1 /*

     2 ** 2001 September 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 ** 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.

    16 **

    17 ** $Id: legacy.cpp 1282 2008-11-13 09:31:33Z LarsPson $

    18 */

    19 

    20 #include "sqliteInt.h"

    21 #include <ctype.h>

    22 

    23 /*

    24 ** Execute SQL code.  Return one of the SQLITE_ success/failure

    25 ** codes.  Also write an error message into memory obtained from

    26 ** malloc() and make *pzErrMsg point to that message.

    27 **

    28 ** If the SQL is a query, then for each row in the query result

    29 ** the xCallback() function is called.  pArg becomes the first

    30 ** argument to xCallback().  If xCallback=NULL then no callback

    31 ** is invoked, even for queries.

    32 */

    33 EXPORT_C int sqlite3_exec(

    34   sqlite3 *db,                /* The database on which the SQL executes */

    35   const char *zSql,           /* The SQL to be executed */

    36   sqlite3_callback xCallback, /* Invoke this callback routine */

    37   void *pArg,                 /* First argument to xCallback() */

    38   char **pzErrMsg             /* Write error messages here */

    39 ){

    40   int rc = SQLITE_OK;

    41   const char *zLeftover;

    42   sqlite3_stmt *pStmt = 0;

    43   char **azCols = 0;

    44 

    45   int nRetry = 0;

    46   int nCallback;

    47 

    48   if( zSql==0 ) return SQLITE_OK;

    49 

    50   sqlite3_mutex_enter(db->mutex);

    51   while( (rc==SQLITE_OK || (rc==SQLITE_SCHEMA && (++nRetry)<2)) && zSql[0] ){

    52     int nCol;

    53     char **azVals = 0;

    54 

    55     pStmt = 0;

    56     rc = sqlite3_prepare(db, zSql, -1, &pStmt, &zLeftover);

    57     assert( rc==SQLITE_OK || pStmt==0 );

    58     if( rc!=SQLITE_OK ){

    59       continue;

    60     }

    61     if( !pStmt ){

    62       /* this happens for a comment or white-space */

    63       zSql = zLeftover;

    64       continue;

    65     }

    66 

    67     nCallback = 0;

    68 

    69     nCol = sqlite3_column_count(pStmt);

    70     azCols = (char**)sqlite3DbMallocZero(db, 2*nCol*sizeof(const char *) + 1);

    71     if( azCols==0 ){

    72       goto exec_out;

    73     }

    74 

    75     while( 1 ){

    76       int i;

    77       rc = sqlite3_step(pStmt);

    78 

    79       /* Invoke the callback function if required */

    80       if( xCallback && (SQLITE_ROW==rc || 

    81           (SQLITE_DONE==rc && !nCallback && db->flags&SQLITE_NullCallback)) ){

    82         if( 0==nCallback ){

    83           for(i=0; i<nCol; i++){

    84             azCols[i] = (char *)sqlite3_column_name(pStmt, i);

    85           }

    86           nCallback++;

    87         }

    88         if( rc==SQLITE_ROW ){

    89           azVals = &azCols[nCol];

    90           for(i=0; i<nCol; i++){

    91             azVals[i] = (char *)sqlite3_column_text(pStmt, i);

    92           }

    93         }

    94         if( xCallback(pArg, nCol, azVals, azCols) ){

    95           rc = SQLITE_ABORT;

    96           goto exec_out;

    97         }

    98       }

    99 

   100       if( rc!=SQLITE_ROW ){

   101         rc = sqlite3_finalize(pStmt);

   102         pStmt = 0;

   103         if( rc!=SQLITE_SCHEMA ){

   104           nRetry = 0;

   105           zSql = zLeftover;

   106           while( isspace((unsigned char)zSql[0]) ) zSql++;

   107         }

   108         break;

   109       }

   110     }

   111 

   112     sqlite3_free(azCols);

   113     azCols = 0;

   114   }

   115 

   116 exec_out:

   117   if( pStmt ) sqlite3_finalize(pStmt);

   118   if( azCols ) sqlite3_free(azCols);

   119 

   120   rc = sqlite3ApiExit(db, rc);

   121   if( rc!=SQLITE_OK && rc==sqlite3_errcode(db) && pzErrMsg ){

   122     int nErrMsg = 1 + strlen(sqlite3_errmsg(db));

   123     *pzErrMsg = (char*)sqlite3_malloc(nErrMsg);

   124     if( *pzErrMsg ){

   125       memcpy(*pzErrMsg, sqlite3_errmsg(db), nErrMsg);

   126     }

   127   }else if( pzErrMsg ){

   128     *pzErrMsg = 0;

   129   }

   130 

   131   assert( (rc&db->errMask)==rc );

   132   sqlite3_mutex_leave(db->mutex);

   133   return rc;

   134 }