If the entity persisted in transaction is further modified, then the @CreationTimestamp field will become null. Are there any solutions to this problem? Magic hibernate flags? Or do we only have to create the field manually in the @PrePersist method? I also don’t want to flush the data after the persist method, as this is an unnecessary database call.

@Entity
public class MyEntity {
    @Id
    @GeneratedValue(strategy = GenerationType.UUID)
    private String uuid;

    @CreationTimestamp
    private Instant created;

    private String userID;

    public void setUserID(String userID) {
        this.userID = userID;
    }
}

public class TestResource {
    @Inject
    EntityManager entityManager;

    @Transactional
    public void test() {
        MyEntity myEntity = new MyEntity();
        entityManager.persist(myEntity);
        // If this line is executed, the value of "created" will be set to null.
        myEntity.setUserID("userID");
    }
}

insert into MyEntity (created, userID, uuid) values (?, ?, ?)
update MyEntity set created=?, userID=? where uuid=?

created=? - i'm 99% sure 'null' here