Binding to inherited linq types in asp.net

I have a Linq-to-SQL data model that includes a type Party

that is subclassed twice for Company

and Individual

. I am trying to link two repeaters with Linq-to-SQL queries as follows

    Dim oComp As IEnumerable(Of Company)
    Dim oInd As IEnumerable(Of Individual)

        oComp = From oP As Company In ERM.Parties _
                 Where TypeOf (oP) Is Company And _
                 oP.Name.StartsWith(sSearchString)

        oInd = From oP As Individual In ERM.Parties _
                Where TypeOf (oP) Is Individual And _
                (oP.FirstName.StartsWith(sSearchString) Or _
                oP.LastName.StartsWith(sSearchString))

        rptIndividuals.DataSource = oInd
        rptCompanies.DataSource = oComp

        rptCompanies.DataBind()
        rptIndividuals.DataBind()

      

        
        
        
      

    

when i execute the code oComp

and oInd

as expected IEnumerable<Company>

and IEnumerable<Individual>

but i get the following exception when the first call is reachedDataBind

Fixing System.MissingMethodException was not handled by user code Message = "Constructor by type" System.Data.Linq.Provider.DataBindingList 1[[DataModel.Party, DataModel, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]]' not found." Source="mscorlib" StackTrace: at System.RuntimeType.CreateInstanceImpl(BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes) at System.Activator.CreateInstance(Type type, BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes) at System.Data.Linq.Provider.BindingList.Create[T](DataContext context, IEnumerable

1 sequence) in System.Data.Linq.DataQuery1.GetNewBindingList() at System.Data.Linq.DataQuery

1.System.ComponentModel.IListSource.GetList () at System.Web.UI.DataSourceHelper.GetResolvedDataSource (Object dataSource, String dataMember) at System.Web.UI.WebControls.ReadOnlyDataSource.System.Web.UI.IDataSource.GetView viewName) to System.Web.UI.WebControls.Repeater.ConnectToDataSourceView () to System.Web.UI.WebControls.Repeater.GetData () to System.Web.UI.WebControls.Repeater.CreateControlHierarchy (Boolean useDataSource) to System.Web.UI.WebControls.Repeater.CreateControlHierarchy (Boolean useDataSource) .UI.WebControls.Repeater.OnDataBinding (EventArgs e) at System.Web.UI.WebControls.Repeater.DataBind () at parties.lbHiddenPostback_Click (object sender, EventArgs e) at \ parties.aspx.vb: line 491 at System. Web.UI.WebControls.LinkButton.OnClick (EventArgs e) in System.Web.UI.WebControls.LinkButton.RaisePostBackEvent (String eventArgument) at System.Web.UI.WebControls.LinkButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent (String eventArgument) at System.Web.UI.Page.RaisePostBackment (System.Web.UI.Page.RaisePostBackEvent (System IPostBackEvent) .UI.Page.RaisePostBackEvent (NameValueCollection postData) at System.Web.UI.Page.ProcessRequestMain (Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) InnerException:ProcessRequestMain (Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) InnerException:ProcessRequestMain (Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) InnerException:

if i then select everything as sides, but like this: everything works fine

    Dim oComp As IEnumerable(Of Party)
    Dim oInd As IEnumerable(Of Party)


        oComp = From oP In ERM.Parties _
                Where TypeOf (oP) Is Company And _
                CType(oP, Company).Name.StartsWith(sSearchString)

        oInd = From oP In ERM.Parties _
                Where TypeOf (oP) Is Individual And _
                (CType(oP, Individual).FirstName.StartsWith(sSearchString) Or _
                CType(oP, Individual).LastName.StartsWith(sSearchString))

        rptIndividuals.DataSource = oInd
        rptCompanies.DataSource = oComp

        rptCompanies.DataBind()
        rptIndividuals.DataBind()

      

        
        
        
      

    

There is nothing in the repeater to do with the returned data, just a label in the item template to show me how many records are being returned for each request.

It doesn't make sense to me that I need to bind to the parent type, I won't be able to access the Individual and Company related attributes without first clicking on that type!