite_int64; 276 typedef unsigned long long int sqlite_uint64; 277#endif 278typedef sqlite_int64 sqlite3_int64; 279typedef sqlite_uint64 sqlite3_uint64; 280 281/* 282** If compiling for a processor that lacks floating point support, 283** substitute integer for floating-point. 284*/ 285#ifdef SQLITE_OMIT_FLOATING_POINT 286# define double sqlite3_int64 287#endif 288 289/* 290** CAPI3REF: Closing A Database Connection 291** DESTRUCTOR: sqlite3 292** 293** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 294** for the [sqlite3] object. 295** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 296** the [sqlite3] object is successfully destroyed and all associated 297** resources are deallocated. 298** 299** ^If the database connection is associated with unfinalized prepared 300** statements or unfinished sqlite3_backup objects then sqlite3_close() 301** will leave the database connection open and return [SQLITE_BUSY]. 302** ^If sqlite3_close_v2() is called with unfinalized prepared statements 303** and/or unfinished sqlite3_backups, then the database connection becomes 304** an unusable "zombie" which will automatically be deallocated when the 305** last prepared statement is finalized or the last sqlite3_backup is 306** finished. The sqlite3_close_v2() interface is intended for use with 307** host languages that are garbage collected, and where the order in which 308** destructors are called is arbitrary. 309** 310** Applications should [sqlite3_finalize | finalize] all [prepared statements], 311** [sqlite3_blob_close | close] all [BLOB handles], and 312** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 313** with the [sqlite3] object prior to attempting to close the object. ^If 314** sqlite3_close_v2() is called on a [database connection] that still has 315** outstanding [prepared statements], [BLOB handles], and/or 316** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 317** of resources is deferred until all [prepared statements], [BLOB handles], 318** and [sqlite3_backup] objects are also destroyed. 319** 320** ^If an [sqlite3] object is destroyed while a transaction is open, 321** the transaction is automatically rolled back. 322** 323** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 324** must be either a NULL 325** pointer or an [sqlite3] object pointer obtained 326** from [sqlite3_open()], [sqlite3_open16()], or 327** [sqlite3_open_v2()], and not previously closed. 328** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 329** argument is a harmless no-op. 330*/ 331int sqlite3_close(sqlite3*); 332int sqlite3_close_v2(sqlite3*); 333 334/* 335** The type for a callback function. 336** This is legacy and deprecated. It is included for historical 337** compatibility and is not documented. 338*/ 339typedef int (*sqlite3_callback)(void*,int,char**, char**); 340 341/* 342** CAPI3REF: One-Step Query Execution Interface 343** METHOD: sqlite3 344** 345** The sqlite3_exec() interface is a convenience wrapper around 346** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 347** that allows an application to run multiple statements of SQL 348** without having to use a lot of C code. 349** 350** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 351** semicolon-separate SQL statements passed into its 2nd argument, 352** in the context of the [database connection] passed in as its 1st 353** argument. ^If the callback function of the 3rd argument to 354** sqlite3_exec() is not NULL, then it is invoked for each result row 355** coming out of the evaluated SQL statements. ^The 4th argument to 356** sqlite3_exec() is relayed through to the 1st argument of each 357** callback invocation. ^If the callback pointer to sqlite3_exec() 358** is NULL, then no callback is ever invoked and result rows are 359** ignored. 360** 361** ^If an error occurs while evaluating the SQL statements passed into 362** sqlite3_exec(), then execution of the current statement stops and 363** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 364** is not NULL then any error message is written into memory obtained 365** from [sqlite3_malloc()] and passed back through the 5th parameter. 366** To avoid memory leaks, the application should invoke [sqlite3_free()] 367** on error message strings returned through the 5th parameter of 368** sqlite3_exec() after the error message string is no longer needed. 369** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 370** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 371** NULL before returning. 372** 373** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 374** routine returns SQLITE_ABORT without invoking the callback again and 375** without running any subsequent SQL statements. 376** 377** ^The 2nd argument to the sqlite3_exec() callback function is the 378** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 379** callback is an array of pointers to strings obtained as if from 380** [sqlite3_column_text()], one for each column. ^If an element of a 381** result row is NULL then the corresponding string pointer for the 382** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 383** sqlite3_exec() callback is an array of pointers to strings where each 384** entry represents the name of corresponding result column as obtained 385** from [sqlite3_column_name()]. 386** 387** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 388** to an empty string, or a pointer that contains only whitespace and/or 389** SQL comments, then no SQL statements are evaluated and the database 390** is not changed. 391** 392** Restrictions: 393** 394** <ul> 395** <li> The application must ensure that the 1st parameter to sqlite3_exec() 396** is a valid and open [database connection]. 397** <li> The application must not close the [database connection] specified by 398** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 399** <li> The application must not modify the SQL statement text passed into 400** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 401** </ul> 402*/ 403int sqlite3_exec( 404 sqlite3*, /* An open database */ 405 const char *sql, /* SQL to be evaluated */ 406 int (*callback)(void*,int,char**,char**), /* Callback function */ 407 void *, /* 1st argument to callback */ 408 char **errmsg /* Error msg written here */ 409); 410 411/* 412** CAPI3REF: Result Codes 413** KEYWORDS: {result code definitions} 414** 415** Many SQLite functions return an integer result code from the set shown 416** here in order to indicate success or failure. 417** 418** New error codes may be added in future versions of SQLite. 419** 420** See also: [extended result code definitions] 421*/ 422#define SQLITE_OK 0 /* Successful result */ 423/* beginning-of-error-codes */ 424#define SQLITE_ERROR 1 /* Generic error */ 425#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 426#define SQLITE_PERM 3 /* Access permission denied */ 427#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 428#define SQLITE_BUSY 5 /* The database file is locked */ 429#define SQLITE_LOCKED 6 /* A table in the database is locked */ 430#define SQLITE_NOMEM 7 /* A malloc() failed */ 431#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 432#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 433#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 434#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 435#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 436#define SQLITE_FULL 13 /* Insertion failed because database is full */ 437#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 438#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 439#define SQLITE_EMPTY 16 /* Internal use only */ 440#define SQLITE_SCHEMA 17 /* The database schema changed */ 441#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 442#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 443#define SQLITE_MISMATCH 20 /* Data type mismatch */ 444#define SQLITE_MISUSE 21 /* Library used incorrectly */ 445#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 446#define SQLITE_AUTH 23 /* Authorization denied */ 447#define SQLITE_FORMAT 24 /* Not used */ 448#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 449#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 450#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 451#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 452#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 453#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 454/* end-of-error-codes */ 455 456/* 457** CAPI3REF: Extended Result Codes 458** KEYWORDS: {extended result code definitions} 459** 460** In its default configuration, SQLite API routines return one of 30 integer 461** [result codes]. However, experience has shown that many of 462** these result codes are too coarse-grained. They do not provide as 463** much information about problems as programmers might like. In an effort to 464** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 465** and later) include 466** support for additional result codes that provide more detailed information 467** about errors. These [extended result codes] are enabled or disabled 468** on a per database connection basis using the 469** [sqlite3_extended_result_codes()] API. Or, the extended code for 470** the most recent error can be obtained using 471** [sqlite3_extended_errcode()]. 472*/ 473#define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 474#define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 475#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 476#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 477#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 478#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 479#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 480#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 481#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 482#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 483#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 484#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 485#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 486#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 487#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 488#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 489#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 490#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 491#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 492#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 493#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 494#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 495#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 496#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 497#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 498#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 499#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 500#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 501#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 502#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 503#define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 504#define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 505#define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 506#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 507#define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 508#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 509#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 510#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 511#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 512#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 513#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 514#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 515#define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 516#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 517#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 518#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 519#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 520#define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 521#define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 522#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 523#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 524#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 525#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 526#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 527#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 528#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 529#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 530#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 531#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 532#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 533#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 534#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 535#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 536#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 537#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 538 539/* 540** CAPI3REF: Flags For File Open Operations 541** 542** These bit values are intended for use in the 543** 3rd parameter to the [sqlite3_open_v2()] interface and 544** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 545*/ 546#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 547#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 548#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 549#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 550#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 551#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 552#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 553#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 554#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 555#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 556#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 557#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 558#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 559#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 560#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 561#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 562#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 563#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 564#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 565#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 566 567/* Reserved: 0x00F00000 */ 568 569/* 570** CAPI3REF: Device Characteristics 571** 572** The xDeviceCharacteristics method of the [sqlite3_io_methods] 573** object returns an integer which is a vector of these 574** bit values expressing I/O characteristics of the mass storage 575** device that holds the file that the [sqlite3_io_methods] 576** refers to. 577** 578** The SQLITE_IOCAP_ATOMIC property means that all writes of 579** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 580** mean that writes of blocks that are nnn bytes in size and 581** are aligned to an address which is an integer multiple of 582** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 583** that when data is appended to a file, the data is appended 584** first then the size of the file is extended, never the other 585** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 586** information is written to disk in the same order as calls 587** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 588** after reboot following a crash or power loss, the only bytes in a 589** file that were written at the application level might have changed 590** and that adjacent bytes, even bytes within the same sector are 591** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 592** flag indicates that a file cannot be deleted when open. The 593** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 594** read-only media and cannot be changed even by processes with 595** elevated privileges. 596** 597** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 598** filesystem supports doing multiple write operations atomically when those 599** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 600** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 601*/ 602#define SQLITE_IOCAP_ATOMIC 0x00000001 603#define SQLITE_IOCAP_ATOMIC512 0x00000002 604#define SQLITE_IOCAP_ATOMIC1K 0x00000004 605#define SQLITE_IOCAP_ATOMIC2K 0x00000008 606#define SQLITE_IOCAP_ATOMIC4K 0x00000010 607#define SQLITE_IOCAP_ATOMIC8K 0x00000020 608#define SQLITE_IOCAP_ATOMIC16K 0x00000040 609#define SQLITE_IOCAP_ATOMIC32K 0x00000080 610#define SQLITE_IOCAP_ATOMIC64K 0x00000100 611#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 612#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 613#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 614#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 615#define SQLITE_IOCAP_IMMUTABLE 0x00002000 616#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 617 618/* 619** CAPI3REF: File Locking Levels 620** 621** SQLite uses one of these integer values as the second 622** argument to calls it makes to the xLock() and xUnlock() methods 623** of an [sqlite3_io_methods] object. 624*/ 625#define SQLITE_LOCK_NONE 0 626#define SQLITE_LOCK_SHARED 1 627#define SQLITE_LOCK_RESERVED 2 628#define SQLITE_LOCK_PENDING 3 629#define SQLITE_LOCK_EXCLUSIVE 4 630 631/* 632** CAPI3REF: Synchronization Type Flags 633** 634** When SQLite invokes the xSync() method of an 635** [sqlite3_io_methods] object it uses a combination of 636** these integer values as the second argument. 637** 638** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 639** sync operation only needs to flush data to mass storage. Inode 640** information need not be flushed. If the lower four bits of the flag 641** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 642** If the lower four bits equal SQLITE_SYNC_FULL, that means 643** to use Mac OS X style fullsync instead of fsync(). 644** 645** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 646** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 647** settings. The [synchronous pragma] determines when calls to the 648** xSync VFS method occur and applies uniformly across all platforms. 649** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 650** energetic or rigorous or forceful the sync operations are and 651** only make a difference on Mac OSX for the default SQLite code. 652** (Third-party VFS implementations might also make the distinction 653** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 654** operating systems natively supported by SQLite, only Mac OSX 655** cares about the difference.) 656*/ 657#define SQLITE_SYNC_NORMAL 0x00002 658#define SQLITE_SYNC_FULL 0x00003 659#define SQLITE_SYNC_DATAONLY 0x00010 660 661/* 662** CAPI3REF: OS Interface Open File Handle 663** 664** An [sqlite3_file] object represents an open file in the 665** [sqlite3_vfs | OS interface layer]. Individual OS interface 666** implementations will 667** want to subclass this object by appending additional fields 668** for their own use. The pMethods entry is a pointer to an 669** [sqlite3_io_methods] object that defines methods for performing 670** I/O operations on the open file. 671*/ 672typedef struct sqlite3_file sqlite3_file; 673struct sqlite3_file { 674 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 675}; 676 677/* 678** CAPI3REF: OS Interface File Virtual Methods Object 679** 680** Every file opened by the [sqlite3_vfs.xOpen] method populates an 681** [sqlite3_file] object (or, more commonly, a subclass of the 682** [sqlite3_file] object) with a pointer to an instance of this object. 683** This object defines the methods used to perform various operations 684** against the open file represented by the [sqlite3_file] object. 685** 686** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 687** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 688** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 689** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 690** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 691** to NULL. 692** 693** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 694** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 695** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 696** flag may be ORed in to indicate that only the data of the file 697** and not its inode needs to be synced. 698** 699** The integer values to xLock() and xUnlock() are one of 700** <ul> 701** <li> [SQLITE_LOCK_NONE], 702** <li> [SQLITE_LOCK_SHARED], 703** <li> [SQLITE_LOCK_RESERVED], 704** <li> [SQLITE_LOCK_PENDING], or 705** <li> [SQLITE_LOCK_EXCLUSIVE]. 706** </ul> 707** xLock() increases the lock. xUnlock() decreases the lock. 708** The xCheckReservedLock() method checks whether any database connection, 709** either in this process or in some other process, is holding a RESERVED, 710** PENDING, or EXCLUSIVE lock on the file. It returns true 711** if such a lock exists and false otherwise. 712** 713** The xFileControl() method is a generic interface that allows custom 714** VFS implementations to directly control an open file using the 715** [sqlite3_file_control()] interface. The second "op" argument is an 716** integer opcode. The third argument is a generic pointer intended to 717** point to a structure that may contain arguments or space in which to 718** write return values. Potential uses for xFileControl() might be 719** functions to enable blocking locks with timeouts, to change the 720** locking strategy (for example to use dot-file locks), to inquire 721** about the status of a lock, or to break stale locks. The SQLite 722** core reserves all opcodes less than 100 for its own use. 723** A [file control opcodes | list of opcodes] less than 100 is available. 724** Applications that define a custom xFileControl method should use opcodes 725** greater than 100 to avoid conflicts. VFS implementations should 726** return [SQLITE_NOTFOUND] for file control opcodes that they do not 727** recognize. 728** 729** The xSectorSize() method returns the sector size of the 730** device that underlies the file. The sector size is the 731** minimum write that can be performed without disturbing 732** other bytes in the file. The xDeviceCharacteristics() 733** method returns a bit vector describing behaviors of the 734** underlying device: 735** 736** <ul> 737** <li> [SQLITE_IOCAP_ATOMIC] 738** <li> [SQLITE_IOCAP_ATOMIC512] 739** <li> [SQLITE_IOCAP_ATOMIC1K] 740** <li> [SQLITE_IOCAP_ATOMIC2K] 741** <li> [SQLITE_IOCAP_ATOMIC4K] 742** <li> [SQLITE_IOCAP_ATOMIC8K] 743** <li> [SQLITE_IOCAP_ATOMIC16K] 744** <li> [SQLITE_IOCAP_ATOMIC32K] 745** <li> [SQLITE_IOCAP_ATOMIC64K] 746** <li> [SQLITE_IOCAP_SAFE_APPEND] 747** <li> [SQLITE_IOCAP_SEQUENTIAL] 748** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 749** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 750** <li> [SQLITE_IOCAP_IMMUTABLE] 751** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 752** </ul> 753** 754** The SQLITE_IOCAP_ATOMIC property means that all writes of 755** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 756** mean that writes of blocks that are nnn bytes in size and 757** are aligned to an address which is an integer multiple of 758** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 759** that when data is appended to a file, the data is appended 760** first then the size of the file is extended, never the other 761** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 762** information is written to disk in the same order as calls 763** to xWrite(). 764** 765** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 766** in the unread portions of the buffer with zeros. A VFS that 767** fails to zero-fill short reads might seem to work. However, 768** failure to zero-fill short reads will eventually lead to 769** database corruption. 770*/ 771typedef struct sqlite3_io_methods sqlite3_io_methods; 772struct sqlite3_io_methods { 773 int iVersion; 774 int (*xClose)(sqlite3_file*); 775 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 776 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 777 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 778 int (*xSync)(sqlite3_file*, int flags); 779 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 780 int (*xLock)(sqlite3_file*, int); 781 int (*xUnlock)(sqlite3_file*, int); 782 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 783 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 784 int (*xSectorSize)(sqlite3_file*); 785 int (*xDeviceCharacteristics)(sqlite3_file*); 786 /* Methods above are valid for version 1 */ 787 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 788 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 789 void (*xShmBarrier)(sqlite3_file*); 790 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 791 /* Methods above are valid for version 2 */ 792 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 793 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 794 /* Methods above are valid for version 3 */ 795 /* Additional methods may be added in future releases */ 796}; 797 798/* 799** CAPI3REF: Standard File Control Opcodes 800** KEYWORDS: {file control opcodes} {file control opcode} 801** 802** These integer constants are opcodes for the xFileControl method 803** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 804** interface. 805** 806** <ul> 807** <li>[[SQLITE_FCNTL_LOCKSTATE]] 808** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 809** opcode causes the xFileControl method to write the current state of 810** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 811** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 812** into an integer that the pArg argument points to. This capability 813** is used during testing and is only available when the SQLITE_TEST 814** compile-time option is used. 815** 816** <li>[[SQLITE_FCNTL_SIZE_HINT]] 817** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 818** layer a hint of how large the database file will grow to be during the 819** current transaction. This hint is not guaranteed to be accurate but it 820** is often close. The underlying VFS might choose to preallocate database 821** file space based on this hint in order to help writes to the database 822** file run faster. 823** 824** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 825** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 826** extends and truncates the database file in chunks of a size specified 827** by the user. The fourth argument to [sqlite3_file_control()] should 828** point to an integer (type int) containing the new chunk-size to use 829** for the nominated database. Allocating database file space in large 830** chunks (say 1MB at a time), may reduce file-system fragmentation and 831** improve performance on some systems. 832** 833** <li>[[SQLITE_FCNTL_FILE_POINTER]] 834** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 835** to the [sqlite3_file] object associated with a particular database 836** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 837** 838** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 839** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 840** to the [sqlite3_file] object associated with the journal file (either 841** the [rollback journal] or the [write-ahead log]) for a particular database 842** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 843** 844** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 845** No longer in use. 846** 847** <li>[[SQLITE_FCNTL_SYNC]] 848** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 849** sent to the VFS immediately before the xSync method is invoked on a 850** database file descriptor. Or, if the xSync method is not invoked 851** because the user has configured SQLite with 852** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 853** of the xSync method. In most cases, the pointer argument passed with 854** this file-control is NULL. However, if the database file is being synced 855** as part of a multi-database commit, the argument points to a nul-terminated 856** string containing the transactions master-journal file name. VFSes that 857** do not need this signal should silently ignore this opcode. Applications 858** should not call [sqlite3_file_control()] with this opcode as doing so may 859** disrupt the operation of the specialized VFSes that do require it. 860** 861** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 862** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 863** and sent to the VFS after a transaction has been committed immediately 864** but before the database is unlocked. VFSes that do not need this signal 865** should silently ignore this opcode. Applications should not call 866** [sqlite3_file_control()] with this opcode as doing so may disrupt the 867** operation of the specialized VFSes that do require it. 868** 869** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 870** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 871** retry counts and intervals for certain disk I/O operations for the 872** windows [VFS] in order to provide robustness in the presence of 873** anti-virus programs. By default, the windows VFS will retry file read, 874** file write, and file delete operations up to 10 times, with a delay 875** of 25 milliseconds before the first retry and with the delay increasing 876** by an additional 25 milliseconds with each subsequent retry. This 877** opcode allows these two values (10 retries and 25 milliseconds of delay) 878** to be adjusted. The values are changed for all database connections 879** within the same process. The argument is a pointer to an array of two 880** integers where the first integer is the new retry count and the second 881** integer is the delay. If either integer is negative, then the setting 882** is not changed but instead the prior value of that setting is written 883** into the array entry, allowing the current retry settings to be 884** interrogated. The zDbName parameter is ignored. 885** 886** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 887** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 888** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 889** write ahead log and shared memory files used for transaction control 890** are automatically deleted when the latest connection to the database 891** closes. Setting persistent WAL mode causes those files to persist after 892** close. Persisting the files is useful when other processes that do not 893** have write permission on the directory containing the database file want 894** to read the database file, as the WAL and shared memory files must exist 895** in order for the database to be readable. The fourth parameter to 896** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 897** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 898** WAL mode. If the integer is -1, then it is overwritten with the current 899** WAL persistence setting. 900** 901** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 902** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 903** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 904** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 905** xDeviceCharacteristics methods. The fourth parameter to 906** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 907** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 908** mode. If the integer is -1, then it is overwritten with the current 909** zero-damage mode setting. 910** 911** <li>[[SQLITE_FCNTL_OVERWRITE]] 912** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 913** a write transaction to indicate that, unless it is rolled back for some 914** reason, the entire database file will be overwritten by the current 915** transaction. This is used by VACUUM operations. 916** 917** <li>[[SQLITE_FCNTL_VFSNAME]] 918** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 919** all [VFSes] in the VFS stack. The names are of all VFS shims and the 920** final bottom-level VFS are written into memory obtained from 921** [sqlite3_malloc()] and the result is stored in the char* variable 922** that the fourth parameter of [sqlite3_file_control()] points to. 923** The caller is responsible for freeing the memory when done. As with 924** all file-control actions, there is no guarantee that this will actually 925** do anything. Callers should initialize the char* variable to a NULL 926** pointer in case this file-control is not implemented. This file-control 927** is intended for diagnostic use only. 928** 929** <li>[[SQLITE_FCNTL_VFS_POINTER]] 930** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 931** [VFSes] currently in use. ^(The argument X in 932** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 933** of type "[sqlite3_vfs] **". This opcodes will set *X 934** to a pointer to the top-level VFS.)^ 935** ^When there are multiple VFS shims in the stack, this opcode finds the 936** upper-most shim only. 937** 938** <li>[[SQLITE_FCNTL_PRAGMA]] 939** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 940** file control is sent to the open [sqlite3_file] object corresponding 941** to the database file to which the pragma statement refers. ^The argument 942** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 943** pointers to strings (char**) in which the second element of the array 944** is the name of the pragma and the third element is the argument to the 945** pragma or NULL if the pragma has no argument. ^The handler for an 946** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 947** of the char** argument point to a string obtained from [sqlite3_mprintf()] 948** or the equivalent and that string will become the result of the pragma or 949** the error message if the pragma fails. ^If the 950** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 951** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 952** file control returns [SQLITE_OK], then the parser assumes that the 953** VFS has handled the PRAGMA itself and the parser generates a no-op 954** prepared statement if result string is NULL, or that returns a copy 955** of the result string if the string is non-NULL. 956** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 957** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 958** that the VFS encountered an error while handling the [PRAGMA] and the 959** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 960** file control occurs at the beginning of pragma statement analysis and so 961** it is able to override built-in [PRAGMA] statements. 962** 963** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 964** ^The [SQLITE_FCNTL_BUSYHANDLER] 965** file-control may be invoked by SQLite on the database file handle 966** shortly after it is opened in order to provide a custom VFS with access 967** to the connections busy-handler callback. The argument is of type (void **) 968** - an array of two (void *) values. The first (void *) actually points 969** to a function of type (int (*)(void *)). In order to invoke the connections 970** busy-handler, this function should be invoked with the second (void *) in 971** the array as the only argument. If it returns non-zero, then the operation 972** should be retried. If it returns zero, the custom VFS should abandon the 973** current operation. 974** 975** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 976** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 977** to have SQLite generate a 978** temporary filename using the same algorithm that is followed to generate 979** temporary filenames for TEMP tables and other internal uses. The 980** argument should be a char** which will be filled with the filename 981** written into memory obtained from [sqlite3_malloc()]. The caller should 982** invoke [sqlite3_free()] on the result to avoid a memory leak. 983** 984** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 985** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 986** maximum number of bytes that will be used for memory-mapped I/O. 987** The argument is a pointer to a value of type sqlite3_int64 that 988** is an advisory maximum number of bytes in the file to memory map. The 989** pointer is overwritten with the old value. The limit is not changed if 990** the value originally pointed to is negative, and so the current limit 991** can be queried by passing in a pointer to a negative number. This 992** file-control is used internally to implement [PRAGMA mmap_size]. 993** 994** <li>[[SQLITE_FCNTL_TRACE]] 995** The [SQLITE_FCNTL_TRACE] file control provides advisory information 996** to the VFS about what the higher layers of the SQLite stack are doing. 997** This file control is used by some VFS activity tracing [shims]. 998** The argument is a zero-terminated string. Higher layers in the 999** SQLite stack may generate instances of this file control if 1000** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1001** 1002** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1003** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1004** pointer to an integer and it writes a boolean into that integer depending 1005** on whether or not the file has been renamed, moved, or deleted since it 1006** was first opened. 1007** 1008** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1009** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1010** underlying native file handle associated with a file handle. This file 1011** control interprets its argument as a pointer to a native file handle and 1012** writes the resulting value there. 1013** 1014** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1015** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1016** opcode causes the xFileControl method to swap the file handle with the one 1017** pointed to by the pArg argument. This capability is used during testing 1018** and only needs to be supported when SQLITE_TEST is defined. 1019** 1020** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1021** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1022** be advantageous to block on the next WAL lock if the lock is not immediately 1023** available. The WAL subsystem issues this signal during rare 1024** circumstances in order to fix a problem with priority inversion. 1025** Applications should <em>not</em> use this file-control. 1026** 1027** <li>[[SQLITE_FCNTL_ZIPVFS]] 1028** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1029** VFS should return SQLITE_NOTFOUND for this opcode. 1030** 1031** <li>[[SQLITE_FCNTL_RBU]] 1032** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1033** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1034** this opcode. 1035** 1036** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1037** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1038** the file descriptor is placed in "batch write mode", which 1039** means all subsequent write operations will be deferred and done 1040** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1041** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1042** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1043** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1044** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1045** no VFS interface calls on the same [sqlite3_file] file descriptor 1046** except for calls to the xWrite method and the xFileControl method 1047** with [SQLITE_FCNTL_SIZE_HINT]. 1048** 1049** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1050** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1051** operations since the previous successful call to 1052** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1053** This file control returns [SQLITE_OK] if and only if the writes were 1054** all performed successfully and have been committed to persistent storage. 1055** ^Regardless of whether or not it is successful, this file control takes 1056** the file descriptor out of batch write mode so that all subsequent 1057** write operations are independent. 1058** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1059** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1060** 1061** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1062** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1063** operations since the previous successful call to 1064** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1065** ^This file control takes the file descriptor out of batch write mode 1066** so that all subsequent write operations are independent. 1067** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1068** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1069** 1070** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1071** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode causes attempts to obtain 1072** a file lock using the xLock or xShmLock methods of the VFS to wait 1073** for up to M milliseconds before failing, where M is the single 1074** unsigned integer parameter. 1075** </ul> 1076*/ 1077#define SQLITE_FCNTL_LOCKSTATE 1 1078#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1079#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1080#define SQLITE_FCNTL_LAST_ERRNO 4 1081#define SQLITE_FCNTL_SIZE_HINT 5 1082#define SQLITE_FCNTL_CHUNK_SIZE 6 1083#define SQLITE_FCNTL_FILE_POINTER 7 1084#define SQLITE_FCNTL_SYNC_OMITTED 8 1085#define SQLITE_FCNTL_WIN32_AV_RETRY 9 1086#define SQLITE_FCNTL_PERSIST_WAL 10 1087#define SQLITE_FCNTL_OVERWRITE 11 1088#define SQLITE_FCNTL_VFSNAME 12 1089#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1090#define SQLITE_FCNTL_PRAGMA 14 1091#define SQLITE_FCNTL_BUSYHANDLER 15 1092#define SQLITE_FCNTL_TEMPFILENAME 16 1093#define SQLITE_FCNTL_MMAP_SIZE 18 1094#define SQLITE_FCNTL_TRACE 19 1095#define SQLITE_FCNTL_HAS_MOVED 20 1096#define SQLITE_FCNTL_SYNC 21 1097#define SQLITE_FCNTL_COMMIT_PHASETWO 22 1098#define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1099#define SQLITE_FCNTL_WAL_BLOCK 24 1100#define SQLITE_FCNTL_ZIPVFS 25 1101#define SQLITE_FCNTL_RBU 26 1102#define SQLITE_FCNTL_VFS_POINTER 27 1103#define SQLITE_FCNTL_JOURNAL_POINTER 28 1104#define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1105#define SQLITE_FCNTL_PDB 30 1106#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1107#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1108#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1109#define SQLITE_FCNTL_LOCK_TIMEOUT 34 1110 1111/* deprecated names */ 1112#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1113#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1114#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1115 1116 1117/* 1118** CAPI3REF: Mutex Handle 1119** 1120** The mutex module within SQLite defines [sqlite3_mutex] to be an 1121** abstract type for a mutex object. The SQLite core never looks 1122** at the internal representation of an [sqlite3_mutex]. It only 1123** deals with pointers to the [sqlite3_mutex] object. 1124** 1125** Mutexes are created using [sqlite3_mutex_alloc()]. 1126*/ 1127typedef struct sqlite3_mutex sqlite3_mutex; 1128 1129/* 1130** CAPI3REF: Loadable Extension Thunk 1131** 1132** A pointer to the opaque sqlite3_api_routines structure is passed as 1133** the third parameter to entry points of [loadable extensions]. This 1134** structure must be typedefed in order to work around compiler warnings 1135** on some platforms. 1136*/ 1137typedef struct sqlite3_api_routines sqlite3_api_routines; 1138 1139/* 1140** CAPI3REF: OS Interface Object 1141** 1142** An instance of the sqlite3_vfs object defines the interface between 1143** the SQLite core and the underlying operating system. The "vfs" 1144** in the name of the object stands for "virtual file system". See 1145** the [VFS | VFS documentation] for further information. 1146** 1147** The VFS interface is sometimes extended by adding new methods onto 1148** the end. Each time such an extension occurs, the iVersion field 1149** is incremented. The iVersion value started out as 1 in 1150** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1151** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1152** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1153** may be appended to the sqlite3_vfs object and the iVersion value 1154** may increase again in future versions of SQLite. 1155** Note that the structure 1156** of the sqlite3_vfs object changes in the transition from 1157** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1158** and yet the iVersion field was not modified. 1159** 1160** The szOsFile field is the size of the subclassed [sqlite3_file] 1161** structure used by this VFS. mxPathname is the maximum length of 1162** a pathname in this VFS. 1163** 1164** Registered sqlite3_vfs objects are kept on a linked list formed by 1165** the pNext pointer. The [sqlite3_vfs_register()] 1166** and [sqlite3_vfs_unregister()] interfaces manage this list 1167** in a thread-safe way. The [sqlite3_vfs_find()] interface 1168** searches the list. Neither the application code nor the VFS 1169** implementation should use the pNext pointer. 1170** 1171** The pNext field is the only field in the sqlite3_vfs 1172** structure that SQLite will ever modify. SQLite will only access 1173** or modify this field while holding a particular static mutex. 1174** The application should never modify anything within the sqlite3_vfs 1175** object once the object has been registered. 1176** 1177** The zName field holds the name of the VFS module. The name must 1178** be unique across all VFS modules. 1179** 1180** [[sqlite3_vfs.xOpen]] 1181** ^SQLite guarantees that the zFilename parameter to xOpen 1182** is either a NULL pointer or string obtained 1183** from xFullPathname() with an optional suffix added. 1184** ^If a suffix is added to the zFilename parameter, it will 1185** consist of a single "-" character followed by no more than 1186** 11 alphanumeric and/or "-" characters. 1187** ^SQLite further guarantees that 1188** the string will be valid and unchanged until xClose() is 1189** called. Because of the previous sentence, 1190** the [sqlite3_file] can safely store a pointer to the 1191** filename if it needs to remember the filename for some reason. 1192** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1193** must invent its own temporary name for the file. ^Whenever the 1194** xFilename parameter is NULL it will also be the case that the 1195** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1196** 1197** The flags argument to xOpen() includes all bits set in 1198** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1199** or [sqlite3_open16()] is used, then flags includes at least 1200** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1201** If xOpen() opens a file read-only then it sets *pOutFlags to 1202** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1203** 1204** ^(SQLite will also add one of the following flags to the xOpen() 1205** call, depending on the object being opened: 1206** 1207** <ul> 1208** <li> [SQLITE_OPEN_MAIN_DB] 1209** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1210** <li> [SQLITE_OPEN_TEMP_DB] 1211** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1212** <li> [SQLITE_OPEN_TRANSIENT_DB] 1213** <li> [SQLITE_OPEN_SUBJOURNAL] 1214** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1215** <li> [SQLITE_OPEN_WAL] 1216** </ul>)^ 1217** 1218** The file I/O implementation can use the object type flags to 1219** change the way it deals with files. For example, an application 1220** that does not care about crash recovery or rollback might make 1221** the open of a journal file a no-op. Writes to this journal would 1222** also be no-ops, and any attempt to read the journal would return 1223** SQLITE_IOERR. Or the implementation might recognize that a database 1224** file will be doing page-aligned sector reads and writes in a random 1225** order and set up its I/O subsystem accordingly. 1226** 1227** SQLite might also add one of the following flags to the xOpen method: 1228** 1229** <ul> 1230** <li> [SQLITE_OPEN_DELETEONCLOSE] 1231** <li> [SQLITE_OPEN_EXCLUSIVE] 1232** </ul> 1233** 1234** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1235** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1236** will be set for TEMP databases and their journals, transient 1237** databases, and subjournals. 1238** 1239** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1240** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1241** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1242** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1243** SQLITE_OPEN_CREATE, is used to indicate that file should always 1244** be created, and that it is an error if it already exists. 1245** It is <i>not</i> used to indicate the file should be opened 1246** for exclusive access. 1247** 1248** ^At least szOsFile bytes of memory are allocated by SQLite 1249** to hold the [sqlite3_file] structure passed as the third 1250** argument to xOpen. The xOpen method does not have to 1251** allocate the structure; it should just fill it in. Note that 1252** the xOpen method must set the sqlite3_file.pMethods to either 1253** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1254** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1255** element will be valid after xOpen returns regardless of the success 1256** or failure of the xOpen call. 1257** 1258** [[sqlite3_vfs.xAccess]] 1259** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1260** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1261** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1262** to test whether a file is at least readable. The file can be a 1263** directory. 1264** 1265** ^SQLite will always allocate at least mxPathname+1 bytes for the 1266** output buffer xFullPathname. The exact size of the output buffer 1267** is also passed as a parameter to both methods. If the output buffer 1268** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1269** handled as a fatal error by SQLite, vfs implementations should endeavor 1270** to prevent this by setting mxPathname to a sufficiently large value. 1271** 1272** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1273** interfaces are not strictly a part of the filesystem, but they are 1274** included in the VFS structure for completeness. 1275** The xRandomness() function attempts to return nBytes bytes 1276** of good-quality randomness into zOut. The return value is 1277** the actual number of bytes of randomness obtained. 1278** The xSleep() method causes the calling thread to sleep for at 1279** least the number of microseconds given. ^The xCurrentTime() 1280** method returns a Julian Day Number for the current date and time as 1281** a floating point value. 1282** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1283** Day Number multiplied by 86400000 (the number of milliseconds in 1284** a 24-hour day). 1285** ^SQLite will use the xCurrentTimeInt64() method to get the current 1286** date and time if that method is available (if iVersion is 2 or 1287** greater and the function pointer is not NULL) and will fall back 1288** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1289** 1290** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1291** are not used by the SQLite core. These optional interfaces are provided 1292** by some VFSes to facilitate testing of the VFS code. By overriding 1293** system calls with functions under its control, a test program can 1294** simulate faults and error conditions that would otherwise be difficult 1295** or impossible to induce. The set of system calls that can be overridden 1296** varies from one VFS to another, and from one version of the same VFS to the 1297** next. Applications that use these interfaces must be prepared for any 1298** or all of these interfaces to be NULL or for their behavior to change 1299** from one release to the next. Applications must not attempt to access 1300** any of these methods if the iVersion of the VFS is less than 3. 1301*/ 1302typedef struct sqlite3_vfs sqlite3_vfs; 1303typedef void (*sqlite3_syscall_ptr)(void); 1304struct sqlite3_vfs { 1305 int iVersion; /* Structure version number (currently 3) */ 1306 int szOsFile; /* Size of subclassed sqlite3_file */ 1307 int mxPathname; /* Maximum file pathname length */ 1308 sqlite3_vfs *pNext; /* Next registered VFS */ 1309 const char *zName; /* Name of this virtual file system */ 1310 void *pAppData; /* Pointer to application-specific data */ 1311 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1312 int flags, int *pOutFlags); 1313 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1314 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1315 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1316 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1317 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1318 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1319 void (*xDlClose)(sqlite3_vfs*, void*); 1320 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1321 int (*xSleep)(sqlite3_vfs*, int microseconds); 1322 int (*xCurrentTime)(sqlite3_vfs*, double*); 1323 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1324 /* 1325 ** The methods above are in version 1 of the sqlite_vfs object 1326 ** definition. Those that follow are added in version 2 or later 1327 */ 1328 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1329 /* 1330 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1331 ** Those below are for version 3 and greater. 1332 */ 1333 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1334 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1335 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1336 /* 1337 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1338 ** New fields may be appended in future versions. The iVersion 1339 ** value will increment whenever this happens. 1340 */ 1341}; 1342 1343/* 1344** CAPI3REF: Flags for the xAccess VFS method 1345** 1346** These integer constants can be used as the third parameter to 1347** the xAccess method of an [sqlite3_vfs] object. They determine 1348** what kind of permissions the xAccess method is looking for. 1349** With SQLITE_ACCESS_EXISTS, the xAccess method 1350** simply checks whether the file exists. 1351** With SQLITE_ACCESS_READWRITE, the xAccess method 1352** checks whether the named directory is both readable and writable 1353** (in other words, if files can be added, removed, and renamed within 1354** the directory). 