实体框架中的父级null

Question

I have a Group class that allows nested Groups. My setup is like so:

class Group
{
    [InverseProperty("Children")]
    public Group Parent { get; set; }

    public virtual ICollection<Group> Children { get; set; }
}

If I retrieve a folder with children, they are populated and their Parent field is filled in. If I just get a child folder directly Parent is null.

Why is this happening?

Answer 1

Group.Parent isn't virtual. Hence, lazy loading doesn't triggers here.
Either make it virtual, or use Include(g => g.Parent) , when loading child directly.