You represent a database connection string with the SqlDataSource control's ConnectionString property. <%@ Page Language="C#" %>"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd"> Show Local Connection id="grdProducts" DataSourceID="srcProducts" Runat="server" /> id="srcProducts" SelectCommand="SELECT * FROM Products" ConnectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|MyDatabase.mdf;Integrated Security=True;User Instance=True" Runat="server" />