ds@1952: /*
ds@1952: ** 2001 September 15
ds@1952: **
ds@1952: ** The author disclaims copyright to this source code.  In place of
ds@1952: ** a legal notice, here is a blessing:
ds@1952: **
ds@1952: **    May you do good and not evil.
ds@1952: **    May you find forgiveness for yourself and forgive others.
ds@1952: **    May you share freely, never taking more than you give.
ds@1952: **
ds@1952: *************************************************************************
ds@1952: ** This file contains the sqlite3_get_table() and sqlite3_free_table()
ds@1952: ** interface routines.  These are just wrappers around the main
ds@1952: ** interface routine of sqlite3_exec().
ds@1952: **
ds@1952: ** These routines are in a separate files so that they will not be linked
ds@1952: ** if they are not used.
ds@1952: */
ds@1952: #include "sqliteInt.h"
ds@1952: #include <stdlib.h>
ds@1952: #include <string.h>
ds@1952: 
ds@1952: #ifndef SQLITE_OMIT_GET_TABLE
ds@1952: 
ds@1952: /*
ds@1952: ** This structure is used to pass data from sqlite3_get_table() through
ds@1952: ** to the callback function is uses to build the result.
ds@1952: */
ds@1952: typedef struct TabResult {
ds@1952:   char **azResult;
ds@1952:   char *zErrMsg;
ds@1952:   int nResult;
ds@1952:   int nAlloc;
ds@1952:   int nRow;
ds@1952:   int nColumn;
ds@1952:   int nData;
ds@1952:   int rc;
ds@1952: } TabResult;
ds@1952: 
ds@1952: /*
ds@1952: ** This routine is called once for each row in the result table.  Its job
ds@1952: ** is to fill in the TabResult structure appropriately, allocating new
ds@1952: ** memory as necessary.
ds@1952: */
ds@1952: static int sqlite3_get_table_cb(void *pArg, int nCol, char **argv, char **colv){
ds@1952:   TabResult *p = (TabResult*)pArg;
ds@1952:   int need;
ds@1952:   int i;
ds@1952:   char *z;
ds@1952: 
ds@1952:   /* Make sure there is enough space in p->azResult to hold everything
ds@1952:   ** we need to remember from this invocation of the callback.
ds@1952:   */
ds@1952:   if( p->nRow==0 && argv!=0 ){
ds@1952:     need = nCol*2;
ds@1952:   }else{
ds@1952:     need = nCol;
ds@1952:   }
ds@1952:   if( p->nData + need >= p->nAlloc ){
ds@1952:     char **azNew;
ds@1952:     p->nAlloc = p->nAlloc*2 + need + 1;
ds@1952:     azNew = sqlite3_realloc( p->azResult, sizeof(char*)*p->nAlloc );
ds@1952:     if( azNew==0 ) goto malloc_failed;
ds@1952:     p->azResult = azNew;
ds@1952:   }
ds@1952: 
ds@1952:   /* If this is the first row, then generate an extra row containing
ds@1952:   ** the names of all columns.
ds@1952:   */
ds@1952:   if( p->nRow==0 ){
ds@1952:     p->nColumn = nCol;
ds@1952:     for(i=0; i<nCol; i++){
ds@1952:       if( colv[i]==0 ){
ds@1952:         z = sqlite3_mprintf("");
ds@1952:       }else{
ds@1952:         z = sqlite3_mprintf("%s", colv[i]);
ds@1952:       }
ds@1952:       p->azResult[p->nData++] = z;
ds@1952:     }
ds@1952:   }else if( p->nColumn!=nCol ){
ds@1952:     sqlite3SetString(&p->zErrMsg,
ds@1952:        "sqlite3_get_table() called with two or more incompatible queries",
ds@1952:        (char*)0);
ds@1952:     p->rc = SQLITE_ERROR;
ds@1952:     return 1;
ds@1952:   }
ds@1952: 
ds@1952:   /* Copy over the row data
ds@1952:   */
ds@1952:   if( argv!=0 ){
ds@1952:     for(i=0; i<nCol; i++){
ds@1952:       if( argv[i]==0 ){
ds@1952:         z = 0;
ds@1952:       }else{
ds@1952:         int n = strlen(argv[i])+1;
ds@1952:         z = sqlite3_malloc( n );
ds@1952:         if( z==0 ) goto malloc_failed;
ds@1952:         memcpy(z, argv[i], n);
ds@1952:       }
ds@1952:       p->azResult[p->nData++] = z;
ds@1952:     }
ds@1952:     p->nRow++;
ds@1952:   }
ds@1952:   return 0;
ds@1952: 
ds@1952: malloc_failed:
ds@1952:   p->rc = SQLITE_NOMEM;
ds@1952:   return 1;
ds@1952: }
ds@1952: 
ds@1952: /*
ds@1952: ** Query the database.  But instead of invoking a callback for each row,
ds@1952: ** malloc() for space to hold the result and return the entire results
ds@1952: ** at the conclusion of the call.
