急！读取字段！asp.net

Question

我想读取某个表中的所有字段下面这个方法对吗要是错了应该怎么改啊！ 

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 数量："+reader["Nums"].ToString();
                 str += "\n 数量："+reader["UnitPrice"].ToString();  }
            return str;

        }

我调用这个方法在lable上显示lable.text=o.QeryList();