示例#1
0
// Lua 调用入口函数
// 参数:1个,sql string 
// 返回:2个,table_result, errMsg
static int parse(lua_State * L) {
    const char *sql = luaL_checkstring(L, 1);

    if (sql == NULL || strlen(sql)==0){
        return _parse_error(L, "args 1:sql can not be empty string.");
    }

    Parse *p = sqlite3ParseNew();
    resetParseObject(p);
    char *errMsg = 0;

    sqlite3RunParser(p, sql, &errMsg);
    if( sqlite3MallocFailed() ){
        sqlite3ParseDelete(p);
        return _parse_error(L, "malloc memory failed.");
    }
    if ( errMsg != NULL ){
        _parse_error(L, errMsg);
        free(errMsg);
        sqlite3ParseDelete(p);
        return 2;
    }
    if( p->rc == SQLITE_DONE ){
        p->rc = SQLITE_OK;
    }
    if (p->rc != SQLITE_OK){
        sqlite3ParseDelete(p);
        static const int len =1024;
        char buff[len];
        memset(buff, 0, len);
        snprintf(buff, len, "unknown parse result. rc=[%d].", p->rc);
        printf(buff);
        return _parse_error(L, buff);
    }

    lua_newtable(L); // push return 1: result-table

    set_table_field_n(L, "rc", p->rc);
    set_table_field_n(L, "explain", p->explain);
    set_table_field_n(L, "flags", p->flags);
    set_table_field_n(L, "nErr", p->nErr);
    set_table_field_n(L, "nTab", p->nTab);

    set_table_field_s(L, "sql", p->zSql, strlen(p->zSql));
    set_table_field_s(L, "tail", p->zTail, strlen(p->zTail));

    _to_lua_parse_result_array(L, &(p->parsed));


    printf("[lua c-model]return success.\n");

    ///// end set result-table field ////////////////
    lua_pushnil(L); // push return 2: err = nil
    sqlite3ParseDelete(p);
    return 2;
}
示例#2
0
/*
** This function is used to set the schema of a virtual table.  It is only
** valid to call this function from within the xCreate() or xConnect() of a
** virtual table module.
*/
int sqlite3_declare_vtab(sqlite3 *db, const char *zCreateTable){
  Parse *pParse;

  int rc = SQLITE_OK;
  Table *pTab;
  char *zErr = 0;

  sqlite3_mutex_enter(db->mutex);
  if( !db->pVtabCtx || !(pTab = db->pVtabCtx->pTab) ){
    sqlite3Error(db, SQLITE_MISUSE);
    sqlite3_mutex_leave(db->mutex);
    return SQLITE_MISUSE_BKPT;
  }
  assert( (pTab->tabFlags & TF_Virtual)!=0 );

  pParse = sqlite3StackAllocZero(db, sizeof(*pParse));
  if( pParse==0 ){
    rc = SQLITE_NOMEM;
  }else{
    pParse->declareVtab = 1;
    pParse->db = db;
    pParse->nQueryLoop = 1;
  
    if( SQLITE_OK==sqlite3RunParser(pParse, zCreateTable, &zErr) 
     && pParse->pNewTable
     && !db->mallocFailed
     && !pParse->pNewTable->pSelect
     && (pParse->pNewTable->tabFlags & TF_Virtual)==0
    ){
      if( !pTab->aCol ){
        pTab->aCol = pParse->pNewTable->aCol;
        pTab->nCol = pParse->pNewTable->nCol;
        pParse->pNewTable->nCol = 0;
        pParse->pNewTable->aCol = 0;
      }
      db->pVtabCtx->pTab = 0;
    }else{
      sqlite3ErrorWithMsg(db, SQLITE_ERROR, (zErr ? "%s" : 0), zErr);
      sqlite3DbFree(db, zErr);
      rc = SQLITE_ERROR;
    }
    pParse->declareVtab = 0;
  