1355** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1356** [temp_store_directory pragma], though this could change in a future 1357** release of SQLite. 1358** With SQLITE_ACCESS_READ, the xAccess method 1359** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1360** currently unused, though it might be used in a future release of 1361** SQLite. 1362*/ 1363#define SQLITE_ACCESS_EXISTS 0 1364#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1365#define SQLITE_ACCESS_READ 2 /* Unused */ 1366 1367/* 1368** CAPI3REF: Flags for the xShmLock VFS method 1369** 1370** These integer constants define the various locking operations 1371** allowed by the xShmLock method of [sqlite3_io_methods]. The 1372** following are the only legal combinations of flags to the 1373** xShmLock method: 1374** 1375** <ul> 1376** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1377** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1378** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1379** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1380** </ul> 1381** 1382** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1383** was given on the corresponding lock. 1384** 1385** The xShmLock method can transition between unlocked and SHARED or 1386** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1387** and EXCLUSIVE. 1388*/ 1389#define SQLITE_SHM_UNLOCK 1 1390#define SQLITE_SHM_LOCK 2 1391#define SQLITE_SHM_SHARED 4 1392#define SQLITE_SHM_EXCLUSIVE 8 1393 1394/* 1395** CAPI3REF: Maximum xShmLock index 1396** 1397** The xShmLock method on [sqlite3_io_methods] may use values 1398** between 0 and this upper bound as its "offset" argument. 1399** The SQLite core will never attempt to acquire or release a 1400** lock outside of this range 1401*/ 1402#define SQLITE_SHM_NLOCK 8 1403 1404 1405/* 1406** CAPI3REF: Initialize The SQLite Library 1407** 1408** ^The sqlite3_initialize() routine initializes the 1409** SQLite library. ^The sqlite3_shutdown() routine 1410** deallocates any resources that were allocated by sqlite3_initialize(). 1411** These routines are designed to aid in process initialization and 1412** shutdown on embedded systems. Workstation applications using 1413** SQLite normally do not need to invoke either of these routines. 1414** 1415** A call to sqlite3_initialize() is an "effective" call if it is 1416** the first time sqlite3_initialize() is invoked during the lifetime of 1417** the process, or if it is the first time sqlite3_initialize() is invoked 1418** following a call to sqlite3_shutdown(). ^(Only an effective call 1419** of sqlite3_initialize() does any initialization. All other calls 1420** are harmless no-ops.)^ 1421** 1422** A call to sqlite3_shutdown() is an "effective" call if it is the first 1423** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1424** an effective call to sqlite3_shutdown() does any deinitialization. 1425** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1426** 1427** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1428** is not. The sqlite3_shutdown() interface must only be called from a 1429** single thread. All open [database connections] must be closed and all 1430** other SQLite resources must be deallocated prior to invoking 1431** sqlite3_shutdown(). 1432** 1433** Among other things, ^sqlite3_initialize() will invoke 1434** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1435** will invoke sqlite3_os_end(). 1436** 1437** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1438** ^If for some reason, sqlite3_initialize() is unable to initialize 1439** the library (perhaps it is unable to allocate a needed resource such 1440** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1441** 1442** ^The sqlite3_initialize() routine is called internally by many other 1443** SQLite interfaces so that an application usually does not need to 1444** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1445** calls sqlite3_initialize() so the SQLite library will be automatically 1446** initialized when [sqlite3_open()] is called if it has not be initialized 1447** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1448** compile-time option, then the automatic calls to sqlite3_initialize() 1449** are omitted and the application must call sqlite3_initialize() directly 1450** prior to using any other SQLite interface. For maximum portability, 1451** it is recommended that applications always invoke sqlite3_initialize() 1452** directly prior to using any other SQLite interface. Future releases 1453** of SQLite may require this. In other words, the behavior exhibited 1454** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1455** default behavior in some future release of SQLite. 1456** 1457** The sqlite3_os_init() routine does operating-system specific 1458** initialization of the SQLite library. The sqlite3_os_end() 1459** routine undoes the effect of sqlite3_os_init(). Typical tasks 1460** performed by these routines include allocation or deallocation 1461** of static resources, initialization of global variables, 1462** setting up a default [sqlite3_vfs] module, or setting up 1463** a default configuration using [sqlite3_config()]. 1464** 1465** The application should never invoke either sqlite3_os_init() 1466** or sqlite3_os_end() directly. The application should only invoke 1467** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1468** interface is called automatically by sqlite3_initialize() and 1469** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1470** implementations for sqlite3_os_init() and sqlite3_os_end() 1471** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1472** When [custom builds | built for other platforms] 1473** (using the [SQLITE_OS_OTHER=1] compile-time 1474** option) the application must supply a suitable implementation for 1475** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1476** implementation of sqlite3_os_init() or sqlite3_os_end() 1477** must return [SQLITE_OK] on success and some other [error code] upon 1478** failure. 1479*/ 1480int sqlite3_initialize(void); 1481int sqlite3_shutdown(void); 1482int sqlite3_os_init(void); 1483int sqlite3_os_end(void); 1484 1485/* 1486** CAPI3REF: Configuring The SQLite Library 1487** 1488** The sqlite3_config() interface is used to make global configuration 1489** changes to SQLite in order to tune SQLite to the specific needs of 1490** the application. The default configuration is recommended for most 1491** applications and so this routine is usually not necessary. It is 1492** provided to support rare applications with unusual needs. 1493** 1494** <b>The sqlite3_config() interface is not threadsafe. The application 1495** must ensure that no other SQLite interfaces are invoked by other 1496** threads while sqlite3_config() is running.</b> 1497** 1498** The sqlite3_config() interface 1499** may only be invoked prior to library initialization using 1500** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1501** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1502** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1503** Note, however, that ^sqlite3_config() can be called as part of the 1504** implementation of an application-defined [sqlite3_os_init()]. 1505** 1506** The first argument to sqlite3_config() is an integer 1507** [configuration option] that determines 1508** what property of SQLite is to be configured. Subsequent arguments 1509** vary depending on the [configuration option] 1510** in the first argument. 1511** 1512** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1513** ^If the option is unknown or SQLite is unable to set the option 1514** then this routine returns a non-zero [error code]. 1515*/ 1516int sqlite3_config(int, ...); 1517 1518/* 1519** CAPI3REF: Configure database connections 1520** METHOD: sqlite3 1521** 1522** The sqlite3_db_config() interface is used to make configuration 1523** changes to a [database connection]. The interface is similar to 1524** [sqlite3_config()] except that the changes apply to a single 1525** [database connection] (specified in the first argument). 1526** 1527** The second argument to sqlite3_db_config(D,V,...) is the 1528** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1529** that indicates what aspect of the [database connection] is being configured. 1530** Subsequent arguments vary depending on the configuration verb. 1531** 1532** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1533** the call is considered successful. 1534*/ 1535int sqlite3_db_config(sqlite3*, int op, ...); 1536 1537/* 1538** CAPI3REF: Memory Allocation Routines 1539** 1540** An instance of this object defines the interface between SQLite 1541** and low-level memory allocation routines. 1542** 1543** This object is used in only one place in the SQLite interface. 1544** A pointer to an instance of this object is the argument to 1545** [sqlite3_config()] when the configuration option is 1546** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1547** By creating an instance of this object 1548** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1549** during configuration, an application can specify an alternative 1550** memory allocation subsystem for SQLite to use for all of its 1551** dynamic memory needs. 1552** 1553** Note that SQLite comes with several [built-in memory allocators] 1554** that are perfectly adequate for the overwhelming majority of applications 1555** and that this object is only useful to a tiny minority of applications 1556** with specialized memory allocation requirements. This object is 1557** also used during testing of SQLite in order to specify an alternative 1558** memory allocator that simulates memory out-of-memory conditions in 1559** order to verify that SQLite recovers gracefully from such 1560** conditions. 1561** 1562** The xMalloc, xRealloc, and xFree methods must work like the 1563** malloc(), realloc() and free() functions from the standard C library. 1564** ^SQLite guarantees that the second argument to 1565** xRealloc is always a value returned by a prior call to xRoundup. 1566** 1567** xSize should return the allocated size of a memory allocation 1568** previously obtained from xMalloc or xRealloc. The allocated size 1569** is always at least as big as the requested size but may be larger. 1570** 1571** The xRoundup method returns what would be the allocated size of 1572** a memory allocation given a particular requested size. Most memory 1573** allocators round up memory allocations at least to the next multiple 1574** of 8. Some allocators round up to a larger multiple or to a power of 2. 1575** Every memory allocation request coming in through [sqlite3_malloc()] 1576** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1577** that causes the corresponding memory allocation to fail. 1578** 1579** The xInit method initializes the memory allocator. For example, 1580** it might allocate any require mutexes or initialize internal data 1581** structures. The xShutdown method is invoked (indirectly) by 1582** [sqlite3_shutdown()] and should deallocate any resources acquired 1583** by xInit. The pAppData pointer is used as the only parameter to 1584** xInit and xShutdown. 1585** 1586** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1587** the xInit method, so the xInit method need not be threadsafe. The 1588** xShutdown method is only called from [sqlite3_shutdown()] so it does 1589** not need to be threadsafe either. For all other methods, SQLite 1590** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1591** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1592** it is by default) and so the methods are automatically serialized. 1593** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1594** methods must be threadsafe or else make their own arrangements for 1595** serialization. 1596** 1597** SQLite will never invoke xInit() more than once without an intervening 1598** call to xShutdown(). 1599*/ 1600typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1601struct sqlite3_mem_methods { 1602 void *(*xMalloc)(int); /* Memory allocation function */ 1603 void (*xFree)(void*); /* Free a prior allocation */ 1604 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1605 int (*xSize)(void*); /* Return the size of an allocation */ 1606 int (*xRoundup)(int); /* Round up request size to allocation size */ 1607 int (*xInit)(void*); /* Initialize the memory allocator */ 1608 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1609 void *pAppData; /* Argument to xInit() and xShutdown() */ 1610}; 1611 1612/* 1613** CAPI3REF: Configuration Options 1614** KEYWORDS: {configuration option} 1615** 1616** These constants are the available integer configuration options that 1617** can be passed as the first argument to the [sqlite3_config()] interface. 1618** 1619** New configuration options may be added in future releases of SQLite. 1620** Existing configuration options might be discontinued. Applications 1621** should check the return code from [sqlite3_config()] to make sure that 1622** the call worked. The [sqlite3_config()] interface will return a 1623** non-zero [error code] if a discontinued or unsupported configuration option 1624** is invoked. 1625** 1626** <dl> 1627** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1628** <dd>There are no arguments to this option. ^This option sets the 1629** [threading mode] to Single-thread. In other words, it disables 1630** all mutexing and puts SQLite into a mode where it can only be used 1631** by a single thread. ^If SQLite is compiled with 1632** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1633** it is not possible to change the [threading mode] from its default 1634** value of Single-thread and so [sqlite3_config()] will return 1635** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1636** configuration option.</dd> 1637** 1638** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1639** <dd>There are no arguments to this option. ^This option sets the 1640** [threading mode] to Multi-thread. In other words, it disables 1641** mutexing on [database connection] and [prepared statement] objects. 1642** The application is responsible for serializing access to 1643** [database connections] and [prepared statements]. But other mutexes 1644** are enabled so that SQLite will be safe to use in a multi-threaded 1645** environment as long as no two threads attempt to use the same 1646** [database connection] at the same time. ^If SQLite is compiled with 1647** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1648** it is not possible to set the Multi-thread [threading mode] and 1649** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1650** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1651** 1652** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1653** <dd>There are no arguments to this option. ^This option sets the 1654** [threading mode] to Serialized. In other words, this option enables 1655** all mutexes including the recursive 1656** mutexes on [database connection] and [prepared statement] objects. 1657** In this mode (which is the default when SQLite is compiled with 1658** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1659** to [database connections] and [prepared statements] so that the 1660** application is free to use the same [database connection] or the 1661** same [prepared statement] in different threads at the same time. 1662** ^If SQLite is compiled with 1663** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1664** it is not possible to set the Serialized [threading mode] and 1665** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1666** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1667** 1668** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1669** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1670** a pointer to an instance of the [sqlite3_mem_methods] structure. 1671** The argument specifies 1672** alternative low-level memory allocation routines to be used in place of 1673** the memory allocation routines built into SQLite.)^ ^SQLite makes 1674** its own private copy of the content of the [sqlite3_mem_methods] structure 1675** before the [sqlite3_config()] call returns.</dd> 1676** 1677** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1678** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1679** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1680** The [sqlite3_mem_methods] 1681** structure is filled with the currently defined memory allocation routines.)^ 1682** This option can be used to overload the default memory allocation 1683** routines with a wrapper that simulations memory allocation failure or 1684** tracks memory usage, for example. </dd> 1685** 1686** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1687** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1688** type int, interpreted as a boolean, which if true provides a hint to 1689** SQLite that it should avoid large memory allocations if possible. 1690** SQLite will run faster if it is free to make large memory allocations, 1691** but some application might prefer to run slower in exchange for 1692** guarantees about memory fragmentation that are possible if large 1693** allocations are avoided. This hint is normally off. 1694** </dd> 1695** 1696** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1697** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1698** interpreted as a boolean, which enables or disables the collection of 1699** memory allocation statistics. ^(When memory allocation statistics are 1700** disabled, the following SQLite interfaces become non-operational: 1701** <ul> 1702** <li> [sqlite3_memory_used()] 1703** <li> [sqlite3_memory_highwater()] 1704** <li> [sqlite3_soft_heap_limit64()] 1705** <li> [sqlite3_status64()] 1706** </ul>)^ 1707** ^Memory allocation statistics are enabled by default unless SQLite is 1708** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1709** allocation statistics are disabled by default. 1710** </dd> 1711** 1712** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1713** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1714** </dd> 1715** 1716** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1717** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1718** that SQLite can use for the database page cache with the default page 1719** cache implementation. 1720** This configuration option is a no-op if an application-define page 1721** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1722** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1723** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1724** and the number of cache lines (N). 1725** The sz argument should be the size of the largest database page 1726** (a power of two between 512 and 65536) plus some extra bytes for each 1727** page header. ^The number of extra bytes needed by the page header 1728** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1729** ^It is harmless, apart from the wasted memory, 1730** for the sz parameter to be larger than necessary. The pMem 1731** argument must be either a NULL pointer or a pointer to an 8-byte 1732** aligned block of memory of at least sz*N bytes, otherwise 1733** subsequent behavior is undefined. 1734** ^When pMem is not NULL, SQLite will strive to use the memory provided 1735** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1736** a page cache line is larger than sz bytes or if all of the pMem buffer 1737** is exhausted. 1738** ^If pMem is NULL and N is non-zero, then each database connection 1739** does an initial bulk allocation for page cache memory 1740** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1741** of -1024*N bytes if N is negative, . ^If additional 1742** page cache memory is needed beyond what is provided by the initial 1743** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1744** additional cache line. </dd> 1745** 1746** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1747** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1748** that SQLite will use for all of its dynamic memory allocation needs 1749** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1750** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1751** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1752** [SQLITE_ERROR] if invoked otherwise. 1753** ^There are three arguments to SQLITE_CONFIG_HEAP: 1754** An 8-byte aligned pointer to the memory, 1755** the number of bytes in the memory buffer, and the minimum allocation size. 1756** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1757** to using its default memory allocator (the system malloc() implementation), 1758** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1759** memory pointer is not NULL then the alternative memory 1760** allocator is engaged to handle all of SQLites memory allocation needs. 1761** The first pointer (the memory pointer) must be aligned to an 8-byte 1762** boundary or subsequent behavior of SQLite will be undefined. 1763** The minimum allocation size is capped at 2**12. Reasonable values 1764** for the minimum allocation size are 2**5 through 2**8.</dd> 1765** 1766** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1767** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1768** pointer to an instance of the [sqlite3_mutex_methods] structure. 1769** The argument specifies alternative low-level mutex routines to be used 1770** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1771** the content of the [sqlite3_mutex_methods] structure before the call to 1772** [sqlite3_config()] returns. ^If SQLite is compiled with 1773** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1774** the entire mutexing subsystem is omitted from the build and hence calls to 1775** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1776** return [SQLITE_ERROR].</dd> 1777** 1778** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1779** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1780** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1781** [sqlite3_mutex_methods] 1782** structure is filled with the currently defined mutex routines.)^ 1783** This option can be used to overload the default mutex allocation 1784** routines with a wrapper used to track mutex usage for performance 1785** profiling or testing, for example. ^If SQLite is compiled with 1786** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1787** the entire mutexing subsystem is omitted from the build and hence calls to 1788** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1789** return [SQLITE_ERROR].</dd> 1790** 1791** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1792** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1793** the default size of lookaside memory on each [database connection]. 1794** The first argument is the 1795** size of each lookaside buffer slot and the second is the number of 1796** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1797** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1798** option to [sqlite3_db_config()] can be used to change the lookaside 1799** configuration on individual connections.)^ </dd> 1800** 1801** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1802** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1803** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1804** the interface to a custom page cache implementation.)^ 1805** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1806** 1807** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1808** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1809** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1810** the current page cache implementation into that object.)^ </dd> 1811** 1812** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1813** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1814** global [error log]. 1815** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1816** function with a call signature of void(*)(void*,int,const char*), 1817** and a pointer to void. ^If the function pointer is not NULL, it is 1818** invoked by [sqlite3_log()] to process each logging event. ^If the 1819** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1820** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1821** passed through as the first parameter to the application-defined logger 1822** function whenever that function is invoked. ^The second parameter to 1823** the logger function is a copy of the first parameter to the corresponding 1824** [sqlite3_log()] call and is intended to be a [result code] or an 1825** [extended result code]. ^The third parameter passed to the logger is 1826** log message after formatting via [sqlite3_snprintf()]. 1827** The SQLite logging interface is not reentrant; the logger function 1828** supplied by the application must not invoke any SQLite interface. 1829** In a multi-threaded application, the application-defined logger 1830** function must be threadsafe. </dd> 1831** 1832** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1833** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1834** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1835** then URI handling is globally disabled.)^ ^If URI handling is globally 1836** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1837** [sqlite3_open16()] or 1838** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1839** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1840** connection is opened. ^If it is globally disabled, filenames are 1841** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1842** database connection is opened. ^(By default, URI handling is globally 1843** disabled. The default value may be changed by compiling with the 1844** [SQLITE_USE_URI] symbol defined.)^ 1845** 1846** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1847** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1848** argument which is interpreted as a boolean in order to enable or disable 1849** the use of covering indices for full table scans in the query optimizer. 1850** ^The default setting is determined 1851** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1852** if that compile-time option is omitted. 1853** The ability to disable the use of covering indices for full table scans 1854** is because some incorrectly coded legacy applications might malfunction 1855** when the optimization is enabled. Providing the ability to 1856** disable the optimization allows the older, buggy application code to work 1857** without change even with newer versions of SQLite. 1858** 1859** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1860** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1861** <dd> These options are obsolete and should not be used by new code. 1862** They are retained for backwards compatibility but are now no-ops. 1863** </dd> 1864** 1865** [[SQLITE_CONFIG_SQLLOG]] 1866** <dt>SQLITE_CONFIG_SQLLOG 1867** <dd>This option is only available if sqlite is compiled with the 1868** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1869** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1870** The second should be of type (void*). The callback is invoked by the library 1871** in three separate circumstances, identified by the value passed as the 1872** fourth parameter. If the fourth parameter is 0, then the database connection 1873** passed as the second argument has just been opened. The third argument 1874** points to a buffer containing the name of the main database file. If the 1875** fourth parameter is 1, then the SQL statement that the third parameter 1876** points to has just been executed. Or, if the fourth parameter is 2, then 1877** the connection being passed as the second parameter is being closed. The 1878** third parameter is passed NULL In this case. An example of using this 1879** configuration option can be seen in the "test_sqllog.c" source file in 1880** the canonical SQLite source tree.</dd> 1881** 1882** [[SQLITE_CONFIG_MMAP_SIZE]] 1883** <dt>SQLITE_CONFIG_MMAP_SIZE 1884** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1885** that are the default mmap size limit (the default setting for 1886** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1887** ^The default setting can be overridden by each database connection using 1888** either the [PRAGMA mmap_size] command, or by using the 1889** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1890** will be silently truncated if necessary so that it does not exceed the 1891** compile-time maximum mmap size set by the 1892** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1893** ^If either argument to this option is negative, then that argument is 1894** changed to its compile-time default. 1895** 1896** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1897** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1898** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1899** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1900** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1901** that specifies the maximum size of the created heap. 1902** 1903** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1904** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1905** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1906** is a pointer to an integer and writes into that integer the number of extra 1907** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1908** The amount of extra space required can change depending on the compiler, 1909** target platform, and SQLite version. 1910** 1911** [[SQLITE_CONFIG_PMASZ]] 1912** <dt>SQLITE_CONFIG_PMASZ 1913** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1914** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1915** sorter to that integer. The default minimum PMA Size is set by the 1916** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1917** to help with sort operations when multithreaded sorting 1918** is enabled (using the [PRAGMA threads] command) and the amount of content 1919** to be sorted exceeds the page size times the minimum of the 1920** [PRAGMA cache_size] setting and this value. 1921** 1922** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1923** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1924** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1925** becomes the [statement journal] spill-to-disk threshold. 1926** [Statement journals] are held in memory until their size (in bytes) 1927** exceeds this threshold, at which point they are written to disk. 1928** Or if the threshold is -1, statement journals are always held 1929** exclusively in memory. 1930** Since many statement journals never become large, setting the spill 1931** threshold to a value such as 64KiB can greatly reduce the amount of 1932** I/O required to support statement rollback. 1933** The default value for this setting is controlled by the 1934** [SQLITE_STMTJRNL_SPILL] compile-time option. 1935** 1936** [[SQLITE_CONFIG_SORTERREF_SIZE]] 1937** <dt>SQLITE_CONFIG_SORTERREF_SIZE 1938** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 1939** of type (int) - the new value of the sorter-reference size threshold. 1940** Usually, when SQLite uses an external sort to order records according 1941** to an ORDER BY clause, all fields required by the caller are present in the 1942** sorted records. However, if SQLite determines based on the declared type 1943** of a table column that its values are likely to be very large - larger 1944** than the configured sorter-reference size threshold - then a reference 1945** is stored in each sorted record and the required column values loaded 1946** from the database as records are returned in sorted order. The default 1947** value for this option is to never use this optimization. Specifying a 1948** negative value for this option restores the default behaviour. 1949** This option is only available if SQLite is compiled with the 1950** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 1951** </dl> 1952*/ 1953#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1954#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1955#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1956#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1957#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1958#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 1959#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1960#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1961#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1962#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1963#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1964/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1965#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1966#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1967#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1968#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1969#define SQLITE_CONFIG_URI 17 /* int */ 1970#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1971#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1972#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1973#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1974#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1975#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 1976#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 1977#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 1978#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 1979#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 1980#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 1981 1982/* 1983** CAPI3REF: Database Connection Configuration Options 1984** 1985** These constants are the available integer configuration options that 1986** can be passed as the second argument to the [sqlite3_db_config()] interface. 1987** 1988** New configuration options may be added in future releases of SQLite. 1989** Existing configuration options might be discontinued. Applications 1990** should check the return code from [sqlite3_db_config()] to make sure that 1991** the call worked. ^The [sqlite3_db_config()] interface will return a 1992** non-zero [error code] if a discontinued or unsupported configuration option 1993** is invoked. 1994** 1995** <dl> 1996** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1997** <dd> ^This option takes three additional arguments that determine the 1998** [lookaside memory allocator] configuration for the [database connection]. 1999** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2000** pointer to a memory buffer to use for lookaside memory. 2001** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2002** may be NULL in which case SQLite will allocate the 2003** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2004** size of each lookaside buffer slot. ^The third argument is the number of 2005** slots. The size of the buffer in the first argument must be greater than 2006** or equal to the product of the second and third arguments. The buffer 2007** must be aligned to an 8-byte boundary. ^If the second argument to 2008** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2009** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2010** configuration for a database connection can only be changed when that 2011** connection is not currently using lookaside memory, or in other words 2012** when the "current value" returned by 2013** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 2014** Any attempt to change the lookaside memory configuration when lookaside 2015** memory is in use leaves the configuration unchanged and returns 2016** [SQLITE_BUSY].)^</dd> 2017** 2018** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2019** <dd> ^This option is used to enable or disable the enforcement of 2020** [foreign key constraints]. There should be two additional arguments. 2021** The first argument is an integer which is 0 to disable FK enforcement, 2022** positive to enable FK enforcement or negative to leave FK enforcement 2023** unchanged. The second parameter is a pointer to an integer into which 2024** is written 0 or 1 to indicate whether FK enforcement is off or on 2025** following this call. The second parameter may be a NULL pointer, in 2026** which case the FK enforcement setting is not reported back. </dd> 2027** 2028** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2029** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2030** There should be two additional arguments. 2031** The first argument is an integer which is 0 to disable triggers, 2032** positive to enable triggers or negative to leave the setting unchanged. 2033** The second parameter is a pointer to an integer into which 2034** is written 0 or 1 to indicate whether triggers are disabled or enabled 2035** following this call. The second parameter may be a NULL pointer, in 2036** which case the trigger setting is not reported back. </dd> 2037** 2038** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2039** <dd> ^This option is used to enable or disable the two-argument 2040** version of the [fts3_tokenizer()] function which is part of the 2041** [FTS3] full-text search engine extension. 2042** There should be two additional arguments. 2043** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2044** positive to enable fts3_tokenizer() or negative to leave the setting 2045** unchanged. 2046** The second parameter is a pointer to an integer into which 2047** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2048** following this call. The second parameter may be a NULL pointer, in 2049** which case the new setting is not reported back. </dd> 2050** 2051** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2052** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2053** interface independently of the [load_extension()] SQL function. 2054** The [sqlite3_enable_load_extension()] API enables or disables both the 2055** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2056** There should be two additional arguments. 2057** When the first argument to this interface is 1, then only the C-API is 2058** enabled and the SQL function remains disabled. If the first argument to 2059** this interface is 0, then both the C-API and the SQL function are disabled. 2060** If the first argument is -1, then no changes are made to state of either the 2061** C-API or the SQL function. 2062** The second parameter is a pointer to an integer into which 2063** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2064** is disabled or enabled following this call. The second parameter may 2065** be a NULL pointer, in which case the new setting is not reported back. 2066** </dd> 2067** 2068** <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2069** <dd> ^This option is used to change the name of the "main" database 2070** schema. ^The sole argument is a pointer to a constant UTF8 string 2071** which will become the new schema name in place of "main". ^SQLite 2072** does not make a copy of the new main schema name string, so the application 2073** must ensure that the argument passed into this DBCONFIG option is unchanged 2074** until after the database connection closes. 2075** </dd> 2076** 2077** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2078** <dd> Usually, when a database in wal mode is closed or detached from a 2079** database handle, SQLite checks if this will mean that there are now no 2080** connections at all to the database. If so, it performs a checkpoint 2081** operation before closing the connection. This option may be used to 2082** override this behaviour. The first parameter passed to this operation 2083** is an integer - positive to disable checkpoints-on-close, or zero (the 2084** default) to enable them, and negative to leave the setting unchanged. 2085** The second parameter is a pointer to an integer 2086** into which is written 0 or 1 to indicate whether checkpoints-on-close 2087** have been disabled - 0 if they are not disabled, 1 if they are. 2088** </dd> 2089** 2090** <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2091** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2092** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2093** a single SQL query statement will always use the same algorithm regardless 2094** of values of [bound parameters].)^ The QPSG disables some query optimizations 2095** that look at the values of bound parameters, which can make some queries 2096** slower. But the QPSG has the advantage of more predictable behavior. With 2097** the QPSG active, SQLite will always use the same query plan in the field as 2098** was used during testing in the lab. 2099** The first argument to this setting is an integer which is 0 to disable 2100** the QPSG, positive to enable QPSG, or negative to leave the setting 2101** unchanged. The second parameter is a pointer to an integer into which 2102** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2103** following this call. 2104** </dd> 2105** 2106** <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2107** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2108** include output for any operations performed by trigger programs. This 2109** option is used to set or clear (the default) a flag that governs this 2110** behavior. The first parameter passed to this operation is an integer - 2111** positive to enable output for trigger programs, or zero to disable it, 2112** or negative to leave the setting unchanged. 2113** The second parameter is a pointer to an integer into which is written 2114** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2115** it is not disabled, 1 if it is. 2116** </dd> 2117** 2118** <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2119** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2120** [VACUUM] in order to reset a database back to an empty database 2121** with no schema and no content. The following process works even for 2122** a badly corrupted database file: 2123** <ol> 2124** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2125** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2126** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2127** </ol> 2128** Because resetting a database is destructive and irreversible, the 2129** process requires the use of this obscure API and multiple steps to help 2130** ensure that it does not happen by accident. 2131** </dd> 2132** </dl> 2133*/ 2134#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2135#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2136#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2137#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2138#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2139#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2140#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2141#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2142#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2143#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2144#define SQLITE_DBCONFIG_MAX 1009 /* Largest DBCONFIG */ 2145 2146/* 2147** CAPI3REF: Enable Or Disable Extended Result Codes 2148** METHOD: sqlite3 2149** 2150** ^The sqlite3_extended_result_codes() routine enables or disables the 2151** [extended result codes] feature of SQLite. ^The extended result 2152** codes are disabled by default for historical compatibility. 2153*/ 2154int sqlite3_extended_result_codes(sqlite3*, int onoff); 2155 2156/* 2157** CAPI3REF: Last Insert Rowid 2158** METHOD: sqlite3 2159** 2160** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2161** has a unique 64-bit signed 2162** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2163** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2164** names are not also used by explicitly declared columns. ^If 2165** the table has a column of type [INTEGER PRIMARY KEY] then that column 2166** is another alias for the rowid. 2167** 2168** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2169** the most recent successful [INSERT] into a rowid table or [virtual table] 2170** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2171** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2172** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2173** zero. 2174** 2175** As well as being set automatically as rows are inserted into database 2176** tables, the value returned by this function may be set explicitly by 2177** [sqlite3_set_last_insert_rowid()] 2178** 2179** Some virtual table implementations may INSERT rows into rowid tables as 2180** part of committing a transaction (e.g. to flush data accumulated in memory 2181** to disk). In this case subsequent calls to this function return the rowid 2182** associated with these internal INSERT operations, which leads to 2183** unintuitive results. Virtual table implementations that do write to rowid 2184** tables in this way can avoid this problem by restoring the original 2185** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2186** control to the user. 2187** 2188** ^(If an [INSERT] occurs within a trigger then this routine will 2189** return the [rowid] of the inserted row as long as the trigger is 2190** running. Once the trigger program ends, the value returned 2191** by this routine reverts to what it was before the trigger was fired.)^ 2192** 2193** ^An [INSERT] that fails due to a constraint violation is not a 2194** successful [INSERT] and does not change the value returned by this 2195** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2196** and INSERT OR ABORT make no changes to the return value of this 2197** routine when their insertion fails. ^(When INSERT OR REPLACE 2198** encounters a constraint violation, it does not fail. The 2199** INSERT continues to completion after deleting rows that caused 2200** the constraint problem so INSERT OR REPLACE will always change 2201** the return value of this interface.)^ 2202** 2203** ^For the purposes of this routine, an [INSERT] is considered to 2204** be successful even if it is subsequently rolled back. 2205** 2206** This function is accessible to SQL statements via the 2207** [last_insert_rowid() SQL function]. 2208** 2209** If a separate thread performs a new [INSERT] on the same 2210** database connection while the [sqlite3_last_insert_rowid()] 2211** function is running and thus changes the last insert [rowid], 2212** then the value returned by [sqlite3_last_insert_rowid()] is 2213** unpredictable and might not equal either the old or the new 2214** last insert [rowid]. 2215*/ 2216sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2217 2218/* 2219** CAPI3REF: Set the Last Insert Rowid value. 2220** METHOD: sqlite3 2221** 2222** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2223** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2224** without inserting a row into the database. 2225*/ 2226void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2227 2228/* 2229** CAPI3REF: Count The Number Of Rows Modified 2230** METHOD: sqlite3 2231** 2232** ^This function returns the number of rows modified, inserted or 2233** deleted by the most recently completed INSERT, UPDATE or DELETE 2234** statement on the database connection specified by the only parameter. 2235** ^Executing any other type of SQL statement does not modify the value 2236** returned by this function. 2237** 2238** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2239** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2240** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2241** 2242** Changes to a view that are intercepted by 2243** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2244** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2245** DELETE statement run on a view is always zero. Only changes made to real 2246** tables are counted. 2247** 2248** Things are more complicated if the sqlite3_changes() function is 2249** executed while a trigger program is running. This may happen if the 2250** program uses the [changes() SQL function], or if some other callback 2251** function invokes sqlite3_changes() directly. Essentially: 2252** 2253** <ul> 2254** <li> ^(Before entering a trigger program the value returned by 2255** sqlite3_changes() function is saved. After the trigger program 2256** has finished, the original value is restored.)^ 2257** 2258** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2259** statement sets the value returned by sqlite3_changes() 2260** upon completion as normal. Of course, this value will not include 2261** any changes performed by sub-triggers, as the sqlite3_changes() 2262** value will be saved and restored after each sub-trigger has run.)^ 2263** </ul> 2264** 2265** ^This means that if the changes() SQL function (or similar) is used 2266** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2267** returns the value as set when the calling statement began executing. 2268** ^If it is used by the second or subsequent such statement within a trigger 2269** program, the value returned reflects the number of rows modified by the 2270** previous INSERT, UPDATE or DELETE statement within the same trigger. 2271** 2272** See also the [sqlite3_total_changes()] interface, the 2273** [count_changes pragma], and the [changes() SQL function]. 2274** 2275** If a separate thread makes changes on the same database connection 2276** while [sqlite3_changes()] is running then the value returned 2277** is unpredictable and not meaningful. 2278*/ 2279int sqlite3_changes(sqlite3*); 2280 2281/* 2282** CAPI3REF: Total Number Of Rows Modified 2283** METHOD: sqlite3 2284** 2285** ^This function returns the total number of rows inserted, modified or 2286** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2287** since the database connection was opened, including those executed as 2288** part of trigger programs. ^Executing any other type of SQL statement 2289** does not affect the value returned by sqlite3_total_changes(). 2290** 2291** ^Changes made as part of [foreign key actions] are included in the 2292** count, but those made as part of REPLACE constraint resolution are 2293** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2294** are not counted. 2295** 2296** See also the [sqlite3_changes()] interface, the 2297** [count_changes pragma], and the [total_changes() SQL function]. 2298** 2299** If a separate thread makes changes on the same database connection 2300** while [sqlite3_total_changes()] is running then the value 2301** returned is unpredictable and not meaningful. 2302*/ 2303int sqlite3_total_changes(sqlite3*); 2304 2305/* 2306** CAPI3REF: Interrupt A Long-Running Query 2307** METHOD: sqlite3 2308** 2309** ^This function causes any pending database operation to abort and 2310** return at its earliest opportunity. This routine is typically 2311** called in response to a user action such as pressing "Cancel" 2312** or Ctrl-C where the user wants a long query operation to halt 2313** immediately. 2314** 2315** ^It is safe to call this routine from a thread different from the 2316** thread that is currently running the database operation. But it 2317** is not safe to call this routine with a [database connection] that 2318** is closed or might close before sqlite3_interrupt() returns. 2319** 2320** ^If an SQL operation is very nearly finished at the time when 2321** sqlite3_interrupt() is called, then it might not have an opportunity 2322** to be interrupted and might continue to completion. 2323** 2324** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2325** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2326** that is inside an explicit transaction, then the entire transaction 2327** will be rolled back automatically. 2328** 2329** ^The sqlite3_interrupt(D) call is in effect until all currently running 2330** SQL statements on [database connection] D complete. ^Any new SQL statements 2331** that are started after the sqlite3_interrupt() call and before the 2332** running statements reaches zero are interrupted as if they had been 2333** running prior to the sqlite3_interrupt() call. ^New SQL statements 2334** that are started after the running statement count reaches zero are 2335** not effected by the sqlite3_interrupt(). 2336** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2337** SQL statements is a no-op and has no effect on SQL statements 2338** that are started after the sqlite3_interrupt() call returns. 2339*/ 2340void sqlite3_interrupt(sqlite3*); 2341 2342/* 2343** CAPI3REF: Determine If An SQL Statement Is Complete 2344** 2345** These routines are useful during command-line input to determine if the 2346** currently entered text seems to form a complete SQL statement or 2347** if additional input is needed before sending the text into 2348** SQLite for parsing. ^These routines return 1 if the input string 2349** appears to be a complete SQL statement. ^A statement is judged to be 2350** complete if it ends with a semicolon token and is not a prefix of a 2351** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2352** string literals or quoted identifier names or comments are not 2353** independent tokens (they are part of the token in which they are 2354** embedded) and thus do not count as a statement terminator. ^Whitespace 2355** and comments that follow the final semicolon are ignored. 2356** 2357** ^These routines return 0 if the statement is incomplete. ^If a 2358** memory allocation fails, then SQLITE_NOMEM is returned. 2359** 2360** ^These routines do not parse the SQL statements thus 2361** will not detect syntactically incorrect SQL. 2362** 2363** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2364** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2365** automatically by sqlite3_complete16(). If that initialization fails, 2366** then the return value from sqlite3_complete16() will be non-zero 2367** regardless of whether or not the input SQL is complete.)^ 2368** 2369** The input to [sqlite3_complete()] must be a zero-terminated 2370** UTF-8 string. 2371** 2372** The input to [sqlite3_complete16()] must be a zero-terminated 2373** UTF-16 string in native byte order. 