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Copy pathprepare.c
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873 lines (817 loc) · 28 KB
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/*
** 2005 May 25
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the implementation of the sqlite3_prepare()
** interface, and routines that contribute to loading the database schema
** from disk.
*/
#include "sqliteInt.h"
/*
** Fill the InitData structure with an error message that indicates
** that the database is corrupt.
*/
static void corruptSchema(
InitData *pData, /* Initialization context */
const char *zObj, /* Object being parsed at the point of error */
const char *zExtra /* Error information */
){
sqlite3 *db = pData->db;
if( !db->mallocFailed && (db->flags & SQLITE_RecoveryMode)==0 ){
if( zObj==0 ) zObj = "?";
sqlite3SetString(pData->pzErrMsg, db,
"malformed database schema (%s)", zObj);
if( zExtra ){
*pData->pzErrMsg = sqlite3MAppendf(db, *pData->pzErrMsg,
"%s - %s", *pData->pzErrMsg, zExtra);
}
}
pData->rc = db->mallocFailed ? SQLITE_NOMEM : SQLITE_CORRUPT_BKPT;
}
/*
** This is the callback routine for the code that initializes the
** database. See sqlite3Init() below for additional information.
** This routine is also called from the OP_ParseSchema opcode of the VDBE.
**
** Each callback contains the following information:
**
** argv[0] = name of thing being created
** argv[1] = root page number for table or index. 0 for trigger or view.
** argv[2] = SQL text for the CREATE statement.
**
*/
int sqlite3InitCallback(void *pInit, int argc, char **argv, char **NotUsed){
InitData *pData = (InitData*)pInit;
sqlite3 *db = pData->db;
int iDb = pData->iDb;
assert( argc==3 );
UNUSED_PARAMETER2(NotUsed, argc);
assert( sqlite3_mutex_held(db->mutex) );
DbClearProperty(db, iDb, DB_Empty);
if( db->mallocFailed ){
corruptSchema(pData, argv[0], 0);
return 1;
}
assert( iDb>=0 && iDb<db->nDb );
if( argv==0 ) return 0; /* Might happen if EMPTY_RESULT_CALLBACKS are on */
if( argv[1]==0 ){
corruptSchema(pData, argv[0], 0);
}else if( argv[2] && argv[2][0] ){
/* Call the parser to process a CREATE TABLE, INDEX or VIEW.
** But because db->init.busy is set to 1, no VDBE code is generated
** or executed. All the parser does is build the internal data
** structures that describe the table, index, or view.
*/
int rc;
sqlite3_stmt *pStmt;
TESTONLY(int rcp); /* Return code from sqlite3_prepare() */
assert( db->init.busy );
db->init.iDb = iDb;
db->init.newTnum = sqlite3Atoi(argv[1]);
db->init.orphanTrigger = 0;
TESTONLY(rcp = ) sqlite3_prepare(db, argv[2], -1, &pStmt, 0);
rc = db->errCode;
assert( (rc&0xFF)==(rcp&0xFF) );
db->init.iDb = 0;
if( SQLITE_OK!=rc ){
if( db->init.orphanTrigger ){
assert( iDb==1 );
}else{
pData->rc = rc;
if( rc==SQLITE_NOMEM ){
db->mallocFailed = 1;
}else if( rc!=SQLITE_INTERRUPT && (rc&0xFF)!=SQLITE_LOCKED ){
corruptSchema(pData, argv[0], sqlite3_errmsg(db));
}
}
}
sqlite3_finalize(pStmt);
}else if( argv[0]==0 ){
corruptSchema(pData, 0, 0);
