<asp:SqlDataSource ID="HopefulDataSource" runat="server"
ConnectionString="<%$ ConnectionStrings:MyConnectionString %>"
SelectCommand= "SELECT id, regGroupID, amountReceived, other FROM table"
UpdateCommand="UPDATE table
SET [amountReceived] = @amountReceived
WHERE [regGroupID] = @regGroupID">
<SelectParameters>
<asp:ControlParameter ControlID="ddlCourses" Name="ddlSelectedCourse" PropertyName="SelectedValue" Type="String" />
</SelectParameters>
<UpdateParameters>
<asp:Parameter Name="regGroupID" Type="Int32" />
<asp:Parameter Name="amountReceived" Type="Decimal" />
other parameters
<asp:Parameter Name="id" Type="Int32" />
</UpdateParameters>
</asp:SqlDataSource>
上記は、「WHERE [regGroupID] = @regGroupID」を次のいずれかに変更すると機能します
WHERE [id] = @id
また
WHERE [regGroupID] = 2