JPA - 更新OneToMany-Relations中的对象

Question

好吧,我有点困惑,因为我找不到解决问题的方法(可能是某种停电)

假设我有以下(简化)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;
}

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

phone.setEmployee(otherEmployee);

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.

我是否必须自己更新Employee对象？不幸的是,我没有在任何教程或其他例子中找到这种情况,所以我希望你能告诉我更多,我很困惑.提前致谢.

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.

Answer 1

这个链接是你问题的答案,你应该自己管理关系,即:

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