Question

org.springframework.dao.DataIntegrityViolationException：具有相同标识符值的另一个对象已与会话关联 Hibernate 5将临时对象的ID保存在数据库中以用作子级父关系后，不会填充该ID。我正在遵循班级等级制度：

public class A{
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    private Long id;
    ....
    @OneToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL,  orphanRemoval = true,  mappedBy = "parent")
    private List<B> listB;
    ....
    private C c;
}

public class B{
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    private Long id;

    ....
    @ManyToOne
    @JoinColumn(name = "parent_id")
    private A parent;
    ....
}

public class C{
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    private Long id;
    ....
    @OneToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL,  orphanRemoval = true,  mappedBy = "parent")
    private List<D> listD;
    ....
}

public class D{
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    private Long id;

    ....
    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "parent_id")
    private C parent;
    ....
}

public interface ADao extends JpaRepository<A, Long>, JpaSpecificationExecutor<A> {}


@Autowired
ADao aDao;

A a = new A();

B b1 = new B();
B b2 = new B();
b1.setParent(a);
b2.setParent(a);

C c = new C();

D d1 = new D();
D d2 = new D();
d1.setParent(c);
d2.setParent(c);

List<B> blist =  new ArrayList<B>();
blist.add(b1);
blist.add(b2);
a.setListB(blist);

List<D> dlist =  new ArrayList<D`>();
dlist.add(d1);
dlist.add(d2);
c.setListD(dlist);

aDao.save(a);

当我尝试保存如下对象时：

我收到以下异常

org.springframework.dao.DataIntegrityViolationException: A different object with the same identifier value was already associated with the session : [D#0]; nested exception is javax.persistence.EntityExistsException: A different object with the same identifier value was already associated with the session : [D#0]

Hibernate5似乎没有为孩子填充父母的ID，就像在调试期间，即使在保存操作之后，我的a.getId和c.getId都为0。

到目前为止，我已经尝试设置

hibernate.id.new_generator_mappings=false
session.flush()
session.merge()
session.refresh()

org.springframework.dao.DataIntegrityViolationException：具有相同标识符值的另一个对象已经与会话相关联

0 个答案: