How does Entity Framework work with recursive hierarchies? Include() seems not to work with it

Question

I have an Item. Item has a Category.

Category has ID, Name, Parent

Answer 1

try this

List list = this.GetQuery()
                .Where(m => m.Parent == null && m.Active == true)
                .Include(m => m.Action)
                .Include(m => m.Parent).ToList();    

if (list == null)
    return null;

this.GetQuery()
    .OrderBy(m => m.SortOrder)
    .Where(m => m.Active == true)
    .Include(m => m.Action)
    .Include(m => m.Parent)
    .ToList();

return list;