SQLDatasource查询更改后，GridView行是否未更新？

Question

I have a grid view and i have bonded sql data source to that. on page i have drop down, as soon as selected value of drop down get changes, i change the select query of sql data source and again binding the data to grid view. before doing this if i update the grid view row its get updated but after doing previous process my update is not working. it don't show me any error. it don't take edited values.

my grid view

<asp:GridView ID="gvTests" runat="server" AutoGenerateColumns="False" EmptyDataText="Testes are not assigned to this sample type."
    CellPadding="4" CssClass="border" DataKeyNames="TestId" DataSourceID="SqlDS"
    AlternatingRowStyle-BackColor="#E0ECF8" HeaderStyle-Height="20px" ForeColor="#333333"
    HeaderStyle-HorizontalAlign="Left" GridLines="None" Width="100%" OnRowCommand="gvTests_RowCommand"
    AllowPaging="True" AllowSorting="True" OnRowDataBound="gvTests_RowDataBound">
    <AlternatingRowStyle />
    <Columns>
        <asp:TemplateField HeaderText="TestId" InsertVisible="False" SortExpression="TestId"
            Visible="False">
            <EditItemTemplate>
                <asp:Label ID="lblId" runat="server" Text='<%# Eval("Id") %>'></asp:Label>
            </EditItemTemplate>
            <ItemTemplate>
                <asp:Label ID="lblId" runat="server" Text='<%# Bind("Id") %>'></asp:Label>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderText="Test" SortExpression="TestName" HeaderStyle-HorizontalAlign="Center">
            <EditItemTemplate>
                <asp:TextBox CssClass="smallinput_t200" Width="100px" Text='<%# Bind("Name") %>'
                    ID="txtTestName" runat="server"></asp:TextBox>
            </EditItemTemplate>
            <ItemTemplate>
                <asp:Label ID="Label1" runat="server" Text='<%# Bind("Name") %>'></asp:Label>
            </ItemTemplate>
        </asp:TemplateField>

        <asp:TemplateField ShowHeader="False">
            <EditItemTemplate>
                <asp:LinkButton ID="LinkButtonUpdate" runat="server" CausesValidation="True" CommandName="Update"
                    Text="Update"></asp:LinkButton>
                &nbsp;<asp:LinkButton ID="LinkButtonCancel" runat="server" CausesValidation="False"
                    CommandName="Cancel" Text="Cancel"></asp:LinkButton>
            </EditItemTemplate>
            <ItemTemplate>
                <asp:LinkButton ID="LinkButtonEdit" runat="server" CausesValidation="False" CommandName="Edit"
                    Text="Edit"></asp:LinkButton>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField ShowHeader="False">
            <ItemTemplate>
                <asp:LinkButton ID="LinkButtonDelete" runat="server" CausesValidation="False" CommandName="Del"
                    Text="Delete" ></asp:LinkButton>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField ShowHeader="False">
            <ItemTemplate>
                <asp:LinkButton ID="LinkButtonSelect" runat="server" CausesValidation="False" CommandName="Select"
                    Text="Edit"></asp:LinkButton>
            </ItemTemplate>
        </asp:TemplateField>
    </Columns>
    <FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
    <HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
    <PagerStyle BackColor="#6B89AD" ForeColor="White" HorizontalAlign="Center" />
    <RowStyle CssClass="mytr" />
    <SelectedRowStyle BackColor="#6B89AD" ForeColor="White" />
    <SortedAscendingCellStyle BackColor="#E9E7E2" />
    <SortedAscendingHeaderStyle BackColor="#506C8C" />
    <SortedDescendingCellStyle BackColor="#FFFDF8" />
    <SortedDescendingHeaderStyle BackColor="#6F8DAE" />
</asp:GridView>

sql data source is like this

<asp:SqlDataSource ID="SqlDS" runat="server" ConnectionString="<%$ ConnectionStrings:ApplicationServices %>"       
    SelectCommand="select * from tests"         
    UpdateCommand="Update [Tests] set [Name]=@TestName where [Id]=@TestId"
   >
   <FilterParameters>
   </FilterParameters>
    <UpdateParameters>
        <asp:Parameter Name="Name" DbType="String" />
        <asp:Parameter Name="Id" DbType="Int32" />
    </UpdateParameters>
</asp:SqlDataSource>

my drop down is as

<asp:DropDownList ID="ddlType" runat="server"
                        DataSourceID="SqlDS" DataTextField="Name" 
                        DataValueField="Id" OnSelectedIndexChanged="ddlType_SelectedIndexChanged"
                        AutoPostBack="True" OnDataBound="ddlSampleType_DataBound">
                    </asp:DropDownList>  

index change code is as

protected void ddlType_SelectedIndexChanged(object sender, EventArgs e)
    {
        SqlDS.SelectCommand = "select * from Tests t where t.Id in (1,2,3,4,5)";
        SqlDS.Select(DataSourceSelectArguments.Empty);
        gvTests.EditIndex = -1;
        gvTests.DataBind();
    }

Row edit code is as

protected void gvTests_RowCommand(object sender, GridViewCommandEventArgs e)
    {
        if (e.CommandName == "Update")
        {
            GridViewRow row = (GridViewRow)((LinkButton)e.CommandSource).NamingContainer;
            SqlDSTests.UpdateParameters["Name"].DefaultValue = (row.FindControl("txtName") as TextBox).Text;
            SqlDSTests.UpdateParameters["Id"].DefaultValue = (row.FindControl("lblId") as Label).Text;
            SqlDSTests.Update();
            SqlDS.Select(DataSourceSelectArguments.Empty);
            gvTests.EditIndex = -1;
            gvTests.DataBind();
        }
   }

Answer 1

I suspect that this is happening because SelectCommand property of Sql Data source is not backed up by view-state (for security purposes). So when you change the select command in one of the event, the change is reflected only for that request. On subsequent post-back (for update event), the design time select command will be used and it may change the data bound to grid-view causing update to fail.

As a solution, you can try using FilterExpression and FilterParameters if it make sense in your scenario (check the example in FilterExpression help).