ASP.NET数据绑定_第四篇_用SqlDataSource控件绑定_01

+++ 页面代码如下：
<asp:GridView ID="GridView1" runat="server" AllowPaging="True" AllowSorting="True"
    AutoGenerateColumns="False" DataKeyNames="username" DataSourceID="SqlDataSource1"
    PageSize="3">
    <Columns>
        <asp:BoundField DataField="username" HeaderText="用户名" SortExpression="username" ReadOnly="true" />
        <asp:BoundField DataField="userpwd" HeaderText="密码" SortExpression="userpwd" />
        <asp:CommandField ShowEditButton="True"/>
        <asp:CommandField ShowDeleteButton="True"/>
    </Columns>
</asp:GridView>
<asp:SqlDataSource ID="SqlDataSource1" runat="server"
    ConnectionString="Data Source=ora9;User ID=scott;Password=tiger;Persist Security Info=True"
    ProviderName="System.Data.OracleClient"
    SelectCommand="SELECT USERNAME, USERPWD from USERS"
    UpdateCommand="UPDATE USERS SET USERPWD =:userpwd where USERNAME = :username"
    DeleteCommand="DELETE from USERS where USERNAME =:username">
    <UpdateParameters>
        <asp:ControlParameter ControlID="GridView1" DefaultValue="username" Name="username"
            PropertyName="SelectedValue" />
        <asp:ControlParameter ControlID="GridView1" DefaultValue="userpwd" Name="userpwd"
            PropertyName="SelectedValue" />
    </UpdateParameters>
    <DeleteParameters>
        <asp:ControlParameter ControlID="GridView1" Default