EF4 Code only mapping inheritance

Question

I've got the following model and I want ShiftRequest and MissionRequest to have a single table in the DB.

    public class RequestBase
    {
        public int Id { get; set; }
        public DateTime? RequestDate { get; set; }
        public int UserId { get; set; }

        public virtual ICollection<Notification> Notifications { get; set; }

    }

    public class ShiftRequest : RequestBase
    {
        public virtual Column Column { get; set; }

    }

    public class MissionRequest : RequestBase
    {
        public virtual Mission Mission { get; set; }
    }

I've tried to do it in the override void OnModelCreating(ModelBuilder modelBuilder) method but only one RequestBases table is created:

modelBuilder.Entity<ShiftRequest>().MapSingleType().ToTable("dbo.ShiftRequests");
modelBuilder.Entity<MissionRequest>().MapSingleType().ToTable("dbo.MissionRequest");

What am I doing wrong?

EDIT

Column and Mission are also entities in my model, is that acceptable?

Answer 1

Check the section about TPH in this article . If Mission and Column are complex types you will also find there how to map them. Generally you have to use MapHiearchy and Case methods instead of MapSingleType.

Edit:

Here is the example:

using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Data.Entity.ModelConfiguration;


namespace EFTest
{
    public class RequestBase
    {
        public int Id { get; set; }
        public DateTime? RequestedDate { get; set; }
        public int UserId { get; set; }
    }

    public class Mission
    {
        public int Id { get; set; }
        public string Name { get; set; }

        public virtual ICollection<MissionRequest> MissionRequests { get; set; }
    }

    public class Column
    {
        public string Name { get; set; }
    }

    public class MissionRequest : RequestBase
    {
        public virtual Mission Mission { get; set; }
    }

    public class ShiftRequest : RequestBase
    {
        public Column Column { get; set; }
    }

    public class TestContext : DbContext
    {
        public DbSet<RequestBase> Requests { get; set; }
        public DbSet<Mission> Missions { get; set; }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            modelBuilder.ContainerName = "EFTest";
            modelBuilder.IncludeMetadataInDatabase = false;

            // Example of complex type mapping. First you have to define 
            // complex type. Than you can access type properties in  
            // MapHiearchy.
            var columnType = modelBuilder.ComplexType<Column>();
            columnType.Property(c => c.Name).HasMaxLength(50);

            modelBuilder.Entity<Mission>()
                .Property(m => m.Id)
                .IsIdentity();

            modelBuilder.Entity<Mission>()
                .HasKey(m => m.Id)
                .MapSingleType(m => new { m.Id, m.Name })
                .ToTable("dbo.Missions");

            modelBuilder.Entity<RequestBase>()
                .Property(r => r.Id)
                .IsIdentity();

            // You map multiple entities to single table. You have to  
            // add some discriminator to differ entity type in the table. 
            modelBuilder.Entity<RequestBase>()
                .HasKey(r => r.Id)
                .MapHierarchy()
                .Case<RequestBase>(r => new { r.Id, r.RequestedDate, r.UserId, Discriminator = 0 })
                .Case<MissionRequest>(m => new { MissionId = m.Mission.Id, Discriminator = 1 })
                .Case<ShiftRequest>(s => new { ColumnName = s.Column.Name, Discriminator = 2 })
                .ToTable("dbo.Requests");
        }
    }
}

Edit 2:

I updated example. Now Mission is entity instead of complex type.