private void detach_CTHoaDons(CTHoaDon entity)
 {
     this.SendPropertyChanging();
     entity.HangHoa = null;
 }
 private void attach_CTHoaDons(CTHoaDon entity)
 {
     this.SendPropertyChanging();
     entity.HangHoa = this;
 }
 partial void UpdateCTHoaDon(CTHoaDon instance);
 partial void DeleteCTHoaDon(CTHoaDon instance);
 partial void InsertCTHoaDon(CTHoaDon instance);