public void Update(Order order)
 {
     using (var db = new OrderDB())
     {
         db.Order.Attach(order);
         db.Entry(order).State = EntityState.Modified;
         List <OrderDetails> odl = GetAllOrderDetails();
         foreach (OrderDetails details in order.orderDetails)
         {
             bool exist = false;
             foreach (OrderDetails detailed in odl)
             {
                 if (detailed.ID == details.ID)
                 {
                     exist = true;
                     break;
                 }
             }
             db.Entry(details).State = EntityState.Modified;
             if (!exist)
             {
                 db.OrderDetail.Add(details);
             }
         }
         //order.orderDetails.ForEach(
         //    item => db.Entry(item).State = EntityState.Modified);
         db.SaveChanges();
     }
 }
 public void Update(Order order)
 {
     using (var db = new OrderDB()) {
         db.Order.Attach(order);
         db.Entry(order).State = EntityState.Modified;
         order.Details.ForEach(
             item => db.Entry(item).State = EntityState.Modified);
         db.SaveChanges();
     }
 }