在休眠中使用复合主键保留1-m实体

Question

对于Mentor to Students的实体,我的关系低于1米.导师有复合主键,我在学生中用作外键

@Entity
public class Mentor implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    private MentorPK id;
    private String email;
    @OneToMany(mappedBy="mentor")
    private Set<Student> students;

    public MentorPK getId() {
        return id;
    }            
    //getters and setters
}

@Embeddable
public class MentorPK implements Serializable {

    private static final long serialVersionUID = 1L;
    private String name;
    private String add;
    //getters and setters
    //override equals and hashcode
}


@Entity
public class Student implements Serializable{
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    private int id;
    private String name;    

    @ManyToOne
    @MapsId("id")
    @JoinColumns({
        @JoinColumn(name="name_fk", referencedColumnName="name"),
        @JoinColumn(name="address_fk", referencedColumnName="address")
    })
    private Mentor mentor;

    //Getters and setters
}

然后我坚持上面的内容如下,但只有导师坚持学生桌是空的.

我怎样才能与学生一起坚持导师？

Set<Student> students = new HashSet<Student>();

Student s1 = new Student();
s1.setName("Student 1");

Student s2 = new Student();
s2.setName("Student 2");

students.add(s1);
students.add(s2);

MentorPK mpk = new MentorPK();
mpk.setAddress("C");
mpk.setName("D");

Mentor m = new Mentor();
m.setId(mpk);
m.setEmail("emaill");
m.setStudents(students);

studentManager.saveMentor(m);

Answer 1

尝试将学生字段的注释更改为

@OneToMany(mappedBy="mentor", cascade = CascadeType.PERSIST)