The argument to DbIsNullExpression must refer to a primitive or reference type

[sL342799]

Hi,

I am trying to implement a grid with ajax binding (backend is using LINQ and Entity Framework). Originally, I was getting the infamous Server Error '500' due to circular references. So I decided to follow the advice on the forums and implement a ViewModel approach (Implementing ViewModel).

I created a simple ViewModel as:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

namespace UndertakingTracker.Models
{

    public class UndertakingViewModel
    {

        public int undertakingID {

            get;
            set;

        }

    public string undertakingReferenceNumber {

        get;
        set;

    }

    public DateTime? dateReceived {

        get;
        set;
    }

    public string portfolioName {

        get;
        set;

    }

    public string propertyName {
        get;
        set;

    }

    public string lenderName {

        get;

        set;

    }
    public string status {

        get;
        set;
    }


    }
}

In my repository I did the following:

public IEnumerable<UndertakingViewModel> listAllUndertakingsAsViewModel() {

        return from u in _entities.Undertaking.Include("Lender").Include("Lender.Address").Include("Property").Include("Property.Address")
            select new UndertakingViewModel{

            undertakingID = u.undertakingID,
            undertakingReferenceNumber = u.undertakingReferenceNumber,
            dateReceived = u.dateReceived,
            portfolioName = u.Property.portfolioName,
            propertyName = u.Property.propertyName,
            lenderName = u.Lender.lenderName,
            status = u.status

            };

        }

In my controller I did the following (where service simply calls the repository and passes back the IEnumerable):

 public ActionResult Index()
        {

            return View(_service.listAllUndertakingsAsViewModel());
        }

        [GridAction]
        public ActionResult _AjaxBinding()
        {


             return View(new GridModel<UndertakingViewModel>
        {
            Data = _service.listAllUndertakingsAsViewModel()
        });

And Finally my view:

<%@ Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<IEnumerable<UndertakingTracker.Models.UndertakingViewModel>>" %>

[snip]

<%
        Html.Telerik().Grid(Model)
            .Name("Undertakings")
            .Ajax(ajax => ajax.Action("_AjaxBinding", "Undertaking"))
            .Columns(columns =>
            {
                columns.Add(u => u.undertakingReferenceNumber).Title("UTI").Filterable(true);
                columns.Add(u => u.dateReceived).Title("Date Received").Format("{0:dd/MM/yyyy}");
                columns.Add(u => u.portfolioName).Title("Portfolio");
                columns.Add(u => u.propertyName).Title("Property");
                columns.Add(u => u.lenderName).Title("Lender");
                columns.Add(u => u.status).Title("Status");
                columns.Add(u => u.undertakingID).Format(Html.ActionLink("Edit", "Edit", new { id = "{0}" })).Encoded(false).Title("Edit").Filterable(false).Sortable(false);
                columns.Add(u => u.undertakingID).Format(Html.ActionLink("Details", "Details", new { id = "{0}" })).Encoded(false).Title("Details").Filterable(false).Sortable(false);
                columns.Add(u => u.undertakingID).Format(Url.Action("Create", "UndertakingActivity", new { id = "{0}" })).Encoded(false).Title("&nbsp;").Filterable(false).Sortable(false);

            })

            .Pageable()
            .Sortable()
            .Filterable()
            .Render();
%>

Upon rendering, i get the following exception and stacktrace:

