Hibernate "object references an unsaved transient instance"

Question

My Users are in Organisations in a ManyToOne relationship, when a user is created with an existing Organisation I am trying to assign it to it without creating a new one.

In my service, here is how I create a user:

@Override
public UserInfo createUser(UserInfo newUser) {
    // Check if organisation exists
    OrganisationEntity orga = organisationDao.findByName(newUser.getOrganisation());

    if (orga != null) {
        // Organisation exists, we save it with the correct ID
        return mapper.map(userDao.save(mapper.map(newUser, orga.getId())));
    } else {
        // Organisation does NOT exists, we save it and create a new one
        return mapper.map(userDao.save(mapper.map(newUser, (long) -1)));
    }
}

With my Mapper (helping me to convert a model to an entity) being:

 public UserEntity map(UserInfo userInfo, Long orgaId) {
    UserEntity user = new UserEntity();
    user.setEmail(userInfo.getEmail());
    user.setFirstName(userInfo.getFirstName());
    user.setLastName(userInfo.getLastName());
    user.setPassword(userInfo.getPassword());

    OrganisationEntity orga = new OrganisationEntity();
    orga.setName(userInfo.getOrganisation());

    // We set the organisation's ID
    if (orgaId != -1)
       orga.setId(orgaId);
    user.setOrganisation(orga);
    return user;
}

And here is my UserDao:

@Transactional
public interface UserDao extends CrudRepository<UserEntity, Long> {
    UserEntity save(UserEntity user);  
}

And finally the relation in my UserEntity:

@ManyToOne(targetEntity = OrganisationEntity.class, cascade = CascadeType.ALL)
@JoinColumn(name = "orga_id")
private OrganisationEntity organisation;

Creating a user with a new Organisation work but when I input an existing one, I get the following:

detached entity passed to persist

From my understanding it is a bidirectional consistency problem, but the answers did not help me so far.

Finally here are my Entity classes:

@Entity
@Table(name = "\"user\"")
public class UserEntity {

    @Id
    @Column(name = "user_id")
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    @NotNull
    private String email;

    @NotNull
    private String firstName;

    @NotNull
    private String lastName;

    @NotNull
    private String password;

    @ManyToOne(targetEntity = OrganisationEntity.class, cascade = CascadeType.ALL)
    @JoinColumn(name = "orga_id")
    private OrganisationEntity organisation;

    // Getters & Setters
}

and

@Entity
@Table(name = "organisation")
public class OrganisationEntity {
    @Id
    @Column(name = "orga_id", unique = true)
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    @NotNull
    @Column(unique = true)
    private String name;

    // Getters & Setters
}

why not let hibernate do the mapping for you? you can use annotations on your classes and for inserting use `session.save();` method. no need to implement it by yourself. — XtremeBaumer, Apr 27 '17 at 10:07
Could you please develop in an answer? It's not very clear to me. — Christopher, Apr 27 '17 at 10:12

score 0 · Answer 1 · answered Apr 27 '17 at 13:19

I have solved my problem,

As you can see in the mapper above, I am creating a new instance of OrganisatonEntity no matter what, even if it already exists !

So a small change in my code solved it:

public UserEntity map(UserInfo userInfo, OrganisationEntity organisationEntity);

instead of

public UserEntity map(UserInfo userInfo, Long orgaId);

When the organisation already exists, I then assign it to my UserEntity like such:

user.setOrganisation(organisationEntity);

instead of instantiating a new object.

Problem solved !

Hibernate "object references an unsaved transient instance"

1 Answers1