Can I use and return EF4 POCO code objects as my interface?

Question

Given the code later in the question, I get the following error from the first EF4 API:

This Roles property is not a supported navigation property. Property item type "IRole" is not a supported entity type. Interface types are not supported.

Basically, I have a repository similar to the following:

public class Repository : IRepository {
    private IEntityProvider _provider;
    public Repository(IEntityProvider provider) {
        _provider = provider;
    }
    public IUser GetUser(int id) {
        return _provider.FindUser(id);
    }
}

Note that IRepository.GetUser returns an IUser.

Say my implementation of IEntityProvider looks like this.

public class EntityProvider : IEntityProvider {
    public IUser FindUser(int id) {
        /* Using Entity Framework */
        IUser entity;
        using (var ctx = new MyDbContext()) {
            entity = (from n in ctx.Users 
                  where n.Id == id 
                  select (IUser)n).FirstOrDefault();
        }
        return entity;
    }
}

The key point here is that the IUser interface has a List <IRole> property called Roles. Because of this, it seems that the Entity Framework code at first cannot figure out which class to use to execute the IRole interface, which requires a property.

POCO, , , EF4.

public interface IUser {
    int Id { get; set; }
    string Name { get; set; }
    List<IRole> Roles { get; set; }
}

public interface IRole {
    int Id { get; set; }
    string Name { get; set; }
}

public class User : IUser {
    public int Id { get; set; }
    public string Name { get; set; }
    public List<IRole> Roles { get; set; }
}

public class Role : IRole {
    public int Id { get; set; }
    public string Name { get; set; }
}

? API- EF4?

:

• (List <Role> DbRoles), EF4. , , <IRole> EF4.
• , EF4 , , .

Answer 1

EF 4 Code First ( CTP5) , , RTM. , DbContext, .

Answer 2

, ( EF), RootEntity , , Id, InsertedBy, UpdateBy, , .