}else{
/* If the SQL column is blank it means this is an index that
** was created to be the PRIMARY KEY or to fulfill a UNIQUE
** constraint for a CREATE TABLE. The index should have already
** been created when we processed the CREATE TABLE. All we have
** to do here is record the root page number for that index.
*/
Index *pIndex;
pIndex = sqlite3FindIndex(db, argv[0], db->aDb[iDb].zName);
if( pIndex==0 ){
/* This can occur if there exists an index on a TEMP table which
** has the same name as another index on a permanent index. Since
** the permanent table is hidden by the TEMP table, we can also
** safely ignore the index on the permanent table.
*/
/* Do Nothing */;
}else if( sqlite3GetInt32(argv[1], &pIndex->tnum)==0 ){
corruptSchema(pData, argv[0], "invalid rootpage");
}
}
return 0;
}
/*
** Attempt to read the database schema and initialize internal
** data structures for a single database file. The index of the
** database file is given by iDb. iDb==0 is used for the main
** database. iDb==1 should never be used. iDb>=2 is used for
** auxiliary databases. Return one of the SQLITE_ error codes to
** indicate success or failure.
*/
static int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg){
int rc;
int i;
#ifndef SQLITE_OMIT_DEPRECATED
int size;
#endif
Table *pTab;
Db *pDb;
char const *azArg[4];
int meta[5];
InitData initData;
char const *zMasterSchema;
char const *zMasterName;
int openedTransaction = 0;
/*
** The master database table has a structure like this
*/
static const char master_schema[] =
"CREATE TABLE sqlite_master(\n"
" type text,\n"
" name text,\n"
" tbl_name text,\n"
" rootpage integer,\n"
" sql text\n"
")"
;
#ifndef SQLITE_OMIT_TEMPDB
static const char temp_master_schema[] =
"CREATE TEMP TABLE sqlite_temp_master(\n"
" type text,\n"
" name text,\n"
" tbl_name text,\n"
" rootpage integer,\n"
" sql text\n"
")"
;
#else
#define temp_master_schema 0
#endif
assert( iDb>=0 && iDb<db->nDb );
assert( db->aDb[iDb].pSchema );
assert( sqlite3_mutex_held(db->mutex) );
assert( iDb==1 || sqlite3BtreeHoldsMutex(db->aDb[iDb].pBt) );
/* zMasterSchema and zInitScript are set to point at the master schema
** and initialisation script appropriate for the database being
** initialized. zMasterName is the name of the master table.
*/
if( !OMIT_TEMPDB && iDb==1 ){
zMasterSchema = temp_master_schema;
}else{
zMasterSchema = master_schema;
}
zMasterName = SCHEMA_TABLE(iDb);
/* Construct the schema tables. */
azArg[0] = zMasterName;
azArg[1] = "1";
azArg[2] = zMasterSchema;
azArg[3] = 0;
initData.db = db;
initData.iDb = iDb;
initData.rc = SQLITE_OK;
initData.pzErrMsg = pzErrMsg;
sqlite3InitCallback(&initData, 3, (char **)azArg, 0);
if( initData.rc ){
rc = initData.rc;
goto error_out;
}
pTab = sqlite3FindTable(db, zMasterName, db->aDb[iDb].zName);
if( ALWAYS(pTab) ){
pTab->tabFlags |= TF_Readonly;
}
/* Create a cursor to hold the database open
*/
pDb = &db->aDb[iDb];
if( pDb->pBt==0 ){
if( !OMIT_TEMPDB && ALWAYS(iDb==1) ){
DbSetProperty(db, 1, DB_SchemaLoaded);
}
return SQLITE_OK;
}
/* If there is not already a read-only (or read-write) transaction opened
** on the b-tree database, open one now. If a transaction is opened, it
** will be closed before this function returns. */
sqlite3BtreeEnter(pDb->pBt);
if( !sqlite3BtreeIsInReadTrans(pDb->pBt) ){
rc = sqlite3BtreeBeginTrans(pDb->pBt, 0);
if( rc!=SQLITE_OK ){
sqlite3SetString(pzErrMsg, db, "%s", sqlite3ErrStr(rc));
goto initone_error_out;
}
openedTransaction = 1;
}
/* Get the database meta information.
