Question

I’m creating a EF5 entity model with the designer (VS2012), and used the EF5 DbContext generator as code generation item.

My model contains an entity deriving from another (not abstract).

So let’s say the base entity is called BaseEntity, and the derived entity is DerivedEntity.

Now I see in the generated context class, that there is no

Public DbSet<DerivedEntity> DerivedEntities { get; set; }

defined.

Only

Public DbSet<BaseEntity> BaseEntities { get; set; }

is defined.

Is this normal ? And if yes, how do I query the derived entities in linq ?

I’m used to query like this:

using(var ctx = new EntityContainer)
{
var q = from e in ctx.DerivedEntities <-- but this is now not possible since it doesn't exist
select e;

return q.ToList();
}

Thanks for replying.

EDIT:

As requested, generated classes posted:

public partial class Scheduling
    {
        public int Id { get; set; }
        public string Subject { get; set; }
        public System.DateTime BeginDate { get; set; }
        public System.DateTime EndDate { get; set; }
    }

public partial class TeamScheduling : Scheduling
    {
        public int TeamId { get; set; }
        public Nullable<int> AssignmentId { get; set; }

        public virtual Team Team { get; set; }
        public virtual Assignment Assignment { get; set; }
    }


public partial class EntityContainer : DbContext
    {
        public EntityContainer()
            : base("name=EntityContainer")
        {
        }

        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            throw new UnintentionalCodeFirstException();
        }

        public DbSet<Team> Teams { get; set; }
        public DbSet<Location> Locations { get; set; }
        public DbSet<Country> Countries { get; set; }
        public DbSet<Assignment> Assignments { get; set; }
        public DbSet<ProductType> ProductTypes { get; set; }
        public DbSet<AssignmentPreference> AssignmentPreferences { get; set; }
        public DbSet<Scheduling> Schedulings { get; set; }
    }

As you see, the EntityContainer class does not contain

public DbSet<TeamScheduling> TeamSchedulings { get; set; }

Answer 1

This is expected when you use inheritance the way you have. context.Schedulings contains both Scheduling objects and TeamScheduling objects. You can get the TeamScheduling objects only by asking for context.Schedulings.OfType<TeamScheduling>(). Note that you cannot meaningfully use context.Schedulings.OfType<Scheduling>() to get the others: that will also include the TeamScheduling objects.

You could alternatively try context.Set<TeamScheduling>(), but I’m not entirely sure that will work.