    if( pParse->pVdbe ){
      sqlite3VdbeFinalize(pParse->pVdbe);
    }
    sqlite3DeleteTable(db, pParse->pNewTable);
    sqlite3ParserReset(pParse);
    sqlite3StackFree(db, pParse);
  }

  assert( (rc&0xff)==rc );
  rc = sqlite3ApiExit(db, rc);
  sqlite3_mutex_leave(db->mutex);
  return rc;
}
示例#3
0
文件: vtab.c 项目: berte/mediaplayer
/*
** This function is used to set the schema of a virtual table.  It is only
** valid to call this function from within the xCreate() or xConnect() of a
** virtual table module.
*/
int sqlite3_declare_vtab(sqlite3 *db, const char *zCreateTable){
  Parse sParse;

  int rc = SQLITE_OK;
  Table *pTab;
  char *zErr = 0;

  sqlite3_mutex_enter(db->mutex);
  pTab = db->pVTab;
  if( !pTab ){
    sqlite3Error(db, SQLITE_MISUSE, 0);
    sqlite3_mutex_leave(db->mutex);
    return SQLITE_MISUSE;
  }
  assert(pTab->isVirtual && pTab->nCol==0 && pTab->aCol==0);

  memset(&sParse, 0, sizeof(Parse));
  sParse.declareVtab = 1;
  sParse.db = db;

  if( 
      SQLITE_OK == sqlite3RunParser(&sParse, zCreateTable, &zErr) && 
      sParse.pNewTable && 
      !sParse.pNewTable->pSelect && 
      !sParse.pNewTable->isVirtual 
  ){
    pTab->aCol = sParse.pNewTable->aCol;
    pTab->nCol = sParse.pNewTable->nCol;
    sParse.pNewTable->nCol = 0;
    sParse.pNewTable->aCol = 0;
    db->pVTab = 0;
  } else {
    sqlite3Error(db, SQLITE_ERROR, zErr);
    sqlite3_free(zErr);
    rc = SQLITE_ERROR;
  }
  sParse.declareVtab = 0;

  sqlite3_finalize((sqlite3_stmt*)sParse.pVdbe);
  sqlite3DeleteTable(sParse.pNewTable);
  sParse.pNewTable = 0;

  assert( (rc&0xff)==rc );
  rc = sqlite3ApiExit(db, rc);
  sqlite3_mutex_leave(db->mutex);
  return rc;
}
示例#4
0
/*
** This function is used to set the schema of a virtual table.  It is only
** valid to call this function from within the xCreate() or xConnect() of a
** virtual table module.
*/
int sqlite3_declare_vtab(sqlite3 *db, const char *zCreateTable){
  VtabCtx *pCtx;
  Parse *pParse;
  int rc = SQLITE_OK;
  Table *pTab;
  char *zErr = 0;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) || zCreateTable==0 ){
    return SQLITE_MISUSE_BKPT;
  }
#endif
  sqlite3_mutex_enter(db->mutex);
  pCtx = db->pVtabCtx;
  if( !pCtx || pCtx->bDeclared ){
    sqlite3Error(db, SQLITE_MISUSE);
    sqlite3_mutex_leave(db->mutex);
    return SQLITE_MISUSE_BKPT;
  }
  pTab = pCtx->pTab;
  assert( (pTab->tabFlags & TF_Virtual)!=0 );

  pParse = sqlite3StackAllocZero(db, sizeof(*pParse));
  if( pParse==0 ){
    rc = SQLITE_NOMEM_BKPT;
  }else{
    pParse->declareVtab = 1;
    pParse->db = db;
    pParse->nQueryLoop = 1;
  
