The method adds an output parameter to the SqlCommand object : SqlParameter « ADO.net Database « ASP.NET Tutorial






File: GetTotals.sql

CREATE PROCEDURE dbo.GetTotals
(
  @SumTotals Money OUTPUT
)
AS
SELECT @SumTotals = SUM(Totals) FROM Products


File: App_Code\Product.cs

using System;
using System.Data;
using System.Data.SqlClient;
using System.Web.Configuration;
using System.Collections.Generic;

public class Product
{
    private static readonly string _connectionString;

    private string _title;
    private decimal _boxOfficeTotals;

    public string Title
    {
        get { return _title; }
        set { _title = value; }
    }

    public decimal Totals
    {
        get { return _boxOfficeTotals; }
        set { _boxOfficeTotals = value; }
    }

    public List<Product> GetPrice(out decimal SumTotals)
    {
        List<Product> results = new List<Product>();
        SqlConnection con = new SqlConnection(_connectionString);
        SqlCommand cmd = new SqlCommand("GetTotals", con);
        cmd.CommandType = CommandType.StoredProcedure;
        cmd.Parameters.Add("@SumTotals", SqlDbType.Money).Direction = ParameterDirection.Output;
        using (con)
        {
            con.Open();
            SqlDataReader reader = cmd.ExecuteReader();

            while (reader.Read())
            {
                Product newProduct = new Product();
                newProduct.Title = (string)reader["Title"];
                newProduct.Totals = (decimal)reader["Totals"];
                results.Add(newProduct);
            }
            reader.Close();
            SumTotals = (decimal)cmd.Parameters["@SumTotals"].Value;
       }
       return results;
    }    static Product()
    {
        _connectionString = WebConfigurationManager.ConnectionStrings["Products"].ConnectionString;
    }
}

File: Web.config

<configuration>
  <connectionStrings>
    <add name="Products" 
         connectionString="Data Source=.\SQLEXPRESS;
         AttachDbFilename=|DataDirectory|MyDatabase.mdf;Integrated Security=True;User Instance=True" />
  </connectionStrings>
</configuration>            


File: ShowProduct.aspx

<%@ Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
    protected void srcProducts_Selected(object sender, ObjectDataSourceStatusEventArgs e)
    {
        decimal sum = (decimal)e.OutputParameters["SumTotals"];
        lblSum.Text = sum.ToString("c");
    }
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>Show Product</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>

    <asp:GridView
        id="grdProducts"
        DataSourceID="srcProducts"
        AutoGenerateColumns="false"
        Runat="server">
        <Columns>
        <asp:BoundField DataField="Title" HeaderText="Title" />
        <asp:BoundField
            DataField="Totals"
            HeaderText="Box Office"
            HtmlEncode="false"
            DataFormatString="{0:c}" />
        </Columns>
    </asp:GridView>
    <br />
    Sum of Box Office Totals:
    <asp:Label
        id="lblSum"
        Runat="server" />

    <asp:ObjectDataSource
        id="srcProducts"
        TypeName="Product"
        SelectMethod="GetPrice"
        Runat="server" OnSelected="srcProducts_Selected">
        <SelectParameters>
        <asp:Parameter
            Name="SumTotals"
            Type="Decimal"
            Direction="Output" />
        </SelectParameters>
    </asp:ObjectDataSource>

    </div>
    </form>
</body>
</html>








18.7.SqlParameter
18.7.1.Use a SqlParameter to represent stored procedure return values and output parameters
18.7.2.The method adds an output parameter to the SqlCommand object
18.7.3.The use of a parameterized SQL statement (C#)
18.7.4.The use of a parameterized SQL statement (VB)