**
** Meta values are as follows:
** meta[0] Schema cookie. Changes with each schema change.
** meta[1] File format of schema layer.
** meta[2] Size of the page cache.
** meta[3] Largest rootpage (auto/incr_vacuum mode)
** meta[4] Db text encoding. 1:UTF-8 2:UTF-16LE 3:UTF-16BE
** meta[5] User version
** meta[6] Incremental vacuum mode
** meta[7] unused
** meta[8] unused
** meta[9] unused
**
** Note: The #defined SQLITE_UTF* symbols in sqliteInt.h correspond to
** the possible values of meta[4].
*/
for(i=0; i<ArraySize(meta); i++){
sqlite3BtreeGetMeta(pDb->pBt, i+1, (u32 *)&meta[i]);
}
pDb->pSchema->schema_cookie = meta[BTREE_SCHEMA_VERSION-1];
/* If opening a non-empty database, check the text encoding. For the
** main database, set sqlite3.enc to the encoding of the main database.
** For an attached db, it is an error if the encoding is not the same
** as sqlite3.enc.
*/
if( meta[BTREE_TEXT_ENCODING-1] ){ /* text encoding */
if( iDb==0 ){
#ifndef SQLITE_OMIT_UTF16
u8 encoding;
/* If opening the main database, set ENC(db). */
encoding = (u8)meta[BTREE_TEXT_ENCODING-1] & 3;
if( encoding==0 ) encoding = SQLITE_UTF8;
ENC(db) = encoding;
#else
ENC(db) = SQLITE_UTF8;
#endif
}else{
/* If opening an attached database, the encoding much match ENC(db) */
if( meta[BTREE_TEXT_ENCODING-1]!=ENC(db) ){
sqlite3SetString(pzErrMsg, db, "attached databases must use the same"
" text encoding as main database");
rc = SQLITE_ERROR;
goto initone_error_out;
}
}
}else{
DbSetProperty(db, iDb, DB_Empty);
}
pDb->pSchema->enc = ENC(db);
if( pDb->pSchema->cache_size==0 ){
#ifndef SQLITE_OMIT_DEPRECATED
size = sqlite3AbsInt32(meta[BTREE_DEFAULT_CACHE_SIZE-1]);
if( size==0 ){ size = SQLITE_DEFAULT_CACHE_SIZE; }
pDb->pSchema->cache_size = size;
#else
pDb->pSchema->cache_size = SQLITE_DEFAULT_CACHE_SIZE;
#endif
sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
}
/*
** file_format==1 Version 3.0.0.
** file_format==2 Version 3.1.3. // ALTER TABLE ADD COLUMN
** file_format==3 Version 3.1.4. // ditto but with non-NULL defaults
** file_format==4 Version 3.3.0. // DESC indices. Boolean constants
*/
pDb->pSchema->file_format = (u8)meta[BTREE_FILE_FORMAT-1];
if( pDb->pSchema->file_format==0 ){
pDb->pSchema->file_format = 1;
}
if( pDb->pSchema->file_format>SQLITE_MAX_FILE_FORMAT ){
sqlite3SetString(pzErrMsg, db, "unsupported file format");
rc = SQLITE_ERROR;
goto initone_error_out;
