dvander@1203: /*
dvander@1203: ** 2001 September 15
dvander@1203: **
dvander@1203: ** The author disclaims copyright to this source code.  In place of
dvander@1203: ** a legal notice, here is a blessing:
dvander@1203: **
dvander@1203: **    May you do good and not evil.
dvander@1203: **    May you find forgiveness for yourself and forgive others.
dvander@1203: **    May you share freely, never taking more than you give.
dvander@1203: **
dvander@1203: *************************************************************************
dvander@1203: ** This file contains the sqlite3_get_table() and sqlite3_free_table()
dvander@1203: ** interface routines.  These are just wrappers around the main
dvander@1203: ** interface routine of sqlite3_exec().
dvander@1203: **
dvander@1203: ** These routines are in a separate files so that they will not be linked
dvander@1203: ** if they are not used.
dvander@1203: */
dvander@1203: #include "sqliteInt.h"
dvander@1203: #include <stdlib.h>
dvander@1203: #include <string.h>
dvander@1203: 
dvander@1203: #ifndef SQLITE_OMIT_GET_TABLE
dvander@1203: 
dvander@1203: /*
dvander@1203: ** This structure is used to pass data from sqlite3_get_table() through
dvander@1203: ** to the callback function is uses to build the result.
dvander@1203: */
dvander@1203: typedef struct TabResult {
dvander@1203:   char **azResult;
dvander@1203:   char *zErrMsg;
dvander@1203:   int nResult;
dvander@1203:   int nAlloc;
dvander@1203:   int nRow;
dvander@1203:   int nColumn;
dvander@1203:   int nData;
dvander@1203:   int rc;
dvander@1203: } TabResult;
dvander@1203: 
dvander@1203: /*
dvander@1203: ** This routine is called once for each row in the result table.  Its job
dvander@1203: ** is to fill in the TabResult structure appropriately, allocating new
dvander@1203: ** memory as necessary.
dvander@1203: */
dvander@1203: static int sqlite3_get_table_cb(void *pArg, int nCol, char **argv, char **colv){
dvander@1203:   TabResult *p = (TabResult*)pArg;
dvander@1203:   int need;
dvander@1203:   int i;
dvander@1203:   char *z;
dvander@1203: 
dvander@1203:   /* Make sure there is enough space in p->azResult to hold everything
dvander@1203:   ** we need to remember from this invocation of the callback.
dvander@1203:   */
dvander@1203:   if( p->nRow==0 && argv!=0 ){
dvander@1203:     need = nCol*2;
dvander@1203:   }else{
dvander@1203:     need = nCol;
dvander@1203:   }
dvander@1203:   if( p->nData + need >= p->nAlloc ){
dvander@1203:     char **azNew;
dvander@1203:     p->nAlloc = p->nAlloc*2 + need + 1;
dvander@1203:     azNew = sqlite3_realloc( p->azResult, sizeof(char*)*p->nAlloc );
dvander@1203:     if( azNew==0 ) goto malloc_failed;
dvander@1203:     p->azResult = azNew;
dvander@1203:   }
dvander@1203: 
dvander@1203:   /* If this is the first row, then generate an extra row containing
dvander@1203:   ** the names of all columns.
dvander@1203:   */
dvander@1203:   if( p->nRow==0 ){
dvander@1203:     p->nColumn = nCol;
dvander@1203:     for(i=0; i<nCol; i++){
dvander@1203:       if( colv[i]==0 ){
dvander@1203:         z = sqlite3_mprintf("");
dvander@1203:       }else{
dvander@1203:         z = sqlite3_mprintf("%s", colv[i]);
dvander@1203:       }
dvander@1203:       p->azResult[p->nData++] = z;
dvander@1203:     }
dvander@1203:   }else if( p->nColumn!=nCol ){
dvander@1203:     sqlite3SetString(&p->zErrMsg,
dvander@1203:        "sqlite3_get_table() called with two or more incompatible queries",
dvander@1203:        (char*)0);
dvander@1203:     p->rc = SQLITE_ERROR;
dvander@1203:     return 1;
dvander@1203:   }
dvander@1203: 
dvander@1203:   /* Copy over the row data
dvander@1203:   */
dvander@1203:   if( argv!=0 ){
dvander@1203:     for(i=0; i<nCol; i++){
dvander@1203:       if( argv[i]==0 ){
dvander@1203:         z = 0;
dvander@1203:       }else{
dvander@1203:         int n = strlen(argv[i])+1;
dvander@1203:         z = sqlite3_malloc( n );
dvander@1203:         if( z==0 ) goto malloc_failed;
dvander@1203:         memcpy(z, argv[i], n);
dvander@1203:       }
dvander@1203:       p->azResult[p->nData++] = z;
dvander@1203:     }
dvander@1203:     p->nRow++;
dvander@1203:   }
dvander@1203:   return 0;
dvander@1203: 
dvander@1203: malloc_failed:
dvander@1203:   p->rc = SQLITE_NOMEM;
dvander@1203:   return 1;
dvander@1203: }
dvander@1203: 
dvander@1203: /*
dvander@1203: ** Query the database.  But instead of invoking a callback for each row,
dvander@1203: ** malloc() for space to hold the result and return the entire results
dvander@1203: ** at the conclusion of the call.
