I am using EntityFramework 4.1.
I have the following model:
public class User
{
[Key]
public int Id { get; set; }
public string Username { get; set; }
public string Password { get; set; }
public virtual User Creator { get; set; }
public virtual User LastEditor { get; set; }
}
When I try to generate my database I got this error:
Unable to determine the principal end of an association between the types 'User' and 'User'. The principal end of this association must be explicitly configured using either the relationship fluent API or data annotations.
But I also have this class:
public class Course
{
[Key]
public int Id { get; set; }
public string Name { get; set; }
public virtual User Creator { get; set; }
public virtual User LastEditor { get; set; }
}
And it works ok, I have these foreign keys generated:
Creator_Id
LastEditor_Id
Do I have anything to add in my User model to make it works?
EF tries - by convention - to create a one-to-one relationship between User.Creator
and User.LastEditor
because they both refer to the User
class where they are themselves located in. That's not the case for the Course
class. For Course.Creator
and Course.LastEditor
EF creates two one-to-many relationships to the User
. To achieve the same for the properties in User
you will have to configure the relationships with Fluent API:
modelBuilder.Entity<User>()
.HasOptional(u => u.Creator) // or HasRequired
.WithMany();
modelBuilder.Entity<User>()
.HasOptional(u => u.LastEditor) // or HasRequired
.WithMany();