Hibernate (SpringBoot JPA) invert save sequence - spring-boot

Question

I'm using SpringBoot 2.2.6 with JPA and I'm run into following problem:
#Transactional
public void batch() {
....
....
repository.save(data) // this is an update
....
....
repository.save(data) // this is a normal save
}
the Hibernate logging says to me that the save is executed before the update and this generate a constraint violation error on my db.
Do you have some idea why happend something like this?
Thanks
UPDATE
The Entity is something like this, clearly there are other Entity nested but the logic is similar
#Id
#Column(name="id")
#GeneratedValue(generator = "domande_dom_stati_domanda_id_seq", strategy = GenerationType.SEQUENCE)
#SequenceGenerator(name = "domande_dom_stati_domanda_id_seq", sequenceName = "domande_dom_stati_domanda_id_seq",allocationSize=1)
private Integer id;
#Audited(targetAuditMode = RelationTargetAuditMode.NOT_AUDITED)
#ManyToOne
#JoinColumn(name="id_dom_stato_domanda", nullable=false)
private DomStatoDomanda domandaStatoDomanda;
#Audited(targetAuditMode = RelationTargetAuditMode.NOT_AUDITED)
#ManyToOne
#JoinColumn(name="id_domanda", nullable=false)
private Domanda domande;
#Temporal(TemporalType.DATE)
#Column(name="data_validita")
private Date dataValidita;
#Temporal(TemporalType.TIMESTAMP)
#Column(name="data_registrazione")
private Date dataRegistrazione;
#Temporal(TemporalType.TIMESTAMP)
#Column(name="data_registrazione_fine")
private Date dataRegistrazioneFine;
#Column(length=50)
private String utente;
#Column(length=250)
private String note;
#Audited(targetAuditMode = RelationTargetAuditMode.NOT_AUDITED)
#ManyToOne
#JoinColumn(name="id_ruolo", nullable=false)
private Ruolo ruolo;

Answer 1

JPA/Hibernate queues the operations in its session whenever possible, does not call the database instantly and then just before the transaction is completing, order those operations based on type and execute them. This is called Transactional write-behind in hibernate. As you can see, even though you called the insert last, hibernate will order it as first if it was queued.
Inserts, in the order they were performed
Updates
Deletion of collection elements
Insertion of collection elements
Deletes, in the order they were performed
You can tell hibernate to flush it rather than queue it. So replace repository.save(data) with repository.saveAndFlush(data) so it executes in the order you wanted
Reference
Executions Order