Entity Framework CTP4 and composite keys

Question

I was playing with EntityFramework CTP4 and decided to apply it to one of my current projects. The application uses a SQLServer database and there is one table with a composite key. Say, table "MyEntity" has "Key1" and "Key2" as both foreign keys (individually) and as a composite primary key.

I made a configuration class derived from EntityConfiguration :

class MyEntityConfiguration : EntityConfiguration<MyEntity>
{
    public MyEntityConfiguration()
    {
        HasKey(m => m.Key1);
        HasKey(m => m.Key2);
    }
}

Then in my DataContext (derived from DbContext) :

    public DbSet<MyEntity> MyEntities { get; set; }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Configurations.Add(new MyEntityConfiguration());
    }

The problem is that when I query "MyEntities" for all its records :

var entities = from e in MyModel.Instance.MyEntities
               select e;

I get a really weird result consisting of the first record repeated 18 times, then the second repeated 18 times (for the record, my table has 36 records).

I suspect the problem is with the composite key as no other entity is showing this problem.

Any help would be appreciated, thanks :)

Convoy

CTP4??? Why not use the release version? It's out! – Regazzi

My bad, I meant the just released Feature CTP4 which improves the Code-First approach. – Convoy

EntityConfiguration looks like it is EntityTypeConfiguration in EF4.1. – Gantry

Answer 1

I haven't tested it with my current database & CTP4 but in CTP3 you'd create a composite key like this:

HasKey(m => new { m.Key1, m.Key2 });

Coze

As incredible as it may sound it actually worked :o I always assumed those were different ways to do the same thing, guess I was wrong. Thanks :) – Convoy

Glad it worked! Yeah it's not entirely clear how to do all things with the lack of documentation currently. – Coze

Just had this issue myself and this is the correct way of setting composite keys. Thanks @TheCloudlessSky. NB. using HasKey repeatedly as follows: HasKey(m => m.Key1); HasKey(m => m.Key2); will only remember the last key that was set. – Monosyllable