ds@1952: **
ds@1952: ** The result that is written to ***pazResult is held in memory obtained
ds@1952: ** from malloc().  But the caller cannot free this memory directly.  
ds@1952: ** Instead, the entire table should be passed to sqlite3_free_table() when
ds@1952: ** the calling procedure is finished using it.
ds@1952: */
ds@1952: int sqlite3_get_table(
ds@1952:   sqlite3 *db,                /* The database on which the SQL executes */
ds@1952:   const char *zSql,           /* The SQL to be executed */
ds@1952:   char ***pazResult,          /* Write the result table here */
ds@1952:   int *pnRow,                 /* Write the number of rows in the result here */
ds@1952:   int *pnColumn,              /* Write the number of columns of result here */
ds@1952:   char **pzErrMsg             /* Write error messages here */
ds@1952: ){
ds@1952:   int rc;
ds@1952:   TabResult res;
ds@1952:   if( pazResult==0 ){ return SQLITE_ERROR; }
ds@1952:   *pazResult = 0;
ds@1952:   if( pnColumn ) *pnColumn = 0;
ds@1952:   if( pnRow ) *pnRow = 0;
ds@1952:   res.zErrMsg = 0;
ds@1952:   res.nResult = 0;
ds@1952:   res.nRow = 0;
ds@1952:   res.nColumn = 0;
ds@1952:   res.nData = 1;
ds@1952:   res.nAlloc = 20;
ds@1952:   res.rc = SQLITE_OK;
ds@1952:   res.azResult = sqlite3_malloc( sizeof(char*)*res.nAlloc );
ds@1952:   if( res.azResult==0 ) return SQLITE_NOMEM;
ds@1952:   res.azResult[0] = 0;
ds@1952:   rc = sqlite3_exec(db, zSql, sqlite3_get_table_cb, &res, pzErrMsg);
ds@1952: #ifndef NDEBUG
ds@1952:   sqlite3_mutex_enter(db->mutex);
ds@1952:   assert((rc&db->errMask)==rc && (res.rc&db->errMask)==res.rc);
ds@1952:   sqlite3_mutex_leave(db->mutex);
ds@1952: #endif
ds@1952:   if( res.azResult ){
ds@1952:     assert( sizeof(res.azResult[0])>= sizeof(res.nData) );
ds@1952:     res.azResult[0] = (char*)res.nData;
ds@1952:   }
ds@1952:   if( (rc&0xff)==SQLITE_ABORT ){
ds@1952:     sqlite3_free_table(&res.azResult[1]);
ds@1952:     if( res.zErrMsg ){
ds@1952:       if( pzErrMsg ){
ds@1952:         sqlite3_free(*pzErrMsg);
ds@1952:         *pzErrMsg = sqlite3_mprintf("%s",res.zErrMsg);
ds@1952:       }
ds@1952:       sqlite3_free(res.zErrMsg);
ds@1952:     }
ds@1952:     sqlite3_mutex_enter(db->mutex);
ds@1952:     db->errCode = res.rc;
ds@1952:     sqlite3_mutex_leave(db->mutex);
ds@1952:     return res.rc;
ds@1952:   }
ds@1952:   sqlite3_free(res.zErrMsg);
ds@1952:   if( rc!=SQLITE_OK ){
ds@1952:     sqlite3_free_table(&res.azResult[1]);
ds@1952:     return rc;
ds@1952:   }
ds@1952:   if( res.nAlloc>res.nData ){
ds@1952:     char **azNew;
ds@1952:     azNew = sqlite3_realloc( res.azResult, sizeof(char*)*(res.nData+1) );
ds@1952:     if( azNew==0 ){
ds@1952:       sqlite3_free_table(&res.azResult[1]);
ds@1952:       return SQLITE_NOMEM;
ds@1952:     }
ds@1952:     res.nAlloc = res.nData+1;
ds@1952:     res.azResult = azNew;
ds@1952:   }
ds@1952:   *pazResult = &res.azResult[1];
ds@1952:   if( pnColumn ) *pnColumn = res.nColumn;
ds@1952:   if( pnRow ) *pnRow = res.nRow;
ds@1952:   return rc;
ds@1952: }
ds@1952: 
ds@1952: /*
ds@1952: ** This routine frees the space the sqlite3_get_table() malloced.
ds@1952: */
ds@1952: void sqlite3_free_table(
ds@1952:   char **azResult            /* Result returned from from sqlite3_get_table() */
ds@1952: ){
ds@1952:   if( azResult ){
ds@1952:     int i, n;
ds@1952:     azResult--;
ds@1952:     if( azResult==0 ) return;
ds@1952:     n = (int)azResult[0];
ds@1952:     for(i=1; i<n; i++){ if( azResult[i] ) sqlite3_free(azResult[i]); }
ds@1952:     sqlite3_free(azResult);
ds@1952:   }
ds@1952: }
ds@1952: 
ds@1952: #endif /* SQLITE_OMIT_GET_TABLE */