2374*/ 2375int sqlite3_complete(const char *sql); 2376int sqlite3_complete16(const void *sql); 2377 2378/* 2379** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2380** KEYWORDS: {busy-handler callback} {busy handler} 2381** METHOD: sqlite3 2382** 2383** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2384** that might be invoked with argument P whenever 2385** an attempt is made to access a database table associated with 2386** [database connection] D when another thread 2387** or process has the table locked. 2388** The sqlite3_busy_handler() interface is used to implement 2389** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2390** 2391** ^If the busy callback is NULL, then [SQLITE_BUSY] 2392** is returned immediately upon encountering the lock. ^If the busy callback 2393** is not NULL, then the callback might be invoked with two arguments. 2394** 2395** ^The first argument to the busy handler is a copy of the void* pointer which 2396** is the third argument to sqlite3_busy_handler(). ^The second argument to 2397** the busy handler callback is the number of times that the busy handler has 2398** been invoked previously for the same locking event. ^If the 2399** busy callback returns 0, then no additional attempts are made to 2400** access the database and [SQLITE_BUSY] is returned 2401** to the application. 2402** ^If the callback returns non-zero, then another attempt 2403** is made to access the database and the cycle repeats. 2404** 2405** The presence of a busy handler does not guarantee that it will be invoked 2406** when there is lock contention. ^If SQLite determines that invoking the busy 2407** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2408** to the application instead of invoking the 2409** busy handler. 2410** Consider a scenario where one process is holding a read lock that 2411** it is trying to promote to a reserved lock and 2412** a second process is holding a reserved lock that it is trying 2413** to promote to an exclusive lock. The first process cannot proceed 2414** because it is blocked by the second and the second process cannot 2415** proceed because it is blocked by the first. If both processes 2416** invoke the busy handlers, neither will make any progress. Therefore, 2417** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2418** will induce the first process to release its read lock and allow 2419** the second process to proceed. 2420** 2421** ^The default busy callback is NULL. 2422** 2423** ^(There can only be a single busy handler defined for each 2424** [database connection]. Setting a new busy handler clears any 2425** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2426** or evaluating [PRAGMA busy_timeout=N] will change the 2427** busy handler and thus clear any previously set busy handler. 2428** 2429** The busy callback should not take any actions which modify the 2430** database connection that invoked the busy handler. In other words, 2431** the busy handler is not reentrant. Any such actions 2432** result in undefined behavior. 2433** 2434** A busy handler must not close the database connection 2435** or [prepared statement] that invoked the busy handler. 2436*/ 2437int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2438 2439/* 2440** CAPI3REF: Set A Busy Timeout 2441** METHOD: sqlite3 2442** 2443** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2444** for a specified amount of time when a table is locked. ^The handler 2445** will sleep multiple times until at least "ms" milliseconds of sleeping 2446** have accumulated. ^After at least "ms" milliseconds of sleeping, 2447** the handler returns 0 which causes [sqlite3_step()] to return 2448** [SQLITE_BUSY]. 2449** 2450** ^Calling this routine with an argument less than or equal to zero 2451** turns off all busy handlers. 2452** 2453** ^(There can only be a single busy handler for a particular 2454** [database connection] at any given moment. If another busy handler 2455** was defined (using [sqlite3_busy_handler()]) prior to calling 2456** this routine, that other busy handler is cleared.)^ 2457** 2458** See also: [PRAGMA busy_timeout] 2459*/ 2460int sqlite3_busy_timeout(sqlite3*, int ms); 2461 2462/* 2463** CAPI3REF: Convenience Routines For Running Queries 2464** METHOD: sqlite3 2465** 2466** This is a legacy interface that is preserved for backwards compatibility. 2467** Use of this interface is not recommended. 2468** 2469** Definition: A <b>result table</b> is memory data structure created by the 2470** [sqlite3_get_table()] interface. A result table records the 2471** complete query results from one or more queries. 2472** 2473** The table conceptually has a number of rows and columns. But 2474** these numbers are not part of the result table itself. These 2475** numbers are obtained separately. Let N be the number of rows 2476** and M be the number of columns. 2477** 2478** A result table is an array of pointers to zero-terminated UTF-8 strings. 2479** There are (N+1)*M elements in the array. The first M pointers point 2480** to zero-terminated strings that contain the names of the columns. 2481** The remaining entries all point to query results. NULL values result 2482** in NULL pointers. All other values are in their UTF-8 zero-terminated 2483** string representation as returned by [sqlite3_column_text()]. 2484** 2485** A result table might consist of one or more memory allocations. 2486** It is not safe to pass a result table directly to [sqlite3_free()]. 2487** A result table should be deallocated using [sqlite3_free_table()]. 2488** 2489** ^(As an example of the result table format, suppose a query result 2490** is as follows: 2491** 2492** <blockquote><pre> 2493** Name | Age 2494** ----------------------- 2495** Alice | 43 2496** Bob | 28 2497** Cindy | 21 2498** </pre></blockquote> 2499** 2500** There are two column (M==2) and three rows (N==3). Thus the 2501** result table has 8 entries. Suppose the result table is stored 2502** in an array names azResult. Then azResult holds this content: 2503** 2504** <blockquote><pre> 2505** azResult[0] = "Name"; 2506** azResult[1] = "Age"; 2507** azResult[2] = "Alice"; 2508** azResult[3] = "43"; 2509** azResult[4] = "Bob"; 2510** azResult[5] = "28"; 2511** azResult[6] = "Cindy"; 2512** azResult[7] = "21"; 2513** </pre></blockquote>)^ 2514** 2515** ^The sqlite3_get_table() function evaluates one or more 2516** semicolon-separated SQL statements in the zero-terminated UTF-8 2517** string of its 2nd parameter and returns a result table to the 2518** pointer given in its 3rd parameter. 2519** 2520** After the application has finished with the result from sqlite3_get_table(), 2521** it must pass the result table pointer to sqlite3_free_table() in order to 2522** release the memory that was malloced. Because of the way the 2523** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2524** function must not try to call [sqlite3_free()] directly. Only 2525** [sqlite3_free_table()] is able to release the memory properly and safely. 2526** 2527** The sqlite3_get_table() interface is implemented as a wrapper around 2528** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2529** to any internal data structures of SQLite. It uses only the public 2530** interface defined here. As a consequence, errors that occur in the 2531** wrapper layer outside of the internal [sqlite3_exec()] call are not 2532** reflected in subsequent calls to [sqlite3_errcode()] or 2533** [sqlite3_errmsg()]. 2534*/ 2535int sqlite3_get_table( 2536 sqlite3 *db, /* An open database */ 2537 const char *zSql, /* SQL to be evaluated */ 2538 char ***pazResult, /* Results of the query */ 2539 int *pnRow, /* Number of result rows written here */ 2540 int *pnColumn, /* Number of result columns written here */ 2541 char **pzErrmsg /* Error msg written here */ 2542); 2543void sqlite3_free_table(char **result); 2544 2545/* 2546** CAPI3REF: Formatted String Printing Functions 2547** 2548** These routines are work-alikes of the "printf()" family of functions 2549** from the standard C library. 2550** These routines understand most of the common formatting options from 2551** the standard library printf() 2552** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2553** See the [built-in printf()] documentation for details. 2554** 2555** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2556** results into memory obtained from [sqlite3_malloc64()]. 2557** The strings returned by these two routines should be 2558** released by [sqlite3_free()]. ^Both routines return a 2559** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2560** memory to hold the resulting string. 2561** 2562** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2563** the standard C library. The result is written into the 2564** buffer supplied as the second parameter whose size is given by 2565** the first parameter. Note that the order of the 2566** first two parameters is reversed from snprintf().)^ This is an 2567** historical accident that cannot be fixed without breaking 2568** backwards compatibility. ^(Note also that sqlite3_snprintf() 2569** returns a pointer to its buffer instead of the number of 2570** characters actually written into the buffer.)^ We admit that 2571** the number of characters written would be a more useful return 2572** value but we cannot change the implementation of sqlite3_snprintf() 2573** now without breaking compatibility. 2574** 2575** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2576** guarantees that the buffer is always zero-terminated. ^The first 2577** parameter "n" is the total size of the buffer, including space for 2578** the zero terminator. So the longest string that can be completely 2579** written will be n-1 characters. 2580** 2581** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2582** 2583** See also: [built-in printf()], [printf() SQL function] 2584*/ 2585char *sqlite3_mprintf(const char*,...); 2586char *sqlite3_vmprintf(const char*, va_list); 2587char *sqlite3_snprintf(int,char*,const char*, ...); 2588char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2589 2590/* 2591** CAPI3REF: Memory Allocation Subsystem 2592** 2593** The SQLite core uses these three routines for all of its own 2594** internal memory allocation needs. "Core" in the previous sentence 2595** does not include operating-system specific VFS implementation. The 2596** Windows VFS uses native malloc() and free() for some operations. 2597** 2598** ^The sqlite3_malloc() routine returns a pointer to a block 2599** of memory at least N bytes in length, where N is the parameter. 2600** ^If sqlite3_malloc() is unable to obtain sufficient free 2601** memory, it returns a NULL pointer. ^If the parameter N to 2602** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2603** a NULL pointer. 2604** 2605** ^The sqlite3_malloc64(N) routine works just like 2606** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2607** of a signed 32-bit integer. 2608** 2609** ^Calling sqlite3_free() with a pointer previously returned 2610** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2611** that it might be reused. ^The sqlite3_free() routine is 2612** a no-op if is called with a NULL pointer. Passing a NULL pointer 2613** to sqlite3_free() is harmless. After being freed, memory 2614** should neither be read nor written. Even reading previously freed 2615** memory might result in a segmentation fault or other severe error. 2616** Memory corruption, a segmentation fault, or other severe error 2617** might result if sqlite3_free() is called with a non-NULL pointer that 2618** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2619** 2620** ^The sqlite3_realloc(X,N) interface attempts to resize a 2621** prior memory allocation X to be at least N bytes. 2622** ^If the X parameter to sqlite3_realloc(X,N) 2623** is a NULL pointer then its behavior is identical to calling 2624** sqlite3_malloc(N). 2625** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2626** negative then the behavior is exactly the same as calling 2627** sqlite3_free(X). 2628** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2629** of at least N bytes in size or NULL if insufficient memory is available. 2630** ^If M is the size of the prior allocation, then min(N,M) bytes 2631** of the prior allocation are copied into the beginning of buffer returned 2632** by sqlite3_realloc(X,N) and the prior allocation is freed. 2633** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2634** prior allocation is not freed. 2635** 2636** ^The sqlite3_realloc64(X,N) interfaces works the same as 2637** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2638** of a 32-bit signed integer. 2639** 2640** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2641** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2642** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2643** ^The value returned by sqlite3_msize(X) might be larger than the number 2644** of bytes requested when X was allocated. ^If X is a NULL pointer then 2645** sqlite3_msize(X) returns zero. If X points to something that is not 2646** the beginning of memory allocation, or if it points to a formerly 2647** valid memory allocation that has now been freed, then the behavior 2648** of sqlite3_msize(X) is undefined and possibly harmful. 2649** 2650** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2651** sqlite3_malloc64(), and sqlite3_realloc64() 2652** is always aligned to at least an 8 byte boundary, or to a 2653** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2654** option is used. 2655** 2656** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2657** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2658** implementation of these routines to be omitted. That capability 2659** is no longer provided. Only built-in memory allocators can be used. 2660** 2661** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2662** the system malloc() and free() directly when converting 2663** filenames between the UTF-8 encoding used by SQLite 2664** and whatever filename encoding is used by the particular Windows 2665** installation. Memory allocation errors were detected, but 2666** they were reported back as [SQLITE_CANTOPEN] or 2667** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2668** 2669** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2670** must be either NULL or else pointers obtained from a prior 2671** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2672** not yet been released. 2673** 2674** The application must not read or write any part of 2675** a block of memory after it has been released using 2676** [sqlite3_free()] or [sqlite3_realloc()]. 2677*/ 2678void *sqlite3_malloc(int); 2679void *sqlite3_malloc64(sqlite3_uint64); 2680void *sqlite3_realloc(void*, int); 2681void *sqlite3_realloc64(void*, sqlite3_uint64); 2682void sqlite3_free(void*); 2683sqlite3_uint64 sqlite3_msize(void*); 2684 2685/* 2686** CAPI3REF: Memory Allocator Statistics 2687** 2688** SQLite provides these two interfaces for reporting on the status 2689** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2690** routines, which form the built-in memory allocation subsystem. 2691** 2692** ^The [sqlite3_memory_used()] routine returns the number of bytes 2693** of memory currently outstanding (malloced but not freed). 2694** ^The [sqlite3_memory_highwater()] routine returns the maximum 2695** value of [sqlite3_memory_used()] since the high-water mark 2696** was last reset. ^The values returned by [sqlite3_memory_used()] and 2697** [sqlite3_memory_highwater()] include any overhead 2698** added by SQLite in its implementation of [sqlite3_malloc()], 2699** but not overhead added by the any underlying system library 2700** routines that [sqlite3_malloc()] may call. 2701** 2702** ^The memory high-water mark is reset to the current value of 2703** [sqlite3_memory_used()] if and only if the parameter to 2704** [sqlite3_memory_highwater()] is true. ^The value returned 2705** by [sqlite3_memory_highwater(1)] is the high-water mark 2706** prior to the reset. 2707*/ 2708sqlite3_int64 sqlite3_memory_used(void); 2709sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2710 2711/* 2712** CAPI3REF: Pseudo-Random Number Generator 2713** 2714** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2715** select random [ROWID | ROWIDs] when inserting new records into a table that 2716** already uses the largest possible [ROWID]. The PRNG is also used for 2717** the build-in random() and randomblob() SQL functions. This interface allows 2718** applications to access the same PRNG for other purposes. 2719** 2720** ^A call to this routine stores N bytes of randomness into buffer P. 2721** ^The P parameter can be a NULL pointer. 2722** 2723** ^If this routine has not been previously called or if the previous 2724** call had N less than one or a NULL pointer for P, then the PRNG is 2725** seeded using randomness obtained from the xRandomness method of 2726** the default [sqlite3_vfs] object. 2727** ^If the previous call to this routine had an N of 1 or more and a 2728** non-NULL P then the pseudo-randomness is generated 2729** internally and without recourse to the [sqlite3_vfs] xRandomness 2730** method. 2731*/ 2732void sqlite3_randomness(int N, void *P); 2733 2734/* 2735** CAPI3REF: Compile-Time Authorization Callbacks 2736** METHOD: sqlite3 2737** KEYWORDS: {authorizer callback} 2738** 2739** ^This routine registers an authorizer callback with a particular 2740** [database connection], supplied in the first argument. 2741** ^The authorizer callback is invoked as SQL statements are being compiled 2742** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2743** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 2744** and [sqlite3_prepare16_v3()]. ^At various 2745** points during the compilation process, as logic is being created 2746** to perform various actions, the authorizer callback is invoked to 2747** see if those actions are allowed. ^The authorizer callback should 2748** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2749** specific action but allow the SQL statement to continue to be 2750** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2751** rejected with an error. ^If the authorizer callback returns 2752** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2753** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2754** the authorizer will fail with an error message. 2755** 2756** When the callback returns [SQLITE_OK], that means the operation 2757** requested is ok. ^When the callback returns [SQLITE_DENY], the 2758** [sqlite3_prepare_v2()] or equivalent call that triggered the 2759** authorizer will fail with an error message explaining that 2760** access is denied. 2761** 2762** ^The first parameter to the authorizer callback is a copy of the third 2763** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2764** to the callback is an integer [SQLITE_COPY | action code] that specifies 2765** the particular action to be authorized. ^The third through sixth parameters 2766** to the callback are either NULL pointers or zero-terminated strings 2767** that contain additional details about the action to be authorized. 2768** Applications must always be prepared to encounter a NULL pointer in any 2769** of the third through the sixth parameters of the authorization callback. 2770** 2771** ^If the action code is [SQLITE_READ] 2772** and the callback returns [SQLITE_IGNORE] then the 2773** [prepared statement] statement is constructed to substitute 2774** a NULL value in place of the table column that would have 2775** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2776** return can be used to deny an untrusted user access to individual 2777** columns of a table. 2778** ^When a table is referenced by a [SELECT] but no column values are 2779** extracted from that table (for example in a query like 2780** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 2781** is invoked once for that table with a column name that is an empty string. 2782** ^If the action code is [SQLITE_DELETE] and the callback returns 2783** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2784** [truncate optimization] is disabled and all rows are deleted individually. 2785** 2786** An authorizer is used when [sqlite3_prepare | preparing] 2787** SQL statements from an untrusted source, to ensure that the SQL statements 2788** do not try to access data they are not allowed to see, or that they do not 2789** try to execute malicious statements that damage the database. For 2790** example, an application may allow a user to enter arbitrary 2791** SQL queries for evaluation by a database. But the application does 2792** not want the user to be able to make arbitrary changes to the 2793** database. An authorizer could then be put in place while the 2794** user-entered SQL is being [sqlite3_prepare | prepared] that 2795** disallows everything except [SELECT] statements. 2796** 2797** Applications that need to process SQL from untrusted sources 2798** might also consider lowering resource limits using [sqlite3_limit()] 2799** and limiting database size using the [max_page_count] [PRAGMA] 2800** in addition to using an authorizer. 2801** 2802** ^(Only a single authorizer can be in place on a database connection 2803** at a time. Each call to sqlite3_set_authorizer overrides the 2804** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2805** The authorizer is disabled by default. 2806** 2807** The authorizer callback must not do anything that will modify 2808** the database connection that invoked the authorizer callback. 2809** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2810** database connections for the meaning of "modify" in this paragraph. 2811** 2812** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2813** statement might be re-prepared during [sqlite3_step()] due to a 2814** schema change. Hence, the application should ensure that the 2815** correct authorizer callback remains in place during the [sqlite3_step()]. 2816** 2817** ^Note that the authorizer callback is invoked only during 2818** [sqlite3_prepare()] or its variants. Authorization is not 2819** performed during statement evaluation in [sqlite3_step()], unless 2820** as stated in the previous paragraph, sqlite3_step() invokes 2821** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2822*/ 2823int sqlite3_set_authorizer( 2824 sqlite3*, 2825 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2826 void *pUserData 2827); 2828 2829/* 2830** CAPI3REF: Authorizer Return Codes 2831** 2832** The [sqlite3_set_authorizer | authorizer callback function] must 2833** return either [SQLITE_OK] or one of these two constants in order 2834** to signal SQLite whether or not the action is permitted. See the 2835** [sqlite3_set_authorizer | authorizer documentation] for additional 2836** information. 2837** 2838** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2839** returned from the [sqlite3_vtab_on_conflict()] interface. 2840*/ 2841#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2842#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2843 2844/* 2845** CAPI3REF: Authorizer Action Codes 2846** 2847** The [sqlite3_set_authorizer()] interface registers a callback function 2848** that is invoked to authorize certain SQL statement actions. The 2849** second parameter to the callback is an integer code that specifies 2850** what action is being authorized. These are the integer action codes that 2851** the authorizer callback may be passed. 2852** 2853** These action code values signify what kind of operation is to be 2854** authorized. The 3rd and 4th parameters to the authorization 2855** callback function will be parameters or NULL depending on which of these 2856** codes is used as the second parameter. ^(The 5th parameter to the 2857** authorizer callback is the name of the database ("main", "temp", 2858** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2859** is the name of the inner-most trigger or view that is responsible for 2860** the access attempt or NULL if this access attempt is directly from 2861** top-level SQL code. 2862*/ 2863/******************************************* 3rd ************ 4th ***********/ 2864#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2865#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2866#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2867#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2868#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2869#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2870#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2871#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2872#define SQLITE_DELETE 9 /* Table Name NULL */ 2873#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2874#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2875#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2876#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2877#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2878#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2879#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2880#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2881#define SQLITE_INSERT 18 /* Table Name NULL */ 2882#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2883#define SQLITE_READ 20 /* Table Name Column Name */ 2884#define SQLITE_SELECT 21 /* NULL NULL */ 2885#define SQLITE_TRANSACTION 22 /* Operation NULL */ 2886#define SQLITE_UPDATE 23 /* Table Name Column Name */ 2887#define SQLITE_ATTACH 24 /* Filename NULL */ 2888#define SQLITE_DETACH 25 /* Database Name NULL */ 2889#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2890#define SQLITE_REINDEX 27 /* Index Name NULL */ 2891#define SQLITE_ANALYZE 28 /* Table Name NULL */ 2892#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2893#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2894#define SQLITE_FUNCTION 31 /* NULL Function Name */ 2895#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2896#define SQLITE_COPY 0 /* No longer used */ 2897#define SQLITE_RECURSIVE 33 /* NULL NULL */ 2898 2899/* 2900** CAPI3REF: Tracing And Profiling Functions 2901** METHOD: sqlite3 2902** 2903** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 2904** instead of the routines described here. 2905** 2906** These routines register callback functions that can be used for 2907** tracing and profiling the execution of SQL statements. 2908** 2909** ^The callback function registered by sqlite3_trace() is invoked at 2910** various times when an SQL statement is being run by [sqlite3_step()]. 2911** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2912** SQL statement text as the statement first begins executing. 2913** ^(Additional sqlite3_trace() callbacks might occur 2914** as each triggered subprogram is entered. The callbacks for triggers 2915** contain a UTF-8 SQL comment that identifies the trigger.)^ 2916** 2917** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2918** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2919** 2920** ^The callback function registered by sqlite3_profile() is invoked 2921** as each SQL statement finishes. ^The profile callback contains 2922** the original statement text and an estimate of wall-clock time 2923** of how long that statement took to run. ^The profile callback 2924** time is in units of nanoseconds, however the current implementation 2925** is only capable of millisecond resolution so the six least significant 2926** digits in the time are meaningless. Future versions of SQLite 2927** might provide greater resolution on the profiler callback. The 2928** sqlite3_profile() function is considered experimental and is 2929** subject to change in future versions of SQLite. 2930*/ 2931SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 2932 void(*xTrace)(void*,const char*), void*); 2933SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 2934 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2935 2936/* 2937** CAPI3REF: SQL Trace Event Codes 2938** KEYWORDS: SQLITE_TRACE 2939** 2940** These constants identify classes of events that can be monitored 2941** using the [sqlite3_trace_v2()] tracing logic. The M argument 2942** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 2943** the following constants. ^The first argument to the trace callback 2944** is one of the following constants. 2945** 2946** New tracing constants may be added in future releases. 2947** 2948** ^A trace callback has four arguments: xCallback(T,C,P,X). 2949** ^The T argument is one of the integer type codes above. 2950** ^The C argument is a copy of the context pointer passed in as the 2951** fourth argument to [sqlite3_trace_v2()]. 2952** The P and X arguments are pointers whose meanings depend on T. 2953** 2954** <dl> 2955** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 2956** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 2957** first begins running and possibly at other times during the 2958** execution of the prepared statement, such as at the start of each 2959** trigger subprogram. ^The P argument is a pointer to the 2960** [prepared statement]. ^The X argument is a pointer to a string which 2961** is the unexpanded SQL text of the prepared statement or an SQL comment 2962** that indicates the invocation of a trigger. ^The callback can compute 2963** the same text that would have been returned by the legacy [sqlite3_trace()] 2964** interface by using the X argument when X begins with "--" and invoking 2965** [sqlite3_expanded_sql(P)] otherwise. 2966** 2967** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 2968** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 2969** information as is provided by the [sqlite3_profile()] callback. 2970** ^The P argument is a pointer to the [prepared statement] and the 2971** X argument points to a 64-bit integer which is the estimated of 2972** the number of nanosecond that the prepared statement took to run. 2973** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 2974** 2975** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 2976** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 2977** statement generates a single row of result. 2978** ^The P argument is a pointer to the [prepared statement] and the 2979** X argument is unused. 2980** 2981** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 2982** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 2983** connection closes. 2984** ^The P argument is a pointer to the [database connection] object 2985** and the X argument is unused. 2986** </dl> 2987*/ 2988#define SQLITE_TRACE_STMT 0x01 2989#define SQLITE_TRACE_PROFILE 0x02 2990#define SQLITE_TRACE_ROW 0x04 2991#define SQLITE_TRACE_CLOSE 0x08 2992 2993/* 2994** CAPI3REF: SQL Trace Hook 2995** METHOD: sqlite3 2996** 2997** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 2998** function X against [database connection] D, using property mask M 2999** and context pointer P. ^If the X callback is 3000** NULL or if the M mask is zero, then tracing is disabled. The 3001** M argument should be the bitwise OR-ed combination of 3002** zero or more [SQLITE_TRACE] constants. 3003** 3004** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3005** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3006** 3007** ^The X callback is invoked whenever any of the events identified by 3008** mask M occur. ^The integer return value from the callback is currently 3009** ignored, though this may change in future releases. Callback 3010** implementations should return zero to ensure future compatibility. 3011** 3012** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3013** ^The T argument is one of the [SQLITE_TRACE] 3014** constants to indicate why the callback was invoked. 3015** ^The C argument is a copy of the context pointer. 3016** The P and X arguments are pointers whose meanings depend on T. 3017** 3018** The sqlite3_trace_v2() interface is intended to replace the legacy 3019** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3020** are deprecated. 3021*/ 3022int sqlite3_trace_v2( 3023 sqlite3*, 3024 unsigned uMask, 3025 int(*xCallback)(unsigned,void*,void*,void*), 3026 void *pCtx 3027); 3028 3029/* 3030** CAPI3REF: Query Progress Callbacks 3031** METHOD: sqlite3 3032** 3033** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3034** function X to be invoked periodically during long running calls to 3035** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3036** database connection D. An example use for this 3037** interface is to keep a GUI updated during a large query. 3038** 3039** ^The parameter P is passed through as the only parameter to the 3040** callback function X. ^The parameter N is the approximate number of 3041** [virtual machine instructions] that are evaluated between successive 3042** invocations of the callback X. ^If N is less than one then the progress 3043** handler is disabled. 3044** 3045** ^Only a single progress handler may be defined at one time per 3046** [database connection]; setting a new progress handler cancels the 3047** old one. ^Setting parameter X to NULL disables the progress handler. 3048** ^The progress handler is also disabled by setting N to a value less 3049** than 1. 3050** 3051** ^If the progress callback returns non-zero, the operation is 3052** interrupted. This feature can be used to implement a 3053** "Cancel" button on a GUI progress dialog box. 3054** 3055** The progress handler callback must not do anything that will modify 3056** the database connection that invoked the progress handler. 3057** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3058** database connections for the meaning of "modify" in this paragraph. 3059** 3060*/ 3061void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3062 3063/* 3064** CAPI3REF: Opening A New Database Connection 3065** CONSTRUCTOR: sqlite3 3066** 3067** ^These routines open an SQLite database file as specified by the 3068** filename argument. ^The filename argument is interpreted as UTF-8 for 3069** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3070** order for sqlite3_open16(). ^(A [database connection] handle is usually 3071** returned in *ppDb, even if an error occurs. The only exception is that 3072** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3073** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3074** object.)^ ^(If the database is opened (and/or created) successfully, then 3075** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3076** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3077** an English language description of the error following a failure of any 3078** of the sqlite3_open() routines. 3079** 3080** ^The default encoding will be UTF-8 for databases created using 3081** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3082** created using sqlite3_open16() will be UTF-16 in the native byte order. 3083** 3084** Whether or not an error occurs when it is opened, resources 3085** associated with the [database connection] handle should be released by 3086** passing it to [sqlite3_close()] when it is no longer required. 3087** 3088** The sqlite3_open_v2() interface works like sqlite3_open() 3089** except that it accepts two additional parameters for additional control 3090** over the new database connection. ^(The flags parameter to 3091** sqlite3_open_v2() can take one of 3092** the following three values, optionally combined with the 3093** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 3094** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 3095** 3096** <dl> 3097** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3098** <dd>The database is opened in read-only mode. If the database does not 3099** already exist, an error is returned.</dd>)^ 3100** 3101** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3102** <dd>The database is opened for reading and writing if possible, or reading 3103** only if the file is write protected by the operating system. In either 3104** case the database must already exist, otherwise an error is returned.</dd>)^ 3105** 3106** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3107** <dd>The database is opened for reading and writing, and is created if 3108** it does not already exist. This is the behavior that is always used for 3109** sqlite3_open() and sqlite3_open16().</dd>)^ 3110** </dl> 3111** 3112** If the 3rd parameter to sqlite3_open_v2() is not one of the 3113** combinations shown above optionally combined with other 3114** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3115** then the behavior is undefined. 3116** 3117** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 3118** opens in the multi-thread [threading mode] as long as the single-thread 3119** mode has not been set at compile-time or start-time. ^If the 3120** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 3121** in the serialized [threading mode] unless single-thread was 3122** previously selected at compile-time or start-time. 3123** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 3124** eligible to use [shared cache mode], regardless of whether or not shared 3125** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 3126** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 3127** participate in [shared cache mode] even if it is enabled. 3128** 3129** ^The fourth parameter to sqlite3_open_v2() is the name of the 3130** [sqlite3_vfs] object that defines the operating system interface that 3131** the new database connection should use. ^If the fourth parameter is 3132** a NULL pointer then the default [sqlite3_vfs] object is used. 3133** 3134** ^If the filename is ":memory:", then a private, temporary in-memory database 3135** is created for the connection. ^This in-memory database will vanish when 3136** the database connection is closed. Future versions of SQLite might 3137** make use of additional special filenames that begin with the ":" character. 3138** It is recommended that when a database filename actually does begin with 3139** a ":" character you should prefix the filename with a pathname such as 3140** "./" to avoid ambiguity. 3141** 3142** ^If the filename is an empty string, then a private, temporary 3143** on-disk database will be created. ^This private database will be 3144** automatically deleted as soon as the database connection is closed. 3145** 3146** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3147** 3148** ^If [URI filename] interpretation is enabled, and the filename argument 3149** begins with "file:", then the filename is interpreted as a URI. ^URI 3150** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3151** set in the third argument to sqlite3_open_v2(), or if it has 3152** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3153** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3154** URI filename interpretation is turned off 3155** by default, but future releases of SQLite might enable URI filename 3156** interpretation by default. See "[URI filenames]" for additional 3157** information. 3158** 3159** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3160** authority, then it must be either an empty string or the string 3161** "localhost". ^If the authority is not an empty string or "localhost", an 3162** error is returned to the caller. ^The fragment component of a URI, if 3163** present, is ignored. 3164** 3165** ^SQLite uses the path component of the URI as the name of the disk file 3166** which contains the database. ^If the path begins with a '/' character, 3167** then it is interpreted as an absolute path. ^If the path does not begin 3168** with a '/' (meaning that the authority section is omitted from the URI) 3169** then the path is interpreted as a relative path. 3170** ^(On windows, the first component of an absolute path 3171** is a drive specification (e.g. "C:").)^ 3172** 3173** [[core URI query parameters]] 3174** The query component of a URI may contain parameters that are interpreted 3175** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3176** SQLite and its built-in [VFSes] interpret the 3177** following query parameters: 3178** 3179** <ul> 3180** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3181** a VFS object that provides the operating system interface that should 3182** be used to access the database file on disk. ^If this option is set to 3183** an empty string the default VFS object is used. ^Specifying an unknown 3184** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3185** present, then the VFS specified by the option takes precedence over 3186** the value passed as the fourth parameter to sqlite3_open_v2(). 3187** 3188** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3189** "rwc", or "memory". Attempting to set it to any other value is 3190** an error)^. 3191** ^If "ro" is specified, then the database is opened for read-only 3192** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3193** third argument to sqlite3_open_v2(). ^If the mode option is set to 3194** "rw", then the database is opened for read-write (but not create) 3195** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3196** been set. ^Value "rwc" is equivalent to setting both 3197** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3198** set to "memory" then a pure [in-memory database] that never reads 3199** or writes from disk is used. ^It is an error to specify a value for 3200** the mode parameter that is less restrictive than that specified by 3201** the flags passed in the third parameter to sqlite3_open_v2(). 3202** 3203** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3204** "private". ^Setting it to "shared" is equivalent to setting the 3205** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3206** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3207** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3208** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3209** a URI filename, its value overrides any behavior requested by setting 3210** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3211** 3212** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3213** [powersafe overwrite] property does or does not apply to the 3214** storage media on which the database file resides. 3215** 3216** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3217** which if set disables file locking in rollback journal modes. This 3218** is useful for accessing a database on a filesystem that does not 3219** support locking. Caution: Database corruption might result if two 3220** or more processes write to the same database and any one of those 3221** processes uses nolock=1. 3222** 3223** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3224** parameter that indicates that the database file is stored on 3225** read-only media. ^When immutable is set, SQLite assumes that the 3226** database file cannot be changed, even by a process with higher 3227** privilege, and so the database is opened read-only and all locking 3228** and change detection is disabled. Caution: Setting the immutable 3229** property on a database file that does in fact change can result 3230** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3231** See also: [SQLITE_IOCAP_IMMUTABLE]. 3232** 3233** </ul> 3234** 3235** ^Specifying an unknown parameter in the query component of a URI is not an 3236** error. Future versions of SQLite might understand additional query 3237** parameters. See "[query parameters with special meaning to SQLite]" for 3238** additional information. 3239** 3240** [[URI filename examples]] <h3>URI filename examples</h3> 3241** 3242** <table border="1" align=center cellpadding=5> 3243** <tr><th> URI filenames <th> Results 3244** <tr><td> file:data.db <td> 3245** Open the file "data.db" in the current directory. 3246** <tr><td> file:/home/fred/data.db<br> 3247** file:///home/fred/data.db <br> 3248** file://localhost/home/fred/data.db <br> <td> 3249** Open the database file "/home/fred/data.db". 3250** <tr><td> file://darkstar/home/fred/data.db <td> 3251** An error. "darkstar" is not a recognized authority. 3252** <tr><td style="white-space:nowrap"> 3253** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3254** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3255** C:. Note that the %20 escaping in this example is not strictly 3256** necessary - space characters can be used literally 3257** in URI filenames. 3258** <tr><td> file:data.db?mode=ro&cache=private <td> 3259** Open file "data.db" in the current directory for read-only access. 3260** Regardless of whether or not shared-cache mode is enabled by 3261** default, use a private cache. 3262** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3263** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3264** that uses dot-files in place of posix advisory locking. 3265** <tr><td> file:data.db?mode=readonly <td> 3266** An error. "readonly" is not a valid option for the "mode" parameter. 3267** </table> 3268** 3269** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3270** query components of a URI. A hexadecimal escape sequence consists of a 3271** percent sign - "%" - followed by exactly two hexadecimal digits 3272** specifying an octet value. ^Before the path or query components of a 3273** URI filename are interpreted, they are encoded using UTF-8 and all 3274** hexadecimal escape sequences replaced by a single byte containing the 3275** corresponding octet. If this process generates an invalid UTF-8 encoding, 3276** the results are undefined. 3277** 3278** <b>Note to Windows users:</b> The encoding used for the filename argument 3279** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3280** codepage is currently defined. Filenames containing international 3281** characters must be converted to UTF-8 prior to passing them into 3282** sqlite3_open() or sqlite3_open_v2(). 3283** 3284** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3285** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3286** features that require the use of temporary files may fail. 3287** 3288** See also: [sqlite3_temp_directory] 3289*/ 3290int sqlite3_open( 3291 const char *filename, /* Database filename (UTF-8) */ 3292 sqlite3 **ppDb /* OUT: SQLite db handle */ 3293); 3294int sqlite3_open16( 3295 const void *filename, /* Database filename (UTF-16) */ 3296 sqlite3 **ppDb /* OUT: SQLite db handle */ 3297); 3298int sqlite3_open_v2( 3299 const char *filename, /* Database filename (UTF-8) */ 3300 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3301 int flags, /* Flags */ 3302 const char *zVfs /* Name of VFS module to use */ 3303); 3304 3305/* 3306** CAPI3REF: Obtain Values For URI Parameters 3307** 3308** These are utility routines, useful to VFS implementations, that check 3309** to see if a database file was a URI that contained a specific query 3310** parameter, and if so obtains the value of that query parameter. 3311** 3312** If F is the database filename pointer passed into the xOpen() method of 3313** a VFS implementation when the flags parameter to xOpen() has one or 3314** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 3315** P is the name of the query parameter, then 3316** sqlite3_uri_parameter(F,P) returns the value of the P 3317** parameter if it exists or a NULL pointer if P does not appear as a 3318** query parameter on F. If P is a query parameter of F 3319** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3320** a pointer to an empty string. 3321** 3322** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3323** parameter and returns true (1) or false (0) according to the value 3324** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3325** value of query parameter P is one of "yes", "true", or "on" in any 3326** case or if the value begins with a non-zero number. The 3327** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3328** query parameter P is one of "no", "false", or "off" in any case or 3329** if the value begins with a numeric zero. If P is not a query 3330** parameter on F or if the value of P is does not match any of the 3331** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3332** 3333** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3334** 64-bit signed integer and returns that integer, or D if P does not 3335** exist. If the value of P is something other than an integer, then 3336** zero is returned. 3337** 3338** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3339** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3340** is not a database file pathname pointer that SQLite passed into the xOpen 3341** VFS method, then the behavior of this routine is undefined and probably 3342** undesirable. 3343*/ 3344const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3345int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3346sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3347 3348 3349/* 3350** CAPI3REF: Error Codes And Messages 3351** METHOD: sqlite3 3352** 3353** ^If the most recent sqlite3_* API call associated with 3354** [database connection] D failed, then the sqlite3_errcode(D) interface 3355** returns the numeric [result code] or [extended result code] for that 3356** API call. 3357** If the most recent API call was successful, 3358** then the return value from sqlite3_errcode() is undefined. 3359** ^The sqlite3_extended_errcode() 3360** interface is the same except that it always returns the 3361** [extended result code] even when extended result codes are 3362** disabled. 3363** 3364** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3365** text that describes the error, as either UTF-8 or UTF-16 respectively. 3366** ^(Memory to hold the error message string is managed internally. 3367** The application does not need to worry about freeing the result. 3368** However, the error string might be overwritten or deallocated by 3369** subsequent calls to other SQLite interface functions.)^ 3370** 3371** ^The sqlite3_errstr() interface returns the English-language text 3372** that describes the [result code], as UTF-8. 3373** ^(Memory to hold the error message string is managed internally 3374** and must not be freed by the application)^. 3375** 3376** When the serialized [threading mode] is in use, it might be the 3377** case that a second error occurs on a separate thread in between 3378** the time of the first error and the call to these interfaces. 3379** When that happens, the second error will be reported since these 3380** interfaces always report the most recent result. To avoid 3381** this, each thread can obtain exclusive use of the [database connection] D 3382** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3383** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3384** all calls to the interfaces listed here are completed. 3385** 3386** If an interface fails with SQLITE_MISUSE, that means the interface 3387** was invoked incorrectly by the application. In that case, the 3388** error code and message may or may not be set. 3389*/ 3390int sqlite3_errcode(sqlite3 *db); 3391int sqlite3_extended_errcode(sqlite3 *db); 3392const char *sqlite3_errmsg(sqlite3*); 3393const void *sqlite3_errmsg16(sqlite3*); 3394const char *sqlite3_errstr(int); 3395 3396/* 3397** CAPI3REF: Prepared Statement Object 3398** KEYWORDS: {prepared statement} {prepared statements} 3399** 3400** An instance of this object represents a single SQL statement that 3401** has been compiled into binary form and is ready to be evaluated. 3402** 3403** Think of each SQL statement as a separate computer program. The 3404** original SQL text is source code. A prepared statement object 3405** is the compiled object code. All SQL must be converted into a 3406** prepared statement before it can be run. 3407** 3408** The life-cycle of a prepared statement object usually goes like this: 3409** 3410** <ol> 3411** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3412** <li> Bind values to [parameters] using the sqlite3_bind_*() 3413** interfaces. 3414** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3415** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3416** to step 2. Do this zero or more times. 3417** <li> Destroy the object using [sqlite3_finalize()]. 3418** </ol> 3419*/ 3420typedef struct sqlite3_stmt sqlite3_stmt; 3421 3422/* 3423** CAPI3REF: Run-time Limits 3424** METHOD: sqlite3 3425** 3426** ^(This interface allows the size of various constructs to be limited 3427** on a connection by connection basis. The first parameter is the 3428** [database connection] whose limit is to be set or queried. The 3429** second parameter is one of the [limit categories] that define a 3430** class of constructs to be size limited. The third parameter is the 3431** new limit for that construct.)^ 3432** 3433** ^If the new limit is a negative number, the limit is unchanged. 3434** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3435** [limits | hard upper bound] 3436** set at compile-time by a C preprocessor macro called 3437** [limits | SQLITE_MAX_<i>NAME</i>]. 3438** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3439** ^Attempts to increase a limit above its hard upper bound are 3440** silently truncated to the hard upper bound. 3441** 3442** ^Regardless of whether or not the limit was changed, the 3443** [sqlite3_limit()] interface returns the prior value of the limit. 3444** ^Hence, to find the current value of a limit without changing it, 3445** simply invoke this interface with the third parameter set to -1. 3446** 3447** Run-time limits are intended for use in applications that manage 3448** both their own internal database and also databases that are controlled 3449** by untrusted external sources. An example application might be a 3450** web browser that has its own databases for storing history and 3451** separate databases controlled by JavaScript applications downloaded 3452** off the Internet. The internal databases can be given the 3453** large, default limits. Databases managed by external sources can 3454** be given much smaller limits designed to prevent a denial of service 3455** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3456** interface to further control untrusted SQL. The size of the database 3457** created by an untrusted script can be contained using the 3458** [max_page_count] [PRAGMA]. 3459** 3460** New run-time limit categories may be added in future releases. 3461*/ 3462int sqlite3_limit(sqlite3*, int id, int newVal); 3463 3464/* 3465** CAPI3REF: Run-Time Limit Categories 3466** KEYWORDS: {limit category} {*limit categories} 3467** 3468** These constants define various performance limits 3469** that can be lowered at run-time using [sqlite3_limit()]. 