/// <summary>
        /// delete table
        /// 删除表
        /// </summary>
        /// <returns></returns>
        public int Delete()
        {
            //数据库连接
            if (_connectionConfig.IsAutoCloseConnection == false)
            {
                if (_database.CheckStatus() == false)
                {
                    throw new Exception("databse connect not open");
                }
            }
            if (_connectionConfig.IsAutoCloseConnection == true)
            {
                _database.Open();
            }

            _database.DeleteTable(_databasename, _TableName);

            if (_connectionConfig.IsAutoCloseConnection == true)
            {
                _database.Close();
            }

            return(0);
        }