多列的Hibernate MappedBy

Question

我使用Postgresql作为我的数据库，它包含一个名为user的表和一个名为friendship的表，该表有2个外键userA_id和userB_id。我知道如何使用mappedBy来检查基于userA_id的朋友关系，但我不确定如何检查userB_id。有没有办法告诉hibernate检查user表中的用户ID和友好表中的两列？

​

编辑:这是我目前拥有的代码。

@Entity
@Table(name = "users")
public class UserDB implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "userid", nullable=false)
    public int userID; //not null

    @OneToMany (targetEntity = FriendshipDB.class, mappedBy = "userA_ID", cascade = CascadeType.ALL, fetch=FetchType.EAGER)
    //@OneToMany (targetEntity = FriendshipDB.class, mappedBy = "userB_ID", cascade = CascadeType.ALL, fetch=FetchType.EAGER)
    public List<FriendshipDB> friends = new ArrayList<>();
}

@Entity
@Table(name = "friendships")
public class FriendshipDB implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "friendshipid", nullable = false)
    private int friendshipID; //not null

    @ManyToOne
    @JoinColumn(name="usera_id")
    private UserDB userA_ID; //not null

    @ManyToOne
    @JoinColumn(name = "userB_id")
    private UserDB userB_ID;
}

Answer 1

我认为这是非常具体的映射，但我知道的唯一解决方案是像这样使用2关联：

@OneToMany(mappedBy = "user1")
private Collection<User> usersByFirst;
@OneToMany(mappedBy = "user2")
private Collection<User> usersBySecond;