Customized EF data property throw LINQ to Entities Exception when doing a sort

[David]

I have DB table Vehicle and I am using EF4. So I got a partial class Vehicle to map with the db table.
Vehicle is a master table. It has a detail table Fault.  1 vehicle could have many faults.

I am trying to get the count of fault associated with vehicle. So I created one customized property for Vehicle class. FaultCount.

Partial Class Vehicle
{

    public global::System.Int32 FaultCount
        {
            get
            {
                CCF20Entities ccf20Ent = new CCF20Entities();
                return ccf20Ent.Faults.Where(f => f.IsActive && f.FaultType == "Vehcile" && f.VehicleID== this.VehicleID).Count();
            }

        }

}
Everything works fine. I got the data I want and populate the grid. But when I try to sort the column, I get the exception.

"The specified type member 'FaultCount' is not supported in LINQ to Entities. Only initializers, entity members, and entity navigation properties are supported."

Any help?

Thx,
David

[Rossen Hristov]

Hi David,

Unfortunately, this functionality is not supported by the current version of EF.

You will have to add this property to the actual data model, i.e. calculate it in the DB, and use it like a "normal" property.

Best wishes,
Ross
the Telerik team

[TDG]

Does this problem supported yet?
I have many custom properties in many model class.
How do I use this model class with custom properties with MVC?

[Kevin Hendriks]

I just got the same error in my application. I get table of which I need value and then be able to sort/group the data like so:
public partial class CUSTOMER_ORDER
    {
        public string OrderDescription
        {
            get 
            {
                if (ERPConnectionVisualEnterprise._ErpSystem != null && ERPConnectionVisualEnterprise._ErpSystem.USER_DEF_FIELDs.Any(item => item.DOCUMENT_ID.Equals(this.ID) && item.ID.Equals("UDF-0000030")))
                {
                    return ERPConnectionVisualEnterprise._ErpSystem.USER_DEF_FIELDs.Single(item => item.DOCUMENT_ID.Equals(this.ID) && item.ID.Equals("UDF-0000030")).STRING_VAL;
                }
                return "";
            }
        }    
    }

I am unable to modify the DB because it is managed by another application/company

[Mark]

is this possible yet?
I am having the same problem.

Thanks

[Dimitrina]

Hello,

As it turns out this functionality is still not supported. 

As per your request, I logged it into our system as a Feature Request. You can vote for it and follow its progress on our feedback portal here:
Add data operations support for customized EntityFramework data properties. 

Regards,
Dimitrina
Telerik