public IActionResult Add(int Id, string Name)
        {
            var depart = context.Department
                         .Where(d => d.DepartmentId == Id)
                         .Select(d => new { DepartId = d.DepartmentId, DepartHier = d.Hierarchy, DepartParent = d.Parent }).FirstOrDefault();

            var department = context.Set <Department>();

            department.Add(new Department {
                Name = Name, Hierarchy = depart.DepartHier + 1, Parent = depart.DepartId
            });
            context.SaveChanges();
            return(RedirectToAction("Index", "Department"));
        }