多列的 Hibernate MappedBy

Question

I am using Postgresql for my database and it contains a table called user and a table called friendship, which has 2 foreign keys userA_id and userB_id. I know how to use mappedBy to check for friendships based on userA_id but I am not sure how to check for userB_id. Is there a way to tell hibernate to check a user ID from user table with both of columns on friendship table?

EDIT: Here is the code I currently have.

@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

I think this is very specific mapping but the only solution I know is to go with 2 association like this:

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