EF6 extending an TPH hierarchy (mixing TPH and TPT) - entity-framework

Question

I have a table used to store several inherited entities in TPH configuration.
That works well and there are no issues over that.
The issue I'm facing is that I need to extend some of those entities with additional fields and want those new fields stored in its own table using TPT.
To put some context I will give you an example:
The TPH stores a root PERIOD class and several inherited ones like QUARTER, MONTH, WEEK, etc, using a discriminator field.
So now I need to create a special QUARTER with some additional fields and want to store those additional field in its own table.
Is that possible in EF? I'm using EF 6.1 and haven't found a working sample or explanation on how to accomplish this specific scenario.
Thanks in advance,
Andrés.

Answer 1

public abstract class Period
{
public int Id { get; set; }
public string DisplayName { get; set; }
}
public class Month : Period {
public byte MonthValue { get; set; }
}
public class Quarter : Period {
public byte QuarterValue { get; set; }
}
public class SpecialQuarter : Quarter {
public int SpecialQuarterValue { get; set; }
}
public class TestContext : DbContext {
public DbSet<Period> Periods { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Entity<Period>().ToTable("Period");
// TPH
modelBuilder.Entity<Month>().Map(p => p.Requires("PeriodType").HasValue("M"));
modelBuilder.Entity<Quarter>().Map(p => p.Requires("PeriodType").HasValue("Q"));
//TPT
modelBuilder.Entity<SpecialQuarter>().Map(p => p.ToTable("SpecialQuarter"));
}
}
This context maps to these tables.
CREATE TABLE [dbo].[Period] (
[Id] [int] NOT NULL IDENTITY,
[DisplayName] [nvarchar](max),
[MonthValue] [tinyint],
[QuarterValue] [tinyint],
[PeriodType] [nvarchar](128) NOT NULL,
CONSTRAINT [PK_dbo.Period] PRIMARY KEY ([Id])
)
CREATE TABLE [dbo].[SpecialQuarter] (
[Id] [int] NOT NULL,
[SpecialQuarterValue] [int] NOT NULL,
CONSTRAINT [PK_dbo.SpecialQuarter] PRIMARY KEY ([Id])
)