    if( SQLITE_OK==sqlite3RunParser(pParse, zCreateTable, &zErr) 
     && pParse->pNewTable
     && !db->mallocFailed
     && !pParse->pNewTable->pSelect
     && (pParse->pNewTable->tabFlags & TF_Virtual)==0
    ){
      if( !pTab->aCol ){
        Table *pNew = pParse->pNewTable;
        Index *pIdx;
        pTab->aCol = pNew->aCol;
        pTab->nCol = pNew->nCol;
        pTab->tabFlags |= pNew->tabFlags & (TF_WithoutRowid|TF_NoVisibleRowid);
        pNew->nCol = 0;
        pNew->aCol = 0;
        assert( pTab->pIndex==0 );
        if( !HasRowid(pNew) && pCtx->pVTable->pMod->pModule->xUpdate!=0 ){
          rc = SQLITE_ERROR;
        }
        pIdx = pNew->pIndex;
        if( pIdx ){
          assert( pIdx->pNext==0 );
          pTab->pIndex = pIdx;
          pNew->pIndex = 0;
          pIdx->pTable = pTab;
        }
      }
      pCtx->bDeclared = 1;
    }else{
      sqlite3ErrorWithMsg(db, SQLITE_ERROR, (zErr ? "%s" : 0), zErr);
      sqlite3DbFree(db, zErr);
      rc = SQLITE_ERROR;
    }
    pParse->declareVtab = 0;
  
    if( pParse->pVdbe ){
      sqlite3VdbeFinalize(pParse->pVdbe);
    }
    sqlite3DeleteTable(db, pParse->pNewTable);
    sqlite3ParserReset(pParse);
    sqlite3StackFree(db, pParse);
  }

  assert( (rc&0xff)==rc );
  rc = sqlite3ApiExit(db, rc);
  sqlite3_mutex_leave(db->mutex);
  return rc;
}
示例#5
0
文件: prepare.c 项目: 9iky6/amxmodx
/*
** Compile the UTF-8 encoded SQL statement zSql into a statement handle.
*/
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 */
  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
  const char **pzTail       /* OUT: End of parsed string */
){
  Parse sParse;
  char *zErrMsg = 0;
  int rc = SQLITE_OK;
  int i;

  /* Assert that malloc() has not failed */
  assert( !sqlite3MallocFailed() );

  assert( ppStmt );
  *ppStmt = 0;
  if( sqlite3SafetyOn(db) ){
    return SQLITE_MISUSE;
  }

  /* If any attached database schemas are locked, do not proceed with
  ** compilation. Instead return SQLITE_LOCKED immediately.
  */
  for(i=0; i<db->nDb; i++) {
    Btree *pBt = db->aDb[i].pBt;
    if( pBt && sqlite3BtreeSchemaLocked(pBt) ){
      const char *zDb = db->aDb[i].zName;
      sqlite3Error(db, SQLITE_LOCKED, "database schema is locked: %s", zDb);
      sqlite3SafetyOff(db);
      return SQLITE_LOCKED;
    }
  }
  
  memset(&sParse, 0, sizeof(sParse));
  sParse.db = db;
  if( nBytes>=0 && zSql[nBytes]!=0 ){
    char *zSqlCopy = sqlite3StrNDup(zSql, nBytes);
    sqlite3RunParser(&sParse, zSqlCopy, &zErrMsg);
    sParse.zTail += zSql - zSqlCopy;
    sqliteFree(zSqlCopy);
  }else{
    sqlite3RunParser(&sParse, zSql, &zErrMsg);
  }

  if( sqlite3MallocFailed() ){
    sParse.rc = SQLITE_NOMEM;
  }
  if( sParse.rc==SQLITE_DONE ) sParse.rc = SQLITE_OK;
  if( sParse.checkSchema && !schemaIsValid(db) ){
    sParse.rc = SQLITE_SCHEMA;
  }
  if( sParse.rc==SQLITE_SCHEMA ){
    sqlite3ResetInternalSchema(db, 0);
  }
  if( sqlite3MallocFailed() ){
    sParse.rc = SQLITE_NOMEM;
  }
  if( pzTail ){
    *pzTail = sParse.zTail;
  }
  rc = sParse.rc;

