System.AccessViolationException when using TPT inheritance in Entity Framework CTP5
- by Ben
Hi,
I'm using TPT inheritance in EF CTP5 with SQL CE 4.
I have an abstract base class "Widget" with common properties like "Title".
I can successfully save concrete Widget implementations e.g. "TwitterWidget".
However, I have a problem retrieving all widgets (or rather ALL widget implementations).
My repository exposes the following:
public IQueryable<Widget> GetAll();
This effectively returns the IDbSet from the DbContext.
The following queries work fine:
repo.GetAll().ToList();
repo.GetAll().Where(w => w.Title == "Test").ToList();
repo.GetAll().SingleOrDefault(w => w.Title == "Test");
repo.GetAll().Where(w => w.Title == "Test").OrderBy(x => x.Title).ToList();
However, if I write the following query:
repo.GetAll().OrderBy(w => w.Title);
I get the following error:
Test 'PlanetCloud.Portfolio.Tests.Data.PersistenceTestFixture.Can_get_widgets' failed: System.AccessViolationException : Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
at System.Data.SqlServerCe.NativeMethodsHelper.GetValues(IntPtr pSeCursor, Int32 seGetColumn, IntPtr prgBinding, Int32 cDbBinding, IntPtr pData, IntPtr pError)
at System.Data.SqlServerCe.NativeMethods.GetValues(IntPtr pSeCursor, Int32 seGetColumn, IntPtr prgBinding, Int32 cDbBinding, IntPtr pData, IntPtr pError)
at System.Data.SqlServerCe.SqlCeDataReader.FetchValue(Int32 index)
at System.Data.SqlServerCe.SqlCeDataReader.IsDBNull(Int32 ordinal)
at lambda_method(Closure , Shaper )
at System.Data.Common.Internal.Materialization.Shaper.HandleEntityAppendOnly[TEntity](Func`2 constructEntityDelegate, EntityKey entityKey, EntitySet entitySet)
at lambda_method(Closure , Shaper )
at System.Data.Common.Internal.Materialization.Coordinator`1.ReadNextElement(Shaper shaper)
at System.Data.Common.Internal.Materialization.Shaper`1.SimpleEnumerator.MoveNext()
at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
However, I can execute the following query without problems:
var widgets = repo.GetAll().OfType<Widget>().OrderBy(w => w.Title).ToList();
So if I specify the type as the base class prior to my orderby clause it works.
The question is why?