}
/* Ticket #2804: When we open a database in the newer file format,
** clear the legacy_file_format pragma flag so that a VACUUM will
** not downgrade the database and thus invalidate any descending
** indices that the user might have created.
*/
if( iDb==0 && meta[BTREE_FILE_FORMAT-1]>=4 ){
db->flags &= ~SQLITE_LegacyFileFmt;
}
/* Read the schema information out of the schema tables
*/
assert( db->init.busy );
{
char *zSql;
zSql = sqlite3MPrintf(db,
"SELECT name, rootpage, sql FROM '%q'.%s ORDER BY rowid",
db->aDb[iDb].zName, zMasterName);
#ifndef SQLITE_OMIT_AUTHORIZATION
{
int (*xAuth)(void*,int,const char*,const char*,const char*,const char*);
xAuth = db->xAuth;
db->xAuth = 0;
#endif
rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0);
#ifndef SQLITE_OMIT_AUTHORIZATION
db->xAuth = xAuth;
}
#endif
if( rc==SQLITE_OK ) rc = initData.rc;
sqlite3DbFree(db, zSql);
#ifndef SQLITE_OMIT_ANALYZE
if( rc==SQLITE_OK ){
sqlite3AnalysisLoad(db, iDb);
}
#endif
}
if( db->mallocFailed ){
rc = SQLITE_NOMEM;
sqlite3ResetAllSchemasOfConnection(db);
}
if( rc==SQLITE_OK || (db->flags&SQLITE_RecoveryMode)){
/* Black magic: If the SQLITE_RecoveryMode flag is set, then consider
** the schema loaded, even if errors occurred. In this situation the
** current sqlite3_prepare() operation will fail, but the following one
** will attempt to compile the supplied statement against whatever subset
** of the schema was loaded before the error occurred. The primary
** purpose of this is to allow access to the sqlite_master table
** even when its contents have been corrupted.
*/
DbSetProperty(db, iDb, DB_SchemaLoaded);
rc = SQLITE_OK;
}
/* Jump here for an error that occurs after successfully allocating
** curMain and calling sqlite3BtreeEnter(). For an error that occurs
** before that point, jump to error_out.
*/
initone_error_out:
if( openedTransaction ){
sqlite3BtreeCommit(pDb->pBt);
}
sqlite3BtreeLeave(pDb->pBt);
error_out:
if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
db->mallocFailed = 1;
}
return rc;
}
/*
** Initialize all database files - the main database file, the file
** used to store temporary tables, and any additional database files
** created using ATTACH statements. Return a success code. If an
** error occurs, write an error message into *pzErrMsg.
**
** After a database is initialized, the DB_SchemaLoaded bit is set
** bit is set in the flags field of the Db structure. If the database
** file was of zero-length, then the DB_Empty flag is also set.
*/
int sqlite3Init(sqlite3 *db, char **pzErrMsg){
int i, rc;
int commit_internal = !(db->flags&SQLITE_InternChanges);
assert( sqlite3_mutex_held(db->mutex) );
rc = SQLITE_OK;
db->init.busy = 1;
for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
if( DbHasProperty(db, i, DB_SchemaLoaded) || i==1 ) continue;
rc = sqlite3InitOne(db, i, pzErrMsg);
if( rc ){
sqlite3ResetOneSchema(db, i);
}
}
/* Once all the other databases have been initialized, load the schema
** for the TEMP database. This is loaded last, as the TEMP database
** schema may contain references to objects in other databases.
*/
#ifndef SQLITE_OMIT_TEMPDB
if( rc==SQLITE_OK && ALWAYS(db->nDb>1)
&& !DbHasProperty(db, 1, DB_SchemaLoaded) ){
rc = sqlite3InitOne(db, 1, pzErrMsg);
if( rc ){
sqlite3ResetOneSchema(db, 1);
}
}
#endif
db->init.busy = 0;
if( rc==SQLITE_OK && commit_internal ){
sqlite3CommitInternalChanges(db);
}
return rc;
}
/*
** This routine is a no-op if the database schema is already initialized.
** Otherwise, the schema is loaded. An error code is returned.
*/
int sqlite3ReadSchema(Parse *pParse){
int rc = SQLITE_OK;
sqlite3 *db = pParse->db;
assert( sqlite3_mutex_held(db->mutex) );
if( !db->init.busy ){
rc = sqlite3Init(db, &pParse->zErrMsg);
}
if( rc!=SQLITE_OK ){
pParse->rc = rc;
pParse->nErr++;
}
return rc;