3470** The synopsis of the meanings of the various limits is shown below. 3471** Additional information is available at [limits | Limits in SQLite]. 3472** 3473** <dl> 3474** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3475** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3476** 3477** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3478** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3479** 3480** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3481** <dd>The maximum number of columns in a table definition or in the 3482** result set of a [SELECT] or the maximum number of columns in an index 3483** or in an ORDER BY or GROUP BY clause.</dd>)^ 3484** 3485** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3486** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3487** 3488** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3489** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3490** 3491** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3492** <dd>The maximum number of instructions in a virtual machine program 3493** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 3494** the equivalent tries to allocate space for more than this many opcodes 3495** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 3496** 3497** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3498** <dd>The maximum number of arguments on a function.</dd>)^ 3499** 3500** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3501** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3502** 3503** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3504** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3505** <dd>The maximum length of the pattern argument to the [LIKE] or 3506** [GLOB] operators.</dd>)^ 3507** 3508** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3509** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3510** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3511** 3512** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3513** <dd>The maximum depth of recursion for triggers.</dd>)^ 3514** 3515** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3516** <dd>The maximum number of auxiliary worker threads that a single 3517** [prepared statement] may start.</dd>)^ 3518** </dl> 3519*/ 3520#define SQLITE_LIMIT_LENGTH 0 3521#define SQLITE_LIMIT_SQL_LENGTH 1 3522#define SQLITE_LIMIT_COLUMN 2 3523#define SQLITE_LIMIT_EXPR_DEPTH 3 3524#define SQLITE_LIMIT_COMPOUND_SELECT 4 3525#define SQLITE_LIMIT_VDBE_OP 5 3526#define SQLITE_LIMIT_FUNCTION_ARG 6 3527#define SQLITE_LIMIT_ATTACHED 7 3528#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3529#define SQLITE_LIMIT_VARIABLE_NUMBER 9 3530#define SQLITE_LIMIT_TRIGGER_DEPTH 10 3531#define SQLITE_LIMIT_WORKER_THREADS 11 3532 3533/* 3534** CAPI3REF: Prepare Flags 3535** 3536** These constants define various flags that can be passed into 3537** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 3538** [sqlite3_prepare16_v3()] interfaces. 3539** 3540** New flags may be added in future releases of SQLite. 3541** 3542** <dl> 3543** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 3544** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 3545** that the prepared statement will be retained for a long time and 3546** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 3547** and [sqlite3_prepare16_v3()] assume that the prepared statement will 3548** be used just once or at most a few times and then destroyed using 3549** [sqlite3_finalize()] relatively soon. The current implementation acts 3550** on this hint by avoiding the use of [lookaside memory] so as not to 3551** deplete the limited store of lookaside memory. Future versions of 3552** SQLite may act on this hint differently. 3553** </dl> 3554*/ 3555#define SQLITE_PREPARE_PERSISTENT 0x01 3556 3557/* 3558** CAPI3REF: Compiling An SQL Statement 3559** KEYWORDS: {SQL statement compiler} 3560** METHOD: sqlite3 3561** CONSTRUCTOR: sqlite3_stmt 3562** 3563** To execute an SQL statement, it must first be compiled into a byte-code 3564** program using one of these routines. Or, in other words, these routines 3565** are constructors for the [prepared statement] object. 3566** 3567** The preferred routine to use is [sqlite3_prepare_v2()]. The 3568** [sqlite3_prepare()] interface is legacy and should be avoided. 3569** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 3570** for special purposes. 3571** 3572** The use of the UTF-8 interfaces is preferred, as SQLite currently 3573** does all parsing using UTF-8. The UTF-16 interfaces are provided 3574** as a convenience. The UTF-16 interfaces work by converting the 3575** input text into UTF-8, then invoking the corresponding UTF-8 interface. 3576** 3577** The first argument, "db", is a [database connection] obtained from a 3578** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3579** [sqlite3_open16()]. The database connection must not have been closed. 3580** 3581** The second argument, "zSql", is the statement to be compiled, encoded 3582** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 3583** and sqlite3_prepare_v3() 3584** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 3585** and sqlite3_prepare16_v3() use UTF-16. 3586** 3587** ^If the nByte argument is negative, then zSql is read up to the 3588** first zero terminator. ^If nByte is positive, then it is the 3589** number of bytes read from zSql. ^If nByte is zero, then no prepared 3590** statement is generated. 3591** If the caller knows that the supplied string is nul-terminated, then 3592** there is a small performance advantage to passing an nByte parameter that 3593** is the number of bytes in the input string <i>including</i> 3594** the nul-terminator. 3595** 3596** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3597** past the end of the first SQL statement in zSql. These routines only 3598** compile the first statement in zSql, so *pzTail is left pointing to 3599** what remains uncompiled. 3600** 3601** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3602** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3603** to NULL. ^If the input text contains no SQL (if the input is an empty 3604** string or a comment) then *ppStmt is set to NULL. 3605** The calling procedure is responsible for deleting the compiled 3606** SQL statement using [sqlite3_finalize()] after it has finished with it. 3607** ppStmt may not be NULL. 3608** 3609** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3610** otherwise an [error code] is returned. 3611** 3612** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 3613** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 3614** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 3615** are retained for backwards compatibility, but their use is discouraged. 3616** ^In the "vX" interfaces, the prepared statement 3617** that is returned (the [sqlite3_stmt] object) contains a copy of the 3618** original SQL text. This causes the [sqlite3_step()] interface to 3619** behave differently in three ways: 3620** 3621** <ol> 3622** <li> 3623** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3624** always used to do, [sqlite3_step()] will automatically recompile the SQL 3625** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3626** retries will occur before sqlite3_step() gives up and returns an error. 3627** </li> 3628** 3629** <li> 3630** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3631** [error codes] or [extended error codes]. ^The legacy behavior was that 3632** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3633** and the application would have to make a second call to [sqlite3_reset()] 3634** in order to find the underlying cause of the problem. With the "v2" prepare 3635** interfaces, the underlying reason for the error is returned immediately. 3636** </li> 3637** 3638** <li> 3639** ^If the specific value bound to [parameter | host parameter] in the 3640** WHERE clause might influence the choice of query plan for a statement, 3641** then the statement will be automatically recompiled, as if there had been 3642** a schema change, on the first [sqlite3_step()] call following any change 3643** to the [sqlite3_bind_text | bindings] of that [parameter]. 3644** ^The specific value of WHERE-clause [parameter] might influence the 3645** choice of query plan if the parameter is the left-hand side of a [LIKE] 3646** or [GLOB] operator or if the parameter is compared to an indexed column 3647** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3648** </li> 3649** </ol> 3650** 3651** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 3652** the extra prepFlags parameter, which is a bit array consisting of zero or 3653** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 3654** sqlite3_prepare_v2() interface works exactly the same as 3655** sqlite3_prepare_v3() with a zero prepFlags parameter. 3656*/ 3657int sqlite3_prepare( 3658 sqlite3 *db, /* Database handle */ 3659 const char *zSql, /* SQL statement, UTF-8 encoded */ 3660 int nByte, /* Maximum length of zSql in bytes. */ 3661 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3662 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3663); 3664int sqlite3_prepare_v2( 3665 sqlite3 *db, /* Database handle */ 3666 const char *zSql, /* SQL statement, UTF-8 encoded */ 3667 int nByte, /* Maximum length of zSql in bytes. */ 3668 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3669 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3670); 3671int sqlite3_prepare_v3( 3672 sqlite3 *db, /* Database handle */ 3673 const char *zSql, /* SQL statement, UTF-8 encoded */ 3674 int nByte, /* Maximum length of zSql in bytes. */ 3675 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3676 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3677 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3678); 3679int sqlite3_prepare16( 3680 sqlite3 *db, /* Database handle */ 3681 const void *zSql, /* SQL statement, UTF-16 encoded */ 3682 int nByte, /* Maximum length of zSql in bytes. */ 3683 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3684 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3685); 3686int sqlite3_prepare16_v2( 3687 sqlite3 *db, /* Database handle */ 3688 const void *zSql, /* SQL statement, UTF-16 encoded */ 3689 int nByte, /* Maximum length of zSql in bytes. */ 3690 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3691 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3692); 3693int sqlite3_prepare16_v3( 3694 sqlite3 *db, /* Database handle */ 3695 const void *zSql, /* SQL statement, UTF-16 encoded */ 3696 int nByte, /* Maximum length of zSql in bytes. */ 3697 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3698 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3699 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3700); 3701 3702/* 3703** CAPI3REF: Retrieving Statement SQL 3704** METHOD: sqlite3_stmt 3705** 3706** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 3707** SQL text used to create [prepared statement] P if P was 3708** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 3709** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 3710** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 3711** string containing the SQL text of prepared statement P with 3712** [bound parameters] expanded. 3713** 3714** ^(For example, if a prepared statement is created using the SQL 3715** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 3716** and parameter :xyz is unbound, then sqlite3_sql() will return 3717** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 3718** will return "SELECT 2345,NULL".)^ 3719** 3720** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 3721** is available to hold the result, or if the result would exceed the 3722** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 3723** 3724** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 3725** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 3726** option causes sqlite3_expanded_sql() to always return NULL. 3727** 3728** ^The string returned by sqlite3_sql(P) is managed by SQLite and is 3729** automatically freed when the prepared statement is finalized. 3730** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 3731** is obtained from [sqlite3_malloc()] and must be free by the application 3732** by passing it to [sqlite3_free()]. 3733*/ 3734const char *sqlite3_sql(sqlite3_stmt *pStmt); 3735char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 3736 3737/* 3738** CAPI3REF: Determine If An SQL Statement Writes The Database 3739** METHOD: sqlite3_stmt 3740** 3741** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3742** and only if the [prepared statement] X makes no direct changes to 3743** the content of the database file. 3744** 3745** Note that [application-defined SQL functions] or 3746** [virtual tables] might change the database indirectly as a side effect. 3747** ^(For example, if an application defines a function "eval()" that 3748** calls [sqlite3_exec()], then the following SQL statement would 3749** change the database file through side-effects: 3750** 3751** <blockquote><pre> 3752** SELECT eval('DELETE FROM t1') FROM t2; 3753** </pre></blockquote> 3754** 3755** But because the [SELECT] statement does not change the database file 3756** directly, sqlite3_stmt_readonly() would still return true.)^ 3757** 3758** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3759** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3760** since the statements themselves do not actually modify the database but 3761** rather they control the timing of when other statements modify the 3762** database. ^The [ATTACH] and [DETACH] statements also cause 3763** sqlite3_stmt_readonly() to return true since, while those statements 3764** change the configuration of a database connection, they do not make 3765** changes to the content of the database files on disk. 3766** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 3767** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 3768** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 3769** sqlite3_stmt_readonly() returns false for those commands. 3770*/ 3771int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3772 3773/* 3774** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3775** METHOD: sqlite3_stmt 3776** 3777** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3778** [prepared statement] S has been stepped at least once using 3779** [sqlite3_step(S)] but has neither run to completion (returned 3780** [SQLITE_DONE] from [sqlite3_step(S)]) nor 3781** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3782** interface returns false if S is a NULL pointer. If S is not a 3783** NULL pointer and is not a pointer to a valid [prepared statement] 3784** object, then the behavior is undefined and probably undesirable. 3785** 3786** This interface can be used in combination [sqlite3_next_stmt()] 3787** to locate all prepared statements associated with a database 3788** connection that are in need of being reset. This can be used, 3789** for example, in diagnostic routines to search for prepared 3790** statements that are holding a transaction open. 3791*/ 3792int sqlite3_stmt_busy(sqlite3_stmt*); 3793 3794/* 3795** CAPI3REF: Dynamically Typed Value Object 3796** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3797** 3798** SQLite uses the sqlite3_value object to represent all values 3799** that can be stored in a database table. SQLite uses dynamic typing 3800** for the values it stores. ^Values stored in sqlite3_value objects 3801** can be integers, floating point values, strings, BLOBs, or NULL. 3802** 3803** An sqlite3_value object may be either "protected" or "unprotected". 3804** Some interfaces require a protected sqlite3_value. Other interfaces 3805** will accept either a protected or an unprotected sqlite3_value. 3806** Every interface that accepts sqlite3_value arguments specifies 3807** whether or not it requires a protected sqlite3_value. The 3808** [sqlite3_value_dup()] interface can be used to construct a new 3809** protected sqlite3_value from an unprotected sqlite3_value. 3810** 3811** The terms "protected" and "unprotected" refer to whether or not 3812** a mutex is held. An internal mutex is held for a protected 3813** sqlite3_value object but no mutex is held for an unprotected 3814** sqlite3_value object. If SQLite is compiled to be single-threaded 3815** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3816** or if SQLite is run in one of reduced mutex modes 3817** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3818** then there is no distinction between protected and unprotected 3819** sqlite3_value objects and they can be used interchangeably. However, 3820** for maximum code portability it is recommended that applications 3821** still make the distinction between protected and unprotected 3822** sqlite3_value objects even when not strictly required. 3823** 3824** ^The sqlite3_value objects that are passed as parameters into the 3825** implementation of [application-defined SQL functions] are protected. 3826** ^The sqlite3_value object returned by 3827** [sqlite3_column_value()] is unprotected. 3828** Unprotected sqlite3_value objects may only be used as arguments 3829** to [sqlite3_result_value()], [sqlite3_bind_value()], and 3830** [sqlite3_value_dup()]. 3831** The [sqlite3_value_blob | sqlite3_value_type()] family of 3832** interfaces require protected sqlite3_value objects. 3833*/ 3834typedef struct sqlite3_value sqlite3_value; 3835 3836/* 3837** CAPI3REF: SQL Function Context Object 3838** 3839** The context in which an SQL function executes is stored in an 3840** sqlite3_context object. ^A pointer to an sqlite3_context object 3841** is always first parameter to [application-defined SQL functions]. 3842** The application-defined SQL function implementation will pass this 3843** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3844** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3845** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3846** and/or [sqlite3_set_auxdata()]. 3847*/ 3848typedef struct sqlite3_context sqlite3_context; 3849 3850/* 3851** CAPI3REF: Binding Values To Prepared Statements 3852** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3853** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3854** METHOD: sqlite3_stmt 3855** 3856** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3857** literals may be replaced by a [parameter] that matches one of following 3858** templates: 3859** 3860** <ul> 3861** <li> ? 3862** <li> ?NNN 3863** <li> :VVV 3864** <li> @VVV 3865** <li> $VVV 3866** </ul> 3867** 3868** In the templates above, NNN represents an integer literal, 3869** and VVV represents an alphanumeric identifier.)^ ^The values of these 3870** parameters (also called "host parameter names" or "SQL parameters") 3871** can be set using the sqlite3_bind_*() routines defined here. 3872** 3873** ^The first argument to the sqlite3_bind_*() routines is always 3874** a pointer to the [sqlite3_stmt] object returned from 3875** [sqlite3_prepare_v2()] or its variants. 3876** 3877** ^The second argument is the index of the SQL parameter to be set. 3878** ^The leftmost SQL parameter has an index of 1. ^When the same named 3879** SQL parameter is used more than once, second and subsequent 3880** occurrences have the same index as the first occurrence. 3881** ^The index for named parameters can be looked up using the 3882** [sqlite3_bind_parameter_index()] API if desired. ^The index 3883** for "?NNN" parameters is the value of NNN. 3884** ^The NNN value must be between 1 and the [sqlite3_limit()] 3885** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3886** 3887** ^The third argument is the value to bind to the parameter. 3888** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3889** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3890** is ignored and the end result is the same as sqlite3_bind_null(). 3891** 3892** ^(In those routines that have a fourth argument, its value is the 3893** number of bytes in the parameter. To be clear: the value is the 3894** number of <u>bytes</u> in the value, not the number of characters.)^ 3895** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3896** is negative, then the length of the string is 3897** the number of bytes up to the first zero terminator. 3898** If the fourth parameter to sqlite3_bind_blob() is negative, then 3899** the behavior is undefined. 3900** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3901** or sqlite3_bind_text16() or sqlite3_bind_text64() then 3902** that parameter must be the byte offset 3903** where the NUL terminator would occur assuming the string were NUL 3904** terminated. If any NUL characters occur at byte offsets less than 3905** the value of the fourth parameter then the resulting string value will 3906** contain embedded NULs. The result of expressions involving strings 3907** with embedded NULs is undefined. 3908** 3909** ^The fifth argument to the BLOB and string binding interfaces 3910** is a destructor used to dispose of the BLOB or 3911** string after SQLite has finished with it. ^The destructor is called 3912** to dispose of the BLOB or string even if the call to bind API fails. 3913** ^If the fifth argument is 3914** the special value [SQLITE_STATIC], then SQLite assumes that the 3915** information is in static, unmanaged space and does not need to be freed. 3916** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3917** SQLite makes its own private copy of the data immediately, before 3918** the sqlite3_bind_*() routine returns. 3919** 3920** ^The sixth argument to sqlite3_bind_text64() must be one of 3921** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 3922** to specify the encoding of the text in the third parameter. If 3923** the sixth argument to sqlite3_bind_text64() is not one of the 3924** allowed values shown above, or if the text encoding is different 3925** from the encoding specified by the sixth parameter, then the behavior 3926** is undefined. 3927** 3928** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3929** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3930** (just an integer to hold its size) while it is being processed. 3931** Zeroblobs are intended to serve as placeholders for BLOBs whose 3932** content is later written using 3933** [sqlite3_blob_open | incremental BLOB I/O] routines. 3934** ^A negative value for the zeroblob results in a zero-length BLOB. 3935** 3936** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 3937** [prepared statement] S to have an SQL value of NULL, but to also be 3938** associated with the pointer P of type T. ^D is either a NULL pointer or 3939** a pointer to a destructor function for P. ^SQLite will invoke the 3940** destructor D with a single argument of P when it is finished using 3941** P. The T parameter should be a static string, preferably a string 3942** literal. The sqlite3_bind_pointer() routine is part of the 3943** [pointer passing interface] added for SQLite 3.20.0. 3944** 3945** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3946** for the [prepared statement] or with a prepared statement for which 3947** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3948** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3949** routine is passed a [prepared statement] that has been finalized, the 3950** result is undefined and probably harmful. 3951** 3952** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3953** ^Unbound parameters are interpreted as NULL. 3954** 3955** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3956** [error code] if anything goes wrong. 3957** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 3958** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 3959** [SQLITE_MAX_LENGTH]. 3960** ^[SQLITE_RANGE] is returned if the parameter 3961** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3962** 3963** See also: [sqlite3_bind_parameter_count()], 3964** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3965*/ 3966int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3967int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 3968 void(*)(void*)); 3969int sqlite3_bind_double(sqlite3_stmt*, int, double); 3970int sqlite3_bind_int(sqlite3_stmt*, int, int); 3971int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3972int sqlite3_bind_null(sqlite3_stmt*, int); 3973int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 3974int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3975int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 3976 void(*)(void*), unsigned char encoding); 3977int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3978int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 3979int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3980int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 3981 3982/* 3983** CAPI3REF: Number Of SQL Parameters 3984** METHOD: sqlite3_stmt 3985** 3986** ^This routine can be used to find the number of [SQL parameters] 3987** in a [prepared statement]. SQL parameters are tokens of the 3988** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3989** placeholders for values that are [sqlite3_bind_blob | bound] 3990** to the parameters at a later time. 3991** 3992** ^(This routine actually returns the index of the largest (rightmost) 3993** parameter. For all forms except ?NNN, this will correspond to the 3994** number of unique parameters. If parameters of the ?NNN form are used, 3995** there may be gaps in the list.)^ 3996** 3997** See also: [sqlite3_bind_blob|sqlite3_bind()], 3998** [sqlite3_bind_parameter_name()], and 3999** [sqlite3_bind_parameter_index()]. 4000*/ 4001int sqlite3_bind_parameter_count(sqlite3_stmt*); 4002 4003/* 4004** CAPI3REF: Name Of A Host Parameter 4005** METHOD: sqlite3_stmt 4006** 4007** ^The sqlite3_bind_parameter_name(P,N) interface returns 4008** the name of the N-th [SQL parameter] in the [prepared statement] P. 4009** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4010** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4011** respectively. 4012** In other words, the initial ":" or "$" or "@" or "?" 4013** is included as part of the name.)^ 4014** ^Parameters of the form "?" without a following integer have no name 4015** and are referred to as "nameless" or "anonymous parameters". 4016** 4017** ^The first host parameter has an index of 1, not 0. 4018** 4019** ^If the value N is out of range or if the N-th parameter is 4020** nameless, then NULL is returned. ^The returned string is 4021** always in UTF-8 encoding even if the named parameter was 4022** originally specified as UTF-16 in [sqlite3_prepare16()], 4023** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4024** 4025** See also: [sqlite3_bind_blob|sqlite3_bind()], 4026** [sqlite3_bind_parameter_count()], and 4027** [sqlite3_bind_parameter_index()]. 4028*/ 4029const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4030 4031/* 4032** CAPI3REF: Index Of A Parameter With A Given Name 4033** METHOD: sqlite3_stmt 4034** 4035** ^Return the index of an SQL parameter given its name. ^The 4036** index value returned is suitable for use as the second 4037** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4038** is returned if no matching parameter is found. ^The parameter 4039** name must be given in UTF-8 even if the original statement 4040** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4041** [sqlite3_prepare16_v3()]. 4042** 4043** See also: [sqlite3_bind_blob|sqlite3_bind()], 4044** [sqlite3_bind_parameter_count()], and 4045** [sqlite3_bind_parameter_name()]. 4046*/ 4047int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4048 4049/* 4050** CAPI3REF: Reset All Bindings On A Prepared Statement 4051** METHOD: sqlite3_stmt 4052** 4053** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4054** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4055** ^Use this routine to reset all host parameters to NULL. 4056*/ 4057int sqlite3_clear_bindings(sqlite3_stmt*); 4058 4059/* 4060** CAPI3REF: Number Of Columns In A Result Set 4061** METHOD: sqlite3_stmt 4062** 4063** ^Return the number of columns in the result set returned by the 4064** [prepared statement]. ^If this routine returns 0, that means the 4065** [prepared statement] returns no data (for example an [UPDATE]). 4066** ^However, just because this routine returns a positive number does not 4067** mean that one or more rows of data will be returned. ^A SELECT statement 4068** will always have a positive sqlite3_column_count() but depending on the 4069** WHERE clause constraints and the table content, it might return no rows. 4070** 4071** See also: [sqlite3_data_count()] 4072*/ 4073int sqlite3_column_count(sqlite3_stmt *pStmt); 4074 4075/* 4076** CAPI3REF: Column Names In A Result Set 4077** METHOD: sqlite3_stmt 4078** 4079** ^These routines return the name assigned to a particular column 4080** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4081** interface returns a pointer to a zero-terminated UTF-8 string 4082** and sqlite3_column_name16() returns a pointer to a zero-terminated 4083** UTF-16 string. ^The first parameter is the [prepared statement] 4084** that implements the [SELECT] statement. ^The second parameter is the 4085** column number. ^The leftmost column is number 0. 4086** 4087** ^The returned string pointer is valid until either the [prepared statement] 4088** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4089** reprepared by the first call to [sqlite3_step()] for a particular run 4090** or until the next call to 4091** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4092** 4093** ^If sqlite3_malloc() fails during the processing of either routine 4094** (for example during a conversion from UTF-8 to UTF-16) then a 4095** NULL pointer is returned. 4096** 4097** ^The name of a result column is the value of the "AS" clause for 4098** that column, if there is an AS clause. If there is no AS clause 4099** then the name of the column is unspecified and may change from 4100** one release of SQLite to the next. 4101*/ 4102const char *sqlite3_column_name(sqlite3_stmt*, int N); 4103const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4104 4105/* 4106** CAPI3REF: Source Of Data In A Query Result 4107** METHOD: sqlite3_stmt 4108** 4109** ^These routines provide a means to determine the database, table, and 4110** table column that is the origin of a particular result column in 4111** [SELECT] statement. 4112** ^The name of the database or table or column can be returned as 4113** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4114** the database name, the _table_ routines return the table name, and 4115** the origin_ routines return the column name. 4116** ^The returned string is valid until the [prepared statement] is destroyed 4117** using [sqlite3_finalize()] or until the statement is automatically 4118** reprepared by the first call to [sqlite3_step()] for a particular run 4119** or until the same information is requested 4120** again in a different encoding. 4121** 4122** ^The names returned are the original un-aliased names of the 4123** database, table, and column. 4124** 4125** ^The first argument to these interfaces is a [prepared statement]. 4126** ^These functions return information about the Nth result column returned by 4127** the statement, where N is the second function argument. 4128** ^The left-most column is column 0 for these routines. 4129** 4130** ^If the Nth column returned by the statement is an expression or 4131** subquery and is not a column value, then all of these functions return 4132** NULL. ^These routine might also return NULL if a memory allocation error 4133** occurs. ^Otherwise, they return the name of the attached database, table, 4134** or column that query result column was extracted from. 4135** 4136** ^As with all other SQLite APIs, those whose names end with "16" return 4137** UTF-16 encoded strings and the other functions return UTF-8. 4138** 4139** ^These APIs are only available if the library was compiled with the 4140** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4141** 4142** If two or more threads call one or more of these routines against the same 4143** prepared statement and column at the same time then the results are 4144** undefined. 4145** 4146** If two or more threads call one or more 4147** [sqlite3_column_database_name | column metadata interfaces] 4148** for the same [prepared statement] and result column 4149** at the same time then the results are undefined. 4150*/ 4151const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4152const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4153const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4154const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4155const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4156const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4157 4158/* 4159** CAPI3REF: Declared Datatype Of A Query Result 4160** METHOD: sqlite3_stmt 4161** 4162** ^(The first parameter is a [prepared statement]. 4163** If this statement is a [SELECT] statement and the Nth column of the 4164** returned result set of that [SELECT] is a table column (not an 4165** expression or subquery) then the declared type of the table 4166** column is returned.)^ ^If the Nth column of the result set is an 4167** expression or subquery, then a NULL pointer is returned. 4168** ^The returned string is always UTF-8 encoded. 4169** 4170** ^(For example, given the database schema: 4171** 4172** CREATE TABLE t1(c1 VARIANT); 4173** 4174** and the following statement to be compiled: 4175** 4176** SELECT c1 + 1, c1 FROM t1; 4177** 4178** this routine would return the string "VARIANT" for the second result 4179** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4180** 4181** ^SQLite uses dynamic run-time typing. ^So just because a column 4182** is declared to contain a particular type does not mean that the 4183** data stored in that column is of the declared type. SQLite is 4184** strongly typed, but the typing is dynamic not static. ^Type 4185** is associated with individual values, not with the containers 4186** used to hold those values. 4187*/ 4188const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4189const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4190 4191/* 4192** CAPI3REF: Evaluate An SQL Statement 4193** METHOD: sqlite3_stmt 4194** 4195** After a [prepared statement] has been prepared using any of 4196** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4197** or [sqlite3_prepare16_v3()] or one of the legacy 4198** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4199** must be called one or more times to evaluate the statement. 4200** 4201** The details of the behavior of the sqlite3_step() interface depend 4202** on whether the statement was prepared using the newer "vX" interfaces 4203** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4204** [sqlite3_prepare16_v2()] or the older legacy 4205** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4206** new "vX" interface is recommended for new applications but the legacy 4207** interface will continue to be supported. 4208** 4209** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4210** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4211** ^With the "v2" interface, any of the other [result codes] or 4212** [extended result codes] might be returned as well. 4213** 4214** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4215** database locks it needs to do its job. ^If the statement is a [COMMIT] 4216** or occurs outside of an explicit transaction, then you can retry the 4217** statement. If the statement is not a [COMMIT] and occurs within an 4218** explicit transaction then you should rollback the transaction before 4219** continuing. 4220** 4221** ^[SQLITE_DONE] means that the statement has finished executing 4222** successfully. sqlite3_step() should not be called again on this virtual 4223** machine without first calling [sqlite3_reset()] to reset the virtual 4224** machine back to its initial state. 4225** 4226** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4227** is returned each time a new row of data is ready for processing by the 4228** caller. The values may be accessed using the [column access functions]. 4229** sqlite3_step() is called again to retrieve the next row of data. 4230** 4231** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4232** violation) has occurred. sqlite3_step() should not be called again on 4233** the VM. More information may be found by calling [sqlite3_errmsg()]. 4234** ^With the legacy interface, a more specific error code (for example, 4235** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4236** can be obtained by calling [sqlite3_reset()] on the 4237** [prepared statement]. ^In the "v2" interface, 4238** the more specific error code is returned directly by sqlite3_step(). 4239** 4240** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4241** Perhaps it was called on a [prepared statement] that has 4242** already been [sqlite3_finalize | finalized] or on one that had 4243** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4244** be the case that the same database connection is being used by two or 4245** more threads at the same moment in time. 4246** 4247** For all versions of SQLite up to and including 3.6.23.1, a call to 4248** [sqlite3_reset()] was required after sqlite3_step() returned anything 4249** other than [SQLITE_ROW] before any subsequent invocation of 4250** sqlite3_step(). Failure to reset the prepared statement using 4251** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4252** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4253** sqlite3_step() began 4254** calling [sqlite3_reset()] automatically in this circumstance rather 4255** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4256** break because any application that ever receives an SQLITE_MISUSE error 4257** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4258** can be used to restore the legacy behavior. 4259** 4260** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4261** API always returns a generic error code, [SQLITE_ERROR], following any 4262** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4263** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4264** specific [error codes] that better describes the error. 4265** We admit that this is a goofy design. The problem has been fixed 4266** with the "v2" interface. If you prepare all of your SQL statements 4267** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4268** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4269** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4270** then the more specific [error codes] are returned directly 4271** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4272*/ 4273int sqlite3_step(sqlite3_stmt*); 4274 4275/* 4276** CAPI3REF: Number of columns in a result set 4277** METHOD: sqlite3_stmt 4278** 4279** ^The sqlite3_data_count(P) interface returns the number of columns in the 4280** current row of the result set of [prepared statement] P. 4281** ^If prepared statement P does not have results ready to return 4282** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 4283** interfaces) then sqlite3_data_count(P) returns 0. 4284** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4285** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4286** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4287** will return non-zero if previous call to [sqlite3_step](P) returned 4288** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4289** where it always returns zero since each step of that multi-step 4290** pragma returns 0 columns of data. 4291** 4292** See also: [sqlite3_column_count()] 4293*/ 4294int sqlite3_data_count(sqlite3_stmt *pStmt); 4295 4296/* 4297** CAPI3REF: Fundamental Datatypes 4298** KEYWORDS: SQLITE_TEXT 4299** 4300** ^(Every value in SQLite has one of five fundamental datatypes: 4301** 4302** <ul> 4303** <li> 64-bit signed integer 4304** <li> 64-bit IEEE floating point number 4305** <li> string 4306** <li> BLOB 4307** <li> NULL 4308** </ul>)^ 4309** 4310** These constants are codes for each of those types. 4311** 4312** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4313** for a completely different meaning. Software that links against both 4314** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4315** SQLITE_TEXT. 4316*/ 4317#define SQLITE_INTEGER 1 4318#define SQLITE_FLOAT 2 4319#define SQLITE_BLOB 4 4320#define SQLITE_NULL 5 4321#ifdef SQLITE_TEXT 4322# undef SQLITE_TEXT 4323#else 4324# define SQLITE_TEXT 3 4325#endif 4326#define SQLITE3_TEXT 3 4327 4328/* 4329** CAPI3REF: Result Values From A Query 4330** KEYWORDS: {column access functions} 4331** METHOD: sqlite3_stmt 4332** 4333** <b>Summary:</b> 4334** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4335** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 4336** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 4337** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 4338** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 4339** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 4340** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 4341** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 4342** [sqlite3_value|unprotected sqlite3_value] object. 4343** <tr><td> <td> <td> 4344** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 4345** or a UTF-8 TEXT result in bytes 4346** <tr><td><b>sqlite3_column_bytes16 </b> 4347** <td>→ <td>Size of UTF-16 4348** TEXT in bytes 4349** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 4350** datatype of the result 4351** </table></blockquote> 4352** 4353** <b>Details:</b> 4354** 4355** ^These routines return information about a single column of the current 4356** result row of a query. ^In every case the first argument is a pointer 4357** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4358** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4359** and the second argument is the index of the column for which information 4360** should be returned. ^The leftmost column of the result set has the index 0. 4361** ^The number of columns in the result can be determined using 4362** [sqlite3_column_count()]. 4363** 4364** If the SQL statement does not currently point to a valid row, or if the 4365** column index is out of range, the result is undefined. 4366** These routines may only be called when the most recent call to 4367** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4368** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4369** If any of these routines are called after [sqlite3_reset()] or 4370** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4371** something other than [SQLITE_ROW], the results are undefined. 4372** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4373** are called from a different thread while any of these routines 4374** are pending, then the results are undefined. 4375** 4376** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 4377** each return the value of a result column in a specific data format. If 4378** the result column is not initially in the requested format (for example, 4379** if the query returns an integer but the sqlite3_column_text() interface 4380** is used to extract the value) then an automatic type conversion is performed. 4381** 4382** ^The sqlite3_column_type() routine returns the 4383** [SQLITE_INTEGER | datatype code] for the initial data type 4384** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4385** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 4386** The return value of sqlite3_column_type() can be used to decide which 4387** of the first six interface should be used to extract the column value. 4388** The value returned by sqlite3_column_type() is only meaningful if no 4389** automatic type conversions have occurred for the value in question. 4390** After a type conversion, the result of calling sqlite3_column_type() 4391** is undefined, though harmless. Future 4392** versions of SQLite may change the behavior of sqlite3_column_type() 4393** following a type conversion. 4394** 4395** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 4396** or sqlite3_column_bytes16() interfaces can be used to determine the size 4397** of that BLOB or string. 4398** 4399** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4400** routine returns the number of bytes in that BLOB or string. 4401** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4402** the string to UTF-8 and then returns the number of bytes. 4403** ^If the result is a numeric value then sqlite3_column_bytes() uses 4404** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4405** the number of bytes in that string. 4406** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4407** 4408** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4409** routine returns the number of bytes in that BLOB or string. 4410** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4411** the string to UTF-16 and then returns the number of bytes. 4412** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4413** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4414** the number of bytes in that string. 4415** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4416** 4417** ^The values returned by [sqlite3_column_bytes()] and 4418** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4419** of the string. ^For clarity: the values returned by 4420** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4421** bytes in the string, not the number of characters. 4422** 4423** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4424** even empty strings, are always zero-terminated. ^The return 4425** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4426** 4427** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4428** [unprotected sqlite3_value] object. In a multithreaded environment, 4429** an unprotected sqlite3_value object may only be used safely with 4430** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4431** If the [unprotected sqlite3_value] object returned by 4432** [sqlite3_column_value()] is used in any other way, including calls 4433** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4434** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4435** Hence, the sqlite3_column_value() interface 4436** is normally only useful within the implementation of 4437** [application-defined SQL functions] or [virtual tables], not within 4438** top-level application code. 4439** 4440** The these routines may attempt to convert the datatype of the result. 4441** ^For example, if the internal representation is FLOAT and a text result 4442** is requested, [sqlite3_snprintf()] is used internally to perform the 4443** conversion automatically. ^(The following table details the conversions 4444** that are applied: 4445** 4446** <blockquote> 4447** <table border="1"> 4448** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4449** 4450** <tr><td> NULL <td> INTEGER <td> Result is 0 4451** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4452** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4453** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4454** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4455** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4456** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4457** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4458** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4459** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4460** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4461** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4462** <tr><td> TEXT <td> BLOB <td> No change 4463** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4464** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4465** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4466** </table> 4467** </blockquote>)^ 4468** 4469** Note that when type conversions occur, pointers returned by prior 4470** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4471** sqlite3_column_text16() may be invalidated. 4472** Type conversions and pointer invalidations might occur 4473** in the following cases: 4474** 4475** <ul> 4476** <li> The initial content is a BLOB and sqlite3_column_text() or 4477** sqlite3_column_text16() is called. A zero-terminator might 4478** need to be added to the string.</li> 4479** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4480** sqlite3_column_text16() is called. The content must be converted 4481** to UTF-16.</li> 4482** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4483** sqlite3_column_text() is called. The content must be converted 4484** to UTF-8.</li> 4485** </ul> 4486** 4487** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4488** not invalidate a prior pointer, though of course the content of the buffer 4489** that the prior pointer references will have been modified. Other kinds 4490** of conversion are done in place when it is possible, but sometimes they 4491** are not possible and in those cases prior pointers are invalidated. 4492** 4493** The safest policy is to invoke these routines 4494** in one of the following ways: 4495** 4496** <ul> 4497** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4498** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4499** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4500** </ul> 4501** 4502** In other words, you should call sqlite3_column_text(), 4503** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4504** into the desired format, then invoke sqlite3_column_bytes() or 4505** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4506** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4507** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4508** with calls to sqlite3_column_bytes(). 4509** 4510** ^The pointers returned are valid until a type conversion occurs as 4511** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4512** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4513** and BLOBs is freed automatically. Do not pass the pointers returned 4514** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4515** [sqlite3_free()]. 4516** 4517** ^(If a memory allocation error occurs during the evaluation of any 4518** of these routines, a default value is returned. The default value 4519** is either the integer 0, the floating point number 0.0, or a NULL 4520** pointer. Subsequent calls to [sqlite3_errcode()] will return 4521** [SQLITE_NOMEM].)^ 4522*/ 4523const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4524double sqlite3_column_double(sqlite3_stmt*, int iCol); 4525int sqlite3_column_int(sqlite3_stmt*, int iCol); 4526sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4527const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4528const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4529sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4530int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4531int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4532int sqlite3_column_type(sqlite3_stmt*, int iCol); 4533 4534/* 4535** CAPI3REF: Destroy A Prepared Statement Object 4536** DESTRUCTOR: sqlite3_stmt 4537** 4538** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4539** ^If the most recent evaluation of the statement encountered no errors 4540** or if the statement is never been evaluated, then sqlite3_finalize() returns 4541** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4542** sqlite3_finalize(S) returns the appropriate [error code] or 4543** [extended error code]. 4544** 4545** ^The sqlite3_finalize(S) routine can be called at any point during 4546** the life cycle of [prepared statement] S: 4547** before statement S is ever evaluated, after 4548** one or more calls to [sqlite3_reset()], or after any call 4549** to [sqlite3_step()] regardless of whether or not the statement has 4550** completed execution. 4551** 4552** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4553** 4554** The application must finalize every [prepared statement] in order to avoid 4555** resource leaks. It is a grievous error for the application to try to use 4556** a prepared statement after it has been finalized. Any use of a prepared 4557** statement after it has been finalized can result in undefined and 4558** undesirable behavior such as segfaults and heap corruption. 4559*/ 4560int sqlite3_finalize(sqlite3_stmt *pStmt); 4561 4562/* 4563** CAPI3REF: Reset A Prepared Statement Object 4564** METHOD: sqlite3_stmt 4565** 4566** The sqlite3_reset() function is called to reset a [prepared statement] 4567** object back to its initial state, ready to be re-executed. 4568** ^Any SQL statement variables that had values bound to them using 4569** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4570** Use [sqlite3_clear_bindings()] to reset the bindings. 4571** 4572** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4573** back to the beginning of its program. 4574** 4575** ^If the most recent call to [sqlite3_step(S)] for the 4576** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4577** or if [sqlite3_step(S)] has never before been called on S, 4578** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4579** 4580** ^If the most recent call to [sqlite3_step(S)] for the 4581** [prepared statement] S indicated an error, then 4582** [sqlite3_reset(S)] returns an appropriate [error code]. 4583** 4584** ^The [sqlite3_reset(S)] interface does not change the values 4585** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4586*/ 4587int sqlite3_reset(sqlite3_stmt *pStmt); 4588 4589/* 4590** CAPI3REF: Create Or Redefine SQL Functions 4591** KEYWORDS: {function creation routines} 4592** KEYWORDS: {application-defined SQL function} 4593** KEYWORDS: {application-defined SQL functions} 4594** METHOD: sqlite3 4595** 4596** ^These functions (collectively known as "function creation routines") 4597** are used to add SQL functions or aggregates or to redefine the behavior 4598** of existing SQL functions or aggregates. The only differences between 4599** these routines are the text encoding expected for 4600** the second parameter (the name of the function being created) 4601** and the presence or absence of a destructor callback for 4602** the application data pointer. 