Hibernate - Uplicate key value violates Unique Constraint

Question

I have the following problem:

Person:

@Entity
@Table(name="tb_pessoa", schema="public")
@Inheritance(strategy = InheritanceType.JOINED)
public class Pessoa implements Serializable {
   private static final long serialVersionUID = 1L;

   @Id
   @SequenceGenerator(name = "tb_pessoa_id_seq", sequenceName = "tb_pessoa_id_seq", schema="public")
   @GeneratedValue(strategy = GenerationType.AUTO, generator = "tb_pessoa_id_seq")
   @Column(name = "id", nullable = false)
   private Integer id;

   ...

Pessoa Fisica:

@Entity  
@Table(name="tb_pessoafisica", schema="public")
@PessoaFisicaAnnotation
@PrimaryKeyJoinColumn(name = "id")
public class PessoaFisica extends Pessoa implements Serializable {
   private static final long serialVersionUID = 1L;

   @Column(name = "email")
   private String email;

   ...

Supposing on the table Person has records with id from 1 to 500. When I execute the code below:

PessoaFisica pessoaFisica = new PessoaFisica();
pessoaFisica.setEmail("[email protected]");

...

em.persist(pessoa);

The following error is happening:

17:26:13,613 ERROR [org.hibernate.engine.jdbc.spi.SqlExceptionHelper] (http--10.36.1.49-8180-1) ERROR: duplicate key value violates unique constraint "tb_pessoa_pkey"
    Detalhe: Key (id)=(438) already exists.
17:26:13,614 WARN  [com.arjuna.ats.arjuna] (http--10.36.1.49-8180-1) ARJUNA012125: TwoPhaseCoordinator.beforeCompletion - failed for SynchronizationImple< 0:ffff7f000101:-7f6ae4e3:558080ed:4f, org.hibernate.engine.transaction.synchronization.internal.RegisteredSynchronization@331af73a >: javax.persistence.PersistenceException: org.hibernate.exception.ConstraintViolationException: ERROR: duplicate key value violates unique constraint "tb_pessoa_pkey"
  Detalhe: Key (id)=(438) already exists.

I haven’t been able to figure out why you’re trying to use the id 438 and not 501

Does anyone know what might be going on?

Thank you very much

CREATE TABLE tb_pessoa
(
    id integer NOT NULL,
    CONSTRAINT tb_pessoa_pkey PRIMARY KEY (id)
)

CREATE TABLE tb_pessoafisica
(
    email character varying(64) NOT NULL,
    CONSTRAINT tb_pessoafisica_pkey PRIMARY KEY (id),
    CONSTRAINT fkee8c050f70415778 FOREIGN KEY (id)
        REFERENCES tb_pessoa (id) MATCH SIMPLE
)

CREATE SEQUENCE tb_pessoa_id_seq
  INCREMENT 1
  MINVALUE 1
  MAXVALUE 9223372036854775807
  START 500
  CACHE 1;

Log Hibernate:

07:50:52,463 INFO  [stdout] (http--10.36.1.49-8180-2) Hibernate: 
07:50:52,463 INFO  [stdout] (http--10.36.1.49-8180-2)     select
07:50:52,464 INFO  [stdout] (http--10.36.1.49-8180-2)         nextval ('public.tb_pessoa_id_seq')
07:50:52,497 INFO  [stdout] (http--10.36.1.49-8180-2) Hibernate: 
07:50:52,498 INFO  [stdout] (http--10.36.1.49-8180-2)     insert 
07:50:52,499 INFO  [stdout] (http--10.36.1.49-8180-2)     into
07:50:52,499 INFO  [stdout] (http--10.36.1.49-8180-2)         public.tb_pessoa
07:50:52,500 INFO  [stdout] (http--10.36.1.49-8180-2)         (id) 
07:50:52,500 INFO  [stdout] (http--10.36.1.49-8180-2)     values
07:50:52,501 INFO  [stdout] (http--10.36.1.49-8180-2)         (?)
07:50:52,519 WARN  [org.hibernate.engine.jdbc.spi.SqlExceptionHelper] (http--10.36.1.49-8180-2) SQL Error: 0, SQLState: 23505
07:50:52,521 ERROR [org.hibernate.engine.jdbc.spi.SqlExceptionHelper] (http--10.36.1.49-8180-2) ERROR: duplicate key value violates unique constraint "tb_pessoa_pkey"
    Detalhe: Key (id)=(438) already exists.

Answer 1

Considering your ORM, Hibernate will execute a query to retrieve the next value of tb_pessoa_id_seq before including the new record, something of this kind:

select nextval ('tb_pessoa_id_seq')

Quoting what you said yourself:

Suppose the Person table has records with an id from 1 to 500.

Well, if you check the starting value on your quence is 467 (START 467), that is, the next will be 468, which is returned in the query by the next value of the quence.

To fix this you can run something that changes the start value of quence, something like that:

ALTER SEQUENCE tb_pessoa_id_seq RESTART WITH 501;