}
/*
** Check schema cookies in all databases. If any cookie is out
** of date set pParse->rc to SQLITE_SCHEMA. If all schema cookies
** make no changes to pParse->rc.
*/
static void schemaIsValid(Parse *pParse){
sqlite3 *db = pParse->db;
int iDb;
int rc;
int cookie;
assert( pParse->checkSchema );
assert( sqlite3_mutex_held(db->mutex) );
for(iDb=0; iDb<db->nDb; iDb++){
int openedTransaction = 0; /* True if a transaction is opened */
Btree *pBt = db->aDb[iDb].pBt; /* Btree database to read cookie from */
if( pBt==0 ) continue;
/* If there is not already a read-only (or read-write) transaction opened
** on the b-tree database, open one now. If a transaction is opened, it
** will be closed immediately after reading the meta-value. */
if( !sqlite3BtreeIsInReadTrans(pBt) ){
rc = sqlite3BtreeBeginTrans(pBt, 0);
if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
db->mallocFailed = 1;
}
if( rc!=SQLITE_OK ) return;
openedTransaction = 1;
}
/* Read the schema cookie from the database. If it does not match the
** value stored as part of the in-memory schema representation,
** set Parse.rc to SQLITE_SCHEMA. */
sqlite3BtreeGetMeta(pBt, BTREE_SCHEMA_VERSION, (u32 *)&cookie);
assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
if( cookie!=db->aDb[iDb].pSchema->schema_cookie ){
sqlite3ResetOneSchema(db, iDb);
pParse->rc = SQLITE_SCHEMA;
}
/* Close the transaction, if one was opened. */
if( openedTransaction ){
sqlite3BtreeCommit(pBt);
}
}
}
/*
** Convert a schema pointer into the iDb index that indicates
** which database file in db->aDb[] the schema refers to.
**
** If the same database is attached more than once, the first
** attached database is returned.
*/
int sqlite3SchemaToIndex(sqlite3 *db, Schema *pSchema){
int i = -1000000;
/* If pSchema is NULL, then return -1000000. This happens when code in
** expr.c is trying to resolve a reference to a transient table (i.e. one
** created by a sub-select). In this case the return value of this
** function should never be used.
**
** We return -1000000 instead of the more usual -1 simply because using
** -1000000 as the incorrect index into db->aDb[] is much
** more likely to cause a segfault than -1 (of course there are assert()
** statements too, but it never hurts to play the odds).
*/
assert( sqlite3_mutex_held(db->mutex) );
if( pSchema ){
for(i=0; ALWAYS(i<db->nDb); i++){
if( db->aDb[i].pSchema==pSchema ){
break;
}
}
assert( i>=0 && i<db->nDb );
}
return i;
}
/*
** Compile the UTF-8 encoded SQL statement zSql into a statement handle.
*/
static int sqlite3Prepare(
sqlite3 *db, /* Database handle. */
const char *zSql, /* UTF-8 encoded SQL statement. */
int nBytes, /* Length of zSql in bytes. */
int saveSqlFlag, /* True to copy SQL text into the sqlite3_stmt */
Vdbe *pReprepare, /* VM being reprepared */
sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */
const char **pzTail /* OUT: End of parsed string */
){
Parse *pParse; /* Parsing context */
char *zErrMsg = 0; /* Error message */
int rc = SQLITE_OK; /* Result code */
int i; /* Loop counter */
/* Allocate the parsing context */
pParse = sqlite3StackAllocZero(db, sizeof(*pParse));
if( pParse==0 ){
rc = SQLITE_NOMEM;
goto end_prepare;
}
pParse->pReprepare = pReprepare;
assert( ppStmt && *ppStmt==0 );
assert( !db->mallocFailed );
assert( sqlite3_mutex_held(db->mutex) );