4603** 4604** ^The first parameter is the [database connection] to which the SQL 4605** function is to be added. ^If an application uses more than one database 4606** connection then application-defined SQL functions must be added 4607** to each database connection separately. 4608** 4609** ^The second parameter is the name of the SQL function to be created or 4610** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4611** representation, exclusive of the zero-terminator. ^Note that the name 4612** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4613** ^Any attempt to create a function with a longer name 4614** will result in [SQLITE_MISUSE] being returned. 4615** 4616** ^The third parameter (nArg) 4617** is the number of arguments that the SQL function or 4618** aggregate takes. ^If this parameter is -1, then the SQL function or 4619** aggregate may take any number of arguments between 0 and the limit 4620** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4621** parameter is less than -1 or greater than 127 then the behavior is 4622** undefined. 4623** 4624** ^The fourth parameter, eTextRep, specifies what 4625** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4626** its parameters. The application should set this parameter to 4627** [SQLITE_UTF16LE] if the function implementation invokes 4628** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4629** implementation invokes [sqlite3_value_text16be()] on an input, or 4630** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4631** otherwise. ^The same SQL function may be registered multiple times using 4632** different preferred text encodings, with different implementations for 4633** each encoding. 4634** ^When multiple implementations of the same function are available, SQLite 4635** will pick the one that involves the least amount of data conversion. 4636** 4637** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4638** to signal that the function will always return the same result given 4639** the same inputs within a single SQL statement. Most SQL functions are 4640** deterministic. The built-in [random()] SQL function is an example of a 4641** function that is not deterministic. The SQLite query planner is able to 4642** perform additional optimizations on deterministic functions, so use 4643** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4644** 4645** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4646** function can gain access to this pointer using [sqlite3_user_data()].)^ 4647** 4648** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 4649** pointers to C-language functions that implement the SQL function or 4650** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4651** callback only; NULL pointers must be passed as the xStep and xFinal 4652** parameters. ^An aggregate SQL function requires an implementation of xStep 4653** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4654** SQL function or aggregate, pass NULL pointers for all three function 4655** callbacks. 4656** 4657** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 4658** then it is destructor for the application data pointer. 4659** The destructor is invoked when the function is deleted, either by being 4660** overloaded or when the database connection closes.)^ 4661** ^The destructor is also invoked if the call to 4662** sqlite3_create_function_v2() fails. 4663** ^When the destructor callback of the tenth parameter is invoked, it 4664** is passed a single argument which is a copy of the application data 4665** pointer which was the fifth parameter to sqlite3_create_function_v2(). 4666** 4667** ^It is permitted to register multiple implementations of the same 4668** functions with the same name but with either differing numbers of 4669** arguments or differing preferred text encodings. ^SQLite will use 4670** the implementation that most closely matches the way in which the 4671** SQL function is used. ^A function implementation with a non-negative 4672** nArg parameter is a better match than a function implementation with 4673** a negative nArg. ^A function where the preferred text encoding 4674** matches the database encoding is a better 4675** match than a function where the encoding is different. 4676** ^A function where the encoding difference is between UTF16le and UTF16be 4677** is a closer match than a function where the encoding difference is 4678** between UTF8 and UTF16. 4679** 4680** ^Built-in functions may be overloaded by new application-defined functions. 4681** 4682** ^An application-defined function is permitted to call other 4683** SQLite interfaces. However, such calls must not 4684** close the database connection nor finalize or reset the prepared 4685** statement in which the function is running. 4686*/ 4687int sqlite3_create_function( 4688 sqlite3 *db, 4689 const char *zFunctionName, 4690 int nArg, 4691 int eTextRep, 4692 void *pApp, 4693 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4694 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4695 void (*xFinal)(sqlite3_context*) 4696); 4697int sqlite3_create_function16( 4698 sqlite3 *db, 4699 const void *zFunctionName, 4700 int nArg, 4701 int eTextRep, 4702 void *pApp, 4703 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4704 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4705 void (*xFinal)(sqlite3_context*) 4706); 4707int sqlite3_create_function_v2( 4708 sqlite3 *db, 4709 const char *zFunctionName, 4710 int nArg, 4711 int eTextRep, 4712 void *pApp, 4713 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4714 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4715 void (*xFinal)(sqlite3_context*), 4716 void(*xDestroy)(void*) 4717); 4718 4719/* 4720** CAPI3REF: Text Encodings 4721** 4722** These constant define integer codes that represent the various 4723** text encodings supported by SQLite. 4724*/ 4725#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4726#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4727#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4728#define SQLITE_UTF16 4 /* Use native byte order */ 4729#define SQLITE_ANY 5 /* Deprecated */ 4730#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4731 4732/* 4733** CAPI3REF: Function Flags 4734** 4735** These constants may be ORed together with the 4736** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4737** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4738** [sqlite3_create_function_v2()]. 4739*/ 4740#define SQLITE_DETERMINISTIC 0x800 4741 4742/* 4743** CAPI3REF: Deprecated Functions 4744** DEPRECATED 4745** 4746** These functions are [deprecated]. In order to maintain 4747** backwards compatibility with older code, these functions continue 4748** to be supported. However, new applications should avoid 4749** the use of these functions. To encourage programmers to avoid 4750** these functions, we will not explain what they do. 4751*/ 4752#ifndef SQLITE_OMIT_DEPRECATED 4753SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 4754SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 4755SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4756SQLITE_DEPRECATED int sqlite3_global_recover(void); 4757SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 4758SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4759 void*,sqlite3_int64); 4760#endif 4761 4762/* 4763** CAPI3REF: Obtaining SQL Values 4764** METHOD: sqlite3_value 4765** 4766** <b>Summary:</b> 4767** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4768** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 4769** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 4770** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 4771** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 4772** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 4773** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 4774** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 4775** the native byteorder 4776** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 4777** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 4778** <tr><td> <td> <td> 4779** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 4780** or a UTF-8 TEXT in bytes 4781** <tr><td><b>sqlite3_value_bytes16 </b> 4782** <td>→ <td>Size of UTF-16 4783** TEXT in bytes 4784** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 4785** datatype of the value 4786** <tr><td><b>sqlite3_value_numeric_type </b> 4787** <td>→ <td>Best numeric datatype of the value 4788** <tr><td><b>sqlite3_value_nochange </b> 4789** <td>→ <td>True if the column is unchanged in an UPDATE 4790** against a virtual table. 4791** </table></blockquote> 4792** 4793** <b>Details:</b> 4794** 4795** These routines extract type, size, and content information from 4796** [protected sqlite3_value] objects. Protected sqlite3_value objects 4797** are used to pass parameter information into implementation of 4798** [application-defined SQL functions] and [virtual tables]. 4799** 4800** These routines work only with [protected sqlite3_value] objects. 4801** Any attempt to use these routines on an [unprotected sqlite3_value] 4802** is not threadsafe. 4803** 4804** ^These routines work just like the corresponding [column access functions] 4805** except that these routines take a single [protected sqlite3_value] object 4806** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4807** 4808** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4809** in the native byte-order of the host machine. ^The 4810** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4811** extract UTF-16 strings as big-endian and little-endian respectively. 4812** 4813** ^If [sqlite3_value] object V was initialized 4814** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 4815** and if X and Y are strings that compare equal according to strcmp(X,Y), 4816** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 4817** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 4818** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 4819** 4820** ^(The sqlite3_value_type(V) interface returns the 4821** [SQLITE_INTEGER | datatype code] for the initial datatype of the 4822** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 4823** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 4824** Other interfaces might change the datatype for an sqlite3_value object. 4825** For example, if the datatype is initially SQLITE_INTEGER and 4826** sqlite3_value_text(V) is called to extract a text value for that 4827** integer, then subsequent calls to sqlite3_value_type(V) might return 4828** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 4829** occurs is undefined and may change from one release of SQLite to the next. 4830** 4831** ^(The sqlite3_value_numeric_type() interface attempts to apply 4832** numeric affinity to the value. This means that an attempt is 4833** made to convert the value to an integer or floating point. If 4834** such a conversion is possible without loss of information (in other 4835** words, if the value is a string that looks like a number) 4836** then the conversion is performed. Otherwise no conversion occurs. 4837** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4838** 4839** ^Within the [xUpdate] method of a [virtual table], the 4840** sqlite3_value_nochange(X) interface returns true if and only if 4841** the column corresponding to X is unchanged by the UPDATE operation 4842** that the xUpdate method call was invoked to implement and if 4843** and the prior [xColumn] method call that was invoked to extracted 4844** the value for that column returned without setting a result (probably 4845** because it queried [sqlite3_vtab_nochange()] and found that the column 4846** was unchanging). ^Within an [xUpdate] method, any value for which 4847** sqlite3_value_nochange(X) is true will in all other respects appear 4848** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 4849** than within an [xUpdate] method call for an UPDATE statement, then 4850** the return value is arbitrary and meaningless. 4851** 4852** Please pay particular attention to the fact that the pointer returned 4853** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4854** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4855** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4856** or [sqlite3_value_text16()]. 4857** 4858** These routines must be called from the same thread as 4859** the SQL function that supplied the [sqlite3_value*] parameters. 4860*/ 4861const void *sqlite3_value_blob(sqlite3_value*); 4862double sqlite3_value_double(sqlite3_value*); 4863int sqlite3_value_int(sqlite3_value*); 4864sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 4865void *sqlite3_value_pointer(sqlite3_value*, const char*); 4866const unsigned char *sqlite3_value_text(sqlite3_value*); 4867const void *sqlite3_value_text16(sqlite3_value*); 4868const void *sqlite3_value_text16le(sqlite3_value*); 4869const void *sqlite3_value_text16be(sqlite3_value*); 4870int sqlite3_value_bytes(sqlite3_value*); 4871int sqlite3_value_bytes16(sqlite3_value*); 4872int sqlite3_value_type(sqlite3_value*); 4873int sqlite3_value_numeric_type(sqlite3_value*); 4874int sqlite3_value_nochange(sqlite3_value*); 4875 4876/* 4877** CAPI3REF: Finding The Subtype Of SQL Values 4878** METHOD: sqlite3_value 4879** 4880** The sqlite3_value_subtype(V) function returns the subtype for 4881** an [application-defined SQL function] argument V. The subtype 4882** information can be used to pass a limited amount of context from 4883** one SQL function to another. Use the [sqlite3_result_subtype()] 4884** routine to set the subtype for the return value of an SQL function. 4885*/ 4886unsigned int sqlite3_value_subtype(sqlite3_value*); 4887 4888/* 4889** CAPI3REF: Copy And Free SQL Values 4890** METHOD: sqlite3_value 4891** 4892** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 4893** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 4894** is a [protected sqlite3_value] object even if the input is not. 4895** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 4896** memory allocation fails. 4897** 4898** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 4899** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 4900** then sqlite3_value_free(V) is a harmless no-op. 4901*/ 4902sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 4903void sqlite3_value_free(sqlite3_value*); 4904 4905/* 4906** CAPI3REF: Obtain Aggregate Function Context 4907** METHOD: sqlite3_context 4908** 4909** Implementations of aggregate SQL functions use this 4910** routine to allocate memory for storing their state. 4911** 4912** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4913** for a particular aggregate function, SQLite 4914** allocates N of memory, zeroes out that memory, and returns a pointer 4915** to the new memory. ^On second and subsequent calls to 4916** sqlite3_aggregate_context() for the same aggregate function instance, 4917** the same buffer is returned. Sqlite3_aggregate_context() is normally 4918** called once for each invocation of the xStep callback and then one 4919** last time when the xFinal callback is invoked. ^(When no rows match 4920** an aggregate query, the xStep() callback of the aggregate function 4921** implementation is never called and xFinal() is called exactly once. 4922** In those cases, sqlite3_aggregate_context() might be called for the 4923** first time from within xFinal().)^ 4924** 4925** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 4926** when first called if N is less than or equal to zero or if a memory 4927** allocate error occurs. 4928** 4929** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4930** determined by the N parameter on first successful call. Changing the 4931** value of N in subsequent call to sqlite3_aggregate_context() within 4932** the same aggregate function instance will not resize the memory 4933** allocation.)^ Within the xFinal callback, it is customary to set 4934** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 4935** pointless memory allocations occur. 4936** 4937** ^SQLite automatically frees the memory allocated by 4938** sqlite3_aggregate_context() when the aggregate query concludes. 4939** 4940** The first parameter must be a copy of the 4941** [sqlite3_context | SQL function context] that is the first parameter 4942** to the xStep or xFinal callback routine that implements the aggregate 4943** function. 4944** 4945** This routine must be called from the same thread in which 4946** the aggregate SQL function is running. 4947*/ 4948void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4949 4950/* 4951** CAPI3REF: User Data For Functions 4952** METHOD: sqlite3_context 4953** 4954** ^The sqlite3_user_data() interface returns a copy of 4955** the pointer that was the pUserData parameter (the 5th parameter) 4956** of the [sqlite3_create_function()] 4957** and [sqlite3_create_function16()] routines that originally 4958** registered the application defined function. 4959** 4960** This routine must be called from the same thread in which 4961** the application-defined function is running. 4962*/ 4963void *sqlite3_user_data(sqlite3_context*); 4964 4965/* 4966** CAPI3REF: Database Connection For Functions 4967** METHOD: sqlite3_context 4968** 4969** ^The sqlite3_context_db_handle() interface returns a copy of 4970** the pointer to the [database connection] (the 1st parameter) 4971** of the [sqlite3_create_function()] 4972** and [sqlite3_create_function16()] routines that originally 4973** registered the application defined function. 4974*/ 4975sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 4976 4977/* 4978** CAPI3REF: Function Auxiliary Data 4979** METHOD: sqlite3_context 4980** 4981** These functions may be used by (non-aggregate) SQL functions to 4982** associate metadata with argument values. If the same value is passed to 4983** multiple invocations of the same SQL function during query execution, under 4984** some circumstances the associated metadata may be preserved. An example 4985** of where this might be useful is in a regular-expression matching 4986** function. The compiled version of the regular expression can be stored as 4987** metadata associated with the pattern string. 4988** Then as long as the pattern string remains the same, 4989** the compiled regular expression can be reused on multiple 4990** invocations of the same function. 4991** 4992** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 4993** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 4994** value to the application-defined function. ^N is zero for the left-most 4995** function argument. ^If there is no metadata 4996** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 4997** returns a NULL pointer. 4998** 4999** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 5000** argument of the application-defined function. ^Subsequent 5001** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5002** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 5003** NULL if the metadata has been discarded. 5004** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5005** SQLite will invoke the destructor function X with parameter P exactly 5006** once, when the metadata is discarded. 5007** SQLite is free to discard the metadata at any time, including: <ul> 5008** <li> ^(when the corresponding function parameter changes)^, or 5009** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5010** SQL statement)^, or 5011** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5012** parameter)^, or 5013** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5014** allocation error occurs.)^ </ul> 5015** 5016** Note the last bullet in particular. The destructor X in 5017** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5018** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5019** should be called near the end of the function implementation and the 5020** function implementation should not make any use of P after 5021** sqlite3_set_auxdata() has been called. 5022** 5023** ^(In practice, metadata is preserved between function calls for 5024** function parameters that are compile-time constants, including literal 5025** values and [parameters] and expressions composed from the same.)^ 5026** 5027** The value of the N parameter to these interfaces should be non-negative. 5028** Future enhancements may make use of negative N values to define new 5029** kinds of function caching behavior. 5030** 5031** These routines must be called from the same thread in which 5032** the SQL function is running. 5033*/ 5034void *sqlite3_get_auxdata(sqlite3_context*, int N); 5035void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5036 5037 5038/* 5039** CAPI3REF: Constants Defining Special Destructor Behavior 5040** 5041** These are special values for the destructor that is passed in as the 5042** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5043** argument is SQLITE_STATIC, it means that the content pointer is constant 5044** and will never change. It does not need to be destroyed. ^The 5045** SQLITE_TRANSIENT value means that the content will likely change in 5046** the near future and that SQLite should make its own private copy of 5047** the content before returning. 5048** 5049** The typedef is necessary to work around problems in certain 5050** C++ compilers. 5051*/ 5052typedef void (*sqlite3_destructor_type)(void*); 5053#define SQLITE_STATIC ((sqlite3_destructor_type)0) 5054#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5055 5056/* 5057** CAPI3REF: Setting The Result Of An SQL Function 5058** METHOD: sqlite3_context 5059** 5060** These routines are used by the xFunc or xFinal callbacks that 5061** implement SQL functions and aggregates. See 5062** [sqlite3_create_function()] and [sqlite3_create_function16()] 5063** for additional information. 5064** 5065** These functions work very much like the [parameter binding] family of 5066** functions used to bind values to host parameters in prepared statements. 5067** Refer to the [SQL parameter] documentation for additional information. 5068** 5069** ^The sqlite3_result_blob() interface sets the result from 5070** an application-defined function to be the BLOB whose content is pointed 5071** to by the second parameter and which is N bytes long where N is the 5072** third parameter. 5073** 5074** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5075** interfaces set the result of the application-defined function to be 5076** a BLOB containing all zero bytes and N bytes in size. 5077** 5078** ^The sqlite3_result_double() interface sets the result from 5079** an application-defined function to be a floating point value specified 5080** by its 2nd argument. 5081** 5082** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5083** cause the implemented SQL function to throw an exception. 5084** ^SQLite uses the string pointed to by the 5085** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5086** as the text of an error message. ^SQLite interprets the error 5087** message string from sqlite3_result_error() as UTF-8. ^SQLite 5088** interprets the string from sqlite3_result_error16() as UTF-16 in native 5089** byte order. ^If the third parameter to sqlite3_result_error() 5090** or sqlite3_result_error16() is negative then SQLite takes as the error 5091** message all text up through the first zero character. 5092** ^If the third parameter to sqlite3_result_error() or 5093** sqlite3_result_error16() is non-negative then SQLite takes that many 5094** bytes (not characters) from the 2nd parameter as the error message. 5095** ^The sqlite3_result_error() and sqlite3_result_error16() 5096** routines make a private copy of the error message text before 5097** they return. Hence, the calling function can deallocate or 5098** modify the text after they return without harm. 5099** ^The sqlite3_result_error_code() function changes the error code 5100** returned by SQLite as a result of an error in a function. ^By default, 5101** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5102** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5103** 5104** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5105** error indicating that a string or BLOB is too long to represent. 5106** 5107** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5108** error indicating that a memory allocation failed. 5109** 5110** ^The sqlite3_result_int() interface sets the return value 5111** of the application-defined function to be the 32-bit signed integer 5112** value given in the 2nd argument. 5113** ^The sqlite3_result_int64() interface sets the return value 5114** of the application-defined function to be the 64-bit signed integer 5115** value given in the 2nd argument. 5116** 5117** ^The sqlite3_result_null() interface sets the return value 5118** of the application-defined function to be NULL. 5119** 5120** ^The sqlite3_result_text(), sqlite3_result_text16(), 5121** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5122** set the return value of the application-defined function to be 5123** a text string which is represented as UTF-8, UTF-16 native byte order, 5124** UTF-16 little endian, or UTF-16 big endian, respectively. 5125** ^The sqlite3_result_text64() interface sets the return value of an 5126** application-defined function to be a text string in an encoding 5127** specified by the fifth (and last) parameter, which must be one 5128** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5129** ^SQLite takes the text result from the application from 5130** the 2nd parameter of the sqlite3_result_text* interfaces. 5131** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5132** is negative, then SQLite takes result text from the 2nd parameter 5133** through the first zero character. 5134** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5135** is non-negative, then as many bytes (not characters) of the text 5136** pointed to by the 2nd parameter are taken as the application-defined 5137** function result. If the 3rd parameter is non-negative, then it 5138** must be the byte offset into the string where the NUL terminator would 5139** appear if the string where NUL terminated. If any NUL characters occur 5140** in the string at a byte offset that is less than the value of the 3rd 5141** parameter, then the resulting string will contain embedded NULs and the 5142** result of expressions operating on strings with embedded NULs is undefined. 5143** ^If the 4th parameter to the sqlite3_result_text* interfaces 5144** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5145** function as the destructor on the text or BLOB result when it has 5146** finished using that result. 5147** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5148** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 5149** assumes that the text or BLOB result is in constant space and does not 5150** copy the content of the parameter nor call a destructor on the content 5151** when it has finished using that result. 5152** ^If the 4th parameter to the sqlite3_result_text* interfaces 5153** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 5154** then SQLite makes a copy of the result into space obtained 5155** from [sqlite3_malloc()] before it returns. 5156** 5157** ^The sqlite3_result_value() interface sets the result of 5158** the application-defined function to be a copy of the 5159** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 5160** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 5161** so that the [sqlite3_value] specified in the parameter may change or 5162** be deallocated after sqlite3_result_value() returns without harm. 5163** ^A [protected sqlite3_value] object may always be used where an 5164** [unprotected sqlite3_value] object is required, so either 5165** kind of [sqlite3_value] object can be used with this interface. 5166** 5167** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 5168** SQL NULL value, just like [sqlite3_result_null(C)], except that it 5169** also associates the host-language pointer P or type T with that 5170** NULL value such that the pointer can be retrieved within an 5171** [application-defined SQL function] using [sqlite3_value_pointer()]. 5172** ^If the D parameter is not NULL, then it is a pointer to a destructor 5173** for the P parameter. ^SQLite invokes D with P as its only argument 5174** when SQLite is finished with P. The T parameter should be a static 5175** string and preferably a string literal. The sqlite3_result_pointer() 5176** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5177** 5178** If these routines are called from within the different thread 5179** than the one containing the application-defined function that received 5180** the [sqlite3_context] pointer, the results are undefined. 5181*/ 5182void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 5183void sqlite3_result_blob64(sqlite3_context*,const void*, 5184 sqlite3_uint64,void(*)(void*)); 5185void sqlite3_result_double(sqlite3_context*, double); 5186void sqlite3_result_error(sqlite3_context*, const char*, int); 5187void sqlite3_result_error16(sqlite3_context*, const void*, int); 5188void sqlite3_result_error_toobig(sqlite3_context*); 5189void sqlite3_result_error_nomem(sqlite3_context*); 5190void sqlite3_result_error_code(sqlite3_context*, int); 5191void sqlite3_result_int(sqlite3_context*, int); 5192void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5193void sqlite3_result_null(sqlite3_context*); 5194void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5195void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5196 void(*)(void*), unsigned char encoding); 5197void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5198void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5199void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5200void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5201void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 5202void sqlite3_result_zeroblob(sqlite3_context*, int n); 5203int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 5204 5205 5206/* 5207** CAPI3REF: Setting The Subtype Of An SQL Function 5208** METHOD: sqlite3_context 5209** 5210** The sqlite3_result_subtype(C,T) function causes the subtype of 5211** the result from the [application-defined SQL function] with 5212** [sqlite3_context] C to be the value T. Only the lower 8 bits 5213** of the subtype T are preserved in current versions of SQLite; 5214** higher order bits are discarded. 5215** The number of subtype bytes preserved by SQLite might increase 5216** in future releases of SQLite. 5217*/ 5218void sqlite3_result_subtype(sqlite3_context*,unsigned int); 5219 5220/* 5221** CAPI3REF: Define New Collating Sequences 5222** METHOD: sqlite3 5223** 5224** ^These functions add, remove, or modify a [collation] associated 5225** with the [database connection] specified as the first argument. 5226** 5227** ^The name of the collation is a UTF-8 string 5228** for sqlite3_create_collation() and sqlite3_create_collation_v2() 5229** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 5230** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 5231** considered to be the same name. 5232** 5233** ^(The third argument (eTextRep) must be one of the constants: 5234** <ul> 5235** <li> [SQLITE_UTF8], 5236** <li> [SQLITE_UTF16LE], 5237** <li> [SQLITE_UTF16BE], 5238** <li> [SQLITE_UTF16], or 5239** <li> [SQLITE_UTF16_ALIGNED]. 5240** </ul>)^ 5241** ^The eTextRep argument determines the encoding of strings passed 5242** to the collating function callback, xCallback. 5243** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 5244** force strings to be UTF16 with native byte order. 5245** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 5246** on an even byte address. 5247** 5248** ^The fourth argument, pArg, is an application data pointer that is passed 5249** through as the first argument to the collating function callback. 5250** 5251** ^The fifth argument, xCallback, is a pointer to the collating function. 5252** ^Multiple collating functions can be registered using the same name but 5253** with different eTextRep parameters and SQLite will use whichever 5254** function requires the least amount of data transformation. 5255** ^If the xCallback argument is NULL then the collating function is 5256** deleted. ^When all collating functions having the same name are deleted, 5257** that collation is no longer usable. 5258** 5259** ^The collating function callback is invoked with a copy of the pArg 5260** application data pointer and with two strings in the encoding specified 5261** by the eTextRep argument. The collating function must return an 5262** integer that is negative, zero, or positive 5263** if the first string is less than, equal to, or greater than the second, 5264** respectively. A collating function must always return the same answer 5265** given the same inputs. If two or more collating functions are registered 5266** to the same collation name (using different eTextRep values) then all 5267** must give an equivalent answer when invoked with equivalent strings. 5268** The collating function must obey the following properties for all 5269** strings A, B, and C: 5270** 5271** <ol> 5272** <li> If A==B then B==A. 5273** <li> If A==B and B==C then A==C. 5274** <li> If A<B THEN B>A. 5275** <li> If A<B and B<C then A<C. 5276** </ol> 5277** 5278** If a collating function fails any of the above constraints and that 5279** collating function is registered and used, then the behavior of SQLite 5280** is undefined. 5281** 5282** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 5283** with the addition that the xDestroy callback is invoked on pArg when 5284** the collating function is deleted. 5285** ^Collating functions are deleted when they are overridden by later 5286** calls to the collation creation functions or when the 5287** [database connection] is closed using [sqlite3_close()]. 5288** 5289** ^The xDestroy callback is <u>not</u> called if the 5290** sqlite3_create_collation_v2() function fails. Applications that invoke 5291** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5292** check the return code and dispose of the application data pointer 5293** themselves rather than expecting SQLite to deal with it for them. 5294** This is different from every other SQLite interface. The inconsistency 5295** is unfortunate but cannot be changed without breaking backwards 5296** compatibility. 5297** 5298** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5299*/ 5300int sqlite3_create_collation( 5301 sqlite3*, 5302 const char *zName, 5303 int eTextRep, 5304 void *pArg, 5305 int(*xCompare)(void*,int,const void*,int,const void*) 5306); 5307int sqlite3_create_collation_v2( 5308 sqlite3*, 5309 const char *zName, 5310 int eTextRep, 5311 void *pArg, 5312 int(*xCompare)(void*,int,const void*,int,const void*), 5313 void(*xDestroy)(void*) 5314); 5315int sqlite3_create_collation16( 5316 sqlite3*, 5317 const void *zName, 5318 int eTextRep, 5319 void *pArg, 5320 int(*xCompare)(void*,int,const void*,int,const void*) 5321); 5322 5323/* 5324** CAPI3REF: Collation Needed Callbacks 5325** METHOD: sqlite3 5326** 5327** ^To avoid having to register all collation sequences before a database 5328** can be used, a single callback function may be registered with the 5329** [database connection] to be invoked whenever an undefined collation 5330** sequence is required. 5331** 5332** ^If the function is registered using the sqlite3_collation_needed() API, 5333** then it is passed the names of undefined collation sequences as strings 5334** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5335** the names are passed as UTF-16 in machine native byte order. 5336** ^A call to either function replaces the existing collation-needed callback. 5337** 5338** ^(When the callback is invoked, the first argument passed is a copy 5339** of the second argument to sqlite3_collation_needed() or 5340** sqlite3_collation_needed16(). The second argument is the database 5341** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5342** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5343** sequence function required. The fourth parameter is the name of the 5344** required collation sequence.)^ 5345** 5346** The callback function should register the desired collation using 5347** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5348** [sqlite3_create_collation_v2()]. 5349*/ 5350int sqlite3_collation_needed( 5351 sqlite3*, 5352 void*, 5353 void(*)(void*,sqlite3*,int eTextRep,const char*) 5354); 5355int sqlite3_collation_needed16( 5356 sqlite3*, 5357 void*, 5358 void(*)(void*,sqlite3*,int eTextRep,const void*) 5359); 5360 5361#ifdef SQLITE_HAS_CODEC 5362/* 5363** Specify the key for an encrypted database. This routine should be 5364** called right after sqlite3_open(). 5365** 5366** The code to implement this API is not available in the public release 5367** of SQLite. 5368*/ 5369int sqlite3_key( 5370 sqlite3 *db, /* Database to be rekeyed */ 5371 const void *pKey, int nKey /* The key */ 5372); 5373int sqlite3_key_v2( 5374 sqlite3 *db, /* Database to be rekeyed */ 5375 const char *zDbName, /* Name of the database */ 5376 const void *pKey, int nKey /* The key */ 5377); 5378 5379/* 5380** Change the key on an open database. If the current database is not 5381** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 5382** database is decrypted. 5383** 5384** The code to implement this API is not available in the public release 5385** of SQLite. 5386*/ 5387int sqlite3_rekey( 5388 sqlite3 *db, /* Database to be rekeyed */ 5389 const void *pKey, int nKey /* The new key */ 5390); 5391int sqlite3_rekey_v2( 5392 sqlite3 *db, /* Database to be rekeyed */ 5393 const char *zDbName, /* Name of the database */ 5394 const void *pKey, int nKey /* The new key */ 5395); 5396 5397/* 5398** Specify the activation key for a SEE database. Unless 5399** activated, none of the SEE routines will work. 5400*/ 5401void sqlite3_activate_see( 5402 const char *zPassPhrase /* Activation phrase */ 5403); 5404#endif 5405 5406#ifdef SQLITE_ENABLE_CEROD 5407/* 5408** Specify the activation key for a CEROD database. Unless 5409** activated, none of the CEROD routines will work. 5410*/ 5411void sqlite3_activate_cerod( 5412 const char *zPassPhrase /* Activation phrase */ 5413); 5414#endif 5415 5416/* 5417** CAPI3REF: Suspend Execution For A Short Time 5418** 5419** The sqlite3_sleep() function causes the current thread to suspend execution 5420** for at least a number of milliseconds specified in its parameter. 5421** 5422** If the operating system does not support sleep requests with 5423** millisecond time resolution, then the time will be rounded up to 5424** the nearest second. The number of milliseconds of sleep actually 5425** requested from the operating system is returned. 5426** 5427** ^SQLite implements this interface by calling the xSleep() 5428** method of the default [sqlite3_vfs] object. If the xSleep() method 5429** of the default VFS is not implemented correctly, or not implemented at 5430** all, then the behavior of sqlite3_sleep() may deviate from the description 5431** in the previous paragraphs. 5432*/ 5433int sqlite3_sleep(int); 5434 5435/* 5436** CAPI3REF: Name Of The Folder Holding Temporary Files 5437** 5438** ^(If this global variable is made to point to a string which is 5439** the name of a folder (a.k.a. directory), then all temporary files 5440** created by SQLite when using a built-in [sqlite3_vfs | VFS] 5441** will be placed in that directory.)^ ^If this variable 5442** is a NULL pointer, then SQLite performs a search for an appropriate 5443** temporary file directory. 5444** 5445** Applications are strongly discouraged from using this global variable. 5446** It is required to set a temporary folder on Windows Runtime (WinRT). 5447** But for all other platforms, it is highly recommended that applications 5448** neither read nor write this variable. This global variable is a relic 5449** that exists for backwards compatibility of legacy applications and should 5450** be avoided in new projects. 5451** 5452** It is not safe to read or modify this variable in more than one 5453** thread at a time. It is not safe to read or modify this variable 5454** if a [database connection] is being used at the same time in a separate 5455** thread. 5456** It is intended that this variable be set once 5457** as part of process initialization and before any SQLite interface 5458** routines have been called and that this variable remain unchanged 5459** thereafter. 5460** 5461** ^The [temp_store_directory pragma] may modify this variable and cause 5462** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5463** the [temp_store_directory pragma] always assumes that any string 5464** that this variable points to is held in memory obtained from 5465** [sqlite3_malloc] and the pragma may attempt to free that memory 5466** using [sqlite3_free]. 5467** Hence, if this variable is modified directly, either it should be 5468** made NULL or made to point to memory obtained from [sqlite3_malloc] 5469** or else the use of the [temp_store_directory pragma] should be avoided. 5470** Except when requested by the [temp_store_directory pragma], SQLite 5471** does not free the memory that sqlite3_temp_directory points to. If 5472** the application wants that memory to be freed, it must do 5473** so itself, taking care to only do so after all [database connection] 5474** objects have been destroyed. 5475** 5476** <b>Note to Windows Runtime users:</b> The temporary directory must be set 5477** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 5478** features that require the use of temporary files may fail. Here is an 5479** example of how to do this using C++ with the Windows Runtime: 5480** 5481** <blockquote><pre> 5482** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 5483** TemporaryFolder->Path->Data(); 5484** char zPathBuf[MAX_PATH + 1]; 5485** memset(zPathBuf, 0, sizeof(zPathBuf)); 5486** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 5487** NULL, NULL); 5488** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 5489** </pre></blockquote> 5490*/ 5491SQLITE_EXTERN char *sqlite3_temp_directory; 5492 5493/* 5494** CAPI3REF: Name Of The Folder Holding Database Files 5495** 5496** ^(If this global variable is made to point to a string which is 5497** the name of a folder (a.k.a. directory), then all database files 5498** specified with a relative pathname and created or accessed by 5499** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 5500** to be relative to that directory.)^ ^If this variable is a NULL 5501** pointer, then SQLite assumes that all database files specified 5502** with a relative pathname are relative to the current directory 5503** for the process. Only the windows VFS makes use of this global 5504** variable; it is ignored by the unix VFS. 5505** 5506** Changing the value of this variable while a database connection is 5507** open can result in a corrupt database. 5508** 5509** It is not safe to read or modify this variable in more than one 5510** thread at a time. It is not safe to read or modify this variable 5511** if a [database connection] is being used at the same time in a separate 5512** thread. 5513** It is intended that this variable be set once 5514** as part of process initialization and before any SQLite interface 5515** routines have been called and that this variable remain unchanged 5516** thereafter. 5517** 5518** ^The [data_store_directory pragma] may modify this variable and cause 5519** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5520** the [data_store_directory pragma] always assumes that any string 5521** that this variable points to is held in memory obtained from 5522** [sqlite3_malloc] and the pragma may attempt to free that memory 5523** using [sqlite3_free]. 5524** Hence, if this variable is modified directly, either it should be 5525** made NULL or made to point to memory obtained from [sqlite3_malloc] 5526** or else the use of the [data_store_directory pragma] should be avoided. 5527*/ 5528SQLITE_EXTERN char *sqlite3_data_directory; 5529 5530/* 5531** CAPI3REF: Win32 Specific Interface 5532** 5533** These interfaces are available only on Windows. The 5534** [sqlite3_win32_set_directory] interface is used to set the value associated 5535** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 5536** zValue, depending on the value of the type parameter. The zValue parameter 5537** should be NULL to cause the previous value to be freed via [sqlite3_free]; 5538** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 5539** prior to being used. The [sqlite3_win32_set_directory] interface returns 5540** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 5541** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 5542** [sqlite3_data_directory] variable is intended to act as a replacement for 5543** the current directory on the sub-platforms of Win32 where that concept is 5544** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 5545** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 5546** sqlite3_win32_set_directory interface except the string parameter must be 5547** UTF-8 or UTF-16, respectively. 5548*/ 5549int sqlite3_win32_set_directory( 5550 unsigned long type, /* Identifier for directory being set or reset */ 5551 void *zValue /* New value for directory being set or reset */ 5552); 5553int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 5554int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 5555 5556/* 5557** CAPI3REF: Win32 Directory Types 5558** 5559** These macros are only available on Windows. They define the allowed values 5560** for the type argument to the [sqlite3_win32_set_directory] interface. 5561*/ 5562#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 5563#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 5564 5565/* 5566** CAPI3REF: Test For Auto-Commit Mode 5567** KEYWORDS: {autocommit mode} 5568** METHOD: sqlite3 5569** 5570** ^The sqlite3_get_autocommit() interface returns non-zero or 5571** zero if the given database connection is or is not in autocommit mode, 5572** respectively. ^Autocommit mode is on by default. 5573** ^Autocommit mode is disabled by a [BEGIN] statement. 5574** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 5575** 5576** If certain kinds of errors occur on a statement within a multi-statement 5577** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 5578** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 5579** transaction might be rolled back automatically. The only way to 5580** find out whether SQLite automatically rolled back the transaction after 5581** an error is to use this function. 5582** 5583** If another thread changes the autocommit status of the database 5584** connection while this routine is running, then the return value 5585** is undefined. 5586*/ 5587int sqlite3_get_autocommit(sqlite3*); 5588 5589/* 5590** CAPI3REF: Find The Database Handle Of A Prepared Statement 5591** METHOD: sqlite3_stmt 5592** 5593** ^The sqlite3_db_handle interface returns the [database connection] handle 5594** to which a [prepared statement] belongs. ^The [database connection] 5595** returned by sqlite3_db_handle is the same [database connection] 5596** that was the first argument 5597** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 5598** create the statement in the first place. 5599*/ 5600sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 5601 5602/* 5603** CAPI3REF: Return The Filename For A Database Connection 5604** METHOD: sqlite3 5605** 5606** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 5607** associated with database N of connection D. ^The main database file 5608** has the name "main". If there is no attached database N on the database 5609** connection D, or if database N is a temporary or in-memory database, then 5610** a NULL pointer is returned. 5611** 5612** ^The filename returned by this function is the output of the 5613** xFullPathname method of the [VFS]. ^In other words, the filename 5614** will be an absolute pathname, even if the filename used 5615** to open the database originally was a URI or relative pathname. 5616*/ 5617const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 5618 5619/* 5620** CAPI3REF: Determine if a database is read-only 5621** METHOD: sqlite3 5622** 5623** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 5624** of connection D is read-only, 0 if it is read/write, or -1 if N is not 5625** the name of a database on connection D. 5626*/ 5627int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 5628 5629/* 5630** CAPI3REF: Find the next prepared statement 5631** METHOD: sqlite3 5632** 5633** ^This interface returns a pointer to the next [prepared statement] after 5634** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 5635** then this interface returns a pointer to the first prepared statement 5636** associated with the database connection pDb. ^If no prepared statement 5637** satisfies the conditions of this routine, it returns NULL. 5638** 5639** The [database connection] pointer D in a call to 5640** [sqlite3_next_stmt(D,S)] must refer to an open database 5641** connection and in particular must not be a NULL pointer. 5642*/ 5643sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 5644 5645/* 5646** CAPI3REF: Commit And Rollback Notification Callbacks 5647** METHOD: sqlite3 5648** 5649** ^The sqlite3_commit_hook() interface registers a callback 5650** function to be invoked whenever a transaction is [COMMIT | committed]. 5651** ^Any callback set by a previous call to sqlite3_commit_hook() 5652** for the same database connection is overridden. 5653** ^The sqlite3_rollback_hook() interface registers a callback 5654** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 5655** ^Any callback set by a previous call to sqlite3_rollback_hook() 5656** for the same database connection is overridden. 5657** ^The pArg argument is passed through to the callback. 5658** ^If the callback on a commit hook function returns non-zero, 5659** then the commit is converted into a rollback. 5660** 5661** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 5662** return the P argument from the previous call of the same function 5663** on the same [database connection] D, or NULL for 5664** the first call for each function on D. 5665** 5666** The commit and rollback hook callbacks are not reentrant. 5667** The callback implementation must not do anything that will modify 5668** the database connection that invoked the callback. Any actions 5669** to modify the database connection must be deferred until after the 5670** completion of the [sqlite3_step()] call that triggered the commit 5671** or rollback hook in the first place. 5672** Note that running any other SQL statements, including SELECT statements, 5673** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5674** the database connections for the meaning of "modify" in this paragraph. 5675** 5676** ^Registering a NULL function disables the callback. 5677** 5678** ^When the commit hook callback routine returns zero, the [COMMIT] 5679** operation is allowed to continue normally. ^If the commit hook 5680** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5681** ^The rollback hook is invoked on a rollback that results from a commit 5682** hook returning non-zero, just as it would be with any other rollback. 5683** 5684** ^For the purposes of this API, a transaction is said to have been 5685** rolled back if an explicit "ROLLBACK" statement is executed, or 5686** an error or constraint causes an implicit rollback to occur. 5687** ^The rollback callback is not invoked if a transaction is 5688** automatically rolled back because the database connection is closed. 5689** 5690** See also the [sqlite3_update_hook()] interface. 5691*/ 5692void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5693void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5694 5695/* 5696** CAPI3REF: Data Change Notification Callbacks 5697** METHOD: sqlite3 5698** 5699** ^The sqlite3_update_hook() interface registers a callback function 5700** with the [database connection] identified by the first argument 5701** to be invoked whenever a row is updated, inserted or deleted in 5702** a [rowid table]. 5703** ^Any callback set by a previous call to this function 5704** for the same database connection is overridden. 5705** 5706** ^The second argument is a pointer to the function to invoke when a 5707** row is updated, inserted or deleted in a rowid table. 5708** ^The first argument to the callback is a copy of the third argument 5709** to sqlite3_update_hook(). 5710** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 5711** or [SQLITE_UPDATE], depending on the operation that caused the callback 5712** to be invoked. 5713** ^The third and fourth arguments to the callback contain pointers to the 5714** database and table name containing the affected row. 5715** ^The final callback parameter is the [rowid] of the row. 5716** ^In the case of an update, this is the [rowid] after the update takes place. 5717** 5718** ^(The update hook is not invoked when internal system tables are 5719** modified (i.e. sqlite_master and sqlite_sequence).)^ 5720** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 5721** 5722** ^In the current implementation, the update hook 5723** is not invoked when conflicting rows are deleted because of an 5724** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 5725** invoked when rows are deleted using the [truncate optimization]. 5726** The exceptions defined in this paragraph might change in a future 5727** release of SQLite. 5728** 5729** The update hook implementation must not do anything that will modify 5730** the database connection that invoked the update hook. Any actions 5731** to modify the database connection must be deferred until after the 5732** completion of the [sqlite3_step()] call that triggered the update hook. 5733** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 5734** database connections for the meaning of "modify" in this paragraph. 5735** 5736** ^The sqlite3_update_hook(D,C,P) function 5737** returns the P argument from the previous call 5738** on the same [database connection] D, or NULL for 5739** the first call on D. 5740** 5741** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 5742** and [sqlite3_preupdate_hook()] interfaces. 