ef code first - Linq Query With Entities and Group By -

i have entities shown below (using .net code first repository pattern):

public abstract class basecontent : entity {     public guid id { get; set; }     public virtual icollection<assignedmedia> assignedmedias { get; set; } }  public partial class library : basecontent {     public library()     {         this.assignedmedias = new list<assignedmedia>();     } }  public class media : basecontent {     public media()     {         this.assignedmedias = new list<assignedmedia>();     } }  public class assignedmedia : entity {     public int id { get; set; }      //basecontent reference id     public guid assignedid { get; set; }      public guid mediaid { get; set; }      public virtual media media { get; set; }     public virtual basecontent basecontent { get; set; } } 

then i'm trying query (as dictionary<string, list<media>>) group by! instance:

var list = bc in libraries     join in assignedmedias on bc.id equals a.assignedid     join m in medias on a.mediaid equals m.id     select new {         libraryname = bc.name, medialist = ???      }; 

you don't need use join when have entity associations mapped properly. can write query so:

var libraryassignedmedia = libraries.todictionary(     l => l.name, // key selection.     l => l.assignedmedias.select(am => am.media)); // value selection.