/* Check to verify that it is possible to get a read lock on all
** database schemas. The inability to get a read lock indicates that
** some other database connection is holding a write-lock, which in
** turn means that the other connection has made uncommitted changes
** to the schema.
**
** Were we to proceed and prepare the statement against the uncommitted
** schema changes and if those schema changes are subsequently rolled
** back and different changes are made in their place, then when this
** prepared statement goes to run the schema cookie would fail to detect
** the schema change. Disaster would follow.
**
** This thread is currently holding mutexes on all Btrees (because
** of the sqlite3BtreeEnterAll() in sqlite3LockAndPrepare()) so it
** is not possible for another thread to start a new schema change
** while this routine is running. Hence, we do not need to hold
** locks on the schema, we just need to make sure nobody else is
** holding them.
**
** Note that setting READ_UNCOMMITTED overrides most lock detection,
** but it does *not* override schema lock detection, so this all still
** works even if READ_UNCOMMITTED is set.
*/
for(i=0; i<db->nDb; i++) {
Btree *pBt = db->aDb[i].pBt;
if( pBt ){
assert( sqlite3BtreeHoldsMutex(pBt) );
rc = sqlite3BtreeSchemaLocked(pBt);
if( rc ){
const char *zDb = db->aDb[i].zName;
sqlite3Error(db, rc, "database schema is locked: %s", zDb);
testcase( db->flags & SQLITE_ReadUncommitted );
goto end_prepare;
}
}
}
sqlite3VtabUnlockList(db);
pParse->db = db;
pParse->nQueryLoop = 0; /* Logarithmic, so 0 really means 1 */
if( nBytes>=0 && (nBytes==0 || zSql[nBytes-1]!=0) ){
char *zSqlCopy;
int mxLen = db->aLimit[SQLITE_LIMIT_SQL_LENGTH];
testcase( nBytes==mxLen );
testcase( nBytes==mxLen+1 );
if( nBytes>mxLen ){
sqlite3Error(db, SQLITE_TOOBIG, "statement too long");
rc = sqlite3ApiExit(db, SQLITE_TOOBIG);
goto end_prepare;
}
zSqlCopy = sqlite3DbStrNDup(db, zSql, nBytes);
if( zSqlCopy ){
sqlite3RunParser(pParse, zSqlCopy, &zErrMsg);
sqlite3DbFree(db, zSqlCopy);
pParse->zTail = &zSql[pParse->zTail-zSqlCopy];
}else{
pParse->zTail = &zSql[nBytes];
}
}else{
sqlite3RunParser(pParse, zSql, &zErrMsg);
}
assert( 0==pParse->nQueryLoop );
if( db->mallocFailed ){
pParse->rc = SQLITE_NOMEM;
}
if( pParse->rc==SQLITE_DONE ) pParse->rc = SQLITE_OK;
if( pParse->checkSchema ){
schemaIsValid(pParse);
}
if( db->mallocFailed ){
pParse->rc = SQLITE_NOMEM;
}
if( pzTail ){
*pzTail = pParse->zTail;
}
rc = pParse->rc;
#ifndef SQLITE_OMIT_EXPLAIN
if( rc==SQLITE_OK && pParse->pVdbe && pParse->explain ){
static const char * const azColName[] = {
"addr", "opcode", "p1", "p2", "p3", "p4", "p5", "comment",
"selectid", "order", "from", "detail"
};
int iFirst, mx;
if( pParse->explain==2 ){
sqlite3VdbeSetNumCols(pParse->pVdbe, 4);
iFirst = 8;