System.ArgumentException was unhandled by user code
  Message="The argument to DbIsNullExpression must refer to a primitive or reference type."
  Source="System.Data.Entity"
  StackTrace:
       at System.Data.Common.CommandTrees.DbIsNullExpression..ctor(DbCommandTree cmdTree, DbExpression arg, Boolean isRowTypeArgumentAllowed)
       at System.Data.Objects.ELinq.ExpressionConverter.CreateIsNullExpression(DbExpression operand, Type operandClrType)
       at System.Data.Objects.ELinq.ExpressionConverter.EqualsTranslator.CreateIsNullExpression(ExpressionConverter parent, Expression input)
       at System.Data.Objects.ELinq.ExpressionConverter.EqualsTranslator.TypedTranslate(ExpressionConverter parent, BinaryExpression linq)
       at System.Data.Objects.ELinq.ExpressionConverter.TypedTranslator`1.Translate(ExpressionConverter parent, Expression linq)
       at System.Data.Objects.ELinq.ExpressionConverter.TranslateExpression(Expression linq)
       at System.Data.Objects.ELinq.ExpressionConverter.NotTranslator.TypedTranslate(ExpressionConverter parent, UnaryExpression linq)
       at System.Data.Objects.ELinq.ExpressionConverter.TypedTranslator`1.Translate(ExpressionConverter parent, Expression linq)
       at System.Data.Objects.ELinq.ExpressionConverter.TranslateExpression(Expression linq)
       at System.Data.Objects.ELinq.ExpressionConverter.NotEqualsTranslator.TypedTranslate(ExpressionConverter parent, BinaryExpression linq)
       at System.Data.Objects.ELinq.ExpressionConverter.TypedTranslator`1.Translate(ExpressionConverter parent, Expression linq)
       at System.Data.Objects.ELinq.ExpressionConverter.TranslateExpression(Expression linq)
       at System.Data.Objects.ELinq.ExpressionConverter.ConditionalTranslator.TypedTranslate(ExpressionConverter parent, ConditionalExpression linq)
       at System.Data.Objects.ELinq.ExpressionConverter.TypedTranslator`1.Translate(ExpressionConverter parent, Expression linq)
       at System.Data.Objects.ELinq.ExpressionConverter.TranslateExpression(Expression linq)
       at System.Data.Objects.ELinq.ExpressionConverter.TranslateLambda(LambdaExpression lambda, DbExpression input)
       at System.Data.Objects.ELinq.ExpressionConverter.TranslateLambda(LambdaExpression lambda, DbExpression input, DbExpressionBinding& binding)
       at System.Data.Objects.ELinq.ExpressionConverter.MethodCallTranslator.OneLambdaTranslator.Translate(ExpressionConverter parent, MethodCallExpression call, DbExpression& source, DbExpressionBinding& sourceBinding, DbExpression& lambda)
       at System.Data.Objects.ELinq.ExpressionConverter.MethodCallTranslator.OneLambdaTranslator.Translate(ExpressionConverter parent, MethodCallExpression call)
       at System.Data.Objects.ELinq.ExpressionConverter.MethodCallTranslator.SequenceMethodTranslator.Translate(ExpressionConverter parent, MethodCallExpression call, SequenceMethod sequenceMethod)
       at System.Data.Objects.ELinq.ExpressionConverter.MethodCallTranslator.TypedTranslate(ExpressionConverter parent, MethodCallExpression linq)
       at System.Data.Objects.ELinq.ExpressionConverter.TypedTranslator`1.Translate(ExpressionConverter parent, Expression linq)
       at System.Data.Objects.ELinq.ExpressionConverter.TranslateExpression(Expression linq)
       at System.Data.Objects.ELinq.ExpressionConverter.MethodCallTranslator.UnarySequenceMethodTranslator.Translate(ExpressionConverter parent, MethodCallExpression call)
       at System.Data.Objects.ELinq.ExpressionConverter.MethodCallTranslator.SequenceMethodTranslator.Translate(ExpressionConverter parent, MethodCallExpression call, SequenceMethod sequenceMethod)
       at System.Data.Objects.ELinq.ExpressionConverter.MethodCallTranslator.TypedTranslate(ExpressionConverter parent, MethodCallExpression linq)
       at System.Data.Objects.ELinq.ExpressionConverter.TypedTranslator`1.Translate(ExpressionConverter parent, Expression linq)
       at System.Data.Objects.ELinq.ExpressionConverter.TranslateExpression(Expression linq)
       at System.Data.Objects.ELinq.ExpressionConverter.Convert()
       at System.Data.Objects.ELinq.ELinqQueryState.GetExecutionPlan(Nullable`1 forMergeOption)
       at System.Data.Objects.ObjectQuery`1.GetResults(Nullable`1 forMergeOption)
       at System.Data.Objects.ObjectQuery`1.System.Collections.Generic.IEnumerable<T>.GetEnumerator()
       at Telerik.Web.Mvc.Extensions.EnumerableExtensions.Each[T](IEnumerable`1 instance, Action`1 action)
       at Telerik.Web.Mvc.UI.Grid`1.WriteRows(IGridRenderer`1 renderer)
       at Telerik.Web.Mvc.UI.Grid`1.WriteTable(IGridRenderer`1 renderer)
       at Telerik.Web.Mvc.UI.Grid`1.WriteHtml(HtmlTextWriter writer)
       at Telerik.Web.Mvc.UI.ViewComponentBase.Render()
       at Telerik.Web.Mvc.UI.ViewComponentBuilderBase`2.Render()
       at ASP.views_undertaking_index_aspx.__RenderContent2(HtmlTextWriter __w, Control parameterContainer) in c:\Documents and Settings\Administrator\My Documents\Visual Studio 2008\Projects\UndertakingTracker\UndertakingTracker\Views\Undertaking\Index.aspx:line 16
       at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)
       at System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
       at System.Web.UI.Control.Render(HtmlTextWriter writer)
       at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
       at System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
       at System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
       at ASP.views_shared_site_master.__Render__control1(HtmlTextWriter __w, Control parameterContainer) in c:\Documents and Settings\Administrator\My Documents\Visual Studio 2008\Projects\UndertakingTracker\UndertakingTracker\Views\Shared\Site.Master:line 48
       at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)
       at System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
       at System.Web.UI.Control.Render(HtmlTextWriter writer)
       at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
       at System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
       at System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
       at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)
       at System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
       at System.Web.UI.Page.Render(HtmlTextWriter writer)
       at System.Web.Mvc.ViewPage.Render(HtmlTextWriter writer)
       at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
       at System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
       at System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
       at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
  InnerException:

