EF Code First, map two navigation properties to the same object type

Question

If I have a User class that has these properties:

    public Guid UserPreferenceId { get; set; }
    public virtual DefaultUserPreference UserP         


        

Answer 1

Entity Framework creates relationships with Cascade Delete on by default. Creating two relationships from one entity to another type tries to create two cascade-delete relationships, which the database will throw the error you saw for.

Use the Code-First Fluent Configuration to remove the Cascade Delete on one or both of the relationships:

modelBuilder.Entity<User>()
    .HasOptional(u => u.UserPreference)
    .WithMany()
    .WillCascadeOnDelete(false);
modelBuilder.Entity<User>()
    .HasOptional(u => u.SecondaryUserPreference)
    .WithMany()
    .WillCascadeOnDelete(false);