mx = 12;
}else{
sqlite3VdbeSetNumCols(pParse->pVdbe, 8);
iFirst = 0;
mx = 8;
}
for(i=iFirst; i<mx; i++){
sqlite3VdbeSetColName(pParse->pVdbe, i-iFirst, COLNAME_NAME,
azColName[i], SQLITE_STATIC);
}
}
#endif
if( db->init.busy==0 ){
Vdbe *pVdbe = pParse->pVdbe;
sqlite3VdbeSetSql(pVdbe, zSql, (int)(pParse->zTail-zSql), saveSqlFlag);
}
if( pParse->pVdbe && (rc!=SQLITE_OK || db->mallocFailed) ){
sqlite3VdbeFinalize(pParse->pVdbe);
assert(!(*ppStmt));
}else{
*ppStmt = (sqlite3_stmt*)pParse->pVdbe;
}
if( zErrMsg ){
sqlite3Error(db, rc, "%s", zErrMsg);
sqlite3DbFree(db, zErrMsg);
}else{
sqlite3Error(db, rc, 0);
}
/* Delete any TriggerPrg structures allocated while parsing this statement. */
while( pParse->pTriggerPrg ){
TriggerPrg *pT = pParse->pTriggerPrg;
pParse->pTriggerPrg = pT->pNext;
sqlite3DbFree(db, pT);
}
end_prepare:
sqlite3StackFree(db, pParse);
rc = sqlite3ApiExit(db, rc);
assert( (rc&db->errMask)==rc );
return rc;
}
static int sqlite3LockAndPrepare(
sqlite3 *db, /* Database handle. */
const char *zSql, /* UTF-8 encoded SQL statement. */
int nBytes, /* Length of zSql in bytes. */
int saveSqlFlag, /* True to copy SQL text into the sqlite3_stmt */
Vdbe *pOld, /* VM being reprepared */
sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */
const char **pzTail /* OUT: End of parsed string */
){
int rc;
assert( ppStmt!=0 );
*ppStmt = 0;
if( !sqlite3SafetyCheckOk(db) ){
return SQLITE_MISUSE_BKPT;
}
sqlite3_mutex_enter(db->mutex);
sqlite3BtreeEnterAll(db);
rc = sqlite3Prepare(db, zSql, nBytes, saveSqlFlag, pOld, ppStmt, pzTail);
if( rc==SQLITE_SCHEMA ){
sqlite3_finalize(*ppStmt);
rc = sqlite3Prepare(db, zSql, nBytes, saveSqlFlag, pOld, ppStmt, pzTail);
}
sqlite3BtreeLeaveAll(db);
sqlite3_mutex_leave(db->mutex);
assert( rc==SQLITE_OK || *ppStmt==0 );
return rc;
}
/*
** Rerun the compilation of a statement after a schema change.
**
** If the statement is successfully recompiled, return SQLITE_OK. Otherwise,
** if the statement cannot be recompiled because another connection has
** locked the sqlite3_master table, return SQLITE_LOCKED. If any other error
** occurs, return SQLITE_SCHEMA.
*/
int sqlite3Reprepare(Vdbe *p){
int rc;
sqlite3_stmt *pNew;
const char *zSql;
sqlite3 *db;
assert( sqlite3_mutex_held(sqlite3VdbeDb(p)->mutex) );
zSql = sqlite3_sql((sqlite3_stmt *)p);
assert( zSql!=0 ); /* Reprepare only called for prepare_v2() statements */
db = sqlite3VdbeDb(p);
assert( sqlite3_mutex_held(db->mutex) );
rc = sqlite3LockAndPrepare(db, zSql, -1, 0, p, &pNew, 0);
if( rc ){
if( rc==SQLITE_NOMEM ){
db->mallocFailed = 1;
}
assert( pNew==0 );
return rc;
}else{
assert( pNew!=0 );
}
sqlite3VdbeSwap((Vdbe*)pNew, p);
sqlite3TransferBindings(pNew, (sqlite3_stmt*)p);
sqlite3VdbeResetStepResult((Vdbe*)pNew);
sqlite3VdbeFinalize((Vdbe*)pNew);
return SQLITE_OK;
