Exposing only aggregate roots from a DBContext - entity-framework

Question

I am a new bie to DDD. In our DDD project ,we have a requirement that our DBContext should only expose AggregateRoots.. Assuming that our DbContext is as shown below
public class ClassContext : DbContext
{
public DbSet<Class> Classes{ get; set; }
public DbSet<Students> Students{ get; set; }
}
and Class is the aggregate root . Is the following implementation the right way
public class ClassContext : DbContext
{
public DbSet<Class> Classes{ get; set; }
private DbSet<Students> Students{ get; set; }
}
Any comment is appreciated

Answer 1

It's certainly useful to think about aggregate roots in your application, but don't try to apply DDD concepts to an Entity Framework class model.
An Entity Framework class model is not a domain model. It's a data access layer. Any considerations regarding including or hiding entities and/or navigation properties should be motivated by facilitating smooth data access and nothing more.
It's highly unlikely that you're always going to read/create/update/delete students through classes only. That would make unnecessary clunky code. And who says that students will always be in a class?
But maybe this isn't the best example of an aggregate. A Student doesn't have an identifying relationship with a Class, because next time he'll be in another class. It would be different with the classic Order-OrderLine relationship. I can imagine that in that case you might only expose a DbSet<Order>.
So just expose the DbSet<Students> as public class.

Answer 2

I don't think the private declaration for Students is needed.
Presumably the Class object contains something like
public virtual List<Student> Students { get; set; }
so, given the requirement that you are only exposing aggregate roots,your code to find a student will always need to find a class and pull the student from it.