[Solved] RadGrid bound to EntityDataSource

[Justin McMillen]

I have a RadGrid that is bound to an EntityDataSource.  The RadGrid uses an edit form template and two of the controls are bound to Foreign Key tables(objects) of the parent entity object.  I have insert and update working.  But I get "Object reference not set to an instance of an object" when i perform a delete.  Does anyone know why this happens?

Below is a very rough markup of how my code is structured:

<telerik:radgrid id="myGrid" runat="server" DatasourceID="dsCustomers" AllowAutomaticInserts="true" AllowAutomaticUpdates="true" AllowAutomaticDeletes="true">

<MasterTableView CommandItemDisplay="top" DataSourceId="dsCustomers" DataKeyNames="CustomerId" EditMode="EditForms">

<Columns>

<telerik:GridEditCommandColumn ButtonType="ImageButton" EditText="Edit" />

<telerik:GridBoundColumn HeaderText="Title" DataField="Title.Description" />

<telerik:GridBoundColumn HeaderText="Name" DataField="Name" />

<telerik:GridButtonColumn ConfirmText="Delete this Customer?" ConfirmDialogType="Classic" ConfirmTitle="Delete"

ButtonType="ImageButton" CommandName="Delete" Text="Delete" UniqueName="DeleteColumn" />

</Columns>

<EditFormSettings EditFormType="Template">

<FormTemplate>

<table>

<tr>

<td>

<telerik:RadComboBox id="cmbTitle" runat="server" DataSourceID="dsTitles" AppendDataBoundItems="true"

DataTextField="Description" DataValueField="Id" SelectedValue='<%# Bind("Title.Id") %>' >

<Items><telerik:RadComboBoxItem Value="0" Text="" Selected="true" /></Items>

</telerik:RadcomboBox>

</td>

<td>

<telerik:RadTextBox id="txtName" runat="server" Text='<% Bind("Name") %>;' />

</td>           </tr>         </table>

</FormTemplate>

</EditFormSettings>

</MasterTableView>

</telerik:radgrid>

<asp:EntityDataSource ID="dsCustomers" runat="server" ConnectionString="name=CustomerEntities" DefaultContainerName="CustomerEntities" EnableUpdate="true" EnableInsert="true" EnableDelete="true" EntitySetName="Customer" Include="Title" />

<asp:EntityDataSource ID="dsTitles" runat="server" ConnectionString="name=CustomerEntities" DefaultContainerName="CustomerEntities" EntitySetName="Title" />

[Tsvetoslav]

Hi Justin,

 You need to make sure that you do not have any referential contstaints in the database that are preventing the delete operation. If so, you need to enable cascading deletes on the tables concerned.

I hope this helps.

Regards,
Tsvetoslav
the Telerik team

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[Justin McMillen]

Hi Tsvetoslav,
    Thank you for your quick response.  I don't think my problem is referential constraints because I can manually perform the delete in the DeleteCommand event of the RadGrid.  Do you have any idea why I can't delete the record from the EntityDataSource?

[Justin McMillen]

Hi Tsvetoslav,
    I would also like to mention that I just tried the EntityDataSource bound to an ASP.NET GridView and the delete works fine with no additional code.  Is there a limitation with the RadGrid? 

Please See my code example below:

<asp:GridView ID="gvTest" runat="server" DataSourceID="eDsCustomers" AutoGenerateColumns="false" DataKeyNames="CustomerId">
        <Columns>
            <asp:TemplateField HeaderText="Title">
                <ItemTemplate>
                    <%# Eval("Title.Description") %>
                </ItemTemplate>
            </asp:TemplateField>
            <asp:BoundField DataField="Name" HeaderText="Customer Name"  />
            <asp:CommandField ButtonType="Button" DeleteText="Delete"   ShowDeleteButton="true" />

        </Columns>
    </asp:GridView>

<asp:EntityDataSource ID="eDsCustomers" runat="server" ConnectionString="name=CustomerEntities" EnableDelete="true"
    DefaultContainerName="CustomerEntities" EnableUpdate="true" EnableInsert="true"  EntitySetName="Customer"
    Include="Title" />

[Tsvetoslav]

Hi Justin,

There is no known problem with RadGrid's delete operations on entity data-source. Could you try setting  EnableLinqExpressions=false for the grid and if the issue persists, please, send us a small runnable example of your implementation through a formal support ticket.

Thanks in advance.

Regards,
Tsvetoslav
the Telerik team

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