Can not get database generated value after saving

Question

I'm using SpringBoot, Spring data and postgresql.

In postgres I created one table.

CREATE EXTENSION "uuid-ossp";
CREATE TABLE user (
    id serial PRIMARY KEY not null,          
    user_id varchar(255) not null default uuid_generate_v4()
);

Than create entity

@Entity
public class User implements Serializable {

  private static final long serialVersionUID = 9129894781337596497L;

  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  @Column(columnDefinition = "serial")
  private Integer id;

  @Column(insertable = false)
  private String userId;

  public static User create(){
    User user = new User();
    return user;
  }

  public String getUserId(){
    return userId;
  }

}

Than create jpa repository like this

@Repository
public interface UserRepository extends JpaRepository<User, Integer> {}

When I save the user I need to get id and userId but I get null instead and in database is generated UUID.

User user = userRepository.save(User.create());
assertThat(user.getUserId()).isNotNull();

How can I get those generated values from database?

The primary key is id not user_id, you should check assertThat(user.getId()).isNotNull(). — Mayur
– Mayur, Commented Jul 6, 2017 at 12:47
I want to get userId. And even if I save and after that try with .findOne(user.getId()) the userId, generated UUID form database, is not retrieved. — Aleksandar
– Aleksandar, Commented Jul 6, 2017 at 13:30
What happens if you change the table like this: user_id varchar(255) not null default 'abc' ? In that case will you get 'abc' or null? — riskop
– riskop, Commented Jul 6, 2017 at 13:37
on this page: docs.jboss.org/hibernate/orm/5.0/topical/html/generated/… It woks with this Hibernate anottattion @Generated(GenerationTime.INSERT) — Aleksandar
– Aleksandar, Commented Jul 6, 2017 at 14:56

riskop · Accepted Answer · 2017-07-07 10:17:37Z

You have to re-read the inserted entity OR (since Hibernate 3.2?) you can specify @Generated(GenerationTime.INSERT) on the column ( https://docs.jboss.org/hibernate/orm/5.0/topical/html/generated/GeneratedValues.html#_legacy_support_in_database_generation ), which causes hibernate to re-read the attribute value after insert.

I've created a little demo:

http://peter.risko.hu/java_incubator/spring_data_postgres_uuid.zip

The User entity:

@Id
@SequenceGenerator(name="seq", sequenceName="seq")
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator="seq")
@Column(columnDefinition = "serial")
private Integer id;

@Column(insertable = false, name="user_id")
private String userId;

public String getUserId(){
    return userId;
}

public static User create(){
    User user = new User();
    log.info("user created in memory: " + user);
    return user;
}

public Integer getId(){
    return id;
}

@Override
public String toString() {
    return "[id: " + id + ", userId: " + userId + "]";
}

The test:

@Test
public void testInsert() {
    User u = userRepository.save(User.create());
    log.info("user after save: " + u);
    log.info("users queried from db: " + userRepository.findAll());
}

The output:

tst.User - user created in memory: [id: null, userId: null]
tst.UserRepositoryTest - user after save: [id: 960, userId: null]
tst.UserRepositoryTest - users queried from db: [[id: 960, userId: dc7cdc53-984d-4051-a3f3-ecc7136d9fd8]]

If I apply the @Generated(GenerationTime.INSERT):

@Column(insertable = false, name="user_id")
@Generated(GenerationTime.INSERT)
private String userId;

Then the result is:

tst.User - user created in memory: [id: null, userId: null]
tst.UserRepositoryTest - user after save: [id: 961, userId: c68ea300-2f20-47ea-a76d-6e1aaf97a5ea]
tst.UserRepositoryTest - users queried from db: [[id: 960, userId: dc7cdc53-984d-4051-a3f3-ecc7136d9fd8], [id: 961, userId: c68ea300-2f20-47ea-a76d-6e1aaf97a5ea]]

Mike Adamenko · Accepted Answer · 2017-07-06 16:19:45Z

0

You should add missing getters and setters for properties id and userId into the User class.

answered Jul 6, 2017 at 16:19

Mike Adamenko

3,0021 gold badge18 silver badges28 bronze badges

Collectives™ on Stack Overflow

Can not get database generated value after saving

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related