partial void DeleteOrderDetail(OrderDetail instance);
 partial void UpdateOrderDetail(OrderDetail instance);
 private void detach_OrderDetails(OrderDetail entity)
 {
     this.SendPropertyChanging();
     entity.Product = null;
 }
 partial void InsertOrderDetail(OrderDetail instance);
 private void attach_OrderDetails(OrderDetail entity)
 {
     this.SendPropertyChanging();
     entity.Order = this;
 }