Migrations: Exception thrown with model containing TPH in certain cases: The entity type should derive from to reflect the hierarchy of the corresponding CLR types.

[stitch84]

Describe what is not working as expected.

When I try to add a migration via dotnet ef add migrations I get an exception:

I also have a many-to-many relationship in my model which is configured in
OnModelCreating

I figured out that the migration gets created when I remove the code for the many-to-many relationship in OnModelCreating and when I remove the properties for the Join Table class.

My Test project is attached.

Exception message:
The entity type 'SingleExpense' should derive from 'SingleMoneyItem' to reflect the hierarchy of the corresponding CLR types.

Stack trace:
System.InvalidOperationException: The entity type 'SingleExpense' should derive from 'SingleMoneyItem' to reflect the hierarchy of the co
rresponding CLR types.
   at Microsoft.EntityFrameworkCore.Internal.ModelValidator.ShowError(String message)
   at Microsoft.EntityFrameworkCore.Internal.ModelValidator.EnsureClrInheritance(IModel model, IEntityType entityType, HashSet`1 validEnt
ityTypes)
   at Microsoft.EntityFrameworkCore.Internal.ModelValidator.EnsureClrInheritance(IModel model)
   at Microsoft.EntityFrameworkCore.Internal.ModelValidator.Validate(IModel model)
   at Microsoft.EntityFrameworkCore.Internal.RelationalModelValidator.Validate(IModel model)
   at Microsoft.EntityFrameworkCore.Infrastructure.ModelSource.CreateModel(DbContext context, IConventionSetBuilder conventionSetBuilder,
 IModelValidator validator)
   at System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory)
   at Microsoft.EntityFrameworkCore.Internal.DbContextServices.CreateModel()
   at Microsoft.EntityFrameworkCore.Internal.LazyRef`1.get_Value()
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScoped(ScopedCallSite scopedCallSite, ServicePr
ovider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceProvider.<>c__DisplayClass16_0.<RealizeService>b__0(ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetService[T](IServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitTransient(TransientCallSite transientCallSite,
ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitConstructor(ConstructorCallSite constructorCall
Site, ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitTransient(TransientCallSite transientCallSite,
ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceProvider.<>c__DisplayClass16_0.<RealizeService>b__0(ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService(IServiceProvider provider, Type servic
eType)
   at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService[T](IServiceProvider provider)
   at Microsoft.EntityFrameworkCore.Design.Internal.MigrationsOperations.RemoveMigration(String contextType, Boolean force)
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.<RemoveMigrationImpl>d__16.MoveNext()
   at System.Collections.Generic.EnumerableHelpers.ToArray[T](IEnumerable`1 source, Int32& length)
   at System.Collections.Generic.EnumerableHelpers.ToArray[T](IEnumerable`1 source)
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.<>c__DisplayClass4_0`1.<Execute>b__0()
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute(Action action)

Steps to reproduce

dotnet ef migrations add Initial

Further technical details

EF Core version: 1.1.1
Database Provider: Microsoft.EntityFrameworkCore.SqlServer
Operating system: Windows 10
IDE: Visual Studio Code

WebAPIApplication.zip

[ajcvickers]

@stitch84 Can you post a project or complete code listing that reproduces what you are seeing? Specifically, what your entity types look like, including inheritance, and the code you have in OnModelCreating?

[stitch84]

@ajcvickers Please see my first comment. At the end there is a link to my WebAPIApplication project.

[smitpatel]

I tested the model in the sample project provided in OP. It throws exception as above in 1.1.1 packages. But it works correctly in preview1 bits.
Probable cause of exception - While adding entity type SingleExpense we discover the base types, but for some reason DerivedTypeDiscoveryConvention did not run correctly. Therefore we threw exception. Since we use batching in conventions running, it is running correctly and creating valid model so it works.

Sidenote: You are mixing 1.0.x & 1.1.x packages of ASP.NET core in same project. You should align them.

[stitch84]

@smitpatel Sorry for my stupid question, but I didn't get your point.
Will it work in a future release of EF Core?

[smitpatel]

@stitch84 - Yes. The next public release of EF Core with version 2.0.0-preview1 has fix for this issue.

[stitch84]

@smitpatel Thank you!!!

[smitpatel]

@divega - to update title.

[smitpatel]

I removed many-to-many part, since it was not specific to many-to-many table. In this case, it just provided a way to discover types in certain order.

[divega]

@smitpatel thanks!