Any ideas on how to resolve?

Thanks!

[Atanas Korchev]

Hello sL342799,

 Unfortunately I am not sure why this exception is thrown. The only thing which comes to mind is to ask you if the ViewModel class contains the DB key of the actual model entity. If not please add it to the ViewModel class. If it already does I have to ask you to send a runnable sample showing the problem. Please send it to atanas.korchev at telerik.com

Regards,
Atanas Korchev
the Telerik team

Instantly find answers to your questions on the new Telerik Support Portal.
Watch a video on how to optimize your support resource searches and check out more tips on the blogs.

[IQworks]

  HI Atanas,
     Was a running sample ever submitted for this Entity Framework issue ?  Forgive me, I am already speaking to this in another post, but I thought I would ask here as well.
 
  thanks for your time.    
    

[Atanas Korchev]

Hi IQworks,

No, we haven't received a running sample demonstrating this problem.

Regards,
Atanas Korchev
the Telerik team

Instantly find answers to your questions on the new Telerik Support Portal.
Watch a video on how to optimize your support resource searches and check out more tips on the blogs.

[Roy Wang]

Hi, sL342799

Did you solve the problem? I have the same problem. Thanks!

regards,
Roy

[Atanas Korchev]

Hi,

To all guys getting this exception - please try upgrading to the latest version 2009.3.1320. Let me know if the problem persists.

Regards,
Atanas Korchev
the Telerik team

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[Raman]

Hi Guys,

Were you able to reproduce and debug this problem? I'm facing similar problem as mentioned by "sL342799".
But in my case, I'm using Server binding and it throws this exception only when I try to filter any column.

Thanks,
WebExpert

[IQworks]

Hi webXpert Xpert ,

     I have a note I made to myself here that might help .....

     

When i first got this error, it was because I needed to use the telerik version that had the fix - 2009.3.1320. This went for scripts and content as well. Telerik.web.mvc.dll for this version has to be in the references.

If its not, you have to add it as a reference and do a "Clean" and "Rebuild". When you do the clean it should remove the dll from your bin folder as well - yep, it goes to your bin and deletes old files. at that point, you may have to add it manually to the bin, and make sure its referenced and then you do a build.

NOW THIS WAS A JUMBLED SEQUENCE OF EVENTS, BUT MAKING SURE THE DLL VERSION WAS REFERENCED, CLEANED AND REBUILT (not neccessarily in that order) fixed it.

I know its not much to answer why, I should of noted it, but hope this is helpful. ?

[Makoto]

I too am having this issue.

I only get this issue when I filter a column, I don't have a problem getting data, sorting or paging.

Seems to be an issue with Entity Framework.  I'm guessing it's the way that the Grid control is add expressions to my IQueryable<> object.

I don't want to convert this to a memory list (.ToList()) since then I'll lose the small SQL data sets, and will end up grabbing the whole dataset before the Grid gets a chance to build up the expressions on the SQL side.

I might have to crack open the original Telerik.Web.Mvc code and see where it uses DbIsNullExpression.

[amir ehsani]

I have exactly the same problem as Makoto, and im using Telerik.web.mvc.dll 2010.1.309, ajax binding and viewmodel. viewmodel contains primary key of entity.

[IQworks]

Hi Amir and Makoto,

     If you have not already seen this post, it might give further clues.

      http://www.telerik.com/community/forums/wpf/gridview/dbisnullexpression.aspx 
best wishes

[amir ehsani]

well, I prefer to keep LINQ query as long as possible and do not use ToList until its really necessary. Currently I'm using ToList to solve the problem, but im looking for alternative solution to add filters to LINQ query, if there is any.

[Alan Wong]

I also am getting this error, using the exact same pattern, but only when I try to apply a filter. The error is generated from within EF. Something with the Telerik grid filter is causing this... is it trying to apply a null filter on a non-nullable column perhaps?

