Table Per Type Fluent Mapping in Entity Framework

Question

With Entity Framework I can map related tables as a class inheritance and There are three different approaches to representing an inheritance hierarchy (by weblogs):

Table per Hierarchy (TPH)
Table per Type (TPT)
Table per Concrete class (TPC)

The site mscblogs has a nice explanation for each one of these approaches.

I'm trying to understand how to map my tables using the approach TPT (Table per Type), but unlike the example of mscblogs, I need to do the mapping for fluent programming like:

using System.ComponentModel.DataAnnotations.Schema;
using System.Data.Entity.ModelConfiguration;

public class BillingDetailMap : EntityTypeConfiguration<BillingDetailEntity>
{
    public BillingDetailMap()
    {
        // ...
        this.Property(t => t.Number).HasColumnName("Number");
        // ...
    }    
}

// ...

I'm searching for several hours but I couldn't find anything. I found many examples how to do this with diagram, with attributes and others, but nothing with fluent api.

How to Mapping TPT in Entity Framework 4.1 Fluent API?

Yuliam Chandra Yuliam Chandra · Accepted Answer · 2014-07-31T05:06:17

Mapping the Table-Per-Type (TPT) Inheritance

In the TPT mapping scenario, all types are mapped to individual tables. Properties that belong solely to a base type or derived type are stored in a table that maps to that type. Tables that map to derived types also store a foreign key that joins the derived table with the base table.

modelBuilder.Entity<Course>().ToTable("Course");  
modelBuilder.Entity<OnsiteCourse>().ToTable("OnsiteCourse");

Source

Check also my answer on previous question, hopefully it helps.

update complete example

public class AppContext : DbContext
{
    public DbSet<Item> Items { get; set; } // --> this dbset is required for TPT, if removed it will become TPCC
    public DbSet<Food> Books { get; set; }
    public DbSet<Book> Foods { get; set; }
    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.Configurations.Add(new ItemMap());
        modelBuilder.Configurations.Add(new BookMap());
    }
}
public class ItemMap : EntityTypeConfiguration<Food>
{
    public ItemMap()
    {
        ToTable("Foods");
    }
}
public class BookMap : EntityTypeConfiguration<Book>
{
    public BookMap()
    {
        ToTable("Books");
    }
}
public abstract class Item
{
    public int Id { get; set; }
    public string Name { get; set; }
}
public class Food : Item { }
public class Book : Item { }

Table Per Type Fluent Mapping in Entity Framework

1 Answers

update complete example