Efcore: TPH issue with netcore 3

[erwan-joly]

Since the update to EF 3 my project was not working anymore because of TPH (i think).

An error occurred while accessing the Microsoft.Extensions.Hosting services. Continuing without the application service provider. Error: The handle is invalid.
System.InvalidOperationException: The entity type 'WearableInstance' cannot be mapped to a table because it is derived from 'ItemInstance'. Only base entity types can be mapped to a table.
at Microsoft.EntityFrameworkCore.Infrastructure.RelationalModelValidator.ValidateInheritanceMapping(IModel model, IDiagnosticsLogger1 logger) at Microsoft.EntityFrameworkCore.Infrastructure.RelationalModelValidator.Validate(IModel model, IDiagnosticsLogger1 logger)
at Npgsql.EntityFrameworkCore.PostgreSQL.Infrastructure.NpgsqlModelValidator.Validate(IModel model, IDiagnosticsLogger1 logger) at Microsoft.EntityFrameworkCore.Metadata.Conventions.ValidatingConvention.ProcessModelFinalized(IConventionModelBuilder modelBuilder, IConventionContext1 context)
at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.ConventionDispatcher.ImmediateConventionScope.OnModelFinalized(IConventionModelBuilder modelBuilder)
at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.ConventionDispatcher.OnModelFinalized(IConventionModelBuilder modelBuilder)
at Microsoft.EntityFrameworkCore.Metadata.Internal.Model.FinalizeModel()
at Microsoft.EntityFrameworkCore.ModelBuilder.FinalizeModel()
at Microsoft.EntityFrameworkCore.Infrastructure.ModelSource.CreateModel(DbContext context, IConventionSetBuilder conventionSetBuilder)
at Microsoft.EntityFrameworkCore.Infrastructure.ModelSource.<>c__DisplayClass5_0.b__1()
at System.Lazy1.ViaFactory(LazyThreadSafetyMode mode) at System.Lazy1.ExecutionAndPublication(LazyHelper executionAndPublication, Boolean useDefaultConstructor)
at System.Lazy1.CreateValue() at System.Lazy1.get_Value()
at Microsoft.EntityFrameworkCore.Infrastructure.ModelSource.GetModel(DbContext context, IConventionSetBuilder conventionSetBuilder)
at Microsoft.EntityFrameworkCore.Internal.DbContextServices.CreateModel()
at Microsoft.EntityFrameworkCore.Internal.DbContextServices.get_Model()
at Microsoft.EntityFrameworkCore.Infrastructure.EntityFrameworkServicesBuilder.<>c.b__7_3(IServiceProvider p)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitFactory(FactoryCallSite factoryCallSite, RuntimeResolverContext context)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSiteMain(ServiceCallSite callSite, TArgument argument) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitCache(ServiceCallSite callSite, RuntimeResolverContext context, ServiceProviderEngineScope serviceProviderEngine, RuntimeResolverLock lockType) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScopeCache(ServiceCallSite singletonCallSite, RuntimeResolverContext context) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSite(ServiceCallSite callSite, TArgument argument)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitConstructor(ConstructorCallSite constructorCallSite, RuntimeResolverContext context)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSiteMain(ServiceCallSite callSite, TArgument argument) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitCache(ServiceCallSite callSite, RuntimeResolverContext context, ServiceProviderEngineScope serviceProviderEngine, RuntimeResolverLock lockType) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScopeCache(ServiceCallSite singletonCallSite, RuntimeResolverContext context) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSite(ServiceCallSite callSite, TArgument argument)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.Resolve(ServiceCallSite callSite, ServiceProviderEngineScope scope)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.DynamicServiceProviderEngine.<>c__DisplayClass1_0.b__0(ServiceProviderEngineScope scope)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngine.GetService(Type serviceType, ServiceProviderEngineScope serviceProviderEngineScope)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngineScope.GetService(Type serviceType)
at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService(IServiceProvider provider, Type serviceType)
at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService[T](IServiceProvider provider)
at Microsoft.EntityFrameworkCore.DbContext.get_DbContextDependencies()
at Microsoft.EntityFrameworkCore.DbContext.get_InternalServiceProvider()
at Microsoft.EntityFrameworkCore.DbContext.Microsoft.EntityFrameworkCore.Infrastructure.IInfrastructure<System.IServiceProvider>.get_Instance()
at Microsoft.EntityFrameworkCore.Infrastructure.Internal.InfrastructureExtensions.GetService[TService](IInfrastructure1 accessor) at Microsoft.EntityFrameworkCore.Infrastructure.AccessorExtensions.GetService[TService](IInfrastructure1 accessor)
at Microsoft.EntityFrameworkCore.Design.Internal.DbContextOperations.CreateContext(Func1 factory) at Microsoft.EntityFrameworkCore.Design.Internal.DbContextOperations.CreateContext(String contextType) at Microsoft.EntityFrameworkCore.Design.Internal.MigrationsOperations.AddMigration(String name, String outputDir, String contextType) at Microsoft.EntityFrameworkCore.Design.OperationExecutor.AddMigrationImpl(String name, String outputDir, String contextType) at Microsoft.EntityFrameworkCore.Design.OperationExecutor.AddMigration.<>c__DisplayClass0_0.<.ctor>b__0() at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.<>c__DisplayClass3_01.b__0()
at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute(Action action)
The entity type 'WearableInstance' cannot be mapped to a table because it is derived from 'ItemInstance'. Only base entity types can be mapped to a table.

