4 ** The author disclaims copyright to this source code. In place of
5 ** a legal notice, here is a blessing:
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.
11 *************************************************************************
12 ** Main file for the SQLite library. The routines in this file
13 ** implement the programmer interface to the library. Routines in
14 ** other files are for internal use by SQLite and should not be
15 ** accessed by users of the library.
18 #include "sqliteInt.h"
21 ** Execute SQL code. Return one of the SQLITE_ success/failure
22 ** codes. Also write an error message into memory obtained from
23 ** malloc() and make *pzErrMsg point to that message.
25 ** If the SQL is a query, then for each row in the query result
26 ** the xCallback() function is called. pArg becomes the first
27 ** argument to xCallback(). If xCallback=NULL then no callback
28 ** is invoked, even for queries.
31 sqlite3 *db, /* The database on which the SQL executes */
32 const char *zSql, /* The SQL to be executed */
33 sqlite3_callback xCallback, /* Invoke this callback routine */
34 void *pArg, /* First argument to xCallback() */
35 char **pzErrMsg /* Write error messages here */
37 int rc = SQLITE_OK; /* Return code */
38 const char *zLeftover; /* Tail of unprocessed SQL */
39 sqlite3_stmt *pStmt = 0; /* The current SQL statement */
40 char **azCols = 0; /* Names of result columns */
41 int nRetry = 0; /* Number of retry attempts */
42 int callbackIsInit; /* True if callback data is initialized */
44 if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
45 if( zSql==0 ) zSql = "";
47 sqlite3_mutex_enter(db->mutex);
48 sqlite3Error(db, SQLITE_OK, 0);
49 while( (rc==SQLITE_OK || (rc==SQLITE_SCHEMA && (++nRetry)<2)) && zSql[0] ){
54 rc = sqlite3_prepare(db, zSql, -1, &pStmt, &zLeftover);
55 assert( rc==SQLITE_OK || pStmt==0 );
60 /* this happens for a comment or white-space */
66 nCol = sqlite3_column_count(pStmt);
70 rc = sqlite3_step(pStmt);
72 /* Invoke the callback function if required */
73 if( xCallback && (SQLITE_ROW==rc ||
74 (SQLITE_DONE==rc && !callbackIsInit
75 && db->flags&SQLITE_NullCallback)) ){
76 if( !callbackIsInit ){
77 azCols = sqlite3DbMallocZero(db, 2*nCol*sizeof(const char*) + 1);
81 for(i=0; i<nCol; i++){
82 azCols[i] = (char *)sqlite3_column_name(pStmt, i);
83 /* sqlite3VdbeSetColName() installs column names as UTF8
84 ** strings so there is no way for sqlite3_column_name() to fail. */
85 assert( azCols[i]!=0 );
90 azVals = &azCols[nCol];
91 for(i=0; i<nCol; i++){
92 azVals[i] = (char *)sqlite3_column_text(pStmt, i);
93 if( !azVals[i] && sqlite3_column_type(pStmt, i)!=SQLITE_NULL ){
99 if( xCallback(pArg, nCol, azVals, azCols) ){
101 sqlite3VdbeFinalize((Vdbe *)pStmt);
103 sqlite3Error(db, SQLITE_ABORT, 0);
108 if( rc!=SQLITE_ROW ){
109 rc = sqlite3VdbeFinalize((Vdbe *)pStmt);
111 if( rc!=SQLITE_SCHEMA ){
114 while( sqlite3Isspace(zSql[0]) ) zSql++;
120 sqlite3DbFree(db, azCols);
125 if( pStmt ) sqlite3VdbeFinalize((Vdbe *)pStmt);
126 sqlite3DbFree(db, azCols);
128 rc = sqlite3ApiExit(db, rc);
129 if( rc!=SQLITE_OK && ALWAYS(rc==sqlite3_errcode(db)) && pzErrMsg ){
130 int nErrMsg = 1 + sqlite3Strlen30(sqlite3_errmsg(db));
131 *pzErrMsg = sqlite3Malloc(nErrMsg);
133 memcpy(*pzErrMsg, sqlite3_errmsg(db), nErrMsg);
136 sqlite3Error(db, SQLITE_NOMEM, 0);
138 }else if( pzErrMsg ){
142 assert( (rc&db->errMask)==rc );
143 sqlite3_mutex_leave(db->mutex);