How to specify two navigation properties from entity X to the same target entity, Y?

Question

Consider that I have an Instructor class:

public class Instructor
{
    public InstructorTypesEnum Type { get; set; }

    public virtual ICollection<Course> Courses { get; set; }

    public virtual ICollection<Course> CoInstructingCourses { get; set; }
}

Here, InstructorTypesEnum has two values: instructor and co-instructor. So the two navigation properties Courses and CoInstructingCourses are supposed to return those different courses.

Of course I am also having difficulties specifying the coresponding properties in the Course class

    public Guid InstructorId { get; set; }

    public virtual Instructor Instructor { get; set; }

    public virtual ICollection<Instructor> Coinstructors { get; set; }

What is the correct way to do it?

How *exactly* do you want instructors and courses to be related? You only show what you don't think is correct. — Gert Arnold, Jun 03 '14 at 20:27

score 2 · Accepted Answer · answered Jun 03 '14 at 18:21

2

You can use the InversePropertyAttribute

On your model, I think it would be (not verified):

public class Instructor
{
  public InstructorTypesEnum Type { get; set; }

  [InverseProperty("Instructors")]
  public virtual ICollection<Course> Courses { get; set; }

  [InverseProperty("Coinstructors")]
  public virtual ICollection<Course> CoInstructingCourses { get; set; }
}

answered Jun 03 '14 at 18:21

Kit

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But what about the `Course` class? No change needed? – Blaise Jun 03 '14 at 18:51
By specifying it once, EF has enough information to go the reverse diretion. – Kit Jun 03 '14 at 19:15

score 0 · Answer 2 · answered Jun 04 '14 at 18:49

0

What's more - you shouldn't use GUID as entity ID. It hurts performance.

public Guid InstructorId { get; set; }

Try to replace it with for example int.

answered Jun 04 '14 at 18:49

magos

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How to specify two navigation properties from entity X to the same target entity, Y?

2 Answers2

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