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SqlDataSourceView.SelectParameters Property

  • Reference

Definition

Namespace:
System.Web.UI.WebControls
Assembly:
System.Web.dll

Gets the parameters collection containing the parameters that are used by the SelectCommand property.

public:
 property System::Web::UI::WebControls::ParameterCollection ^ SelectParameters { System::Web::UI::WebControls::ParameterCollection ^ get(); };
public System.Web.UI.WebControls.ParameterCollection SelectParameters { get; }
member this.SelectParameters : System.Web.UI.WebControls.ParameterCollection
Public ReadOnly Property SelectParameters As ParameterCollection

Property Value

ParameterCollection

A ParameterCollection that contains the parameters used by the SelectCommand property.

Examples

The following code example demonstrates how to retrieve data from the Northwind database in Microsoft SQL Server by setting the SelectCommand property to an SQL query. The SQL query is parameterized and the placeholder in the SelectCommand property is matched to the ControlParameter object that is added to the SelectParameters collection. In this way, the DropDownList control, to which the ControlParameter is bound, acts as a filter for what is displayed in the ListBox control.

Note

Because the parameter is used in a WHERE clause, the use of the SelectParameters property in this code example is functionally equivalent to using both the FilterExpression and FilterParameters properties.

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>ASP.NET Example</title>
</head>
<body>
    <form id="form1" runat="server">

      <p><asp:dropdownlist
          id="DropDownList1"
          runat="server"
          autopostback="True">
          <asp:listitem selected="True">Sales Representative</asp:listitem>
          <asp:listitem>Sales Manager</asp:listitem>
          <asp:listitem>Vice President, Sales</asp:listitem>
      </asp:dropdownlist></p>

      <asp:sqldatasource
          id="SqlDataSource1"
          runat="server"
          connectionstring="<%$ ConnectionStrings:MyNorthwind%>"
          selectcommand="SELECT LastName FROM Employees WHERE Title = @Title">
          <selectparameters>
              <asp:controlparameter name="Title" controlid="DropDownList1" propertyname="SelectedValue"/>
          </selectparameters>
      </asp:sqldatasource>

      <p><asp:listbox
          id="ListBox1"
          runat="server"
          datasourceid="SqlDataSource1"
          datatextfield="LastName">
      </asp:listbox></p>

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

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>ASP.NET Example</title>
</head>
<body>
    <form id="form1" runat="server">

      <p><asp:dropdownlist
          id="DropDownList1"
          runat="server"
          autopostback="True">
          <asp:listitem selected="True">Sales Representative</asp:listitem>
          <asp:listitem>Sales Manager</asp:listitem>
          <asp:listitem>Vice President, Sales</asp:listitem>
      </asp:dropdownlist></p>

      <asp:sqldatasource
          id="SqlDataSource1"
          runat="server"
          connectionstring="<%$ ConnectionStrings:MyNorthwind%>"
          selectcommand="SELECT LastName FROM Employees WHERE Title = @Title">
          <selectparameters>
              <asp:controlparameter name="Title" controlid="DropDownList1" propertyname="SelectedValue"/>
          </selectparameters>
      </asp:sqldatasource>

      <p><asp:listbox
          id="ListBox1"
          runat="server"
          datasourceid="SqlDataSource1"
          datatextfield="LastName">
      </asp:listbox></p>

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

Remarks

If the SelectCommand property contains a parameterized SQL query, the SelectParameters collection contains any Parameter objects that correspond to the parameter placeholders in the SQL string.

Depending on the ADO.NET provider, the order of the parameters in the SelectParameters collection might be important. The System.Data.OleDb and System.Data.Odbc providers associate the parameters in the collection according to the order in which the parameters appear in the parameterized SQL query. The System.Data.SqlClient provider, which is the default ADO.NET provider for the SqlDataSource control, associates the parameters in the collection by matching the name of the parameter with a placeholder alias in the SQL query. For more information on parameterized SQL queries and commands, see Using Parameters with the SqlDataSource Control.

Applies to

See also