#ifndef SQLITE_OMIT_EXPLAIN
  if( rc==SQLITE_OK && sParse.pVdbe && sParse.explain ){
    if( sParse.explain==2 ){
      sqlite3VdbeSetNumCols(sParse.pVdbe, 3);
      sqlite3VdbeSetColName(sParse.pVdbe, 0, COLNAME_NAME, "order", P3_STATIC);
      sqlite3VdbeSetColName(sParse.pVdbe, 1, COLNAME_NAME, "from", P3_STATIC);
      sqlite3VdbeSetColName(sParse.pVdbe, 2, COLNAME_NAME, "detail", P3_STATIC);
    }else{
      sqlite3VdbeSetNumCols(sParse.pVdbe, 5);
      sqlite3VdbeSetColName(sParse.pVdbe, 0, COLNAME_NAME, "addr", P3_STATIC);
      sqlite3VdbeSetColName(sParse.pVdbe, 1, COLNAME_NAME, "opcode", P3_STATIC);
      sqlite3VdbeSetColName(sParse.pVdbe, 2, COLNAME_NAME, "p1", P3_STATIC);
      sqlite3VdbeSetColName(sParse.pVdbe, 3, COLNAME_NAME, "p2", P3_STATIC);
      sqlite3VdbeSetColName(sParse.pVdbe, 4, COLNAME_NAME, "p3", P3_STATIC);
    }
  }
#endif

  if( sqlite3SafetyOff(db) ){
    rc = SQLITE_MISUSE;
  }
  if( rc==SQLITE_OK ){
    if( saveSqlFlag ){
      sqlite3VdbeSetSql(sParse.pVdbe, zSql, sParse.zTail - zSql);
    }
    *ppStmt = (sqlite3_stmt*)sParse.pVdbe;
  }else if( sParse.pVdbe ){
    sqlite3_finalize((sqlite3_stmt*)sParse.pVdbe);
  }

  if( zErrMsg ){
    sqlite3Error(db, rc, "%s", zErrMsg);
    sqliteFree(zErrMsg);
  }else{
    sqlite3Error(db, rc, 0);
  }

  rc = sqlite3ApiExit(db, rc);
  sqlite3ReleaseThreadData();
  assert( (rc&db->errMask)==rc );
  return rc;
}
示例#6
0
/*
** 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 */
  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
  const char **pzTail       /* OUT: End of parsed string */
){
  Parse sParse;
  char *zErrMsg = 0;
  int rc = SQLITE_OK;
  int i;

  assert( ppStmt );
  *ppStmt = 0;
  if( sqlite3SafetyOn(db) ){
    return SQLITE_MISUSE;
  }
  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);
        (void)sqlite3SafetyOff(db);
        testcase( db->flags & SQLITE_ReadUncommitted );
        return sqlite3ApiExit(db, rc);
      }
    }
  }
  
  memset(&sParse, 0, sizeof(sParse));
  sParse.db = db;
  if( nBytes>=0 && (nBytes==0 || zSql[nBytes-1]!=0) ){
    char *zSqlCopy;
    int mxLen = db->aLimit[SQLITE_LIMIT_SQL_LENGTH];
    if( nBytes>mxLen ){
      sqlite3Error(db, SQLITE_TOOBIG, "statement too long");
      (void)sqlite3SafetyOff(db);
      return sqlite3ApiExit(db, SQLITE_TOOBIG);
    }
    zSqlCopy = sqlite3DbStrNDup(db, zSql, nBytes);
    if( zSqlCopy ){
      sqlite3RunParser(&sParse, zSqlCopy, &zErrMsg);
      sqlite3DbFree(db, zSqlCopy);
      sParse.zTail = &zSql[sParse.zTail-zSqlCopy];
    }else{
      sParse.zTail = &zSql[nBytes];
    }
  }else{
    sqlite3RunParser(&sParse, zSql, &zErrMsg);
  }

