如果级联类型不是全部，session.save()不起作用？

@Entity
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    
    private String name;
    
    @OneToMany(cascade = CascadeType.SAVE_UPDATE)
    private List<Order> orders;
    
    // getters and setters
}

@Entity
public class Order {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    
    private String orderNumber;
    
    // getters and setters
}

// 在保存用户时，级联保存订单
User user = new User();
user.setName("John");

Order order1 = new Order();
order1.setOrderNumber("12345");

Order order2 = new Order();
order2.setOrderNumber("67890");

user.setOrders(Arrays.asList(order1, order2));

session.save(user);