java JPA - 更新 OneToMany-Relations 中的对象

JPA - updating objects in OneToMany-Relations

提问by Cyboot

Well I am a little confused because I just can't find any solution on my problem (maybe some kind of a blackout)

好吧，我有点困惑，因为我找不到任何解决我的问题的方法（也许是某种停电）

Lets say I have the following (simplified) Entities:

假设我有以下（简化的）实体：

@Entity
public class Employee {
    @Id
    private long id;
    @OneToMany(mappedBy="owner")
    private Collection<Phone> phones;
}

@Entity
public class Phone {
    @Id
    private long id;
    @ManyToOne
    private Employee owner;
}

and I have a phoneobject managed by JPA. And now i want to change the Employee of that phoneobject with something like that:

我有一个由 JPA 管理的电话对象。现在我想用这样的东西来改变那个电话对象的员工：

phone.setEmployee(otherEmployee);

I thought that JPA would update the corresponding Employee would be updated too. Am I wrong? I experimented with the annotations @ManyToOne and @OneToMany (cascade = CascadeType.ALL, orphanRemoval = true) but it doesn't work.

我认为 JPA 会更新相应的 Employee 也会更新。我错了吗？我尝试了注释@ManyToOne 和@OneToMany（cascade = CascadeType.ALL，orphanRemoval = true）但它不起作用。

Do I have to update the Employee object myself? Unfortunatly I didn't find that case in any tutorial or other example, so I hope you can tell me more, I am confused. Thanks in advance.

我必须自己更新 Employee 对象吗？不幸的是，我在任何教程或其他示例中都没有找到这种情况，所以我希望你能告诉我更多，我很困惑。提前致谢。

Editto make it even clearer:

编辑以使其更清晰：

Phone phone = new Phone();
Employee employee = new Employee();
phone.setEmployee(employee);
em.persist(employee);
em.persist(phone);

employee.getPhones(); //the phone object should be included here.

回答by remigio

This linkis the answer to your question, you should manage relationships by yourself, i. e.:

此链接是您问题的答案，您应该自己管理关系，即：

class Phone {
...
   void setEmployee(Employee employee) {
      owner = employee;
      employee.addPhone(phone);
   }
...
}