private void detach_tbl_ChiTietHDs(tbl_ChiTietHD entity)
 {
     this.SendPropertyChanging();
     entity.tbl_HoaDon = null;
 }
 partial void Deletetbl_ChiTietHD(tbl_ChiTietHD instance);
 partial void Inserttbl_ChiTietHD(tbl_ChiTietHD instance);
 partial void Updatetbl_ChiTietHD(tbl_ChiTietHD instance);
 private void attach_tbl_ChiTietHDs(tbl_ChiTietHD entity)
 {
     this.SendPropertyChanging();
     entity.tbl_SanPham = this;
 }