我想讀取某個表中的所有字段下面這個方法對嗎要是錯了應該怎么改?。?nbsp;public string  QeryList()        {            string str = 0;            string qery = "SELECT Name ,Nums ,UnitPrice from orderList ";            SqlDataReader reader = DBHelper.GetReadData(qery);            if (reader.HasRows)            { reader.Read();                 str += "\n 物品名：" + reader["Name"].ToString();                 str += "\n 數量："+reader["Nums"].ToString();                 str += "\n 數量："+reader["UnitPrice"].ToString();  }            return str;        }我調用這個方法在lable上顯示lable.text=o.QeryList();