5743*/ 5744void *sqlite3_update_hook( 5745 sqlite3*, 5746 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 5747 void* 5748); 5749 5750/* 5751** CAPI3REF: Enable Or Disable Shared Pager Cache 5752** 5753** ^(This routine enables or disables the sharing of the database cache 5754** and schema data structures between [database connection | connections] 5755** to the same database. Sharing is enabled if the argument is true 5756** and disabled if the argument is false.)^ 5757** 5758** ^Cache sharing is enabled and disabled for an entire process. 5759** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 5760** In prior versions of SQLite, 5761** sharing was enabled or disabled for each thread separately. 5762** 5763** ^(The cache sharing mode set by this interface effects all subsequent 5764** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 5765** Existing database connections continue use the sharing mode 5766** that was in effect at the time they were opened.)^ 5767** 5768** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 5769** successfully. An [error code] is returned otherwise.)^ 5770** 5771** ^Shared cache is disabled by default. But this might change in 5772** future releases of SQLite. Applications that care about shared 5773** cache setting should set it explicitly. 5774** 5775** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 5776** and will always return SQLITE_MISUSE. On those systems, 5777** shared cache mode should be enabled per-database connection via 5778** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 5779** 5780** This interface is threadsafe on processors where writing a 5781** 32-bit integer is atomic. 5782** 5783** See Also: [SQLite Shared-Cache Mode] 5784*/ 5785int sqlite3_enable_shared_cache(int); 5786 5787/* 5788** CAPI3REF: Attempt To Free Heap Memory 5789** 5790** ^The sqlite3_release_memory() interface attempts to free N bytes 5791** of heap memory by deallocating non-essential memory allocations 5792** held by the database library. Memory used to cache database 5793** pages to improve performance is an example of non-essential memory. 5794** ^sqlite3_release_memory() returns the number of bytes actually freed, 5795** which might be more or less than the amount requested. 5796** ^The sqlite3_release_memory() routine is a no-op returning zero 5797** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5798** 5799** See also: [sqlite3_db_release_memory()] 5800*/ 5801int sqlite3_release_memory(int); 5802 5803/* 5804** CAPI3REF: Free Memory Used By A Database Connection 5805** METHOD: sqlite3 5806** 5807** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 5808** memory as possible from database connection D. Unlike the 5809** [sqlite3_release_memory()] interface, this interface is in effect even 5810** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 5811** omitted. 5812** 5813** See also: [sqlite3_release_memory()] 5814*/ 5815int sqlite3_db_release_memory(sqlite3*); 5816 5817/* 5818** CAPI3REF: Impose A Limit On Heap Size 5819** 5820** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 5821** soft limit on the amount of heap memory that may be allocated by SQLite. 5822** ^SQLite strives to keep heap memory utilization below the soft heap 5823** limit by reducing the number of pages held in the page cache 5824** as heap memory usages approaches the limit. 5825** ^The soft heap limit is "soft" because even though SQLite strives to stay 5826** below the limit, it will exceed the limit rather than generate 5827** an [SQLITE_NOMEM] error. In other words, the soft heap limit 5828** is advisory only. 5829** 5830** ^The return value from sqlite3_soft_heap_limit64() is the size of 5831** the soft heap limit prior to the call, or negative in the case of an 5832** error. ^If the argument N is negative 5833** then no change is made to the soft heap limit. Hence, the current 5834** size of the soft heap limit can be determined by invoking 5835** sqlite3_soft_heap_limit64() with a negative argument. 5836** 5837** ^If the argument N is zero then the soft heap limit is disabled. 5838** 5839** ^(The soft heap limit is not enforced in the current implementation 5840** if one or more of following conditions are true: 5841** 5842** <ul> 5843** <li> The soft heap limit is set to zero. 5844** <li> Memory accounting is disabled using a combination of the 5845** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 5846** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 5847** <li> An alternative page cache implementation is specified using 5848** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 5849** <li> The page cache allocates from its own memory pool supplied 5850** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 5851** from the heap. 5852** </ul>)^ 5853** 5854** Beginning with SQLite [version 3.7.3] ([dateof:3.7.3]), 5855** the soft heap limit is enforced 5856** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 5857** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 5858** the soft heap limit is enforced on every memory allocation. Without 5859** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 5860** when memory is allocated by the page cache. Testing suggests that because 5861** the page cache is the predominate memory user in SQLite, most 5862** applications will achieve adequate soft heap limit enforcement without 5863** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5864** 5865** The circumstances under which SQLite will enforce the soft heap limit may 5866** changes in future releases of SQLite. 5867*/ 5868sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 5869 5870/* 5871** CAPI3REF: Deprecated Soft Heap Limit Interface 5872** DEPRECATED 5873** 5874** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 5875** interface. This routine is provided for historical compatibility 5876** only. All new applications should use the 5877** [sqlite3_soft_heap_limit64()] interface rather than this one. 5878*/ 5879SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 5880 5881 5882/* 5883** CAPI3REF: Extract Metadata About A Column Of A Table 5884** METHOD: sqlite3 5885** 5886** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 5887** information about column C of table T in database D 5888** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 5889** interface returns SQLITE_OK and fills in the non-NULL pointers in 5890** the final five arguments with appropriate values if the specified 5891** column exists. ^The sqlite3_table_column_metadata() interface returns 5892** SQLITE_ERROR and if the specified column does not exist. 5893** ^If the column-name parameter to sqlite3_table_column_metadata() is a 5894** NULL pointer, then this routine simply checks for the existence of the 5895** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 5896** does not. If the table name parameter T in a call to 5897** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 5898** undefined behavior. 5899** 5900** ^The column is identified by the second, third and fourth parameters to 5901** this function. ^(The second parameter is either the name of the database 5902** (i.e. "main", "temp", or an attached database) containing the specified 5903** table or NULL.)^ ^If it is NULL, then all attached databases are searched 5904** for the table using the same algorithm used by the database engine to 5905** resolve unqualified table references. 5906** 5907** ^The third and fourth parameters to this function are the table and column 5908** name of the desired column, respectively. 5909** 5910** ^Metadata is returned by writing to the memory locations passed as the 5th 5911** and subsequent parameters to this function. ^Any of these arguments may be 5912** NULL, in which case the corresponding element of metadata is omitted. 5913** 5914** ^(<blockquote> 5915** <table border="1"> 5916** <tr><th> Parameter <th> Output<br>Type <th> Description 5917** 5918** <tr><td> 5th <td> const char* <td> Data type 5919** <tr><td> 6th <td> const char* <td> Name of default collation sequence 5920** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 5921** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 5922** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 5923** </table> 5924** </blockquote>)^ 5925** 5926** ^The memory pointed to by the character pointers returned for the 5927** declaration type and collation sequence is valid until the next 5928** call to any SQLite API function. 5929** 5930** ^If the specified table is actually a view, an [error code] is returned. 5931** 5932** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 5933** is not a [WITHOUT ROWID] table and an 5934** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 5935** parameters are set for the explicitly declared column. ^(If there is no 5936** [INTEGER PRIMARY KEY] column, then the outputs 5937** for the [rowid] are set as follows: 5938** 5939** <pre> 5940** data type: "INTEGER" 5941** collation sequence: "BINARY" 5942** not null: 0 5943** primary key: 1 5944** auto increment: 0 5945** </pre>)^ 5946** 5947** ^This function causes all database schemas to be read from disk and 5948** parsed, if that has not already been done, and returns an error if 5949** any errors are encountered while loading the schema. 5950*/ 5951int sqlite3_table_column_metadata( 5952 sqlite3 *db, /* Connection handle */ 5953 const char *zDbName, /* Database name or NULL */ 5954 const char *zTableName, /* Table name */ 5955 const char *zColumnName, /* Column name */ 5956 char const **pzDataType, /* OUTPUT: Declared data type */ 5957 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 5958 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 5959 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 5960 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 5961); 5962 5963/* 5964** CAPI3REF: Load An Extension 5965** METHOD: sqlite3 5966** 5967** ^This interface loads an SQLite extension library from the named file. 5968** 5969** ^The sqlite3_load_extension() interface attempts to load an 5970** [SQLite extension] library contained in the file zFile. If 5971** the file cannot be loaded directly, attempts are made to load 5972** with various operating-system specific extensions added. 5973** So for example, if "samplelib" cannot be loaded, then names like 5974** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 5975** be tried also. 5976** 5977** ^The entry point is zProc. 5978** ^(zProc may be 0, in which case SQLite will try to come up with an 5979** entry point name on its own. It first tries "sqlite3_extension_init". 5980** If that does not work, it constructs a name "sqlite3_X_init" where the 5981** X is consists of the lower-case equivalent of all ASCII alphabetic 5982** characters in the filename from the last "/" to the first following 5983** "." and omitting any initial "lib".)^ 5984** ^The sqlite3_load_extension() interface returns 5985** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 5986** ^If an error occurs and pzErrMsg is not 0, then the 5987** [sqlite3_load_extension()] interface shall attempt to 5988** fill *pzErrMsg with error message text stored in memory 5989** obtained from [sqlite3_malloc()]. The calling function 5990** should free this memory by calling [sqlite3_free()]. 5991** 5992** ^Extension loading must be enabled using 5993** [sqlite3_enable_load_extension()] or 5994** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 5995** prior to calling this API, 5996** otherwise an error will be returned. 5997** 5998** <b>Security warning:</b> It is recommended that the 5999** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 6000** interface. The use of the [sqlite3_enable_load_extension()] interface 6001** should be avoided. This will keep the SQL function [load_extension()] 6002** disabled and prevent SQL injections from giving attackers 6003** access to extension loading capabilities. 6004** 6005** See also the [load_extension() SQL function]. 6006*/ 6007int sqlite3_load_extension( 6008 sqlite3 *db, /* Load the extension into this database connection */ 6009 const char *zFile, /* Name of the shared library containing extension */ 6010 const char *zProc, /* Entry point. Derived from zFile if 0 */ 6011 char **pzErrMsg /* Put error message here if not 0 */ 6012); 6013 6014/* 6015** CAPI3REF: Enable Or Disable Extension Loading 6016** METHOD: sqlite3 6017** 6018** ^So as not to open security holes in older applications that are 6019** unprepared to deal with [extension loading], and as a means of disabling 6020** [extension loading] while evaluating user-entered SQL, the following API 6021** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 6022** 6023** ^Extension loading is off by default. 6024** ^Call the sqlite3_enable_load_extension() routine with onoff==1 6025** to turn extension loading on and call it with onoff==0 to turn 6026** it back off again. 6027** 6028** ^This interface enables or disables both the C-API 6029** [sqlite3_load_extension()] and the SQL function [load_extension()]. 6030** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 6031** to enable or disable only the C-API.)^ 6032** 6033** <b>Security warning:</b> It is recommended that extension loading 6034** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 6035** rather than this interface, so the [load_extension()] SQL function 6036** remains disabled. This will prevent SQL injections from giving attackers 6037** access to extension loading capabilities. 6038*/ 6039int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 6040 6041/* 6042** CAPI3REF: Automatically Load Statically Linked Extensions 6043** 6044** ^This interface causes the xEntryPoint() function to be invoked for 6045** each new [database connection] that is created. The idea here is that 6046** xEntryPoint() is the entry point for a statically linked [SQLite extension] 6047** that is to be automatically loaded into all new database connections. 6048** 6049** ^(Even though the function prototype shows that xEntryPoint() takes 6050** no arguments and returns void, SQLite invokes xEntryPoint() with three 6051** arguments and expects an integer result as if the signature of the 6052** entry point where as follows: 6053** 6054** <blockquote><pre> 6055** int xEntryPoint( 6056** sqlite3 *db, 6057** const char **pzErrMsg, 6058** const struct sqlite3_api_routines *pThunk 6059** ); 6060** </pre></blockquote>)^ 6061** 6062** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 6063** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 6064** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 6065** is NULL before calling the xEntryPoint(). ^SQLite will invoke 6066** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 6067** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 6068** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 6069** 6070** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 6071** on the list of automatic extensions is a harmless no-op. ^No entry point 6072** will be called more than once for each database connection that is opened. 6073** 6074** See also: [sqlite3_reset_auto_extension()] 6075** and [sqlite3_cancel_auto_extension()] 6076*/ 6077int sqlite3_auto_extension(void(*xEntryPoint)(void)); 6078 6079/* 6080** CAPI3REF: Cancel Automatic Extension Loading 6081** 6082** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 6083** initialization routine X that was registered using a prior call to 6084** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 6085** routine returns 1 if initialization routine X was successfully 6086** unregistered and it returns 0 if X was not on the list of initialization 6087** routines. 6088*/ 6089int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 6090 6091/* 6092** CAPI3REF: Reset Automatic Extension Loading 6093** 6094** ^This interface disables all automatic extensions previously 6095** registered using [sqlite3_auto_extension()]. 6096*/ 6097void sqlite3_reset_auto_extension(void); 6098 6099/* 6100** The interface to the virtual-table mechanism is currently considered 6101** to be experimental. The interface might change in incompatible ways. 6102** If this is a problem for you, do not use the interface at this time. 6103** 6104** When the virtual-table mechanism stabilizes, we will declare the 6105** interface fixed, support it indefinitely, and remove this comment. 6106*/ 6107 6108/* 6109** Structures used by the virtual table interface 6110*/ 6111typedef struct sqlite3_vtab sqlite3_vtab; 6112typedef struct sqlite3_index_info sqlite3_index_info; 6113typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 6114typedef struct sqlite3_module sqlite3_module; 6115 6116/* 6117** CAPI3REF: Virtual Table Object 6118** KEYWORDS: sqlite3_module {virtual table module} 6119** 6120** This structure, sometimes called a "virtual table module", 6121** defines the implementation of a [virtual tables]. 6122** This structure consists mostly of methods for the module. 6123** 6124** ^A virtual table module is created by filling in a persistent 6125** instance of this structure and passing a pointer to that instance 6126** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 6127** ^The registration remains valid until it is replaced by a different 6128** module or until the [database connection] closes. The content 6129** of this structure must not change while it is registered with 6130** any database connection. 6131*/ 6132struct sqlite3_module { 6133 int iVersion; 6134 int (*xCreate)(sqlite3*, void *pAux, 6135 int argc, const char *const*argv, 6136 sqlite3_vtab **ppVTab, char**); 6137 int (*xConnect)(sqlite3*, void *pAux, 6138 int argc, const char *const*argv, 6139 sqlite3_vtab **ppVTab, char**); 6140 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 6141 int (*xDisconnect)(sqlite3_vtab *pVTab); 6142 int (*xDestroy)(sqlite3_vtab *pVTab); 6143 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 6144 int (*xClose)(sqlite3_vtab_cursor*); 6145 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 6146 int argc, sqlite3_value **argv); 6147 int (*xNext)(sqlite3_vtab_cursor*); 6148 int (*xEof)(sqlite3_vtab_cursor*); 6149 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 6150 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 6151 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 6152 int (*xBegin)(sqlite3_vtab *pVTab); 6153 int (*xSync)(sqlite3_vtab *pVTab); 6154 int (*xCommit)(sqlite3_vtab *pVTab); 6155 int (*xRollback)(sqlite3_vtab *pVTab); 6156 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 6157 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 6158 void **ppArg); 6159 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 6160 /* The methods above are in version 1 of the sqlite_module object. Those 6161 ** below are for version 2 and greater. */ 6162 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 6163 int (*xRelease)(sqlite3_vtab *pVTab, int); 6164 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 6165}; 6166 6167/* 6168** CAPI3REF: Virtual Table Indexing Information 6169** KEYWORDS: sqlite3_index_info 6170** 6171** The sqlite3_index_info structure and its substructures is used as part 6172** of the [virtual table] interface to 6173** pass information into and receive the reply from the [xBestIndex] 6174** method of a [virtual table module]. The fields under **Inputs** are the 6175** inputs to xBestIndex and are read-only. xBestIndex inserts its 6176** results into the **Outputs** fields. 6177** 6178** ^(The aConstraint[] array records WHERE clause constraints of the form: 6179** 6180** <blockquote>column OP expr</blockquote> 6181** 6182** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 6183** stored in aConstraint[].op using one of the 6184** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 6185** ^(The index of the column is stored in 6186** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 6187** expr on the right-hand side can be evaluated (and thus the constraint 6188** is usable) and false if it cannot.)^ 6189** 6190** ^The optimizer automatically inverts terms of the form "expr OP column" 6191** and makes other simplifications to the WHERE clause in an attempt to 6192** get as many WHERE clause terms into the form shown above as possible. 6193** ^The aConstraint[] array only reports WHERE clause terms that are 6194** relevant to the particular virtual table being queried. 6195** 6196** ^Information about the ORDER BY clause is stored in aOrderBy[]. 6197** ^Each term of aOrderBy records a column of the ORDER BY clause. 6198** 6199** The colUsed field indicates which columns of the virtual table may be 6200** required by the current scan. Virtual table columns are numbered from 6201** zero in the order in which they appear within the CREATE TABLE statement 6202** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 6203** the corresponding bit is set within the colUsed mask if the column may be 6204** required by SQLite. If the table has at least 64 columns and any column 6205** to the right of the first 63 is required, then bit 63 of colUsed is also 6206** set. In other words, column iCol may be required if the expression 6207** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 6208** non-zero. 6209** 6210** The [xBestIndex] method must fill aConstraintUsage[] with information 6211** about what parameters to pass to xFilter. ^If argvIndex>0 then 6212** the right-hand side of the corresponding aConstraint[] is evaluated 6213** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 6214** is true, then the constraint is assumed to be fully handled by the 6215** virtual table and is not checked again by SQLite.)^ 6216** 6217** ^The idxNum and idxPtr values are recorded and passed into the 6218** [xFilter] method. 6219** ^[sqlite3_free()] is used to free idxPtr if and only if 6220** needToFreeIdxPtr is true. 6221** 6222** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 6223** the correct order to satisfy the ORDER BY clause so that no separate 6224** sorting step is required. 6225** 6226** ^The estimatedCost value is an estimate of the cost of a particular 6227** strategy. A cost of N indicates that the cost of the strategy is similar 6228** to a linear scan of an SQLite table with N rows. A cost of log(N) 6229** indicates that the expense of the operation is similar to that of a 6230** binary search on a unique indexed field of an SQLite table with N rows. 6231** 6232** ^The estimatedRows value is an estimate of the number of rows that 6233** will be returned by the strategy. 6234** 6235** The xBestIndex method may optionally populate the idxFlags field with a 6236** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 6237** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 6238** assumes that the strategy may visit at most one row. 6239** 6240** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 6241** SQLite also assumes that if a call to the xUpdate() method is made as 6242** part of the same statement to delete or update a virtual table row and the 6243** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 6244** any database changes. In other words, if the xUpdate() returns 6245** SQLITE_CONSTRAINT, the database contents must be exactly as they were 6246** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 6247** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 6248** the xUpdate method are automatically rolled back by SQLite. 6249** 6250** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 6251** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 6252** If a virtual table extension is 6253** used with an SQLite version earlier than 3.8.2, the results of attempting 6254** to read or write the estimatedRows field are undefined (but are likely 6255** to included crashing the application). The estimatedRows field should 6256** therefore only be used if [sqlite3_libversion_number()] returns a 6257** value greater than or equal to 3008002. Similarly, the idxFlags field 6258** was added for [version 3.9.0] ([dateof:3.9.0]). 6259** It may therefore only be used if 6260** sqlite3_libversion_number() returns a value greater than or equal to 6261** 3009000. 6262*/ 6263struct sqlite3_index_info { 6264 /* Inputs */ 6265 int nConstraint; /* Number of entries in aConstraint */ 6266 struct sqlite3_index_constraint { 6267 int iColumn; /* Column constrained. -1 for ROWID */ 6268 unsigned char op; /* Constraint operator */ 6269 unsigned char usable; /* True if this constraint is usable */ 6270 int iTermOffset; /* Used internally - xBestIndex should ignore */ 6271 } *aConstraint; /* Table of WHERE clause constraints */ 6272 int nOrderBy; /* Number of terms in the ORDER BY clause */ 6273 struct sqlite3_index_orderby { 6274 int iColumn; /* Column number */ 6275 unsigned char desc; /* True for DESC. False for ASC. */ 6276 } *aOrderBy; /* The ORDER BY clause */ 6277 /* Outputs */ 6278 struct sqlite3_index_constraint_usage { 6279 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 6280 unsigned char omit; /* Do not code a test for this constraint */ 6281 } *aConstraintUsage; 6282 int idxNum; /* Number used to identify the index */ 6283 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 6284 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 6285 int orderByConsumed; /* True if output is already ordered */ 6286 double estimatedCost; /* Estimated cost of using this index */ 6287 /* Fields below are only available in SQLite 3.8.2 and later */ 6288 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 6289 /* Fields below are only available in SQLite 3.9.0 and later */ 6290 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 6291 /* Fields below are only available in SQLite 3.10.0 and later */ 6292 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 6293}; 6294 6295/* 6296** CAPI3REF: Virtual Table Scan Flags 6297** 6298** Virtual table implementations are allowed to set the 6299** [sqlite3_index_info].idxFlags field to some combination of 6300** these bits. 6301*/ 6302#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 6303 6304/* 6305** CAPI3REF: Virtual Table Constraint Operator Codes 6306** 6307** These macros defined the allowed values for the 6308** [sqlite3_index_info].aConstraint[].op field. Each value represents 6309** an operator that is part of a constraint term in the wHERE clause of 6310** a query that uses a [virtual table]. 6311*/ 6312#define SQLITE_INDEX_CONSTRAINT_EQ 2 6313#define SQLITE_INDEX_CONSTRAINT_GT 4 6314#define SQLITE_INDEX_CONSTRAINT_LE 8 6315#define SQLITE_INDEX_CONSTRAINT_LT 16 6316#define SQLITE_INDEX_CONSTRAINT_GE 32 6317#define SQLITE_INDEX_CONSTRAINT_MATCH 64 6318#define SQLITE_INDEX_CONSTRAINT_LIKE 65 6319#define SQLITE_INDEX_CONSTRAINT_GLOB 66 6320#define SQLITE_INDEX_CONSTRAINT_REGEXP 67 6321#define SQLITE_INDEX_CONSTRAINT_NE 68 6322#define SQLITE_INDEX_CONSTRAINT_ISNOT 69 6323#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 6324#define SQLITE_INDEX_CONSTRAINT_ISNULL 71 6325#define SQLITE_INDEX_CONSTRAINT_IS 72 6326 6327/* 6328** CAPI3REF: Register A Virtual Table Implementation 6329** METHOD: sqlite3 6330** 6331** ^These routines are used to register a new [virtual table module] name. 6332** ^Module names must be registered before 6333** creating a new [virtual table] using the module and before using a 6334** preexisting [virtual table] for the module. 6335** 6336** ^The module name is registered on the [database connection] specified 6337** by the first parameter. ^The name of the module is given by the 6338** second parameter. ^The third parameter is a pointer to 6339** the implementation of the [virtual table module]. ^The fourth 6340** parameter is an arbitrary client data pointer that is passed through 6341** into the [xCreate] and [xConnect] methods of the virtual table module 6342** when a new virtual table is be being created or reinitialized. 6343** 6344** ^The sqlite3_create_module_v2() interface has a fifth parameter which 6345** is a pointer to a destructor for the pClientData. ^SQLite will 6346** invoke the destructor function (if it is not NULL) when SQLite 6347** no longer needs the pClientData pointer. ^The destructor will also 6348** be invoked if the call to sqlite3_create_module_v2() fails. 6349** ^The sqlite3_create_module() 6350** interface is equivalent to sqlite3_create_module_v2() with a NULL 6351** destructor. 6352*/ 6353int sqlite3_create_module( 6354 sqlite3 *db, /* SQLite connection to register module with */ 6355 const char *zName, /* Name of the module */ 6356 const sqlite3_module *p, /* Methods for the module */ 6357 void *pClientData /* Client data for xCreate/xConnect */ 6358); 6359int sqlite3_create_module_v2( 6360 sqlite3 *db, /* SQLite connection to register module with */ 6361 const char *zName, /* Name of the module */ 6362 const sqlite3_module *p, /* Methods for the module */ 6363 void *pClientData, /* Client data for xCreate/xConnect */ 6364 void(*xDestroy)(void*) /* Module destructor function */ 6365); 6366 6367/* 6368** CAPI3REF: Virtual Table Instance Object 6369** KEYWORDS: sqlite3_vtab 6370** 6371** Every [virtual table module] implementation uses a subclass 6372** of this object to describe a particular instance 6373** of the [virtual table]. Each subclass will 6374** be tailored to the specific needs of the module implementation. 6375** The purpose of this superclass is to define certain fields that are 6376** common to all module implementations. 6377** 6378** ^Virtual tables methods can set an error message by assigning a 6379** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 6380** take care that any prior string is freed by a call to [sqlite3_free()] 6381** prior to assigning a new string to zErrMsg. ^After the error message 6382** is delivered up to the client application, the string will be automatically 6383** freed by sqlite3_free() and the zErrMsg field will be zeroed. 6384*/ 6385struct sqlite3_vtab { 6386 const sqlite3_module *pModule; /* The module for this virtual table */ 6387 int nRef; /* Number of open cursors */ 6388 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 6389 /* Virtual table implementations will typically add additional fields */ 6390}; 6391 6392/* 6393** CAPI3REF: Virtual Table Cursor Object 6394** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 6395** 6396** Every [virtual table module] implementation uses a subclass of the 6397** following structure to describe cursors that point into the 6398** [virtual table] and are used 6399** to loop through the virtual table. Cursors are created using the 6400** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 6401** by the [sqlite3_module.xClose | xClose] method. Cursors are used 6402** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 6403** of the module. Each module implementation will define 6404** the content of a cursor structure to suit its own needs. 6405** 6406** This superclass exists in order to define fields of the cursor that 6407** are common to all implementations. 6408*/ 6409struct sqlite3_vtab_cursor { 6410 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 6411 /* Virtual table implementations will typically add additional fields */ 6412}; 6413 6414/* 6415** CAPI3REF: Declare The Schema Of A Virtual Table 6416** 6417** ^The [xCreate] and [xConnect] methods of a 6418** [virtual table module] call this interface 6419** to declare the format (the names and datatypes of the columns) of 6420** the virtual tables they implement. 6421*/ 6422int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 6423 6424/* 6425** CAPI3REF: Overload A Function For A Virtual Table 6426** METHOD: sqlite3 6427** 6428** ^(Virtual tables can provide alternative implementations of functions 6429** using the [xFindFunction] method of the [virtual table module]. 6430** But global versions of those functions 6431** must exist in order to be overloaded.)^ 6432** 6433** ^(This API makes sure a global version of a function with a particular 6434** name and number of parameters exists. If no such function exists 6435** before this API is called, a new function is created.)^ ^The implementation 6436** of the new function always causes an exception to be thrown. So 6437** the new function is not good for anything by itself. Its only 6438** purpose is to be a placeholder function that can be overloaded 6439** by a [virtual table]. 6440*/ 6441int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 6442 6443/* 6444** The interface to the virtual-table mechanism defined above (back up 6445** to a comment remarkably similar to this one) is currently considered 6446** to be experimental. The interface might change in incompatible ways. 6447** If this is a problem for you, do not use the interface at this time. 6448** 6449** When the virtual-table mechanism stabilizes, we will declare the 6450** interface fixed, support it indefinitely, and remove this comment. 6451*/ 6452 6453/* 6454** CAPI3REF: A Handle To An Open BLOB 6455** KEYWORDS: {BLOB handle} {BLOB handles} 6456** 6457** An instance of this object represents an open BLOB on which 6458** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 6459** ^Objects of this type are created by [sqlite3_blob_open()] 6460** and destroyed by [sqlite3_blob_close()]. 6461** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 6462** can be used to read or write small subsections of the BLOB. 6463** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 6464*/ 6465typedef struct sqlite3_blob sqlite3_blob; 6466 6467/* 6468** CAPI3REF: Open A BLOB For Incremental I/O 6469** METHOD: sqlite3 6470** CONSTRUCTOR: sqlite3_blob 6471** 6472** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 6473** in row iRow, column zColumn, table zTable in database zDb; 6474** in other words, the same BLOB that would be selected by: 6475** 6476** <pre> 6477** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 6478** </pre>)^ 6479** 6480** ^(Parameter zDb is not the filename that contains the database, but 6481** rather the symbolic name of the database. For attached databases, this is 6482** the name that appears after the AS keyword in the [ATTACH] statement. 6483** For the main database file, the database name is "main". For TEMP 6484** tables, the database name is "temp".)^ 6485** 6486** ^If the flags parameter is non-zero, then the BLOB is opened for read 6487** and write access. ^If the flags parameter is zero, the BLOB is opened for 6488** read-only access. 6489** 6490** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 6491** in *ppBlob. Otherwise an [error code] is returned and, unless the error 6492** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 6493** the API is not misused, it is always safe to call [sqlite3_blob_close()] 6494** on *ppBlob after this function it returns. 6495** 6496** This function fails with SQLITE_ERROR if any of the following are true: 6497** <ul> 6498** <li> ^(Database zDb does not exist)^, 6499** <li> ^(Table zTable does not exist within database zDb)^, 6500** <li> ^(Table zTable is a WITHOUT ROWID table)^, 6501** <li> ^(Column zColumn does not exist)^, 6502** <li> ^(Row iRow is not present in the table)^, 6503** <li> ^(The specified column of row iRow contains a value that is not 6504** a TEXT or BLOB value)^, 6505** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 6506** constraint and the blob is being opened for read/write access)^, 6507** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 6508** column zColumn is part of a [child key] definition and the blob is 6509** being opened for read/write access)^. 6510** </ul> 6511** 6512** ^Unless it returns SQLITE_MISUSE, this function sets the 6513** [database connection] error code and message accessible via 6514** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6515** 6516** A BLOB referenced by sqlite3_blob_open() may be read using the 6517** [sqlite3_blob_read()] interface and modified by using 6518** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 6519** different row of the same table using the [sqlite3_blob_reopen()] 6520** interface. However, the column, table, or database of a [BLOB handle] 6521** cannot be changed after the [BLOB handle] is opened. 6522** 6523** ^(If the row that a BLOB handle points to is modified by an 6524** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 6525** then the BLOB handle is marked as "expired". 6526** This is true if any column of the row is changed, even a column 6527** other than the one the BLOB handle is open on.)^ 6528** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 6529** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 6530** ^(Changes written into a BLOB prior to the BLOB expiring are not 6531** rolled back by the expiration of the BLOB. Such changes will eventually 6532** commit if the transaction continues to completion.)^ 6533** 6534** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 6535** the opened blob. ^The size of a blob may not be changed by this 6536** interface. Use the [UPDATE] SQL command to change the size of a 6537** blob. 6538** 6539** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 6540** and the built-in [zeroblob] SQL function may be used to create a 6541** zero-filled blob to read or write using the incremental-blob interface. 6542** 6543** To avoid a resource leak, every open [BLOB handle] should eventually 6544** be released by a call to [sqlite3_blob_close()]. 6545** 6546** See also: [sqlite3_blob_close()], 6547** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 6548** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 6549*/ 6550int sqlite3_blob_open( 6551 sqlite3*, 6552 const char *zDb, 6553 const char *zTable, 6554 const char *zColumn, 6555 sqlite3_int64 iRow, 6556 int flags, 6557 sqlite3_blob **ppBlob 6558); 6559 6560/* 6561** CAPI3REF: Move a BLOB Handle to a New Row 6562** METHOD: sqlite3_blob 6563** 6564** ^This function is used to move an existing [BLOB handle] so that it points 6565** to a different row of the same database table. ^The new row is identified 6566** by the rowid value passed as the second argument. Only the row can be 6567** changed. ^The database, table and column on which the blob handle is open 6568** remain the same. Moving an existing [BLOB handle] to a new row is 6569** faster than closing the existing handle and opening a new one. 6570** 6571** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 6572** it must exist and there must be either a blob or text value stored in 6573** the nominated column.)^ ^If the new row is not present in the table, or if 6574** it does not contain a blob or text value, or if another error occurs, an 6575** SQLite error code is returned and the blob handle is considered aborted. 6576** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 6577** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 6578** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 6579** always returns zero. 6580** 6581** ^This function sets the database handle error code and message. 6582*/ 6583int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 6584 6585/* 6586** CAPI3REF: Close A BLOB Handle 6587** DESTRUCTOR: sqlite3_blob 6588** 6589** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 6590** unconditionally. Even if this routine returns an error code, the 6591** handle is still closed.)^ 6592** 6593** ^If the blob handle being closed was opened for read-write access, and if 6594** the database is in auto-commit mode and there are no other open read-write 6595** blob handles or active write statements, the current transaction is 6596** committed. ^If an error occurs while committing the transaction, an error 6597** code is returned and the transaction rolled back. 6598** 6599** Calling this function with an argument that is not a NULL pointer or an 6600** open blob handle results in undefined behaviour. ^Calling this routine 6601** with a null pointer (such as would be returned by a failed call to 6602** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 6603** is passed a valid open blob handle, the values returned by the 6604** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 6605*/ 6606int sqlite3_blob_close(sqlite3_blob *); 6607 6608/* 6609** CAPI3REF: Return The Size Of An Open BLOB 6610** METHOD: sqlite3_blob 6611** 6612** ^Returns the size in bytes of the BLOB accessible via the 6613** successfully opened [BLOB handle] in its only argument. ^The 6614** incremental blob I/O routines can only read or overwriting existing 6615** blob content; they cannot change the size of a blob. 6616** 6617** This routine only works on a [BLOB handle] which has been created 6618** by a prior successful call to [sqlite3_blob_open()] and which has not 6619** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6620** to this routine results in undefined and probably undesirable behavior. 6621*/ 6622int sqlite3_blob_bytes(sqlite3_blob *); 6623 6624/* 6625** CAPI3REF: Read Data From A BLOB Incrementally 6626** METHOD: sqlite3_blob 6627** 6628** ^(This function is used to read data from an open [BLOB handle] into a 6629** caller-supplied buffer. N bytes of data are copied into buffer Z 6630** from the open BLOB, starting at offset iOffset.)^ 6631** 6632** ^If offset iOffset is less than N bytes from the end of the BLOB, 6633** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 6634** less than zero, [SQLITE_ERROR] is returned and no data is read. 6635** ^The size of the blob (and hence the maximum value of N+iOffset) 6636** can be determined using the [sqlite3_blob_bytes()] interface. 6637** 6638** ^An attempt to read from an expired [BLOB handle] fails with an 6639** error code of [SQLITE_ABORT]. 6640** 6641** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 6642** Otherwise, an [error code] or an [extended error code] is returned.)^ 6643** 6644** This routine only works on a [BLOB handle] which has been created 6645** by a prior successful call to [sqlite3_blob_open()] and which has not 6646** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6647** to this routine results in undefined and probably undesirable behavior. 6648** 6649** See also: [sqlite3_blob_write()]. 6650*/ 6651int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 6652 6653/* 6654** CAPI3REF: Write Data Into A BLOB Incrementally 6655** METHOD: sqlite3_blob 6656** 6657** ^(This function is used to write data into an open [BLOB handle] from a 6658** caller-supplied buffer. N bytes of data are copied from the buffer Z 6659** into the open BLOB, starting at offset iOffset.)^ 6660** 6661** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 6662** Otherwise, an [error code] or an [extended error code] is returned.)^ 6663** ^Unless SQLITE_MISUSE is returned, this function sets the 6664** [database connection] error code and message accessible via 6665** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6666** 6667** ^If the [BLOB handle] passed as the first argument was not opened for 6668** writing (the flags parameter to [sqlite3_blob_open()] was zero), 6669** this function returns [SQLITE_READONLY]. 6670** 6671** This function may only modify the contents of the BLOB; it is 6672** not possible to increase the size of a BLOB using this API. 6673** ^If offset iOffset is less than N bytes from the end of the BLOB, 6674** [SQLITE_ERROR] is returned and no data is written. The size of the 6675** BLOB (and hence the maximum value of N+iOffset) can be determined 6676** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 6677** than zero [SQLITE_ERROR] is returned and no data is written. 6678** 6679** ^An attempt to write to an expired [BLOB handle] fails with an 6680** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 6681** before the [BLOB handle] expired are not rolled back by the 6682** expiration of the handle, though of course those changes might 6683** have been overwritten by the statement that expired the BLOB handle 6684** or by other independent statements. 6685** 6686** This routine only works on a [BLOB handle] which has been created 6687** by a prior successful call to [sqlite3_blob_open()] and which has not 6688** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6689** to this routine results in undefined and probably undesirable behavior. 6690** 6691** See also: [sqlite3_blob_read()]. 6692*/ 6693int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 6694 6695/* 6696** CAPI3REF: Virtual File System Objects 6697** 6698** A virtual filesystem (VFS) is an [sqlite3_vfs] object 6699** that SQLite uses to interact 6700** with the underlying operating system. Most SQLite builds come with a 6701** single default VFS that is appropriate for the host computer. 6702** New VFSes can be registered and existing VFSes can be unregistered. 6703** The following interfaces are provided. 6704** 6705** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 6706** ^Names are case sensitive. 6707** ^Names are zero-terminated UTF-8 strings. 6708** ^If there is no match, a NULL pointer is returned. 6709** ^If zVfsName is NULL then the default VFS is returned. 6710** 6711** ^New VFSes are registered with sqlite3_vfs_register(). 6712** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 6713** ^The same VFS can be registered multiple times without injury. 6714** ^To make an existing VFS into the default VFS, register it again 6715** with the makeDflt flag set. If two different VFSes with the 6716** same name are registered, the behavior is undefined. If a 6717** VFS is registered with a name that is NULL or an empty string, 6718** then the behavior is undefined. 6719** 6720** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 6721** ^(If the default VFS is unregistered, another VFS is chosen as 6722** the default. The choice for the new VFS is arbitrary.)^ 6723*/ 6724sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 6725int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 6726int sqlite3_vfs_unregister(sqlite3_vfs*); 6727 6728/* 6729** CAPI3REF: Mutexes 6730** 6731** The SQLite core uses these routines for thread 6732** synchronization. Though they are intended for internal 6733** use by SQLite, code that links against SQLite is 6734** permitted to use any of these routines. 6735** 6736** The SQLite source code contains multiple implementations 6737** of these mutex routines. An appropriate implementation 6738** is selected automatically at compile-time. The following 6739** implementations are available in the SQLite core: 6740** 6741** <ul> 6742** <li> SQLITE_MUTEX_PTHREADS 6743** <li> SQLITE_MUTEX_W32 6744** <li> SQLITE_MUTEX_NOOP 6745** </ul> 6746** 6747** The SQLITE_MUTEX_NOOP implementation is a set of routines 6748** that does no real locking and is appropriate for use in 6749** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 6750** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 6751** and Windows. 6752** 6753** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 6754** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 6755** implementation is included with the library. In this case the 6756** application must supply a custom mutex implementation using the 6757** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 6758** before calling sqlite3_initialize() or any other public sqlite3_ 6759** function that calls sqlite3_initialize(). 6760** 6761** ^The sqlite3_mutex_alloc() routine allocates a new 6762** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 6763** routine returns NULL if it is unable to allocate the requested 6764** mutex. The argument to sqlite3_mutex_alloc() must one of these 6765** integer constants: 6766** 6767** <ul> 6768** <li> SQLITE_MUTEX_FAST 6769** <li> SQLITE_MUTEX_RECURSIVE 6770** <li> SQLITE_MUTEX_STATIC_MASTER 6771** <li> SQLITE_MUTEX_STATIC_MEM 6772** <li> SQLITE_MUTEX_STATIC_OPEN 6773** <li> SQLITE_MUTEX_STATIC_PRNG 6774** <li> SQLITE_MUTEX_STATIC_LRU 6775** <li> SQLITE_MUTEX_STATIC_PMEM 6776** <li> SQLITE_MUTEX_STATIC_APP1 6777** <li> SQLITE_MUTEX_STATIC_APP2 6778** <li> SQLITE_MUTEX_STATIC_APP3 6779** <li> SQLITE_MUTEX_STATIC_VFS1 6780** <li> SQLITE_MUTEX_STATIC_VFS2 6781** <li> SQLITE_MUTEX_STATIC_VFS3 6782** </ul> 6783** 6784** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 6785** cause sqlite3_mutex_alloc() to create 6786** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 6787** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 6788** The mutex implementation does not need to make a distinction 6789** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 6790** not want to. SQLite will only request a recursive mutex in 6791** cases where it really needs one. If a faster non-recursive mutex 6792** implementation is available on the host platform, the mutex subsystem 6793** might return such a mutex in response to SQLITE_MUTEX_FAST. 6794** 6795** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 6796** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 6797** a pointer to a static preexisting mutex. ^Nine static mutexes are 6798** used by the current version of SQLite. Future versions of SQLite 6799** may add additional static mutexes. Static mutexes are for internal 6800** use by SQLite only. Applications that use SQLite mutexes should 6801** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 6802** SQLITE_MUTEX_RECURSIVE. 6803** 6804** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 6805** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 6806** returns a different mutex on every call. ^For the static 6807** mutex types, the same mutex is returned on every call that has 6808** the same type number. 6809** 6810** ^The sqlite3_mutex_free() routine deallocates a previously 6811** allocated dynamic mutex. Attempting to deallocate a static 6812** mutex results in undefined behavior. 6813** 6814** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 6815** to enter a mutex. ^If another thread is already within the mutex, 6816** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 6817** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 6818** upon successful entry. ^(Mutexes created using 6819** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 6820** In such cases, the 6821** mutex must be exited an equal number of times before another thread 6822** can enter.)^ If the same thread tries to enter any mutex other 6823** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 6824** 6825** ^(Some systems (for example, Windows 95) do not support the operation 6826** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 6827** will always return SQLITE_BUSY. The SQLite core only ever uses 6828** sqlite3_mutex_try() as an optimization so this is acceptable 6829** behavior.)^ 6830** 6831** ^The sqlite3_mutex_leave() routine exits a mutex that was 6832** previously entered by the same thread. The behavior 6833** is undefined if the mutex is not currently entered by the 6834** calling thread or is not currently allocated. 6835** 6836** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 6837** sqlite3_mutex_leave() is a NULL pointer, then all three routines 6838** behave as no-ops. 6839** 6840** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 6841*/ 6842sqlite3_mutex *sqlite3_mutex_alloc(int); 6843void sqlite3_mutex_free(sqlite3_mutex*); 6844void sqlite3_mutex_enter(sqlite3_mutex*); 6845int sqlite3_mutex_try(sqlite3_mutex*); 6846void sqlite3_mutex_leave(sqlite3_mutex*); 6847 6848/* 6849** CAPI3REF: Mutex Methods Object 6850** 6851** An instance of this structure defines the low-level routines 6852** used to allocate and use mutexes. 6853** 6854** Usually, the default mutex implementations provided by SQLite are 6855** sufficient, however the application has the option of substituting a custom 6856** implementation for specialized deployments or systems for which SQLite 6857** does not provide a suitable implementation. In this case, the application 6858** creates and populates an instance of this structure to pass 6859** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 6860** Additionally, an instance of this structure can be used as an 6861** output variable when querying the system for the current mutex 6862** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 6863** 6864** ^The xMutexInit method defined by this structure is invoked as 6865** part of system initialization by the sqlite3_initialize() function. 6866** ^The xMutexInit routine is called by SQLite exactly once for each 6867** effective call to [sqlite3_initialize()]. 6868** 6869** ^The xMutexEnd method defined by this structure is invoked as 6870** part of system shutdown by the sqlite3_shutdown() function. The 6871** implementation of this method is expected to release all outstanding 6872** resources obtained by the mutex methods implementation, especially 6873** those obtained by the xMutexInit method. ^The xMutexEnd() 6874** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 6875** 6876** ^(The remaining seven methods defined by this structure (xMutexAlloc, 6877** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 6878** xMutexNotheld) implement the following interfaces (respectively): 6879** 6880** <ul> 6881** <li> [sqlite3_mutex_alloc()] </li> 6882** <li> [sqlite3_mutex_free()] </li> 6883** <li> [sqlite3_mutex_enter()] </li> 6884** <li> [sqlite3_mutex_try()] </li> 6885** <li> [sqlite3_mutex_leave()] </li> 6886** <li> [sqlite3_mutex_held()] </li> 6887** <li> [sqlite3_mutex_notheld()] </li> 6888** </ul>)^ 6889** 6890** The only difference is that the public sqlite3_XXX functions enumerated 6891** above silently ignore any invocations that pass a NULL pointer instead 6892** of a valid mutex handle. The implementations of the methods defined 6893** by this structure are not required to handle this case, the results 6894** of passing a NULL pointer instead of a valid mutex handle are undefined 6895** (i.e. it is acceptable to provide an implementation that segfaults if 6896** it is passed a NULL pointer). 6897** 6898** The xMutexInit() method must be threadsafe. It must be harmless to 6899** invoke xMutexInit() multiple times within the same process and without 6900** intervening calls to xMutexEnd(). Second and subsequent calls to 6901** xMutexInit() must be no-ops. 6902** 6903** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 6904** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 6905** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 6906** memory allocation for a fast or recursive mutex. 