dvander@1203: **
dvander@1203: ** The result that is written to ***pazResult is held in memory obtained
dvander@1203: ** from malloc().  But the caller cannot free this memory directly.  
dvander@1203: ** Instead, the entire table should be passed to sqlite3_free_table() when
dvander@1203: ** the calling procedure is finished using it.
dvander@1203: */
dvander@1203: int sqlite3_get_table(
dvander@1203:   sqlite3 *db,                /* The database on which the SQL executes */
dvander@1203:   const char *zSql,           /* The SQL to be executed */
dvander@1203:   char ***pazResult,          /* Write the result table here */
dvander@1203:   int *pnRow,                 /* Write the number of rows in the result here */
dvander@1203:   int *pnColumn,              /* Write the number of columns of result here */
dvander@1203:   char **pzErrMsg             /* Write error messages here */
dvander@1203: ){
dvander@1203:   int rc;
dvander@1203:   TabResult res;
dvander@1203:   if( pazResult==0 ){ return SQLITE_ERROR; }
dvander@1203:   *pazResult = 0;
dvander@1203:   if( pnColumn ) *pnColumn = 0;
dvander@1203:   if( pnRow ) *pnRow = 0;
dvander@1203:   res.zErrMsg = 0;
dvander@1203:   res.nResult = 0;
dvander@1203:   res.nRow = 0;
dvander@1203:   res.nColumn = 0;
dvander@1203:   res.nData = 1;
dvander@1203:   res.nAlloc = 20;
dvander@1203:   res.rc = SQLITE_OK;
dvander@1203:   res.azResult = sqlite3_malloc( sizeof(char*)*res.nAlloc );
dvander@1203:   if( res.azResult==0 ) return SQLITE_NOMEM;
dvander@1203:   res.azResult[0] = 0;
dvander@1203:   rc = sqlite3_exec(db, zSql, sqlite3_get_table_cb, &res, pzErrMsg);
dvander@1645: #ifndef NDEBUG
dvander@1645:   sqlite3_mutex_enter(db->mutex);
dvander@1645:   assert((rc&db->errMask)==rc && (res.rc&db->errMask)==res.rc);
dvander@1645:   sqlite3_mutex_leave(db->mutex);
dvander@1645: #endif
dvander@1203:   if( res.azResult ){
dvander@1203:     assert( sizeof(res.azResult[0])>= sizeof(res.nData) );
dvander@1203:     res.azResult[0] = (char*)res.nData;
dvander@1203:   }
dvander@1203:   if( (rc&0xff)==SQLITE_ABORT ){
dvander@1203:     sqlite3_free_table(&res.azResult[1]);
dvander@1203:     if( res.zErrMsg ){
dvander@1203:       if( pzErrMsg ){
dvander@1203:         sqlite3_free(*pzErrMsg);
dvander@1203:         *pzErrMsg = sqlite3_mprintf("%s",res.zErrMsg);
dvander@1203:       }
dvander@1645:       sqlite3_free(res.zErrMsg);
dvander@1203:     }
dvander@1645:     sqlite3_mutex_enter(db->mutex);
dvander@1203:     db->errCode = res.rc;
dvander@1645:     sqlite3_mutex_leave(db->mutex);
dvander@1645:     return res.rc;
dvander@1203:   }
dvander@1645:   sqlite3_free(res.zErrMsg);
dvander@1203:   if( rc!=SQLITE_OK ){
dvander@1203:     sqlite3_free_table(&res.azResult[1]);
dvander@1645:     return rc;
dvander@1203:   }
dvander@1203:   if( res.nAlloc>res.nData ){
dvander@1203:     char **azNew;
dvander@1203:     azNew = sqlite3_realloc( res.azResult, sizeof(char*)*(res.nData+1) );
dvander@1203:     if( azNew==0 ){
dvander@1203:       sqlite3_free_table(&res.azResult[1]);
dvander@1203:       return SQLITE_NOMEM;
dvander@1203:     }
dvander@1203:     res.nAlloc = res.nData+1;
dvander@1203:     res.azResult = azNew;
dvander@1203:   }
dvander@1203:   *pazResult = &res.azResult[1];
dvander@1203:   if( pnColumn ) *pnColumn = res.nColumn;
dvander@1203:   if( pnRow ) *pnRow = res.nRow;
dvander@1645:   return rc;
dvander@1203: }
dvander@1203: 
dvander@1203: /*
dvander@1203: ** This routine frees the space the sqlite3_get_table() malloced.
dvander@1203: */
dvander@1203: void sqlite3_free_table(
dvander@1203:   char **azResult            /* Result returned from from sqlite3_get_table() */
dvander@1203: ){
dvander@1203:   if( azResult ){
dvander@1203:     int i, n;
dvander@1203:     azResult--;
dvander@1203:     if( azResult==0 ) return;
dvander@1203:     n = (int)azResult[0];
dvander@1203:     for(i=1; i<n; i++){ if( azResult[i] ) sqlite3_free(azResult[i]); }
dvander@1203:     sqlite3_free(azResult);
dvander@1203:   }
dvander@1203: }
dvander@1203: 
dvander@1203: #endif /* SQLITE_OMIT_GET_TABLE */