private void detach_Order_Details(Order_Detail entity)
 {
     this.SendPropertyChanging();
     entity.Product = null;
 }
 partial void DeleteOrder_Detail(Order_Detail instance);
 partial void InsertOrder_Detail(Order_Detail instance);
 partial void UpdateOrder_Detail(Order_Detail instance);
 private void attach_Order_Details(Order_Detail entity)
 {
     this.SendPropertyChanging();
     entity.Order = this;
 }