[Atanas Korchev]

Hi Jeff Jorczak,

Is there a chance to send us a sample project? We have not been able to reproduce this exception.

Regards,
Atanas Korchev
the Telerik team

Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking system and vote to affect the priority of the items.

[Alan Wong]

I was able to create a very basic project to reproduce the error. I has been sent to your attention. Thank you for the customer support!

[Mike]

Greetings,

Would just like to add that I'm experiencing the same issue. Ajax binding, EF, using version 2010.1.309.235.

.ToList() does "fix" the issue, but that's not really a good work-around - kind of defeats the purpose.

Regards,
Mike

Edit: Looking at the stack trace and stepping through the source, it no doubt is happening in the .Count method of QueryableExtensions when it tries to call .Execute on the provider. Unfortunately, I don't know how to fix :(

[Mike]

Thanks to Telerik support, turns out it's no longer an issue with the latest drop - 2010.2.825.

Thanks Telerik! I appreciate you opening a support ticket even for your free version.

Mike

[Tom]

I still get the error in version 2011.3.1306.340 when I'm using custom binding to filter a query that includes a projection.

[Atanas Korchev]

Hi,

How are you performing the custom filtering? Are you using custom code or something provided by Telerik?

Regards,
Atanas Korchev
the Telerik team

[Tom]

Updated:  I should add that this is using Entity Framework 4.2.0.0

Hello Atanas.  That was a fast response.

I'm using the custom binding on the server side.  The filtering is almost verbatim from what's listed on the telerik demo site for grid.  The only difference being I'm using a different Model.

public static IQueryable<ProductItemModel> ApplyFiltering(this IQueryable<ProductItemModel> data,
    IList<IFilterDescriptor> filterDescriptors)
{
    if (filterDescriptors.Any())
    {
        data = data.Where(ExpressionBuilder.Expression<ProductItemModel>(filterDescriptors));
    }
    return data;
}

The ApplyFiltering method doesnt get called until after I have a query that includes some joins and a projection in to a viewModel. When the filter is applied the exception occurs when getting the Count.

//Apply filtering

data = data.ApplyFiltering(command.FilterDescriptors);

ViewData["Total"] = data.Count(); // Exception here


[Atanas Korchev]

Hi,

 This could occur if your are having a "select" before the "filter". Entity Framework may get confused in this case. You can try performing the "select" (projection from the db type to the view model) after all other operations (paging, sorting, filtering etc).

Regards,
Atanas Korchev
the Telerik team

[Tom]

That's what I was afraid of.  Since some of the fields in the projected viewmodel include columns from joined tables I'm not sure how well applying the filter before the select will work out.  I'll give it a go anyway.  I'm not really needing this functionality critically.  I can create my own filter controls to work around the issue.

Interesting, If I manually add a filter instead of using the ExpressionBuilder with the GridCommand Entity Framework has no problem with it.

//Apply filtering
data = data.ApplyFiltering(command.FilterDescriptors); // No FilterDescriptors used in this test
data = data.Where(c => c.ProductDesc.Contains("Phone"));
ViewData["Total"] = data.Count(); // This works just fine even with the Where clause up above

[Tom]

Just as a followup for this thread, applying the filters before the select indeed didn't work in this situations because of the joined tables. 

Given a select statement similar to this:

var data = product from data
   select new ProductItemModel()
   {
       ID = product.ID,
      ProductDesc = product.productDescriptor.ProductDesc
   };

ProductDesc wouldnt be able to be filtered.

[Atanas Korchev]

Hello,

Cant you do something like this?

var data = product from data
   where product.productDescriptor.ProductDesc.Contains("Phone")

   select new ProductItemModel()

   {

        ID = product.ID,

      ProductDesc = product.productDescriptor.ProductDesc

   };

Regards,

Atanas Korchev
the Telerik team

[Tom]

I kind of ended up doing something like that.  The trick is to change the FilterDescriptors in the GridCommand object that's passed in to the Grid Select Action.

The algorithm I used looked something like this:

1. Get IQueryable without Select
2. Traverse the GridCommand FilterDescriptors (recursively to handle CompositeFilterDescriptors) and convert filterDescriptor.Member to the non-projected name ( change ProductDesc to product.productDescriptor.ProductDesc in our contrived example)
3. ApplyFiltering
4. ApplySorting (use the non-projected expression, product.productDescriptor.productDesc, in AddSortExpression method)
5. ApplyPaging
6. Add the select (projection)
7. ApplyGrouping (use the projected expression, ProductDesc, in ApplyGrouping method)

Those steps got me to where I wanted to be.  Thanks for your help.