  if( db->mallocFailed ){
    sParse.rc = SQLITE_NOMEM;
  }
  if( sParse.rc==SQLITE_DONE ) sParse.rc = SQLITE_OK;
  if( sParse.checkSchema && !schemaIsValid(db) ){
    sParse.rc = SQLITE_SCHEMA;
  }
  if( sParse.rc==SQLITE_SCHEMA ){
    sqlite3ResetInternalSchema(db, 0);
  }
  if( db->mallocFailed ){
    sParse.rc = SQLITE_NOMEM;
  }
  if( pzTail ){
    *pzTail = sParse.zTail;
  }
  rc = sParse.rc;

#ifndef SQLITE_OMIT_EXPLAIN
  if( rc==SQLITE_OK && sParse.pVdbe && sParse.explain ){
    if( sParse.explain==2 ){
      sqlite3VdbeSetNumCols(sParse.pVdbe, 3);
      sqlite3VdbeSetColName(sParse.pVdbe, 0, COLNAME_NAME, "order", SQLITE_STATIC);
      sqlite3VdbeSetColName(sParse.pVdbe, 1, COLNAME_NAME, "from", SQLITE_STATIC);
      sqlite3VdbeSetColName(sParse.pVdbe, 2, COLNAME_NAME, "detail", SQLITE_STATIC);
    }else{
      sqlite3VdbeSetNumCols(sParse.pVdbe, 8);
      sqlite3VdbeSetColName(sParse.pVdbe, 0, COLNAME_NAME, "addr", SQLITE_STATIC);
      sqlite3VdbeSetColName(sParse.pVdbe, 1, COLNAME_NAME, "opcode", SQLITE_STATIC);
      sqlite3VdbeSetColName(sParse.pVdbe, 2, COLNAME_NAME, "p1", SQLITE_STATIC);
      sqlite3VdbeSetColName(sParse.pVdbe, 3, COLNAME_NAME, "p2", SQLITE_STATIC);
      sqlite3VdbeSetColName(sParse.pVdbe, 4, COLNAME_NAME, "p3", SQLITE_STATIC);
      sqlite3VdbeSetColName(sParse.pVdbe, 5, COLNAME_NAME, "p4", SQLITE_STATIC);
      sqlite3VdbeSetColName(sParse.pVdbe, 6, COLNAME_NAME, "p5", SQLITE_STATIC);
      sqlite3VdbeSetColName(sParse.pVdbe, 7, COLNAME_NAME, "comment", SQLITE_STATIC);
    }
  }
#endif

  if( sqlite3SafetyOff(db) ){
    rc = SQLITE_MISUSE;
  }

  assert( db->init.busy==0 || saveSqlFlag==0 );
  if( db->init.busy==0 ){
    Vdbe *pVdbe = sParse.pVdbe;
    sqlite3VdbeSetSql(pVdbe, zSql, (int)(sParse.zTail-zSql), saveSqlFlag);
  }
  if( sParse.pVdbe && (rc!=SQLITE_OK || db->mallocFailed) ){
    sqlite3VdbeFinalize(sParse.pVdbe);
    assert(!(*ppStmt));
  }else{
    *ppStmt = (sqlite3_stmt*)sParse.pVdbe;
  }

  if( zErrMsg ){
    sqlite3Error(db, rc, "%s", zErrMsg);
    sqlite3DbFree(db, zErrMsg);
  }else{
    sqlite3Error(db, rc, 0);
  }

  rc = sqlite3ApiExit(db, rc);
  assert( (rc&db->errMask)==rc );
  return rc;
}
/*
** Compile the UTF-8 encoded SQL statement zSql into a statement handle.
*/
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 */
){
  Parse sParse;
  char *zErrMsg = 0;
  int rc = SQLITE_OK;

  if( sqlite3_malloc_failed ){
    return SQLITE_NOMEM;
  }

  assert( ppStmt );
  *ppStmt = 0;
  if( sqlite3SafetyOn(db) ){
    return SQLITE_MISUSE;
  }

