Question

I have structure like this

class Lesson {
    List<Sign> signs { get; set; }
}

class Sign {
    List<Media> media { get; set;}
}

class Media {

}

Now I’m using this LINQ to get all lessons

var items = (from lesson in this.db.Lesson.Include("Sign")
                     where lesson.module_id == param
                     select lesson);

It works fine but signs list has ampty media list. I mean that attribute media in each object Sign equals null. What do I need to do to include media objects for each Sign ? Whole data is kept in database

Answer 1

You’d use db.Lesson.Include("signs.media").

The argument to ObjectQuery<T>.Include is a property path, not just a single root property. Note that with “signs.media” you wouldn’t need to also include “signs” separately:

Paths are all-inclusive. For example, if an include call indicates Include(“Orders.OrderLines”), not only will OrderLines be included, but also Orders.

(You should adjust your property names to conform to .NET framework conventions, by the way, so you’d end up with “Signs.Media”.)