sqlite+iPhone - Check if table exists

 

Progressing now with implementing db schema/data version upgrade for one of my iPhone apps – Here&Near. Location notes and tools. So I thought I’d share a snippet for checking if table exists:

+(bool) tableExistsWithName: (NSString *) name dbPath: (NSString *) dbPath error: (NSError **) error

{

    sqlite3 *db;

    sqlite3_stmt *checkStmt;

    int dbrc;

    const char* dbFilePathUTF8 = [dbPath UTF8String]; 

    dbrc = sqlite3_open_v2(dbFilePathUTF8, &db, SQLITE_OPEN_READONLY, nil); 

    const char *sql = "select count(*) from sqlite_master where type='table' AND name=?";

    if(sqlite3_prepare_v2(db, sql, -1, &checkStmt, NULL) == SQLITE_OK)

    {

        const char *cname = [name UTF8String];

        sqlite3_bind_text(checkStmt, 1, cname, -1, SQLITE_TRANSIENT);

        int retCode = sqlite3_step(checkStmt);

        if(SQLITE_ROW == retCode)

        {

            int count = sqlite3_column_int(checkStmt, 0);

            sqlite3_finalize(checkStmt);

            sqlite3_close(db);

            return count == 1;

        }

        else 

        {

            [DbHelper convertSqlError:db error:error];

            sqlite3_finalize(checkStmt);

            sqlite3_close(db);

            return false;

        }

    }

    else {

        [DbHelper convertSqlError:db error:error];

        sqlite3_finalize(checkStmt);

        sqlite3_close(db);

        return false;

    }

    return false;

}

Where [DbHelper convertSqlError:db error:error] is explained in the previous entry.

I guess I have some semantic mess with NSError in the above code, but providing as it is right now…