  memset(&sParse, 0, sizeof(sParse));
  sParse.db = db;
  sqlite3RunParser(&sParse, zSql, &zErrMsg);

  if( sqlite3_malloc_failed ){
    rc = SQLITE_NOMEM;
    sqlite3RollbackAll(db);
    sqlite3ResetInternalSchema(db, 0);
    db->flags &= ~SQLITE_InTrans;
    goto prepare_out;
  }
  if( sParse.rc==SQLITE_DONE ) sParse.rc = SQLITE_OK;
  if( sParse.rc!=SQLITE_OK && sParse.checkSchema && !schemaIsValid(db) ){
    sParse.rc = SQLITE_SCHEMA;
  }
  if( sParse.rc==SQLITE_SCHEMA ){
    sqlite3ResetInternalSchema(db, 0);
  }
  if( pzTail ) *pzTail = sParse.zTail;
  rc = sParse.rc;

#ifndef SQLITE_OMIT_EXPLAIN
  if( rc==SQLITE_OK && sParse.pVdbe && sParse.explain ){
    sqlite3VdbeSetNumCols(sParse.pVdbe, 5);
    sqlite3VdbeSetColName(sParse.pVdbe, 0, "addr", P3_STATIC);
    sqlite3VdbeSetColName(sParse.pVdbe, 1, "opcode", P3_STATIC);
    sqlite3VdbeSetColName(sParse.pVdbe, 2, "p1", P3_STATIC);
    sqlite3VdbeSetColName(sParse.pVdbe, 3, "p2", P3_STATIC);
    sqlite3VdbeSetColName(sParse.pVdbe, 4, "p3", P3_STATIC);
  } 
#endif

prepare_out:
  if( sqlite3SafetyOff(db) ){
    rc = SQLITE_MISUSE;
  }
  if( rc==SQLITE_OK ){
    *ppStmt = (sqlite3_stmt*)sParse.pVdbe;
  }else if( sParse.pVdbe ){
    sqlite3_finalize((sqlite3_stmt*)sParse.pVdbe);
  }

  if( zErrMsg ){
    sqlite3Error(db, rc, "%s", zErrMsg);
    sqliteFree(zErrMsg);
  }else{
    sqlite3Error(db, rc, 0);
  }
  return rc;
}
示例#8
0
/*
** 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;

  if( sqlite3SafetyOn(db) ){
    rc = SQLITE_MISUSE;
    goto end_prepare;
  }
  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);
        (void)sqlite3SafetyOff(db);
        testcase( db->flags & SQLITE_ReadUncommitted );
        goto end_prepare;
      }
    }
  }

  sqlite3VtabUnlockList(db);

  pParse->db = db;
  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");
      (void)sqlite3SafetyOff(db);
      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);
  }

  if( db->mallocFailed ){
    pParse->rc = SQLITE_NOMEM;
  }
  if( pParse->rc==SQLITE_DONE ) pParse->rc = SQLITE_OK;
  if( pParse->checkSchema ){
    schemaIsValid(pParse);
  }
  if( pParse->rc==SQLITE_SCHEMA ){
    sqlite3ResetInternalSchema(db, 0);
  }
  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",
       "order", "from", "detail"
    };
    int iFirst, mx;
    if( pParse->explain==2 ){
      sqlite3VdbeSetNumCols(pParse->pVdbe, 3);
      iFirst = 8;
      mx = 11;
    }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( sqlite3SafetyOff(db) ){
    rc = SQLITE_MISUSE;
  }

  assert( db->init.busy==0 || saveSqlFlag==0 );
  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;
    sqlite3VdbeProgramDelete(db, pT->pProgram, 0);
    sqlite3DbFree(db, pT);
  }

end_prepare:

  sqlite3StackFree(db, pParse);
  rc = sqlite3ApiExit(db, rc);
  assert( (rc&db->errMask)==rc );
  return rc;
}