[DatabaseGenerated(DatabaseGeneratedOption.Identity)] incorrectly configures the column as SqlServer identity

Steps to reproduce

I tried using the [DatabaseGenerated(DatabaseGeneratedOption.Identity)] attribute on a DateTime (which has a default value constraint on the column) as described in the Generated Properties documentation and I got an error as shown below:

Personally I think the documentation is wrong, as the [DatabaseGenerated(DatabaseGeneratedOption.Identity)] attribute is pretty specific. I successfully used the Fluent API .ValueGeneratedOnAdd() to tell EF Core there was a default value constraint.

The issue

1. Create a table with a column ‘DateOfBirth’ with a default constraint on a [datetime2] column, e.g.

[DateOfBirth] [datetime2](7) NOT NULL DEFAULT ('2000-01-01T00:00:00.000'),

1. Map that column to a property ‘DateOfBirth’
2. Use the [DatabaseGenerated(DatabaseGeneratedOption.Identity)] attribute to tell EF Core that the column has a default constraint.
3. Create the DbContext and it fails with the following stack trace

Exception message: Identity value generation cannot be used for the property 'DateOfBirth' on entity type 'PersonWithAddUpdateAttibutes' because the property type is 'DateTime'. Identity value generation can only be used with signed integer properties.
Stack trace:
   at Microsoft.EntityFrameworkCore.Metadata.SqlServerPropertyAnnotations.SetValueGenerationStrategy(Nullable`1 value)
   at Microsoft.EntityFrameworkCore.Metadata.Internal.SqlServerPropertyBuilderAnnotations.ValueGenerationStrategy(Nullable`1 value)
   at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.SqlServerValueGenerationStrategyConvention.Apply(InternalPropertyBuilder propertyBuilder, DatabaseGeneratedAttribute attribute, MemberInfo clrMember)
   at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.PropertyAttributeConvention`1.Apply(InternalPropertyBuilder propertyBuilder)
   at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.ConventionDispatcher.OnPropertyAdded(InternalPropertyBuilder propertyBuilder)
   at Microsoft.EntityFrameworkCore.Metadata.Internal.EntityType.AddProperty(String name, Type propertyType, MemberInfo memberInfo, ConfigurationSource configurationSource, Boolean runConventions)
   at Microsoft.EntityFrameworkCore.Metadata.Internal.EntityType.AddProperty(MemberInfo memberInfo, ConfigurationSource configurationSource, Boolean runConventions)
   at Microsoft.EntityFrameworkCore.Metadata.Internal.InternalEntityTypeBuilder.Property(Property existingProperty, String propertyName, Type propertyType, MemberInfo clrProperty, Nullable`1 configurationSource)
   at Microsoft.EntityFrameworkCore.Metadata.Internal.InternalEntityTypeBuilder.Property(String propertyName, Type propertyType, MemberInfo clrProperty, Nullable`1 configurationSource)
   at Microsoft.EntityFrameworkCore.Metadata.Internal.InternalEntityTypeBuilder.Property(MemberInfo clrProperty, ConfigurationSource configurationSource)
   at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.PropertyDiscoveryConvention.Apply(InternalEntityTypeBuilder entityTypeBuilder)
   at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.ConventionDispatcher.OnEntityTypeAdded(InternalEntityTypeBuilder entityTypeBuilder)
   at Microsoft.EntityFrameworkCore.Metadata.Internal.Model.AddEntityType(EntityType entityType, Boolean runConventions)
   at Microsoft.EntityFrameworkCore.Metadata.Internal.InternalModelBuilder.Entity(Type type, ConfigurationSource configurationSource, Boolean runConventions)
   at Microsoft.EntityFrameworkCore.ModelBuilder.Entity(Type type)
   at Microsoft.EntityFrameworkCore.Infrastructure.ModelSource.FindSets(ModelBuilder modelBuilder, DbContext context)
   at Microsoft.EntityFrameworkCore.Infrastructure.Internal.RelationalModelSource.FindSets(ModelBuilder modelBuilder, DbContext context)
   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, ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitConstructor(ConstructorCallSite constructorCallSite, ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScoped(ScopedCallSite scopedCallSite, ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceProvider.<>c__DisplayClass16_0.<RealizeService>b__0(ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService(IServiceProvider provider, Type serviceType)
   at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService[T](IServiceProvider provider)
   at Microsoft.EntityFrameworkCore.DbContext.get_StateManager()
   at Microsoft.EntityFrameworkCore.DbContext.EntryWithoutDetectChanges[TEntity](TEntity entity)
   at Microsoft.EntityFrameworkCore.DbContext.SetEntityState[TEntity](TEntity entity, EntityState entityState)
   at test.UnitTests.TestPeopleContext.TestPeopleContextExistingDatabaseOk() in C:\Users\Jon\Documents\Visual Studio 2015\Projects\EfCoreInAction\test\UnitTests\TestPeopleContext.cs:line 111

Further technical details

EF Core version: “Microsoft.EntityFrameworkCore.SqlServer”: “1.1.0-preview1-final”, Operating system: Windows 10 Visual Studio version: VS2015 update 3

Other details about my project setup:

[AndriySvyryd]

@rodchenkov Soon™️. Most likely in this month.

[AndriySvyryd]

This has been fixed and should be soon available on the ci-dev feed