6907** 6908** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 6909** called, but only if the prior call to xMutexInit returned SQLITE_OK. 6910** If xMutexInit fails in any way, it is expected to clean up after itself 6911** prior to returning. 6912*/ 6913typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 6914struct sqlite3_mutex_methods { 6915 int (*xMutexInit)(void); 6916 int (*xMutexEnd)(void); 6917 sqlite3_mutex *(*xMutexAlloc)(int); 6918 void (*xMutexFree)(sqlite3_mutex *); 6919 void (*xMutexEnter)(sqlite3_mutex *); 6920 int (*xMutexTry)(sqlite3_mutex *); 6921 void (*xMutexLeave)(sqlite3_mutex *); 6922 int (*xMutexHeld)(sqlite3_mutex *); 6923 int (*xMutexNotheld)(sqlite3_mutex *); 6924}; 6925 6926/* 6927** CAPI3REF: Mutex Verification Routines 6928** 6929** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 6930** are intended for use inside assert() statements. The SQLite core 6931** never uses these routines except inside an assert() and applications 6932** are advised to follow the lead of the core. The SQLite core only 6933** provides implementations for these routines when it is compiled 6934** with the SQLITE_DEBUG flag. External mutex implementations 6935** are only required to provide these routines if SQLITE_DEBUG is 6936** defined and if NDEBUG is not defined. 6937** 6938** These routines should return true if the mutex in their argument 6939** is held or not held, respectively, by the calling thread. 6940** 6941** The implementation is not required to provide versions of these 6942** routines that actually work. If the implementation does not provide working 6943** versions of these routines, it should at least provide stubs that always 6944** return true so that one does not get spurious assertion failures. 6945** 6946** If the argument to sqlite3_mutex_held() is a NULL pointer then 6947** the routine should return 1. This seems counter-intuitive since 6948** clearly the mutex cannot be held if it does not exist. But 6949** the reason the mutex does not exist is because the build is not 6950** using mutexes. And we do not want the assert() containing the 6951** call to sqlite3_mutex_held() to fail, so a non-zero return is 6952** the appropriate thing to do. The sqlite3_mutex_notheld() 6953** interface should also return 1 when given a NULL pointer. 6954*/ 6955#ifndef NDEBUG 6956int sqlite3_mutex_held(sqlite3_mutex*); 6957int sqlite3_mutex_notheld(sqlite3_mutex*); 6958#endif 6959 6960/* 6961** CAPI3REF: Mutex Types 6962** 6963** The [sqlite3_mutex_alloc()] interface takes a single argument 6964** which is one of these integer constants. 6965** 6966** The set of static mutexes may change from one SQLite release to the 6967** next. Applications that override the built-in mutex logic must be 6968** prepared to accommodate additional static mutexes. 6969*/ 6970#define SQLITE_MUTEX_FAST 0 6971#define SQLITE_MUTEX_RECURSIVE 1 6972#define SQLITE_MUTEX_STATIC_MASTER 2 6973#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 6974#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 6975#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 6976#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 6977#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 6978#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 6979#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 6980#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 6981#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 6982#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 6983#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 6984#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 6985#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 6986 6987/* 6988** CAPI3REF: Retrieve the mutex for a database connection 6989** METHOD: sqlite3 6990** 6991** ^This interface returns a pointer the [sqlite3_mutex] object that 6992** serializes access to the [database connection] given in the argument 6993** when the [threading mode] is Serialized. 6994** ^If the [threading mode] is Single-thread or Multi-thread then this 6995** routine returns a NULL pointer. 6996*/ 6997sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 6998 6999/* 7000** CAPI3REF: Low-Level Control Of Database Files 7001** METHOD: sqlite3 7002** 7003** ^The [sqlite3_file_control()] interface makes a direct call to the 7004** xFileControl method for the [sqlite3_io_methods] object associated 7005** with a particular database identified by the second argument. ^The 7006** name of the database is "main" for the main database or "temp" for the 7007** TEMP database, or the name that appears after the AS keyword for 7008** databases that are added using the [ATTACH] SQL command. 7009** ^A NULL pointer can be used in place of "main" to refer to the 7010** main database file. 7011** ^The third and fourth parameters to this routine 7012** are passed directly through to the second and third parameters of 7013** the xFileControl method. ^The return value of the xFileControl 7014** method becomes the return value of this routine. 7015** 7016** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 7017** a pointer to the underlying [sqlite3_file] object to be written into 7018** the space pointed to by the 4th parameter. ^The [SQLITE_FCNTL_FILE_POINTER] 7019** case is a short-circuit path which does not actually invoke the 7020** underlying sqlite3_io_methods.xFileControl method. 7021** 7022** ^If the second parameter (zDbName) does not match the name of any 7023** open database file, then SQLITE_ERROR is returned. ^This error 7024** code is not remembered and will not be recalled by [sqlite3_errcode()] 7025** or [sqlite3_errmsg()]. The underlying xFileControl method might 7026** also return SQLITE_ERROR. There is no way to distinguish between 7027** an incorrect zDbName and an SQLITE_ERROR return from the underlying 7028** xFileControl method. 7029** 7030** See also: [file control opcodes] 7031*/ 7032int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 7033 7034/* 7035** CAPI3REF: Testing Interface 7036** 7037** ^The sqlite3_test_control() interface is used to read out internal 7038** state of SQLite and to inject faults into SQLite for testing 7039** purposes. ^The first parameter is an operation code that determines 7040** the number, meaning, and operation of all subsequent parameters. 7041** 7042** This interface is not for use by applications. It exists solely 7043** for verifying the correct operation of the SQLite library. Depending 7044** on how the SQLite library is compiled, this interface might not exist. 7045** 7046** The details of the operation codes, their meanings, the parameters 7047** they take, and what they do are all subject to change without notice. 7048** Unlike most of the SQLite API, this function is not guaranteed to 7049** operate consistently from one release to the next. 7050*/ 7051int sqlite3_test_control(int op, ...); 7052 7053/* 7054** CAPI3REF: Testing Interface Operation Codes 7055** 7056** These constants are the valid operation code parameters used 7057** as the first argument to [sqlite3_test_control()]. 7058** 7059** These parameters and their meanings are subject to change 7060** without notice. These values are for testing purposes only. 7061** Applications should not use any of these parameters or the 7062** [sqlite3_test_control()] interface. 7063*/ 7064#define SQLITE_TESTCTRL_FIRST 5 7065#define SQLITE_TESTCTRL_PRNG_SAVE 5 7066#define SQLITE_TESTCTRL_PRNG_RESTORE 6 7067#define SQLITE_TESTCTRL_PRNG_RESET 7 7068#define SQLITE_TESTCTRL_BITVEC_TEST 8 7069#define SQLITE_TESTCTRL_FAULT_INSTALL 9 7070#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 7071#define SQLITE_TESTCTRL_PENDING_BYTE 11 7072#define SQLITE_TESTCTRL_ASSERT 12 7073#define SQLITE_TESTCTRL_ALWAYS 13 7074#define SQLITE_TESTCTRL_RESERVE 14 7075#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 7076#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 7077#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 7078#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 7079#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 7080#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 7081#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 7082#define SQLITE_TESTCTRL_VDBE_COVERAGE 21 7083#define SQLITE_TESTCTRL_BYTEORDER 22 7084#define SQLITE_TESTCTRL_ISINIT 23 7085#define SQLITE_TESTCTRL_SORTER_MMAP 24 7086#define SQLITE_TESTCTRL_IMPOSTER 25 7087#define SQLITE_TESTCTRL_PARSER_COVERAGE 26 7088#define SQLITE_TESTCTRL_LAST 26 /* Largest TESTCTRL */ 7089 7090/* 7091** CAPI3REF: SQL Keyword Checking 7092** 7093** These routines provide access to the set of SQL language keywords 7094** recognized by SQLite. Applications can uses these routines to determine 7095** whether or not a specific identifier needs to be escaped (for example, 7096** by enclosing in double-quotes) so as not to confuse the parser. 7097** 7098** The sqlite3_keyword_count() interface returns the number of distinct 7099** keywords understood by SQLite. 7100** 7101** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 7102** makes *Z point to that keyword expressed as UTF8 and writes the number 7103** of bytes in the keyword into *L. The string that *Z points to is not 7104** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 7105** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 7106** or L are NULL or invalid pointers then calls to 7107** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 7108** 7109** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 7110** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 7111** if it is and zero if not. 7112** 7113** The parser used by SQLite is forgiving. It is often possible to use 7114** a keyword as an identifier as long as such use does not result in a 7115** parsing ambiguity. For example, the statement 7116** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 7117** creates a new table named "BEGIN" with three columns named 7118** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 7119** using keywords as identifiers. Common techniques used to avoid keyword 7120** name collisions include: 7121** <ul> 7122** <li> Put all identifier names inside double-quotes. This is the official 7123** SQL way to escape identifier names. 7124** <li> Put identifier names inside [...]. This is not standard SQL, 7125** but it is what SQL Server does and so lots of programmers use this 7126** technique. 7127** <li> Begin every identifier with the letter "Z" as no SQL keywords start 7128** with "Z". 7129** <li> Include a digit somewhere in every identifier name. 7130** </ul> 7131** 7132** Note that the number of keywords understood by SQLite can depend on 7133** compile-time options. For example, "VACUUM" is not a keyword if 7134** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 7135** new keywords may be added to future releases of SQLite. 7136*/ 7137int sqlite3_keyword_count(void); 7138int sqlite3_keyword_name(int,const char**,int*); 7139int sqlite3_keyword_check(const char*,int); 7140 7141/* 7142** CAPI3REF: Dynamic String Object 7143** KEYWORDS: {dynamic string} 7144** 7145** An instance of the sqlite3_str object contains a dynamically-sized 7146** string under construction. 7147** 7148** The lifecycle of an sqlite3_str object is as follows: 7149** <ol> 7150** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 7151** <li> ^Text is appended to the sqlite3_str object using various 7152** methods, such as [sqlite3_str_appendf()]. 7153** <li> ^The sqlite3_str object is destroyed and the string it created 7154** is returned using the [sqlite3_str_finish()] interface. 7155** </ol> 7156*/ 7157typedef struct sqlite3_str sqlite3_str; 7158 7159/* 7160** CAPI3REF: Create A New Dynamic String Object 7161** CONSTRUCTOR: sqlite3_str 7162** 7163** ^The [sqlite3_str_new(D)] interface allocates and initializes 7164** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 7165** [sqlite3_str_new()] must be freed by a subsequent call to 7166** [sqlite3_str_finish(X)]. 7167** 7168** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 7169** valid [sqlite3_str] object, though in the event of an out-of-memory 7170** error the returned object might be a special singleton that will 7171** silently reject new text, always return SQLITE_NOMEM from 7172** [sqlite3_str_errcode()], always return 0 for 7173** [sqlite3_str_length()], and always return NULL from 7174** [sqlite3_str_finish(X)]. It is always safe to use the value 7175** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 7176** to any of the other [sqlite3_str] methods. 7177** 7178** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 7179** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 7180** length of the string contained in the [sqlite3_str] object will be 7181** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 7182** of [SQLITE_MAX_LENGTH]. 7183*/ 7184sqlite3_str *sqlite3_str_new(sqlite3*); 7185 7186/* 7187** CAPI3REF: Finalize A Dynamic String 7188** DESTRUCTOR: sqlite3_str 7189** 7190** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 7191** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 7192** that contains the constructed string. The calling application should 7193** pass the returned value to [sqlite3_free()] to avoid a memory leak. 7194** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 7195** errors were encountered during construction of the string. ^The 7196** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 7197** string in [sqlite3_str] object X is zero bytes long. 7198*/ 7199char *sqlite3_str_finish(sqlite3_str*); 7200 7201/* 7202** CAPI3REF: Add Content To A Dynamic String 7203** METHOD: sqlite3_str 7204** 7205** These interfaces add content to an sqlite3_str object previously obtained 7206** from [sqlite3_str_new()]. 7207** 7208** ^The [sqlite3_str_appendf(X,F,...)] and 7209** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 7210** functionality of SQLite to append formatted text onto the end of 7211** [sqlite3_str] object X. 7212** 7213** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 7214** onto the end of the [sqlite3_str] object X. N must be non-negative. 7215** S must contain at least N non-zero bytes of content. To append a 7216** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 7217** method instead. 7218** 7219** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 7220** zero-terminated string S onto the end of [sqlite3_str] object X. 7221** 7222** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 7223** single-byte character C onto the end of [sqlite3_str] object X. 7224** ^This method can be used, for example, to add whitespace indentation. 7225** 7226** ^The [sqlite3_str_reset(X)] method resets the string under construction 7227** inside [sqlite3_str] object X back to zero bytes in length. 7228** 7229** These methods do not return a result code. ^If an error occurs, that fact 7230** is recorded in the [sqlite3_str] object and can be recovered by a 7231** subsequent call to [sqlite3_str_errcode(X)]. 7232*/ 7233void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 7234void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 7235void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 7236void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 7237void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 7238void sqlite3_str_reset(sqlite3_str*); 7239 7240/* 7241** CAPI3REF: Status Of A Dynamic String 7242** METHOD: sqlite3_str 7243** 7244** These interfaces return the current status of an [sqlite3_str] object. 7245** 7246** ^If any prior errors have occurred while constructing the dynamic string 7247** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 7248** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 7249** [SQLITE_NOMEM] following any out-of-memory error, or 7250** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 7251** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 7252** 7253** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 7254** of the dynamic string under construction in [sqlite3_str] object X. 7255** ^The length returned by [sqlite3_str_length(X)] does not include the 7256** zero-termination byte. 7257** 7258** ^The [sqlite3_str_value(X)] method returns a pointer to the current 7259** content of the dynamic string under construction in X. The value 7260** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 7261** and might be freed or altered by any subsequent method on the same 7262** [sqlite3_str] object. Applications must not used the pointer returned 7263** [sqlite3_str_value(X)] after any subsequent method call on the same 7264** object. ^Applications may change the content of the string returned 7265** by [sqlite3_str_value(X)] as long as they do not write into any bytes 7266** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 7267** write any byte after any subsequent sqlite3_str method call. 7268*/ 7269int sqlite3_str_errcode(sqlite3_str*); 7270int sqlite3_str_length(sqlite3_str*); 7271char *sqlite3_str_value(sqlite3_str*); 7272 7273/* 7274** CAPI3REF: SQLite Runtime Status 7275** 7276** ^These interfaces are used to retrieve runtime status information 7277** about the performance of SQLite, and optionally to reset various 7278** highwater marks. ^The first argument is an integer code for 7279** the specific parameter to measure. ^(Recognized integer codes 7280** are of the form [status parameters | SQLITE_STATUS_...].)^ 7281** ^The current value of the parameter is returned into *pCurrent. 7282** ^The highest recorded value is returned in *pHighwater. ^If the 7283** resetFlag is true, then the highest record value is reset after 7284** *pHighwater is written. ^(Some parameters do not record the highest 7285** value. For those parameters 7286** nothing is written into *pHighwater and the resetFlag is ignored.)^ 7287** ^(Other parameters record only the highwater mark and not the current 7288** value. For these latter parameters nothing is written into *pCurrent.)^ 7289** 7290** ^The sqlite3_status() and sqlite3_status64() routines return 7291** SQLITE_OK on success and a non-zero [error code] on failure. 7292** 7293** If either the current value or the highwater mark is too large to 7294** be represented by a 32-bit integer, then the values returned by 7295** sqlite3_status() are undefined. 7296** 7297** See also: [sqlite3_db_status()] 7298*/ 7299int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 7300int sqlite3_status64( 7301 int op, 7302 sqlite3_int64 *pCurrent, 7303 sqlite3_int64 *pHighwater, 7304 int resetFlag 7305); 7306 7307 7308/* 7309** CAPI3REF: Status Parameters 7310** KEYWORDS: {status parameters} 7311** 7312** These integer constants designate various run-time status parameters 7313** that can be returned by [sqlite3_status()]. 7314** 7315** <dl> 7316** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 7317** <dd>This parameter is the current amount of memory checked out 7318** using [sqlite3_malloc()], either directly or indirectly. The 7319** figure includes calls made to [sqlite3_malloc()] by the application 7320** and internal memory usage by the SQLite library. Auxiliary page-cache 7321** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 7322** this parameter. The amount returned is the sum of the allocation 7323** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 7324** 7325** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 7326** <dd>This parameter records the largest memory allocation request 7327** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 7328** internal equivalents). Only the value returned in the 7329** *pHighwater parameter to [sqlite3_status()] is of interest. 7330** The value written into the *pCurrent parameter is undefined.</dd>)^ 7331** 7332** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 7333** <dd>This parameter records the number of separate memory allocations 7334** currently checked out.</dd>)^ 7335** 7336** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 7337** <dd>This parameter returns the number of pages used out of the 7338** [pagecache memory allocator] that was configured using 7339** [SQLITE_CONFIG_PAGECACHE]. The 7340** value returned is in pages, not in bytes.</dd>)^ 7341** 7342** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 7343** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 7344** <dd>This parameter returns the number of bytes of page cache 7345** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 7346** buffer and where forced to overflow to [sqlite3_malloc()]. The 7347** returned value includes allocations that overflowed because they 7348** where too large (they were larger than the "sz" parameter to 7349** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 7350** no space was left in the page cache.</dd>)^ 7351** 7352** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 7353** <dd>This parameter records the largest memory allocation request 7354** handed to [pagecache memory allocator]. Only the value returned in the 7355** *pHighwater parameter to [sqlite3_status()] is of interest. 7356** The value written into the *pCurrent parameter is undefined.</dd>)^ 7357** 7358** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 7359** <dd>No longer used.</dd> 7360** 7361** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 7362** <dd>No longer used.</dd> 7363** 7364** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 7365** <dd>No longer used.</dd> 7366** 7367** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 7368** <dd>The *pHighwater parameter records the deepest parser stack. 7369** The *pCurrent value is undefined. The *pHighwater value is only 7370** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 7371** </dl> 7372** 7373** New status parameters may be added from time to time. 7374*/ 7375#define SQLITE_STATUS_MEMORY_USED 0 7376#define SQLITE_STATUS_PAGECACHE_USED 1 7377#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 7378#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 7379#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 7380#define SQLITE_STATUS_MALLOC_SIZE 5 7381#define SQLITE_STATUS_PARSER_STACK 6 7382#define SQLITE_STATUS_PAGECACHE_SIZE 7 7383#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 7384#define SQLITE_STATUS_MALLOC_COUNT 9 7385 7386/* 7387** CAPI3REF: Database Connection Status 7388** METHOD: sqlite3 7389** 7390** ^This interface is used to retrieve runtime status information 7391** about a single [database connection]. ^The first argument is the 7392** database connection object to be interrogated. ^The second argument 7393** is an integer constant, taken from the set of 7394** [SQLITE_DBSTATUS options], that 7395** determines the parameter to interrogate. The set of 7396** [SQLITE_DBSTATUS options] is likely 7397** to grow in future releases of SQLite. 7398** 7399** ^The current value of the requested parameter is written into *pCur 7400** and the highest instantaneous value is written into *pHiwtr. ^If 7401** the resetFlg is true, then the highest instantaneous value is 7402** reset back down to the current value. 7403** 7404** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 7405** non-zero [error code] on failure. 7406** 7407** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 7408*/ 7409int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 7410 7411/* 7412** CAPI3REF: Status Parameters for database connections 7413** KEYWORDS: {SQLITE_DBSTATUS options} 7414** 7415** These constants are the available integer "verbs" that can be passed as 7416** the second argument to the [sqlite3_db_status()] interface. 7417** 7418** New verbs may be added in future releases of SQLite. Existing verbs 7419** might be discontinued. Applications should check the return code from 7420** [sqlite3_db_status()] to make sure that the call worked. 7421** The [sqlite3_db_status()] interface will return a non-zero error code 7422** if a discontinued or unsupported verb is invoked. 7423** 7424** <dl> 7425** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 7426** <dd>This parameter returns the number of lookaside memory slots currently 7427** checked out.</dd>)^ 7428** 7429** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 7430** <dd>This parameter returns the number malloc attempts that were 7431** satisfied using lookaside memory. Only the high-water value is meaningful; 7432** the current value is always zero.)^ 7433** 7434** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 7435** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 7436** <dd>This parameter returns the number malloc attempts that might have 7437** been satisfied using lookaside memory but failed due to the amount of 7438** memory requested being larger than the lookaside slot size. 7439** Only the high-water value is meaningful; 7440** the current value is always zero.)^ 7441** 7442** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 7443** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 7444** <dd>This parameter returns the number malloc attempts that might have 7445** been satisfied using lookaside memory but failed due to all lookaside 7446** memory already being in use. 7447** Only the high-water value is meaningful; 7448** the current value is always zero.)^ 7449** 7450** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 7451** <dd>This parameter returns the approximate number of bytes of heap 7452** memory used by all pager caches associated with the database connection.)^ 7453** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 7454** 7455** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 7456** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 7457** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 7458** pager cache is shared between two or more connections the bytes of heap 7459** memory used by that pager cache is divided evenly between the attached 7460** connections.)^ In other words, if none of the pager caches associated 7461** with the database connection are shared, this request returns the same 7462** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 7463** shared, the value returned by this call will be smaller than that returned 7464** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 7465** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 7466** 7467** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 7468** <dd>This parameter returns the approximate number of bytes of heap 7469** memory used to store the schema for all databases associated 7470** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 7471** ^The full amount of memory used by the schemas is reported, even if the 7472** schema memory is shared with other database connections due to 7473** [shared cache mode] being enabled. 7474** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 7475** 7476** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 7477** <dd>This parameter returns the approximate number of bytes of heap 7478** and lookaside memory used by all prepared statements associated with 7479** the database connection.)^ 7480** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 7481** </dd> 7482** 7483** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 7484** <dd>This parameter returns the number of pager cache hits that have 7485** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 7486** is always 0. 7487** </dd> 7488** 7489** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 7490** <dd>This parameter returns the number of pager cache misses that have 7491** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 7492** is always 0. 7493** </dd> 7494** 7495** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 7496** <dd>This parameter returns the number of dirty cache entries that have 7497** been written to disk. Specifically, the number of pages written to the 7498** wal file in wal mode databases, or the number of pages written to the 7499** database file in rollback mode databases. Any pages written as part of 7500** transaction rollback or database recovery operations are not included. 7501** If an IO or other error occurs while writing a page to disk, the effect 7502** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 7503** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 7504** </dd> 7505** 7506** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 7507** <dd>This parameter returns the number of dirty cache entries that have 7508** been written to disk in the middle of a transaction due to the page 7509** cache overflowing. Transactions are more efficient if they are written 7510** to disk all at once. When pages spill mid-transaction, that introduces 7511** additional overhead. This parameter can be used help identify 7512** inefficiencies that can be resolve by increasing the cache size. 7513** </dd> 7514** 7515** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 7516** <dd>This parameter returns zero for the current value if and only if 7517** all foreign key constraints (deferred or immediate) have been 7518** resolved.)^ ^The highwater mark is always 0. 7519** </dd> 7520** </dl> 7521*/ 7522#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 7523#define SQLITE_DBSTATUS_CACHE_USED 1 7524#define SQLITE_DBSTATUS_SCHEMA_USED 2 7525#define SQLITE_DBSTATUS_STMT_USED 3 7526#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 7527#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 7528#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 7529#define SQLITE_DBSTATUS_CACHE_HIT 7 7530#define SQLITE_DBSTATUS_CACHE_MISS 8 7531#define SQLITE_DBSTATUS_CACHE_WRITE 9 7532#define SQLITE_DBSTATUS_DEFERRED_FKS 10 7533#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 7534#define SQLITE_DBSTATUS_CACHE_SPILL 12 7535#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 7536 7537 7538/* 7539** CAPI3REF: Prepared Statement Status 7540** METHOD: sqlite3_stmt 7541** 7542** ^(Each prepared statement maintains various 7543** [SQLITE_STMTSTATUS counters] that measure the number 7544** of times it has performed specific operations.)^ These counters can 7545** be used to monitor the performance characteristics of the prepared 7546** statements. For example, if the number of table steps greatly exceeds 7547** the number of table searches or result rows, that would tend to indicate 7548** that the prepared statement is using a full table scan rather than 7549** an index. 7550** 7551** ^(This interface is used to retrieve and reset counter values from 7552** a [prepared statement]. The first argument is the prepared statement 7553** object to be interrogated. The second argument 7554** is an integer code for a specific [SQLITE_STMTSTATUS counter] 7555** to be interrogated.)^ 7556** ^The current value of the requested counter is returned. 7557** ^If the resetFlg is true, then the counter is reset to zero after this 7558** interface call returns. 7559** 7560** See also: [sqlite3_status()] and [sqlite3_db_status()]. 7561*/ 7562int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 7563 7564/* 7565** CAPI3REF: Status Parameters for prepared statements 7566** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 7567** 7568** These preprocessor macros define integer codes that name counter 7569** values associated with the [sqlite3_stmt_status()] interface. 7570** The meanings of the various counters are as follows: 7571** 7572** <dl> 7573** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 7574** <dd>^This is the number of times that SQLite has stepped forward in 7575** a table as part of a full table scan. Large numbers for this counter 7576** may indicate opportunities for performance improvement through 7577** careful use of indices.</dd> 7578** 7579** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 7580** <dd>^This is the number of sort operations that have occurred. 7581** A non-zero value in this counter may indicate an opportunity to 7582** improvement performance through careful use of indices.</dd> 7583** 7584** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 7585** <dd>^This is the number of rows inserted into transient indices that 7586** were created automatically in order to help joins run faster. 7587** A non-zero value in this counter may indicate an opportunity to 7588** improvement performance by adding permanent indices that do not 7589** need to be reinitialized each time the statement is run.</dd> 7590** 7591** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 7592** <dd>^This is the number of virtual machine operations executed 7593** by the prepared statement if that number is less than or equal 7594** to 2147483647. The number of virtual machine operations can be 7595** used as a proxy for the total work done by the prepared statement. 7596** If the number of virtual machine operations exceeds 2147483647 7597** then the value returned by this statement status code is undefined. 7598** 7599** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 7600** <dd>^This is the number of times that the prepare statement has been 7601** automatically regenerated due to schema changes or change to 7602** [bound parameters] that might affect the query plan. 7603** 7604** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 7605** <dd>^This is the number of times that the prepared statement has 7606** been run. A single "run" for the purposes of this counter is one 7607** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 7608** The counter is incremented on the first [sqlite3_step()] call of each 7609** cycle. 7610** 7611** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 7612** <dd>^This is the approximate number of bytes of heap memory 7613** used to store the prepared statement. ^This value is not actually 7614** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 7615** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 7616** </dd> 7617** </dl> 7618*/ 7619#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 7620#define SQLITE_STMTSTATUS_SORT 2 7621#define SQLITE_STMTSTATUS_AUTOINDEX 3 7622#define SQLITE_STMTSTATUS_VM_STEP 4 7623#define SQLITE_STMTSTATUS_REPREPARE 5 7624#define SQLITE_STMTSTATUS_RUN 6 7625#define SQLITE_STMTSTATUS_MEMUSED 99 7626 7627/* 7628** CAPI3REF: Custom Page Cache Object 7629** 7630** The sqlite3_pcache type is opaque. It is implemented by 7631** the pluggable module. The SQLite core has no knowledge of 7632** its size or internal structure and never deals with the 7633** sqlite3_pcache object except by holding and passing pointers 7634** to the object. 7635** 7636** See [sqlite3_pcache_methods2] for additional information. 7637*/ 7638typedef struct sqlite3_pcache sqlite3_pcache; 7639 7640/* 7641** CAPI3REF: Custom Page Cache Object 7642** 7643** The sqlite3_pcache_page object represents a single page in the 7644** page cache. The page cache will allocate instances of this 7645** object. Various methods of the page cache use pointers to instances 7646** of this object as parameters or as their return value. 7647** 7648** See [sqlite3_pcache_methods2] for additional information. 7649*/ 7650typedef struct sqlite3_pcache_page sqlite3_pcache_page; 7651struct sqlite3_pcache_page { 7652 void *pBuf; /* The content of the page */ 7653 void *pExtra; /* Extra information associated with the page */ 7654}; 7655 7656/* 7657** CAPI3REF: Application Defined Page Cache. 7658** KEYWORDS: {page cache} 7659** 7660** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 7661** register an alternative page cache implementation by passing in an 7662** instance of the sqlite3_pcache_methods2 structure.)^ 7663** In many applications, most of the heap memory allocated by 7664** SQLite is used for the page cache. 7665** By implementing a 7666** custom page cache using this API, an application can better control 7667** the amount of memory consumed by SQLite, the way in which 7668** that memory is allocated and released, and the policies used to 7669** determine exactly which parts of a database file are cached and for 7670** how long. 7671** 7672** The alternative page cache mechanism is an 7673** extreme measure that is only needed by the most demanding applications. 7674** The built-in page cache is recommended for most uses. 7675** 7676** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 7677** internal buffer by SQLite within the call to [sqlite3_config]. Hence 7678** the application may discard the parameter after the call to 7679** [sqlite3_config()] returns.)^ 7680** 7681** [[the xInit() page cache method]] 7682** ^(The xInit() method is called once for each effective 7683** call to [sqlite3_initialize()])^ 7684** (usually only once during the lifetime of the process). ^(The xInit() 7685** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 7686** The intent of the xInit() method is to set up global data structures 7687** required by the custom page cache implementation. 7688** ^(If the xInit() method is NULL, then the 7689** built-in default page cache is used instead of the application defined 7690** page cache.)^ 7691** 7692** [[the xShutdown() page cache method]] 7693** ^The xShutdown() method is called by [sqlite3_shutdown()]. 7694** It can be used to clean up 7695** any outstanding resources before process shutdown, if required. 7696** ^The xShutdown() method may be NULL. 7697** 7698** ^SQLite automatically serializes calls to the xInit method, 7699** so the xInit method need not be threadsafe. ^The 7700** xShutdown method is only called from [sqlite3_shutdown()] so it does 7701** not need to be threadsafe either. All other methods must be threadsafe 7702** in multithreaded applications. 7703** 7704** ^SQLite will never invoke xInit() more than once without an intervening 7705** call to xShutdown(). 7706** 7707** [[the xCreate() page cache methods]] 7708** ^SQLite invokes the xCreate() method to construct a new cache instance. 7709** SQLite will typically create one cache instance for each open database file, 7710** though this is not guaranteed. ^The 7711** first parameter, szPage, is the size in bytes of the pages that must 7712** be allocated by the cache. ^szPage will always a power of two. ^The 7713** second parameter szExtra is a number of bytes of extra storage 7714** associated with each page cache entry. ^The szExtra parameter will 7715** a number less than 250. SQLite will use the 7716** extra szExtra bytes on each page to store metadata about the underlying 7717** database page on disk. The value passed into szExtra depends 7718** on the SQLite version, the target platform, and how SQLite was compiled. 7719** ^The third argument to xCreate(), bPurgeable, is true if the cache being 7720** created will be used to cache database pages of a file stored on disk, or 7721** false if it is used for an in-memory database. The cache implementation 7722** does not have to do anything special based with the value of bPurgeable; 7723** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 7724** never invoke xUnpin() except to deliberately delete a page. 7725** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 7726** false will always have the "discard" flag set to true. 7727** ^Hence, a cache created with bPurgeable false will 7728** never contain any unpinned pages. 7729** 7730** [[the xCachesize() page cache method]] 7731** ^(The xCachesize() method may be called at any time by SQLite to set the 7732** suggested maximum cache-size (number of pages stored by) the cache 7733** instance passed as the first argument. This is the value configured using 7734** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 7735** parameter, the implementation is not required to do anything with this 7736** value; it is advisory only. 7737** 7738** [[the xPagecount() page cache methods]] 7739** The xPagecount() method must return the number of pages currently 7740** stored in the cache, both pinned and unpinned. 7741** 7742** [[the xFetch() page cache methods]] 7743** The xFetch() method locates a page in the cache and returns a pointer to 7744** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 7745** The pBuf element of the returned sqlite3_pcache_page object will be a 7746** pointer to a buffer of szPage bytes used to store the content of a 7747** single database page. The pExtra element of sqlite3_pcache_page will be 7748** a pointer to the szExtra bytes of extra storage that SQLite has requested 7749** for each entry in the page cache. 7750** 7751** The page to be fetched is determined by the key. ^The minimum key value 7752** is 1. After it has been retrieved using xFetch, the page is considered 7753** to be "pinned". 7754** 7755** If the requested page is already in the page cache, then the page cache 7756** implementation must return a pointer to the page buffer with its content 7757** intact. If the requested page is not already in the cache, then the 7758** cache implementation should use the value of the createFlag 7759** parameter to help it determined what action to take: 7760** 7761** <table border=1 width=85% align=center> 7762** <tr><th> createFlag <th> Behavior when page is not already in cache 7763** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 7764** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 7765** Otherwise return NULL. 7766** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 7767** NULL if allocating a new page is effectively impossible. 7768** </table> 7769** 7770** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 7771** will only use a createFlag of 2 after a prior call with a createFlag of 1 7772** failed.)^ In between the to xFetch() calls, SQLite may 7773** attempt to unpin one or more cache pages by spilling the content of 7774** pinned pages to disk and synching the operating system disk cache. 7775** 7776** [[the xUnpin() page cache method]] 7777** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 7778** as its second argument. If the third parameter, discard, is non-zero, 7779** then the page must be evicted from the cache. 7780** ^If the discard parameter is 7781** zero, then the page may be discarded or retained at the discretion of 7782** page cache implementation. ^The page cache implementation 7783** may choose to evict unpinned pages at any time. 7784** 7785** The cache must not perform any reference counting. A single 7786** call to xUnpin() unpins the page regardless of the number of prior calls 7787** to xFetch(). 7788** 7789** [[the xRekey() page cache methods]] 7790** The xRekey() method is used to change the key value associated with the 7791** page passed as the second argument. If the cache 7792** previously contains an entry associated with newKey, it must be 7793** discarded. ^Any prior cache entry associated with newKey is guaranteed not 7794** to be pinned. 7795** 7796** When SQLite calls the xTruncate() method, the cache must discard all 7797** existing cache entries with page numbers (keys) greater than or equal 7798** to the value of the iLimit parameter passed to xTruncate(). If any 7799** of these pages are pinned, they are implicitly unpinned, meaning that 7800** they can be safely discarded. 7801** 7802** [[the xDestroy() page cache method]] 7803** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 7804** All resources associated with the specified cache should be freed. ^After 7805** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 7806** handle invalid, and will not use it with any other sqlite3_pcache_methods2 7807** functions. 7808** 7809** [[the xShrink() page cache method]] 7810** ^SQLite invokes the xShrink() method when it wants the page cache to 7811** free up as much of heap memory as possible. The page cache implementation 7812** is not obligated to free any memory, but well-behaved implementations should 7813** do their best. 7814*/ 7815typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 7816struct sqlite3_pcache_methods2 { 7817 int iVersion; 7818 void *pArg; 7819 int (*xInit)(void*); 7820 void (*xShutdown)(void*); 7821 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 7822 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7823 int (*xPagecount)(sqlite3_pcache*); 7824 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7825 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 7826 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 7827 unsigned oldKey, unsigned newKey); 7828 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7829 void (*xDestroy)(sqlite3_pcache*); 7830 void (*xShrink)(sqlite3_pcache*); 7831}; 7832 7833/* 7834** This is the obsolete pcache_methods object that has now been replaced 7835** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 7836** retained in the header file for backwards compatibility only. 7837*/ 7838typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 7839struct sqlite3_pcache_methods { 7840 void *pArg; 7841 int (*xInit)(void*); 7842 void (*xShutdown)(void*); 7843 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 7844 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7845 int (*xPagecount)(sqlite3_pcache*); 7846 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7847 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 7848 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 7849 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7850 void (*xDestroy)(sqlite3_pcache*); 7851}; 7852 7853 7854/* 7855** CAPI3REF: Online Backup Object 7856** 7857** The sqlite3_backup object records state information about an ongoing 7858** online backup operation. ^The sqlite3_backup object is created by 7859** a call to [sqlite3_backup_init()] and is destroyed by a call to 7860** [sqlite3_backup_finish()]. 7861** 7862** See Also: [Using the SQLite Online Backup API] 7863*/ 7864typedef struct sqlite3_backup sqlite3_backup; 7865 7866/* 7867** CAPI3REF: Online Backup API. 7868** 7869** The backup API copies the content of one database into another. 7870** It is useful either for creating backups of databases or 7871** for copying in-memory databases to or from persistent files. 7872** 7873** See Also: [Using the SQLite Online Backup API] 7874** 7875** ^SQLite holds a write transaction open on the destination database file 7876** for the duration of the backup operation. 7877** ^The source database is read-locked only while it is being read; 7878** it is not locked continuously for the entire backup operation. 7879** ^Thus, the backup may be performed on a live source database without 7880** preventing other database connections from 7881** reading or writing to the source database while the backup is underway. 7882** 7883** ^(To perform a backup operation: 7884** <ol> 7885** <li><b>sqlite3_backup_init()</b> is called once to initialize the 7886** backup, 7887** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 7888** the data between the two databases, and finally 7889** <li><b>sqlite3_backup_finish()</b> is called to release all resources 7890** associated with the backup operation. 7891** </ol>)^ 7892** There should be exactly one call to sqlite3_backup_finish() for each 7893** successful call to sqlite3_backup_init(). 7894** 7895** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 7896** 7897** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 7898** [database connection] associated with the destination database 7899** and the database name, respectively. 7900** ^The database name is "main" for the main database, "temp" for the 7901** temporary database, or the name specified after the AS keyword in 7902** an [ATTACH] statement for an attached database. 7903** ^The S and M arguments passed to 7904** sqlite3_backup_init(D,N,S,M) identify the [database connection] 7905** and database name of the source database, respectively. 7906** ^The source and destination [database connections] (parameters S and D) 7907** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 7908** an error. 7909** 7910** ^A call to sqlite3_backup_init() will fail, returning NULL, if 7911** there is already a read or read-write transaction open on the 7912** destination database. 7913** 7914** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 7915** returned and an error code and error message are stored in the 7916** destination [database connection] D. 7917** ^The error code and message for the failed call to sqlite3_backup_init() 7918** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 7919** [sqlite3_errmsg16()] functions. 7920** ^A successful call to sqlite3_backup_init() returns a pointer to an 7921** [sqlite3_backup] object. 7922** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 7923** sqlite3_backup_finish() functions to perform the specified backup 7924** operation. 7925** 7926** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 7927** 7928** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 7929** the source and destination databases specified by [sqlite3_backup] object B. 7930** ^If N is negative, all remaining source pages are copied. 7931** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 7932** are still more pages to be copied, then the function returns [SQLITE_OK]. 7933** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 7934** from source to destination, then it returns [SQLITE_DONE]. 7935** ^If an error occurs while running sqlite3_backup_step(B,N), 7936** then an [error code] is returned. ^As well as [SQLITE_OK] and 7937** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 7938** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 7939** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 7940** 7941** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 7942** <ol> 7943** <li> the destination database was opened read-only, or 7944** <li> the destination database is using write-ahead-log journaling 7945** and the destination and source page sizes differ, or 7946** <li> the destination database is an in-memory database and the 7947** destination and source page sizes differ. 7948** </ol>)^ 7949** 7950** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 7951** the [sqlite3_busy_handler | busy-handler function] 7952** is invoked (if one is specified). ^If the 7953** busy-handler returns non-zero before the lock is available, then 7954** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 7955** sqlite3_backup_step() can be retried later. ^If the source 7956** [database connection] 7957** is being used to write to the source database when sqlite3_backup_step() 7958** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 7959** case the call to sqlite3_backup_step() can be retried later on. ^(If 7960** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 7961** [SQLITE_READONLY] is returned, then 7962** there is no point in retrying the call to sqlite3_backup_step(). These 7963** errors are considered fatal.)^ The application must accept 7964** that the backup operation has failed and pass the backup operation handle 7965** to the sqlite3_backup_finish() to release associated resources. 7966** 7967** ^The first call to sqlite3_backup_step() obtains an exclusive lock 7968** on the destination file. ^The exclusive lock is not released until either 7969** sqlite3_backup_finish() is called or the backup operation is complete 7970** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 7971** sqlite3_backup_step() obtains a [shared lock] on the source database that 7972** lasts for the duration of the sqlite3_backup_step() call. 7973** ^Because the source database is not locked between calls to 7974** sqlite3_backup_step(), the source database may be modified mid-way 7975** through the backup process. ^If the source database is modified by an 7976** external process or via a database connection other than the one being 7977** used by the backup operation, then the backup will be automatically 7978** restarted by the next call to sqlite3_backup_step(). ^If the source 7979** database is modified by the using the same database connection as is used 7980** by the backup operation, then the backup database is automatically 7981** updated at the same time. 7982** 7983** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 7984** 7985** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 7986** application wishes to abandon the backup operation, the application 7987** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 7988** ^The sqlite3_backup_finish() interfaces releases all 7989** resources associated with the [sqlite3_backup] object. 7990** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 7991** active write-transaction on the destination database is rolled back. 7992** The [sqlite3_backup] object is invalid 7993** and may not be used following a call to sqlite3_backup_finish(). 7994** 7995** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 7996** sqlite3_backup_step() errors occurred, regardless or whether or not 7997** sqlite3_backup_step() completed. 7998** ^If an out-of-memory condition or IO error occurred during any prior 7999** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 8000** sqlite3_backup_finish() returns the corresponding [error code]. 8001** 8002** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 8003** is not a permanent error and does not affect the return value of 8004** sqlite3_backup_finish(). 8005** 8006** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 8007** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 8008** 8009** ^The sqlite3_backup_remaining() routine returns the number of pages still 8010** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 8011** ^The sqlite3_backup_pagecount() routine returns the total number of pages 8012** in the source database at the conclusion of the most recent 8013** sqlite3_backup_step(). 8014** ^(The values returned by these functions are only updated by 8015** sqlite3_backup_step(). If the source database is modified in a way that 8016** changes the size of the source database or the number of pages remaining, 8017** those changes are not reflected in the output of sqlite3_backup_pagecount() 8018** and sqlite3_backup_remaining() until after the next 8019** sqlite3_backup_step().)^ 8020** 8021** <b>Concurrent Usage of Database Handles</b> 8022** 8023** ^The source [database connection] may be used by the application for other 8024** purposes while a backup operation is underway or being initialized. 