Steps to reproduce

This is a small project to reproduce https://github.com/erwan-joly/EFCore3TPHError
it seems like changing the name and using TPH at the same time is facing some issues.

just try to Add-Migration MyMigration

the error seems to be caused by https://github.com/erwan-joly/EFCore3TPHError/blob/master/POC%20EF%20Core%203/PocDbContext.cs#L27

and

https://github.com/erwan-joly/EFCore3TPHError/blob/master/POC%20EF%20Core%203/EquipmentOption.cs#L34

Further technical details

EF Core version: 3.0
Database provider: PGSQL
Target framework: .NET Core 3.0
Operating system: Visual Studio 2019 16.3

The code i'm using here
EDIT i'm able to reproduce it. this is caused by

public static class ModelBuilderExtensions
    {
        public static void RemovePluralizingTableNameConvention(this ModelBuilder modelBuilder)
        {
            foreach (var entity in modelBuilder.Model.GetEntityTypes())
            {
                entity.SetTableName(entity.DisplayName());
            }
        }
    }

is an update to remove a breaking change. This was what i was using before EF3

  public static class ModelBuilderExtensions
    {
        public static void RemovePluralizingTableNameConvention(this ModelBuilder modelBuilder)
        {
            foreach (var entity in modelBuilder.Model.GetEntityTypes())
            {
                entity.SetTableName(entity.DisplayName());
            }
        }
    }

Does anybody has any idea what's going on here ?

I think the issue may be comming from this
https://docs.microsoft.com/en-us/ef/core/what-is-new/ef-core-3.0/breaking-changes#totable-on-a-derived-type-throws-an-exception
https://github.com/aspnet/EntityFrameworkCore/issues/11811

[smitpatel]

Breaking change as of https://github.com/aspnet/EntityFrameworkCore/issues/11811
You cannot set table for derived type.
use following
C# foreach (var entity in modelBuilder.Model.GetEntityTypes()) { if (entity.BaseType == null) { entity.SetTableName(entity.DisplayName()); } }

[vicflamenco]

@smitpatel since I want to customize the name of the Identity tables using derived types like class ApplicationUser : IdentityUser<int> (to use an int PrimaryKey instead of the default string PrimaryKey), then entityType.DisplayName() yields this table name: IdentityUser<int>.

Is there a solution to name the table "ApplicationUser" instead?