partial void Deletereq_mast(req_mast instance);
	private void detach_req_masts(req_mast entity)
	{
		this.SendPropertyChanging();
		entity.book_mast = null;
	}
	private void attach_req_masts(req_mast entity)
	{
		this.SendPropertyChanging();
		entity.book_mast = this;
	}
 partial void Updatereq_mast(req_mast instance);
 partial void Insertreq_mast(req_mast instance);