Returning a Single Value : SqlCommand « ADO.net Database « ASP.NET Tutorial






  1. ASP.NET Tutorial
  2. ADO.net Database
  3. SqlCommand
File: Default.aspx

<%@ Page Language="C#" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>
<%@ Import Namespace="System.Web.Configuration" %>
<!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 btnSearch_Click(object sender, EventArgs e)
    {
        string connectionString = WebConfigurationManager.ConnectionStrings["Products"].ConnectionString;
        SqlConnection con = new SqlConnection(connectionString);
        SqlCommand cmd = new SqlCommand("SELECT Totals FROM Products WHERE Title=@Title", con);
        cmd.Parameters.AddWithValue("@Title", txtTitle.Text);
        using (con)
        {
            con.Open();
            Object result = cmd.ExecuteScalar();
            if (result != null)
                lblResult.Text = String.Format("{0:c}", result);
            else
                lblResult.Text = "No match!";
        }
    }
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>Show Execute Scalar</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>

    <h1>Box Office Totals</h1>

    <asp:Label
        id="lblTitle"
        Text="Product Title:"
        AssociatedControlID="txtTitle"
        Runat="server" />

    <asp:TextBox
        id="txtTitle"
        Runat="server" />

    <asp:Button
        id="btnSearch"
        Text="Search"
        OnClick="btnSearch_Click"
        Runat="server" />

    <hr />

    <asp:Label
        id="lblResult"
        Runat="server" />

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

File: Web.config

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








18.3.SqlCommand
18.3.1.Create SqlCommand from sql statement and connection
18.3.2.Executing a Command
18.3.3.Executing a Command with Parameters
18.3.4.Returning a Single Value
18.3.5.Read scalar data by using SqlCommand
18.3.6.Execute insert command by using SqlCommand
18.3.7.Execuate select command by using the SqlCommand
18.3.8.Execute update command
18.3.9.Attach SqlCommand to DataGrid
18.3.10.Pass a CommandBehavior.CloseConnection parameter to the ExecuteReader() method.
18.3.11.Executing Asynchronous Database Commands
18.3.12.Avoid SQL injection
18.3.13.Avoid SQL Injection attack
18.3.14.Browser Snoop