8025** ^If SQLite is compiled and configured to support threadsafe database 8026** connections, then the source database connection may be used concurrently 8027** from within other threads. 8028** 8029** However, the application must guarantee that the destination 8030** [database connection] is not passed to any other API (by any thread) after 8031** sqlite3_backup_init() is called and before the corresponding call to 8032** sqlite3_backup_finish(). SQLite does not currently check to see 8033** if the application incorrectly accesses the destination [database connection] 8034** and so no error code is reported, but the operations may malfunction 8035** nevertheless. Use of the destination database connection while a 8036** backup is in progress might also also cause a mutex deadlock. 8037** 8038** If running in [shared cache mode], the application must 8039** guarantee that the shared cache used by the destination database 8040** is not accessed while the backup is running. In practice this means 8041** that the application must guarantee that the disk file being 8042** backed up to is not accessed by any connection within the process, 8043** not just the specific connection that was passed to sqlite3_backup_init(). 8044** 8045** The [sqlite3_backup] object itself is partially threadsafe. Multiple 8046** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 8047** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 8048** APIs are not strictly speaking threadsafe. If they are invoked at the 8049** same time as another thread is invoking sqlite3_backup_step() it is 8050** possible that they return invalid values. 8051*/ 8052sqlite3_backup *sqlite3_backup_init( 8053 sqlite3 *pDest, /* Destination database handle */ 8054 const char *zDestName, /* Destination database name */ 8055 sqlite3 *pSource, /* Source database handle */ 8056 const char *zSourceName /* Source database name */ 8057); 8058int sqlite3_backup_step(sqlite3_backup *p, int nPage); 8059int sqlite3_backup_finish(sqlite3_backup *p); 8060int sqlite3_backup_remaining(sqlite3_backup *p); 8061int sqlite3_backup_pagecount(sqlite3_backup *p); 8062 8063/* 8064** CAPI3REF: Unlock Notification 8065** METHOD: sqlite3 8066** 8067** ^When running in shared-cache mode, a database operation may fail with 8068** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 8069** individual tables within the shared-cache cannot be obtained. See 8070** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 8071** ^This API may be used to register a callback that SQLite will invoke 8072** when the connection currently holding the required lock relinquishes it. 8073** ^This API is only available if the library was compiled with the 8074** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 8075** 8076** See Also: [Using the SQLite Unlock Notification Feature]. 8077** 8078** ^Shared-cache locks are released when a database connection concludes 8079** its current transaction, either by committing it or rolling it back. 8080** 8081** ^When a connection (known as the blocked connection) fails to obtain a 8082** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 8083** identity of the database connection (the blocking connection) that 8084** has locked the required resource is stored internally. ^After an 8085** application receives an SQLITE_LOCKED error, it may call the 8086** sqlite3_unlock_notify() method with the blocked connection handle as 8087** the first argument to register for a callback that will be invoked 8088** when the blocking connections current transaction is concluded. ^The 8089** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 8090** call that concludes the blocking connections transaction. 8091** 8092** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 8093** there is a chance that the blocking connection will have already 8094** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 8095** If this happens, then the specified callback is invoked immediately, 8096** from within the call to sqlite3_unlock_notify().)^ 8097** 8098** ^If the blocked connection is attempting to obtain a write-lock on a 8099** shared-cache table, and more than one other connection currently holds 8100** a read-lock on the same table, then SQLite arbitrarily selects one of 8101** the other connections to use as the blocking connection. 8102** 8103** ^(There may be at most one unlock-notify callback registered by a 8104** blocked connection. If sqlite3_unlock_notify() is called when the 8105** blocked connection already has a registered unlock-notify callback, 8106** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 8107** called with a NULL pointer as its second argument, then any existing 8108** unlock-notify callback is canceled. ^The blocked connections 8109** unlock-notify callback may also be canceled by closing the blocked 8110** connection using [sqlite3_close()]. 8111** 8112** The unlock-notify callback is not reentrant. If an application invokes 8113** any sqlite3_xxx API functions from within an unlock-notify callback, a 8114** crash or deadlock may be the result. 8115** 8116** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 8117** returns SQLITE_OK. 8118** 8119** <b>Callback Invocation Details</b> 8120** 8121** When an unlock-notify callback is registered, the application provides a 8122** single void* pointer that is passed to the callback when it is invoked. 8123** However, the signature of the callback function allows SQLite to pass 8124** it an array of void* context pointers. The first argument passed to 8125** an unlock-notify callback is a pointer to an array of void* pointers, 8126** and the second is the number of entries in the array. 8127** 8128** When a blocking connections transaction is concluded, there may be 8129** more than one blocked connection that has registered for an unlock-notify 8130** callback. ^If two or more such blocked connections have specified the 8131** same callback function, then instead of invoking the callback function 8132** multiple times, it is invoked once with the set of void* context pointers 8133** specified by the blocked connections bundled together into an array. 8134** This gives the application an opportunity to prioritize any actions 8135** related to the set of unblocked database connections. 8136** 8137** <b>Deadlock Detection</b> 8138** 8139** Assuming that after registering for an unlock-notify callback a 8140** database waits for the callback to be issued before taking any further 8141** action (a reasonable assumption), then using this API may cause the 8142** application to deadlock. For example, if connection X is waiting for 8143** connection Y's transaction to be concluded, and similarly connection 8144** Y is waiting on connection X's transaction, then neither connection 8145** will proceed and the system may remain deadlocked indefinitely. 8146** 8147** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 8148** detection. ^If a given call to sqlite3_unlock_notify() would put the 8149** system in a deadlocked state, then SQLITE_LOCKED is returned and no 8150** unlock-notify callback is registered. The system is said to be in 8151** a deadlocked state if connection A has registered for an unlock-notify 8152** callback on the conclusion of connection B's transaction, and connection 8153** B has itself registered for an unlock-notify callback when connection 8154** A's transaction is concluded. ^Indirect deadlock is also detected, so 8155** the system is also considered to be deadlocked if connection B has 8156** registered for an unlock-notify callback on the conclusion of connection 8157** C's transaction, where connection C is waiting on connection A. ^Any 8158** number of levels of indirection are allowed. 8159** 8160** <b>The "DROP TABLE" Exception</b> 8161** 8162** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 8163** always appropriate to call sqlite3_unlock_notify(). There is however, 8164** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 8165** SQLite checks if there are any currently executing SELECT statements 8166** that belong to the same connection. If there are, SQLITE_LOCKED is 8167** returned. In this case there is no "blocking connection", so invoking 8168** sqlite3_unlock_notify() results in the unlock-notify callback being 8169** invoked immediately. If the application then re-attempts the "DROP TABLE" 8170** or "DROP INDEX" query, an infinite loop might be the result. 8171** 8172** One way around this problem is to check the extended error code returned 8173** by an sqlite3_step() call. ^(If there is a blocking connection, then the 8174** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 8175** the special "DROP TABLE/INDEX" case, the extended error code is just 8176** SQLITE_LOCKED.)^ 8177*/ 8178int sqlite3_unlock_notify( 8179 sqlite3 *pBlocked, /* Waiting connection */ 8180 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 8181 void *pNotifyArg /* Argument to pass to xNotify */ 8182); 8183 8184 8185/* 8186** CAPI3REF: String Comparison 8187** 8188** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 8189** and extensions to compare the contents of two buffers containing UTF-8 8190** strings in a case-independent fashion, using the same definition of "case 8191** independence" that SQLite uses internally when comparing identifiers. 8192*/ 8193int sqlite3_stricmp(const char *, const char *); 8194int sqlite3_strnicmp(const char *, const char *, int); 8195 8196/* 8197** CAPI3REF: String Globbing 8198* 8199** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 8200** string X matches the [GLOB] pattern P. 8201** ^The definition of [GLOB] pattern matching used in 8202** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 8203** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 8204** is case sensitive. 8205** 8206** Note that this routine returns zero on a match and non-zero if the strings 8207** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8208** 8209** See also: [sqlite3_strlike()]. 8210*/ 8211int sqlite3_strglob(const char *zGlob, const char *zStr); 8212 8213/* 8214** CAPI3REF: String LIKE Matching 8215* 8216** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 8217** string X matches the [LIKE] pattern P with escape character E. 8218** ^The definition of [LIKE] pattern matching used in 8219** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 8220** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 8221** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 8222** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 8223** insensitive - equivalent upper and lower case ASCII characters match 8224** one another. 8225** 8226** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 8227** only ASCII characters are case folded. 8228** 8229** Note that this routine returns zero on a match and non-zero if the strings 8230** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8231** 8232** See also: [sqlite3_strglob()]. 8233*/ 8234int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 8235 8236/* 8237** CAPI3REF: Error Logging Interface 8238** 8239** ^The [sqlite3_log()] interface writes a message into the [error log] 8240** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 8241** ^If logging is enabled, the zFormat string and subsequent arguments are 8242** used with [sqlite3_snprintf()] to generate the final output string. 8243** 8244** The sqlite3_log() interface is intended for use by extensions such as 8245** virtual tables, collating functions, and SQL functions. While there is 8246** nothing to prevent an application from calling sqlite3_log(), doing so 8247** is considered bad form. 8248** 8249** The zFormat string must not be NULL. 8250** 8251** To avoid deadlocks and other threading problems, the sqlite3_log() routine 8252** will not use dynamically allocated memory. The log message is stored in 8253** a fixed-length buffer on the stack. If the log message is longer than 8254** a few hundred characters, it will be truncated to the length of the 8255** buffer. 8256*/ 8257void sqlite3_log(int iErrCode, const char *zFormat, ...); 8258 8259/* 8260** CAPI3REF: Write-Ahead Log Commit Hook 8261** METHOD: sqlite3 8262** 8263** ^The [sqlite3_wal_hook()] function is used to register a callback that 8264** is invoked each time data is committed to a database in wal mode. 8265** 8266** ^(The callback is invoked by SQLite after the commit has taken place and 8267** the associated write-lock on the database released)^, so the implementation 8268** may read, write or [checkpoint] the database as required. 8269** 8270** ^The first parameter passed to the callback function when it is invoked 8271** is a copy of the third parameter passed to sqlite3_wal_hook() when 8272** registering the callback. ^The second is a copy of the database handle. 8273** ^The third parameter is the name of the database that was written to - 8274** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 8275** is the number of pages currently in the write-ahead log file, 8276** including those that were just committed. 8277** 8278** The callback function should normally return [SQLITE_OK]. ^If an error 8279** code is returned, that error will propagate back up through the 8280** SQLite code base to cause the statement that provoked the callback 8281** to report an error, though the commit will have still occurred. If the 8282** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 8283** that does not correspond to any valid SQLite error code, the results 8284** are undefined. 8285** 8286** A single database handle may have at most a single write-ahead log callback 8287** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 8288** previously registered write-ahead log callback. ^Note that the 8289** [sqlite3_wal_autocheckpoint()] interface and the 8290** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 8291** overwrite any prior [sqlite3_wal_hook()] settings. 8292*/ 8293void *sqlite3_wal_hook( 8294 sqlite3*, 8295 int(*)(void *,sqlite3*,const char*,int), 8296 void* 8297); 8298 8299/* 8300** CAPI3REF: Configure an auto-checkpoint 8301** METHOD: sqlite3 8302** 8303** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 8304** [sqlite3_wal_hook()] that causes any database on [database connection] D 8305** to automatically [checkpoint] 8306** after committing a transaction if there are N or 8307** more frames in the [write-ahead log] file. ^Passing zero or 8308** a negative value as the nFrame parameter disables automatic 8309** checkpoints entirely. 8310** 8311** ^The callback registered by this function replaces any existing callback 8312** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 8313** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 8314** configured by this function. 8315** 8316** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 8317** from SQL. 8318** 8319** ^Checkpoints initiated by this mechanism are 8320** [sqlite3_wal_checkpoint_v2|PASSIVE]. 8321** 8322** ^Every new [database connection] defaults to having the auto-checkpoint 8323** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 8324** pages. The use of this interface 8325** is only necessary if the default setting is found to be suboptimal 8326** for a particular application. 8327*/ 8328int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 8329 8330/* 8331** CAPI3REF: Checkpoint a database 8332** METHOD: sqlite3 8333** 8334** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 8335** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 8336** 8337** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 8338** [write-ahead log] for database X on [database connection] D to be 8339** transferred into the database file and for the write-ahead log to 8340** be reset. See the [checkpointing] documentation for addition 8341** information. 8342** 8343** This interface used to be the only way to cause a checkpoint to 8344** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 8345** interface was added. This interface is retained for backwards 8346** compatibility and as a convenience for applications that need to manually 8347** start a callback but which do not need the full power (and corresponding 8348** complication) of [sqlite3_wal_checkpoint_v2()]. 8349*/ 8350int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 8351 8352/* 8353** CAPI3REF: Checkpoint a database 8354** METHOD: sqlite3 8355** 8356** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 8357** operation on database X of [database connection] D in mode M. Status 8358** information is written back into integers pointed to by L and C.)^ 8359** ^(The M parameter must be a valid [checkpoint mode]:)^ 8360** 8361** <dl> 8362** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 8363** ^Checkpoint as many frames as possible without waiting for any database 8364** readers or writers to finish, then sync the database file if all frames 8365** in the log were checkpointed. ^The [busy-handler callback] 8366** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 8367** ^On the other hand, passive mode might leave the checkpoint unfinished 8368** if there are concurrent readers or writers. 8369** 8370** <dt>SQLITE_CHECKPOINT_FULL<dd> 8371** ^This mode blocks (it invokes the 8372** [sqlite3_busy_handler|busy-handler callback]) until there is no 8373** database writer and all readers are reading from the most recent database 8374** snapshot. ^It then checkpoints all frames in the log file and syncs the 8375** database file. ^This mode blocks new database writers while it is pending, 8376** but new database readers are allowed to continue unimpeded. 8377** 8378** <dt>SQLITE_CHECKPOINT_RESTART<dd> 8379** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 8380** that after checkpointing the log file it blocks (calls the 8381** [busy-handler callback]) 8382** until all readers are reading from the database file only. ^This ensures 8383** that the next writer will restart the log file from the beginning. 8384** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 8385** database writer attempts while it is pending, but does not impede readers. 8386** 8387** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 8388** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 8389** addition that it also truncates the log file to zero bytes just prior 8390** to a successful return. 8391** </dl> 8392** 8393** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 8394** the log file or to -1 if the checkpoint could not run because 8395** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 8396** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 8397** log file (including any that were already checkpointed before the function 8398** was called) or to -1 if the checkpoint could not run due to an error or 8399** because the database is not in WAL mode. ^Note that upon successful 8400** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 8401** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 8402** 8403** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 8404** any other process is running a checkpoint operation at the same time, the 8405** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 8406** busy-handler configured, it will not be invoked in this case. 8407** 8408** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 8409** exclusive "writer" lock on the database file. ^If the writer lock cannot be 8410** obtained immediately, and a busy-handler is configured, it is invoked and 8411** the writer lock retried until either the busy-handler returns 0 or the lock 8412** is successfully obtained. ^The busy-handler is also invoked while waiting for 8413** database readers as described above. ^If the busy-handler returns 0 before 8414** the writer lock is obtained or while waiting for database readers, the 8415** checkpoint operation proceeds from that point in the same way as 8416** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 8417** without blocking any further. ^SQLITE_BUSY is returned in this case. 8418** 8419** ^If parameter zDb is NULL or points to a zero length string, then the 8420** specified operation is attempted on all WAL databases [attached] to 8421** [database connection] db. In this case the 8422** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 8423** an SQLITE_BUSY error is encountered when processing one or more of the 8424** attached WAL databases, the operation is still attempted on any remaining 8425** attached databases and SQLITE_BUSY is returned at the end. ^If any other 8426** error occurs while processing an attached database, processing is abandoned 8427** and the error code is returned to the caller immediately. ^If no error 8428** (SQLITE_BUSY or otherwise) is encountered while processing the attached 8429** databases, SQLITE_OK is returned. 8430** 8431** ^If database zDb is the name of an attached database that is not in WAL 8432** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 8433** zDb is not NULL (or a zero length string) and is not the name of any 8434** attached database, SQLITE_ERROR is returned to the caller. 8435** 8436** ^Unless it returns SQLITE_MISUSE, 8437** the sqlite3_wal_checkpoint_v2() interface 8438** sets the error information that is queried by 8439** [sqlite3_errcode()] and [sqlite3_errmsg()]. 8440** 8441** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 8442** from SQL. 8443*/ 8444int sqlite3_wal_checkpoint_v2( 8445 sqlite3 *db, /* Database handle */ 8446 const char *zDb, /* Name of attached database (or NULL) */ 8447 int eMode, /* SQLITE_CHECKPOINT_* value */ 8448 int *pnLog, /* OUT: Size of WAL log in frames */ 8449 int *pnCkpt /* OUT: Total number of frames checkpointed */ 8450); 8451 8452/* 8453** CAPI3REF: Checkpoint Mode Values 8454** KEYWORDS: {checkpoint mode} 8455** 8456** These constants define all valid values for the "checkpoint mode" passed 8457** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 8458** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 8459** meaning of each of these checkpoint modes. 8460*/ 8461#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 8462#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 8463#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 8464#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 8465 8466/* 8467** CAPI3REF: Virtual Table Interface Configuration 8468** 8469** This function may be called by either the [xConnect] or [xCreate] method 8470** of a [virtual table] implementation to configure 8471** various facets of the virtual table interface. 8472** 8473** If this interface is invoked outside the context of an xConnect or 8474** xCreate virtual table method then the behavior is undefined. 8475** 8476** At present, there is only one option that may be configured using 8477** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 8478** may be added in the future. 8479*/ 8480int sqlite3_vtab_config(sqlite3*, int op, ...); 8481 8482/* 8483** CAPI3REF: Virtual Table Configuration Options 8484** 8485** These macros define the various options to the 8486** [sqlite3_vtab_config()] interface that [virtual table] implementations 8487** can use to customize and optimize their behavior. 8488** 8489** <dl> 8490** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 8491** <dd>Calls of the form 8492** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 8493** where X is an integer. If X is zero, then the [virtual table] whose 8494** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 8495** support constraints. In this configuration (which is the default) if 8496** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 8497** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 8498** specified as part of the users SQL statement, regardless of the actual 8499** ON CONFLICT mode specified. 8500** 8501** If X is non-zero, then the virtual table implementation guarantees 8502** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 8503** any modifications to internal or persistent data structures have been made. 8504** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 8505** is able to roll back a statement or database transaction, and abandon 8506** or continue processing the current SQL statement as appropriate. 8507** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 8508** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 8509** had been ABORT. 8510** 8511** Virtual table implementations that are required to handle OR REPLACE 8512** must do so within the [xUpdate] method. If a call to the 8513** [sqlite3_vtab_on_conflict()] function indicates that the current ON 8514** CONFLICT policy is REPLACE, the virtual table implementation should 8515** silently replace the appropriate rows within the xUpdate callback and 8516** return SQLITE_OK. Or, if this is not possible, it may return 8517** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 8518** constraint handling. 8519** </dl> 8520*/ 8521#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 8522 8523/* 8524** CAPI3REF: Determine The Virtual Table Conflict Policy 8525** 8526** This function may only be called from within a call to the [xUpdate] method 8527** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 8528** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 8529** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 8530** of the SQL statement that triggered the call to the [xUpdate] method of the 8531** [virtual table]. 8532*/ 8533int sqlite3_vtab_on_conflict(sqlite3 *); 8534 8535/* 8536** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 8537** 8538** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 8539** method of a [virtual table], then it returns true if and only if the 8540** column is being fetched as part of an UPDATE operation during which the 8541** column value will not change. Applications might use this to substitute 8542** a return value that is less expensive to compute and that the corresponding 8543** [xUpdate] method understands as a "no-change" value. 8544** 8545** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 8546** the column is not changed by the UPDATE statement, then the xColumn 8547** method can optionally return without setting a result, without calling 8548** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 8549** In that case, [sqlite3_value_nochange(X)] will return true for the 8550** same column in the [xUpdate] method. 8551*/ 8552int sqlite3_vtab_nochange(sqlite3_context*); 8553 8554/* 8555** CAPI3REF: Determine The Collation For a Virtual Table Constraint 8556** 8557** This function may only be called from within a call to the [xBestIndex] 8558** method of a [virtual table]. 8559** 8560** The first argument must be the sqlite3_index_info object that is the 8561** first parameter to the xBestIndex() method. The second argument must be 8562** an index into the aConstraint[] array belonging to the sqlite3_index_info 8563** structure passed to xBestIndex. This function returns a pointer to a buffer 8564** containing the name of the collation sequence for the corresponding 8565** constraint. 8566*/ 8567SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 8568 8569/* 8570** CAPI3REF: Conflict resolution modes 8571** KEYWORDS: {conflict resolution mode} 8572** 8573** These constants are returned by [sqlite3_vtab_on_conflict()] to 8574** inform a [virtual table] implementation what the [ON CONFLICT] mode 8575** is for the SQL statement being evaluated. 8576** 8577** Note that the [SQLITE_IGNORE] constant is also used as a potential 8578** return value from the [sqlite3_set_authorizer()] callback and that 8579** [SQLITE_ABORT] is also a [result code]. 8580*/ 8581#define SQLITE_ROLLBACK 1 8582/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 8583#define SQLITE_FAIL 3 8584/* #define SQLITE_ABORT 4 // Also an error code */ 8585#define SQLITE_REPLACE 5 8586 8587/* 8588** CAPI3REF: Prepared Statement Scan Status Opcodes 8589** KEYWORDS: {scanstatus options} 8590** 8591** The following constants can be used for the T parameter to the 8592** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 8593** different metric for sqlite3_stmt_scanstatus() to return. 8594** 8595** When the value returned to V is a string, space to hold that string is 8596** managed by the prepared statement S and will be automatically freed when 8597** S is finalized. 8598** 8599** <dl> 8600** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 8601** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 8602** set to the total number of times that the X-th loop has run.</dd> 8603** 8604** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 8605** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 8606** to the total number of rows examined by all iterations of the X-th loop.</dd> 8607** 8608** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 8609** <dd>^The "double" variable pointed to by the T parameter will be set to the 8610** query planner's estimate for the average number of rows output from each 8611** iteration of the X-th loop. If the query planner's estimates was accurate, 8612** then this value will approximate the quotient NVISIT/NLOOP and the 8613** product of this value for all prior loops with the same SELECTID will 8614** be the NLOOP value for the current loop. 8615** 8616** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 8617** <dd>^The "const char *" variable pointed to by the T parameter will be set 8618** to a zero-terminated UTF-8 string containing the name of the index or table 8619** used for the X-th loop. 8620** 8621** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 8622** <dd>^The "const char *" variable pointed to by the T parameter will be set 8623** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 8624** description for the X-th loop. 8625** 8626** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 8627** <dd>^The "int" variable pointed to by the T parameter will be set to the 8628** "select-id" for the X-th loop. The select-id identifies which query or 8629** subquery the loop is part of. The main query has a select-id of zero. 8630** The select-id is the same value as is output in the first column 8631** of an [EXPLAIN QUERY PLAN] query. 8632** </dl> 8633*/ 8634#define SQLITE_SCANSTAT_NLOOP 0 8635#define SQLITE_SCANSTAT_NVISIT 1 8636#define SQLITE_SCANSTAT_EST 2 8637#define SQLITE_SCANSTAT_NAME 3 8638#define SQLITE_SCANSTAT_EXPLAIN 4 8639#define SQLITE_SCANSTAT_SELECTID 5 8640 8641/* 8642** CAPI3REF: Prepared Statement Scan Status 8643** METHOD: sqlite3_stmt 8644** 8645** This interface returns information about the predicted and measured 8646** performance for pStmt. Advanced applications can use this 8647** interface to compare the predicted and the measured performance and 8648** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 8649** 8650** Since this interface is expected to be rarely used, it is only 8651** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 8652** compile-time option. 8653** 8654** The "iScanStatusOp" parameter determines which status information to return. 8655** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 8656** of this interface is undefined. 8657** ^The requested measurement is written into a variable pointed to by 8658** the "pOut" parameter. 8659** Parameter "idx" identifies the specific loop to retrieve statistics for. 8660** Loops are numbered starting from zero. ^If idx is out of range - less than 8661** zero or greater than or equal to the total number of loops used to implement 8662** the statement - a non-zero value is returned and the variable that pOut 8663** points to is unchanged. 8664** 8665** ^Statistics might not be available for all loops in all statements. ^In cases 8666** where there exist loops with no available statistics, this function behaves 8667** as if the loop did not exist - it returns non-zero and leave the variable 8668** that pOut points to unchanged. 8669** 8670** See also: [sqlite3_stmt_scanstatus_reset()] 8671*/ 8672int sqlite3_stmt_scanstatus( 8673 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 8674 int idx, /* Index of loop to report on */ 8675 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 8676 void *pOut /* Result written here */ 8677); 8678 8679/* 8680** CAPI3REF: Zero Scan-Status Counters 8681** METHOD: sqlite3_stmt 8682** 8683** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 8684** 8685** This API is only available if the library is built with pre-processor 8686** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 8687*/ 8688void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 8689 8690/* 8691** CAPI3REF: Flush caches to disk mid-transaction 8692** 8693** ^If a write-transaction is open on [database connection] D when the 8694** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 8695** pages in the pager-cache that are not currently in use are written out 8696** to disk. A dirty page may be in use if a database cursor created by an 8697** active SQL statement is reading from it, or if it is page 1 of a database 8698** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 8699** interface flushes caches for all schemas - "main", "temp", and 8700** any [attached] databases. 8701** 8702** ^If this function needs to obtain extra database locks before dirty pages 8703** can be flushed to disk, it does so. ^If those locks cannot be obtained 8704** immediately and there is a busy-handler callback configured, it is invoked 8705** in the usual manner. ^If the required lock still cannot be obtained, then 8706** the database is skipped and an attempt made to flush any dirty pages 8707** belonging to the next (if any) database. ^If any databases are skipped 8708** because locks cannot be obtained, but no other error occurs, this 8709** function returns SQLITE_BUSY. 8710** 8711** ^If any other error occurs while flushing dirty pages to disk (for 8712** example an IO error or out-of-memory condition), then processing is 8713** abandoned and an SQLite [error code] is returned to the caller immediately. 8714** 8715** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 8716** 8717** ^This function does not set the database handle error code or message 8718** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 8719*/ 8720int sqlite3_db_cacheflush(sqlite3*); 8721 8722/* 8723** CAPI3REF: The pre-update hook. 8724** 8725** ^These interfaces are only available if SQLite is compiled using the 8726** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 8727** 8728** ^The [sqlite3_preupdate_hook()] interface registers a callback function 8729** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 8730** on a database table. 8731** ^At most one preupdate hook may be registered at a time on a single 8732** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 8733** the previous setting. 8734** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 8735** with a NULL pointer as the second parameter. 8736** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 8737** the first parameter to callbacks. 8738** 8739** ^The preupdate hook only fires for changes to real database tables; the 8740** preupdate hook is not invoked for changes to [virtual tables] or to 8741** system tables like sqlite_master or sqlite_stat1. 8742** 8743** ^The second parameter to the preupdate callback is a pointer to 8744** the [database connection] that registered the preupdate hook. 8745** ^The third parameter to the preupdate callback is one of the constants 8746** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 8747** kind of update operation that is about to occur. 8748** ^(The fourth parameter to the preupdate callback is the name of the 8749** database within the database connection that is being modified. This 8750** will be "main" for the main database or "temp" for TEMP tables or 8751** the name given after the AS keyword in the [ATTACH] statement for attached 8752** databases.)^ 8753** ^The fifth parameter to the preupdate callback is the name of the 8754** table that is being modified. 8755** 8756** For an UPDATE or DELETE operation on a [rowid table], the sixth 8757** parameter passed to the preupdate callback is the initial [rowid] of the 8758** row being modified or deleted. For an INSERT operation on a rowid table, 8759** or any operation on a WITHOUT ROWID table, the value of the sixth 8760** parameter is undefined. For an INSERT or UPDATE on a rowid table the 8761** seventh parameter is the final rowid value of the row being inserted 8762** or updated. The value of the seventh parameter passed to the callback 8763** function is not defined for operations on WITHOUT ROWID tables, or for 8764** INSERT operations on rowid tables. 8765** 8766** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 8767** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 8768** provide additional information about a preupdate event. These routines 8769** may only be called from within a preupdate callback. Invoking any of 8770** these routines from outside of a preupdate callback or with a 8771** [database connection] pointer that is different from the one supplied 8772** to the preupdate callback results in undefined and probably undesirable 8773** behavior. 8774** 8775** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 8776** in the row that is being inserted, updated, or deleted. 8777** 8778** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 8779** a [protected sqlite3_value] that contains the value of the Nth column of 8780** the table row before it is updated. The N parameter must be between 0 8781** and one less than the number of columns or the behavior will be 8782** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 8783** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 8784** behavior is undefined. The [sqlite3_value] that P points to 8785** will be destroyed when the preupdate callback returns. 8786** 8787** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 8788** a [protected sqlite3_value] that contains the value of the Nth column of 8789** the table row after it is updated. The N parameter must be between 0 8790** and one less than the number of columns or the behavior will be 8791** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 8792** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 8793** behavior is undefined. The [sqlite3_value] that P points to 8794** will be destroyed when the preupdate callback returns. 8795** 8796** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 8797** callback was invoked as a result of a direct insert, update, or delete 8798** operation; or 1 for inserts, updates, or deletes invoked by top-level 8799** triggers; or 2 for changes resulting from triggers called by top-level 8800** triggers; and so forth. 8801** 8802** See also: [sqlite3_update_hook()] 8803*/ 8804#if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 8805void *sqlite3_preupdate_hook( 8806 sqlite3 *db, 8807 void(*xPreUpdate)( 8808 void *pCtx, /* Copy of third arg to preupdate_hook() */ 8809 sqlite3 *db, /* Database handle */ 8810 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 8811 char const *zDb, /* Database name */ 8812 char const *zName, /* Table name */ 8813 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 8814 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 8815 ), 8816 void* 8817); 8818int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 8819int sqlite3_preupdate_count(sqlite3 *); 8820int sqlite3_preupdate_depth(sqlite3 *); 8821int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 8822#endif 8823 8824/* 8825** CAPI3REF: Low-level system error code 8826** 8827** ^Attempt to return the underlying operating system error code or error 8828** number that caused the most recent I/O error or failure to open a file. 8829** The return value is OS-dependent. For example, on unix systems, after 8830** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 8831** called to get back the underlying "errno" that caused the problem, such 8832** as ENOSPC, EAUTH, EISDIR, and so forth. 8833*/ 8834int sqlite3_system_errno(sqlite3*); 8835 8836/* 8837** CAPI3REF: Database Snapshot 8838** KEYWORDS: {snapshot} {sqlite3_snapshot} 8839** EXPERIMENTAL 8840** 8841** An instance of the snapshot object records the state of a [WAL mode] 8842** database for some specific point in history. 8843** 8844** In [WAL mode], multiple [database connections] that are open on the 8845** same database file can each be reading a different historical version 8846** of the database file. When a [database connection] begins a read 8847** transaction, that connection sees an unchanging copy of the database 8848** as it existed for the point in time when the transaction first started. 8849** Subsequent changes to the database from other connections are not seen 8850** by the reader until a new read transaction is started. 8851** 8852** The sqlite3_snapshot object records state information about an historical 8853** version of the database file so that it is possible to later open a new read 8854** transaction that sees that historical version of the database rather than 8855** the most recent version. 8856** 8857** The constructor for this object is [sqlite3_snapshot_get()]. The 8858** [sqlite3_snapshot_open()] method causes a fresh read transaction to refer 8859** to an historical snapshot (if possible). The destructor for 8860** sqlite3_snapshot objects is [sqlite3_snapshot_free()]. 8861*/ 8862typedef struct sqlite3_snapshot { 8863 unsigned char hidden[48]; 8864} sqlite3_snapshot; 8865 8866/* 8867** CAPI3REF: Record A Database Snapshot 8868** EXPERIMENTAL 8869** 8870** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 8871** new [sqlite3_snapshot] object that records the current state of 8872** schema S in database connection D. ^On success, the 8873** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 8874** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 8875** If there is not already a read-transaction open on schema S when 8876** this function is called, one is opened automatically. 8877** 8878** The following must be true for this function to succeed. If any of 8879** the following statements are false when sqlite3_snapshot_get() is 8880** called, SQLITE_ERROR is returned. The final value of *P is undefined 8881** in this case. 8882** 8883** <ul> 8884** <li> The database handle must be in [autocommit mode]. 8885** 8886** <li> Schema S of [database connection] D must be a [WAL mode] database. 8887** 8888** <li> There must not be a write transaction open on schema S of database 8889** connection D. 8890** 8891** <li> One or more transactions must have been written to the current wal 8892** file since it was created on disk (by any connection). This means 8893** that a snapshot cannot be taken on a wal mode database with no wal 8894** file immediately after it is first opened. At least one transaction 8895** must be written to it first. 8896** </ul> 8897** 8898** This function may also return SQLITE_NOMEM. If it is called with the 8899** database handle in autocommit mode but fails for some other reason, 8900** whether or not a read transaction is opened on schema S is undefined. 8901** 8902** The [sqlite3_snapshot] object returned from a successful call to 8903** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 8904** to avoid a memory leak. 8905** 8906** The [sqlite3_snapshot_get()] interface is only available when the 8907** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8908*/ 8909SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 8910 sqlite3 *db, 8911 const char *zSchema, 8912 sqlite3_snapshot **ppSnapshot 8913); 8914 8915/* 8916** CAPI3REF: Start a read transaction on an historical snapshot 8917** EXPERIMENTAL 8918** 8919** ^The [sqlite3_snapshot_open(D,S,P)] interface starts a 8920** read transaction for schema S of 8921** [database connection] D such that the read transaction 8922** refers to historical [snapshot] P, rather than the most 8923** recent change to the database. 8924** ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK on success 8925** or an appropriate [error code] if it fails. 8926** 8927** ^In order to succeed, a call to [sqlite3_snapshot_open(D,S,P)] must be 8928** the first operation following the [BEGIN] that takes the schema S 8929** out of [autocommit mode]. 8930** ^In other words, schema S must not currently be in 8931** a transaction for [sqlite3_snapshot_open(D,S,P)] to work, but the 8932** database connection D must be out of [autocommit mode]. 8933** ^A [snapshot] will fail to open if it has been overwritten by a 8934** [checkpoint]. 8935** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 8936** database connection D does not know that the database file for 8937** schema S is in [WAL mode]. A database connection might not know 8938** that the database file is in [WAL mode] if there has been no prior 8939** I/O on that database connection, or if the database entered [WAL mode] 8940** after the most recent I/O on the database connection.)^ 8941** (Hint: Run "[PRAGMA application_id]" against a newly opened 8942** database connection in order to make it ready to use snapshots.) 8943** 8944** The [sqlite3_snapshot_open()] interface is only available when the 8945** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8946*/ 8947SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 8948 sqlite3 *db, 8949 const char *zSchema, 8950 sqlite3_snapshot *pSnapshot 8951); 8952 8953/* 8954** CAPI3REF: Destroy a snapshot 8955** EXPERIMENTAL 8956** 8957** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 8958** The application must eventually free every [sqlite3_snapshot] object 8959** using this routine to avoid a memory leak. 8960** 8961** The [sqlite3_snapshot_free()] interface is only available when the 8962** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8963*/ 8964SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 8965 8966/* 8967** CAPI3REF: Compare the ages of two snapshot handles. 8968** EXPERIMENTAL 8969** 8970** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 8971** of two valid snapshot handles. 8972** 8973** If the two snapshot handles are not associated with the same database 8974** file, the result of the comparison is undefined. 8975** 8976** Additionally, the result of the comparison is only valid if both of the 8977** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 8978** last time the wal file was deleted. The wal file is deleted when the 8979** database is changed back to rollback mode or when the number of database 8980** clients drops to zero. If either snapshot handle was obtained before the 8981** wal file was last deleted, the value returned by this function 8982** is undefined. 8983** 8984** Otherwise, this API returns a negative value if P1 refers to an older 8985** snapshot than P2, zero if the two handles refer to the same database 8986** snapshot, and a positive value if P1 is a newer snapshot than P2. 8987*/ 8988SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 8989 sqlite3_snapshot *p1, 8990 sqlite3_snapshot *p2 8991); 8992 8993/* 8994** CAPI3REF: Recover snapshots from a wal file 8995** EXPERIMENTAL 8996** 8997** If all connections disconnect from a database file but do not perform 8998** a checkpoint, the existing wal file is opened along with the database 8999** file the next time the database is opened. At this point it is only 9000** possible to successfully call sqlite3_snapshot_open() to open the most 9001** recent snapshot of the database (the one at the head of the wal file), 9002** even though the wal file may contain other valid snapshots for which 9003** clients have sqlite3_snapshot handles. 9004** 9005** This function attempts to scan the wal file associated with database zDb 9006** of database handle db and make all valid snapshots available to 9007** sqlite3_snapshot_open(). It is an error if there is already a read 9008** transaction open on the database, or if the database is not a wal mode 9009** database. 9010** 9011** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 9012*/ 9013SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 9014 9015/* 9016** CAPI3REF: Serialize a database 9017** 9018** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 9019** that is a serialization of the S database on [database connection] D. 9020** If P is not a NULL pointer, then the size of the database in bytes 9021** is written into *P. 9022** 9023** For an ordinary on-disk database file, the serialization is just a 9024** copy of the disk file. For an in-memory database or a "TEMP" database, 9025** the serialization is the same sequence of bytes which would be written 9026** to disk if that database where backed up to disk. 9027** 9028** The usual case is that sqlite3_serialize() copies the serialization of 9029** the database into memory obtained from [sqlite3_malloc64()] and returns 9030** a pointer to that memory. The caller is responsible for freeing the 9031** returned value to avoid a memory leak. However, if the F argument 9032** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 9033** are made, and the sqlite3_serialize() function will return a pointer 9034** to the contiguous memory representation of the database that SQLite 9035** is currently using for that database, or NULL if the no such contiguous 9036** memory representation of the database exists. A contiguous memory 9037** representation of the database will usually only exist if there has 9038** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 9039** values of D and S. 9040** The size of the database is written into *P even if the 9041** SQLITE_SERIALIZE_NOCOPY bit is set but no contigious copy 9042** of the database exists. 9043** 9044** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 9045** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 9046** allocation error occurs. 9047** 9048** This interface is only available if SQLite is compiled with the 9049** [SQLITE_ENABLE_DESERIALIZE] option. 9050*/ 9051unsigned char *sqlite3_serialize( 9052 sqlite3 *db, /* The database connection */ 9053 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 9054 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 9055 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 9056); 9057 9058/* 9059** CAPI3REF: Flags for sqlite3_serialize 9060** 9061** Zero or more of the following constants can be OR-ed together for 9062** the F argument to [sqlite3_serialize(D,S,P,F)]. 9063** 9064** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 9065** a pointer to contiguous in-memory database that it is currently using, 9066** without making a copy of the database. If SQLite is not currently using 9067** a contiguous in-memory database, then this option causes 9068** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 9069** using a contiguous in-memory database if it has been initialized by a 9070** prior call to [sqlite3_deserialize()]. 9071*/ 9072#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 9073 9074/* 9075** CAPI3REF: Deserialize a database 9076** 9077** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 9078** [database connection] D to disconnect from database S and then 9079** reopen S as an in-memory database based on the serialization contained 9080** in P. The serialized database P is N bytes in size. M is the size of 9081** the buffer P, which might be larger than N. If M is larger than N, and 9082** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 9083** permitted to add content to the in-memory database as long as the total 9084** size does not exceed M bytes. 9085** 9086** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 9087** invoke sqlite3_free() on the serialization buffer when the database 9088** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 9089** SQLite will try to increase the buffer size using sqlite3_realloc64() 9090** if writes on the database cause it to grow larger than M bytes. 9091** 9092** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 9093** database is currently in a read transaction or is involved in a backup 9094** operation. 9095** 9096** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 9097** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 9098** [sqlite3_free()] is invoked on argument P prior to returning. 9099** 9100** This interface is only available if SQLite is compiled with the 9101** [SQLITE_ENABLE_DESERIALIZE] option. 9102*/ 9103int sqlite3_deserialize( 9104 sqlite3 *db, /* The database connection */ 9105 const char *zSchema, /* Which DB to reopen with the deserialization */ 9106 unsigned char *pData, /* The serialized database content */ 9107 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 9108 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 9109 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 9110); 9111 9112/* 9113** CAPI3REF: Flags for sqlite3_deserialize() 9114** 9115** The following are allowed values for 6th argument (the F argument) to 9116** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 9117** 9118** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 9119** in the P argument is held in memory obtained from [sqlite3_malloc64()] 9120** and that SQLite should take ownership of this memory and automatically 9121** free it when it has finished using it. Without this flag, the caller 9122** is resposible for freeing any dynamically allocated memory. 9123** 9124** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 9125** grow the size of the database using calls to [sqlite3_realloc64()]. This 9126** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 9127** Without this flag, the deserialized database cannot increase in size beyond 9128** the number of bytes specified by the M parameter. 9129** 9130** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 9131** should be treated as read-only. 9132*/ 9133#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 9134#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 9135#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 9136 9137/* 9138** Undo the hack that converts floating point types to integer for 9139** builds on processors without floating point support. 9140*/ 9141#ifdef SQLITE_OMIT_FLOATING_POINT 9142# undef double 9143#endif 9144 9145#ifdef __cplusplus 9146} /* End of the 'extern "C"' block */ 9147#endif 9148#endif /* SQLITE3_H */ 9149