}
/*
** Two versions of the official API. Legacy and new use. In the legacy
** version, the original SQL text is not saved in the prepared statement
** and so if a schema change occurs, SQLITE_SCHEMA is returned by
** sqlite3_step(). In the new version, the original SQL text is retained
** and the statement is automatically recompiled if an schema change
** occurs.
*/
int sqlite3_prepare(
sqlite3 *db, /* Database handle. */
const char *zSql, /* UTF-8 encoded SQL statement. */
int nBytes, /* Length of zSql in bytes. */
sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */
const char **pzTail /* OUT: End of parsed string */
){
int rc;
rc = sqlite3LockAndPrepare(db,zSql,nBytes,0,0,ppStmt,pzTail);
assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 ); /* VERIFY: F13021 */
return rc;
}
int sqlite3_prepare_v2(
sqlite3 *db, /* Database handle. */
const char *zSql, /* UTF-8 encoded SQL statement. */
int nBytes, /* Length of zSql in bytes. */
sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */
const char **pzTail /* OUT: End of parsed string */
){
int rc;
rc = sqlite3LockAndPrepare(db,zSql,nBytes,1,0,ppStmt,pzTail);
assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 ); /* VERIFY: F13021 */
return rc;
}
#ifndef SQLITE_OMIT_UTF16
/*
** Compile the UTF-16 encoded SQL statement zSql into a statement handle.
*/
static int sqlite3Prepare16(
sqlite3 *db, /* Database handle. */
const void *zSql, /* UTF-16 encoded SQL statement. */
int nBytes, /* Length of zSql in bytes. */
int saveSqlFlag, /* True to save SQL text into the sqlite3_stmt */
sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */
const void **pzTail /* OUT: End of parsed string */
){
/* This function currently works by first transforming the UTF-16
** encoded string to UTF-8, then invoking sqlite3_prepare(). The
** tricky bit is figuring out the pointer to return in *pzTail.
*/
char *zSql8;
const char *zTail8 = 0;
int rc = SQLITE_OK;
assert( ppStmt );
*ppStmt = 0;
if( !sqlite3SafetyCheckOk(db) ){
return SQLITE_MISUSE_BKPT;
}
if( nBytes>=0 ){
int sz;
const char *z = (const char*)zSql;
for(sz=0; sz<nBytes && (z[sz]!=0 || z[sz+1]!=0); sz += 2){}
nBytes = sz;
}
sqlite3_mutex_enter(db->mutex);
zSql8 = sqlite3Utf16to8(db, zSql, nBytes, SQLITE_UTF16NATIVE);
if( zSql8 ){
rc = sqlite3LockAndPrepare(db, zSql8, -1, saveSqlFlag, 0, ppStmt, &zTail8);
}
if( zTail8 && pzTail ){
/* If sqlite3_prepare returns a tail pointer, we calculate the
** equivalent pointer into the UTF-16 string by counting the unicode
** characters between zSql8 and zTail8, and then returning a pointer
** the same number of characters into the UTF-16 string.
*/
int chars_parsed = sqlite3Utf8CharLen(zSql8, (int)(zTail8-zSql8));
*pzTail = (u8 *)zSql + sqlite3Utf16ByteLen(zSql, chars_parsed);
}
sqlite3DbFree(db, zSql8);
rc = sqlite3ApiExit(db, rc);
sqlite3_mutex_leave(db->mutex);
return rc;
}
/*
** Two versions of the official API. Legacy and new use. In the legacy
** version, the original SQL text is not saved in the prepared statement
** and so if a schema change occurs, SQLITE_SCHEMA is returned by
** sqlite3_step(). In the new version, the original SQL text is retained
** and the statement is automatically recompiled if an schema change
** occurs.
*/
int sqlite3_prepare16(
sqlite3 *db, /* Database handle. */
const void *zSql, /* UTF-16 encoded SQL statement. */
int nBytes, /* Length of zSql in bytes. */
sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */
const void **pzTail /* OUT: End of parsed string */
){
int rc;
rc = sqlite3Prepare16(db,zSql,nBytes,0,ppStmt,pzTail);
assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 ); /* VERIFY: F13021 */
return rc;
}
int sqlite3_prepare16_v2(
sqlite3 *db, /* Database handle. */
const void *zSql, /* UTF-16 encoded SQL statement. */
int nBytes, /* Length of zSql in bytes. */
sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */
const void **pzTail /* OUT: End of parsed string */
){
int rc;
rc = sqlite3Prepare16(db,zSql,nBytes,1,ppStmt,pzTail);
assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 ); /* VERIFY: F13021 */
return rc;
}
#endif /* SQLITE_OMIT_UTF16 */