Canceling Command Execution when Deleting, Filtering, Inserting, Selecting, Updating : SqlDataSource « ADO.net Database « ASP.NET Tutorial

<%@ Page Language="C#" %>
<%@ Import Namespace="System.Data.SqlClient" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<script runat="server">
    protected void srcProducts_Updating(object sender, SqlDataSourceCommandEventArgs e)
    {
        foreach (SqlParameter param in e.Command.Parameters)
        if (param.Value == null)
        {
            e.Cancel = true;
            lblError.Text = "All fields are required!";
        }
    }
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<body>
    <form id="form1" runat="server">
    <div>

    <asp:Label
        id="lblError"
        EnableViewState="false"
        CssClass="error"
        Runat="server" />

    <asp:DetailsView
        id="dtlProduct"
        DataSourceID="srcProducts"
        DataKeyNames="Id"
        AllowPaging="true"
        AutoGenerateEditButton="true"
        Runat="server" />

    <asp:SqlDataSource
        id="srcProducts"
        SelectCommand="SELECT * FROM Products"
        UpdateCommand="UPDATE Products SET Title=@Title,Director=@Director,DateReleased=@DateReleased WHERE Id=@id"
        ConnectionString="<%$ ConnectionStrings:Products %>"
        Runat="server" 
        OnUpdating="srcProducts_Updating" />

    </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>

18.8.SqlDataSource
	18.8.1.	Connection to a mdf file
	18.8.2.	Connecting to Microsoft SQL Server
	18.8.3.	asp:SqlDataSource select command with parameters
	18.8.4.	Specify column from asp:SqlDataSource
	18.8.5.	Use connection string in asp:SqlDataSource and set the DeleteCommand and SelectCommand
	18.8.6.	Configure two asp:SqlDataSource with different SelectCommand
	18.8.7.	Executing Stored Procedures
	18.8.8.	Filtering Database Rows
	18.8.9.	Retrieves the records from the database by using a DataReader
	18.8.10.	Handling SQL Command Execution Errors
	18.8.11.	Handle the exception at the level of a DataBound control.
	18.8.12.	Canceling Command Execution when Deleting, Filtering, Inserting, Selecting, Updating
	18.8.13.	Using ASP.NET Parameters with the SqlDataSource Control
	18.8.14.	Declare each of the parameters used when executing the update command.
	18.8.15.	Using the ASP.NET ControlParameter Object to represent the value of a control property.
	18.8.16.	Show Page Control Parameter
	18.8.17.	Using the ASP.NET CookieParameter Object
	18.8.18.	Using the ASP.NET FormParameter Object
	18.8.19.	Using the ASP.NET ProfileParameter Object
	18.8.20.	Using the QueryStringParameter Object
	18.8.21.	Using the SessionParameter Object
	18.8.22.	Caching Database Data with the SqlDataSource Control
	18.8.23.	Link asp:GridView with asp:SqlDataSource
	18.8.24.	Bind asp:SqlDataSource with CheckBoxList and RadioButtonList (VB.net)
	18.8.25.	Link asp:DropDownList with asp:SqlDataSource
	18.8.26.	SqlDataSource with dynamic parameter