SqlDataSourceView.DeleteCommand Property
Definition
Important
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Gets or sets the SQL string that the SqlDataSourceView uses to delete data from the underlying database.
public:
property System::String ^ DeleteCommand { System::String ^ get(); void set(System::String ^ value); };public string DeleteCommand { get; set; }member this.DeleteCommand : string with get, setPublic Property DeleteCommand As StringProperty Value
An SQL string that the SqlDataSourceView uses to delete data.
Examples
The following code example demonstrates how to set the DeleteCommand text to delete an order from the Northwind database Orders table. Data is retrieved from the Orders table and displayed in a GridView control. The GridView renders a Delete button automatically when the AutoGenerateDeleteButton property is set to true and automatically populates the DeleteParameters collection and calls the Delete method when the Delete button is clicked. Finally, because this example deletes data, an event handler is added to attempt to back up the database to disk before the delete operation is performed.
<%@Page Language="C#" %>
<%@Import Namespace="System.Data.SqlClient" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
private void OnRecordDeleting(Object source, SqlDataSourceCommandEventArgs e) {
// Cancel the delete operation if the checkbox is not checked.
if (!CheckBox1.Checked) {
e.Cancel = true;
Label1.Text = "The command was cancelled because the CheckBox was not checked.";
}
}
private void OnRecordDeleted(object source, SqlDataSourceStatusEventArgs e) {
Label1.Text = e.AffectedRows + " row(s) were deleted";
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>ASP.NET Example</title>
</head>
<body>
<form id="form1" runat="server">
<asp:SqlDataSource
id="SqlDataSource1"
runat="server"
DataSourceMode="DataSet"
ConnectionString="<%$ ConnectionStrings:MyNorthwind%>"
SelectCommand="SELECT * FROM Orders"
DeleteCommand="DELETE FROM [Order Details] WHERE OrderID=@OrderID;DELETE FROM Orders WHERE OrderID=@OrderID;"
OnDeleting="OnRecordDeleting"
OnDeleted="OnRecordDeleted">
</asp:SqlDataSource>
<br />
<asp:CheckBox
id="CheckBox1"
runat="server"
autopostback="true"
text="Check To Delete Data" />
<br />
<br />
<asp:GridView
id="GridView1"
runat="server"
AutoGenerateColumns="False"
DataKeyNames="OrderID"
AutoGenerateDeleteButton="True"
AllowPaging="True"
PageSize="20"
DataSourceID="SqlDataSource1">
<Columns>
<asp:BoundField HeaderText="Order ID" DataField="OrderID" />
<asp:BoundField HeaderText="Customer" DataField="CustomerID" />
<asp:BoundField HeaderText="Order Placed" DataField="OrderDate" />
<asp:BoundField HeaderText="Order Shipped" DataField="ShippedDate" />
</Columns>
</asp:GridView>
<asp:Label
id="Label1"
runat="server">
</asp:Label>
</form>
</body>
</html>
<%@Page Language="VB" %>
<%@Import Namespace="System.Data.SqlClient" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
Sub On_Record_Deleting(ByVal source As Object, ByVal e As SqlDataSourceCommandEventArgs)
' Cancel the delete operation if the checkbox is not checked.
If Not CheckBox1.Checked
e.Cancel = True
Label1.Text = "The command was cancelled because the CheckBox was not checked."
End If
End Sub 'On_Record_Deleting
Sub On_Record_Deleted(ByVal source As Object, ByVal e As SqlDataSourceStatusEventArgs)
Label1.Text = e.AffectedRows & " row(s) were deleted"
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>ASP.NET Example</title>
</head>
<body>
<form id="form1" runat="server">
<asp:SqlDataSource
id="SqlDataSource1"
runat="server"
DataSourceMode="DataSet"
ConnectionString="<%$ ConnectionStrings:MyNorthwind%>"
SelectCommand="SELECT * FROM Orders"
DeleteCommand="DELETE FROM [Order Details] WHERE OrderID=@OrderID;DELETE FROM Orders WHERE OrderID=@OrderID;"
OnDeleting="On_Record_Deleting"
OnDeleted="On_Record_Deleted">
</asp:SqlDataSource>
<br />
<asp:CheckBox
id="CheckBox1"
runat="server"
autopostback="true"
text="Check To Delete Data" />
<br />
<br />
<asp:GridView
id="GridView1"
runat="server"
AutoGenerateColumns="False"
DataKeyNames="OrderID"
AutoGenerateDeleteButton="True"
AllowPaging="True"
PageSize="20"
DataSourceID="SqlDataSource1">
<Columns>
<asp:BoundField HeaderText="Order ID" DataField="OrderID" />
<asp:BoundField HeaderText="Customer" DataField="CustomerID" />
<asp:BoundField HeaderText="Order Placed" DataField="OrderDate" />
<asp:BoundField HeaderText="Order Shipped" DataField="ShippedDate" />
</Columns>
</asp:GridView>
<asp:Label
id="Label1"
runat="server">
</asp:Label>
</form>
</body>
</html>
Remarks
Because different database products use different varieties of SQL, the syntax of the SQL string depends on the current ADO.NET provider being used, which is identified by the ProviderName property.
If the SQL string is a parameterized query or command, the placeholder of the parameter also depends on the ADO.NET provider being used. For example, if the provider is the System.Data.SqlClient, which is the default provider for the SqlDataSource class, the placeholder of the parameter is '@parameterName'. However, if the provider is set to the System.Data.Odbc or System.Data.OleDb, the placeholder of the parameter is '?'. For more information on parameterized SQL queries and commands, see Using Parameters with the SqlDataSource Control.
The DeleteCommand can be an SQL string or the name of a stored procedure, if the underlying database supports stored procedures.
The value of the DeleteCommand property is stored in view state.
