Hibernate(JPA)为同一模型多个@OneToMany

Question

我有两个型号.

@Entity
public class Student
{
    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    protected long id;

    @?
    protected Address homeAddress;

    @?
    protected Address schoolAddress;
}

@Entity
public class Address
{
   @Id
   @GeneratedValue(strategy=GenerationType.AUTO)
   protected long id;

   @?
   protected List<Student> students;
}

做什么JPA /休眠批注我需要把上面homeAddress,schoolAddress并且students使协会工作？

当然,我尝试了很多东西,没有任何效果.例如,设置

    @ManyToOne
    @JoinColumn (name="student_homeAddress_id", updatable = false, insertable = false)
    protected Address homeAddress;

    @ManyToOne
    @JoinColumn (name="student_schoolAddress_id", updatable = false, insertable = false)
    protected Address schoolAddress;

和

    @OneToMany(cascade={CascadeType.PERSIST, CascadeType.MERGE, CascadeType.REFRESH}, fetch = FetchType.EAGER)
    @JoinColumns({
    @JoinColumn(name = "student_homeAddress_id", referencedColumnName = "student_homeAddress_id"),
    @JoinColumn(name = "student_schoolAddress_id", referencedColumnName = "student_schoolAddress_id")})
    @IndexColumn(name="students_index")
    protected List<Student> students;

yealds Unable to find column with logical name: student_homeAddress_id in org.hibernate.mapping.Table(Address) and its related supertables and secondary tables.也尝试使用mappedBy但只需要一个参数(不能这样做)mappedBy="student_homeAddress_id, student_schoolAddress_id".

还考虑了移动JoinColumns到Student平板电脑,但我不确定OneToMany和ManyToOne的注释应该是什么样的,因为我有多个地址,其中JoinColumns没有多大意义.

做了但没有创建关联的事情是:

    @OneToMany(cascade={CascadeType.PERSIST, CascadeType.MERGE, CascadeType.REFRESH}, fetch = FetchType.EAGER)
    @JoinColumn(name="address_id")
    @IndexColumn(name="students_index")
    protected List<Student> students;

使用此功能,当在DB中存储模型时,即使存储了两端(Student和Address模型),student_homeAddress_id和student_schoolAddress_id也始终为null.

我的想法是,在Address桌面上将有3个额外的列:student_homeAddress_id(homeAddress的Student表中Student的id),student_schoolAddress_id(studentAddress的Student表中Student的id)和students_index(0基于students列表的位置).这应该足够了,对吗？

有任何想法吗？

非常感谢!

Answer 1

我们尝试了 mael 的建议，但无法实现。

我们最终遵循了这个可行的方法。

换句话说，我们有OneToMany关系：

在Student：

protected List<AddressStudentAssociation> addresses;

在Address：

protected List<AddressStudentAssociation> students;

并在AddressStudentAssociation：

@ManyToOne
@PrimaryKeyJoinColumn(name="STUDENTID", referencedColumnName="id")
private Student student;
@ManyToOne
@PrimaryKeyJoinColumn(name="ADDRESSID", referencedColumnName="id")
private Address address;

加上一个参数以将一个地址与另一个地址分开 ( isHome)。

最后，在里面Student我们有public Address getHomeAddress()它遍历addresses列表并返回正确的地址。我们还必须使用注释才能使其工作。通常不是最佳的，但它有效，我们已经花了太多时间试图让事情发挥作用。:|