< asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="< %$ ConnectionStrings:NorthwindConnectionString %> "
            SelectCommand="SELECT [CustomerID], [CompanyName], [ContactName], [Address], [City] FROM [Customers]"> 
        < /asp:SqlDataSource> 
An entry will be added to the web.config file as shown below:
      < connectionStrings> 
            < add name="NorthwindConnectionString" connectionString="Data Source=(local);Initial Catalog=Northwind;Integrated Security=True" providerName="System.Data.SqlClient"/> 
      < /connectionStrings> 

< asp:GridView ID="GridView1" runat="server" AllowPaging="True" AllowSorting="True"
            AutoGenerateColumns="False" DataKeyNames="CustomerID" DataSourceID="SqlDataSource1"
            OnRowDataBound="GridView1_RowDataBound" Font-Names="Verdana" Font-Size="Small"> 
            < Columns> 
                < asp:BoundField DataField="CustomerID" HeaderText="CustomerID" ReadOnly="True" SortExpression="CustomerID" /> 
                < asp:BoundField DataField="CompanyName" HeaderText="CompanyName" SortExpression="CompanyName" /> 
                < asp:BoundField DataField="ContactName" HeaderText="ContactName" SortExpression="ContactName" /> 
                < asp:BoundField DataField="Address" HeaderText="Address" SortExpression="Address" /> 
                < asp:BoundField DataField="City" HeaderText="City" SortExpression="City" /> 
            < /Columns> 
        < /asp:GridView>