public IActionResult Create(OrderDtail orderDetail) { if (ModelState.IsValid) { if (orderDetailRepository.CreateOrderDetail(orderDetail) > 0 && orderDetail.Quantity > 0) { return(RedirectToAction("WatchOrderDetail", "OrderDetail", orderDetailRepository.GetOrderByid(orderDetail.OderId))); } ModelState.AddModelError("", "Quantity is not Null"); } else { ModelState.AddModelError("", "Error"); } return(View(orderDetail)); }