partial void DeleteOrder_Details(Order_Details instance);
 partial void UpdateOrder_Details(Order_Details instance);
 private void detach_Order_Details(Order_Details entity)
 {
     this.SendPropertyChanging();
     entity.Products = null;
 }
 partial void InsertOrder_Details(Order_Details instance);
 private void attach_Order_Details(Order_Details entity)
 {
     this.SendPropertyChanging();
     entity.Orders = this;
 }