Detail Table Not expanding

[Frank]

I have a screen with a radgird that has a master table and a detail table.  When I Expand a record that has no detail information the grid expands and shows No Child Record To Display, but when I click on a record that has detail information nothin happens.

<telerik:RadGrid ID="RadGrid1" runat="server" Skin="Office2007" AllowPaging="True" EnableLinqExpressions="false" AllowCustomPaging="true" AutoGenerateColumns="False" GridLines="None" AllowSorting="true" AllowFilteringByColumn="false" AlternatingItemStyle-BackColor="#eeeeee" ShowGroupPanel="False" ShowStatusBar="True" OnNeedDataSource="RadGrid1_NeedDataSource"                                  OnPreRender="RadGrid1_PreRender" OnDetailTableDataBind="HistoryDetail_NeedDataSource">
             <AlternatingItemStyle BackColor="#EEEEEE"></AlternatingItemStyle>
             <MasterTableView DataKeyNames="MarketingID"  PagerStyle-Mode="NextPrevNumericAndAdvanced" >
                    <GroupByExpressions>
                            <telerik:GridGroupByExpression>
                                   <SelectFields>
                                            <telerik:GridGroupByField FieldAlias="ClientName" HeaderText="Client" FieldName="ClientName"
                                                     HeaderValueSeparator=" : "></telerik:GridGroupByField>
                                   </SelectFields>
                      <GroupByFields>
                          <telerik:GridGroupByField FieldName="ClientName" HeaderText="Client" SortOrder="Ascending">
                          </telerik:GridGroupByField>
                      </GroupByFields>
                   </telerik:GridGroupByExpression>
              </GroupByExpressions>
              <RowIndicatorColumn>
                 <HeaderStyle Width="20px"></HeaderStyle>
               </RowIndicatorColumn>
               <ExpandCollapseColumn>
                     <HeaderStyle Width="20px"></HeaderStyle>
               </ExpandCollapseColumn>
                    <Columns>
                           <telerik:GridBoundColumn DataField="MarketingID" HeaderText="MarketingID" SortExpression="MarketingID"  UniqueName="MarketingID" Visible="false">
                           </telerik:GridBoundColumn>
                            <telerik:GridBoundColumn DataField="ClientID" UniqueName="ClientID" Visible="false">
                            </telerik:GridBoundColumn>
                            <telerik:GridBoundColumn DataField="MarketingFormattedID" HeaderText="Marketing ID"
                                       ItemStyle-Width="85" SortExpression="MarketingFormattedID" UniqueName="MarketingFormattedID"
                                        Visible="true" ItemStyle-VerticalAlign="Top">
                             </telerik:GridBoundColumn>
                             <telerik:GridBoundColumn DataField="MarketingTypeName" HeaderText="Marketing Type"
                                              ItemStyle-VerticalAlign="Top" SortExpression="" AllowSorting="false"  UniqueName="MarketingTypeName"        Visible="true">
                             </telerik:GridBoundColumn>
                   </Columns>
                  <PagerStyle Mode="NextPrevNumericAndAdvanced"></PagerStyle>

                  <DetailTables>
                       <telerik:GridTableView DataKeyNames="MarketingID"  runat="server"  >
                             <ParentTableRelation>
                                     <telerik:GridRelationFields DetailKeyField="MarketingID" MasterKeyField="MarketingID" />
                             </ParentTableRelation>
                             <Columns>
                                    <telerik:GridBoundColumn HeaderText="Status"  DataField="MarketingStatusTypeName" UniqueName="MarketingStatusTypeName">
                                    </telerik:GridBoundColumn>
                                    <telerik:GridBoundColumn  HeaderText="Changed By"  DataField="ChangedBy" UniqueName="ChangedBy">
                                    </telerik:GridBoundColumn>
                                    <telerik:GridBoundColumn HeaderText="Date Changed"  DataField="DateChanged" UniqueName="DateChanged">
                                    </telerik:GridBoundColumn>
                        </Columns>
              </telerik:GridTableView>
         </DetailTables>
      </MasterTableView>
     <ClientSettings AllowDragToGroup="True">
          <Selecting AllowRowSelect="True" />
     </ClientSettings>
     <FilterMenu Skin="Office2007" EnableTheming="True">
          <CollapseAnimation Type="OutQuint" Duration="200"></CollapseAnimation>
     </FilterMenu>
  </telerik:RadGrid>

and here is the OnDetailTableDataBind Code

protected void HistoryDetail_NeedDataSource(object source, Telerik.Web.UI.GridDetailTableDataBindEventArgs e)
        {

            GridDataItem dataItem = e.DetailTableView.ParentItem;

            ClientDataContext db = new ClientDataContext();
            var query = from m in db.MarketingStatusChangeLogs
                        where (m.MarketingID == int.Parse(dataItem.GetDataKeyValue("MarketingID").ToString()))
                        select new
                        {
                            m.MarketingStatusType.MarketingStatusTypeName,
                            m.ChangedBy,
                            m.DateChanged
                        };
            e.DetailTableView.DataSource = query;
        }

am I missing something?

[Eric Klein]

The issue is in the HistoryDetail_NeedDataSource, you need to include MarketingID in the query.

[Angel Petrov]

Hello Frank,

I have examined the provided code and I think that the problem is in the query. I received and exception in the query saying that LINQ to Entities does not recognize the parse method. Try extracting the MarketingID before the query. Here is a code snippet:

protected void HistoryDetail_NeedDataSource(object source, Telerik.Web.UI.GridDetailTableDataBindEventArgs e)
    {

        GridDataItem dataItem = e.DetailTableView.ParentItem;

        ClientDataContext db = new ClientDataContext();
        int marketingID = int.Parse(dataItem.GetDataKeyValue("MarketingID").ToString());
        var query = from m in db.MarketingStatusChangeLogs
                    where (m.MarketingID == marketingID)
                    select new
                    {
                        m.MarketingStatusType.MarketingStatusTypeName,
                        m.ChangedBy,
                        m.DateChanged
                    };
        e.DetailTableView.DataSource = query;
    }

I am also attaching a sample project which is replicating your scenario.

Regards,
Angel Petrov
the Telerik team