private void detach_CHITIETDONHANGs(CHITIETDONHANG entity)
 {
     this.SendPropertyChanging();
     entity.SANPHAM = null;
 }
 partial void DeleteCHITIETDONHANG(CHITIETDONHANG instance);
 partial void InsertCHITIETDONHANG(CHITIETDONHANG instance);
 partial void UpdateCHITIETDONHANG(CHITIETDONHANG instance);
 private void attach_CHITIETDONHANGs(CHITIETDONHANG entity)
 {
     this.SendPropertyChanging();
     entity.DONDATHANG = this;
 }