public override bool HasNextEvent()
{
DateTime now = DateTime.Now;
String cmdText = String.Format(@"Select TOP 1 row_id FROM {0} WHERE status = {1} AND fire_time < {2} ",
TableName, QCDBClient.EscapeString(Status_Live),
QCDBClient.EscapeString(now.ToString()));
return(DB.ExecuteScalar(cmdText) != null);
}