You represent a database connection string with the SqlDataSource control's ConnectionString property. <%@ Page Language="C#" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" > <head id="Head1" runat="server"> <title>Show Local Connection</title> </head> <body> <form id="form1" runat="server"> <div> <asp:GridView id="grdProducts" DataSourceID="srcProducts" Runat="server" /> <asp:SqlDataSource id="srcProducts" SelectCommand="SELECT * FROM Products" ConnectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|MyDatabase.mdf;Integrated Security=True;User Instance=True" Runat="server" /> </div> </form> </body> </html>