protected long[] SelectIDsCustom(string cmd)
 {
     using (DataCommandBase dtc = new LongsDataCommand(cmd))
     {
         _file.AddCommand(dtc);
         dtc.Wait();
         return((long[])dtc.Result);
     }
 }
 protected long[] SelectIDs(string cmd, params SQLiteParameter[] parameters)
 {
     using (DataCommandBase dtc = new LongsDataCommand(cmd, parameters))
     {
         _file.AddCommand(dtc);
         dtc.Wait();
         return((long[])dtc.Result);
     }
 }