Hello guys, I have some trouble with Hibernate. I use the following mapping : @Entity public class Candidacy { @ManyToOne(optional = false) @ForeignKey(name = "fk_candidacy_team") private Team team; } @Entity public class Team { @OneToMany(mappedBy = "team") @OnDelete(action = OnDeleteAction.CASCADE) private final Collection<Candidacy> candidacies; } When I want to create a new candidacy, I use the current code : public class CandidacyDao { public Candidacy apply(Team team) { Candidacy candidacy = new Candidacy(); candidacy.setTeam(team); team.getCandidacies().add(candidacy); getCurrentSession().save(candidacy); return candidacy; } } But this code doesn't work in all case. This test case don't works : @Test public void testFail() { final Team team = this.teamDao.get(1); // team created from dbunit final Candidacy candidacy = this.apply(team); assertThat(team.getCandidacies()).hasSize(1).contains(candidacy); // java.lang.AssertionError: expected size:<1> but was:<2> // for <[Candidacy@70dc0648, Candidacy@70dc0648]> } Note the duplicated candidacy on the list at the end. After a (lot of) debug, I understand why : public class org.hibernate.collection.PersistentBag { public boolean add(Object object) { if ( !isOperationQueueEnabled() ) { write(); return bag.add(object); } else { queueOperation( new SimpleAdd(object) ); return true; } } protected boolean isOperationQueueEnabled() { return !initialized && isConnectedToSession() && isInverseCollection(); } } So, « team.getCandidacies() » is not previously resolved (lazy-loaded) before the « .add(candidacy) », and even this « .add » doesn't trigger the resolution (write access) and postpone it when the « .getCandidacies() » will be really read (on « assert »). At « assert » time, the children are really resolved, so a SELECT is done in database, fetch all the candidacies including the newly created, and realize the real addition, leading to a duplicated one. If I force the « .getCandidacies() » or create directly the team from the test, all is good : @Test public void testSuccess1() { final Team team = this.teamDao.get(1); this.logger.debug("{}", team.getCandidacies()); // force the read final Candidacy candidacy = this.apply(team); assertThat(team.getCandidacies()).hasSize(1).contains(candidacy); } @Test public void testSuccess2() { final Team team = new Team(); getCurrentSession().save(team); // native initialization final Candidacy candidacy = this.apply(team); assertThat(team.getCandidacies()).hasSize(1).contains(candidacy); } If I remove the « .add » on the DAO, the behaviour is the opposite : — If lazy-loaded before the « .apply », failure at the end because the candidacy is not in the list of the team. — If not, test success because the « assert » will trigger the resolution, but with no « .add » this time so no duplicate and correct list (fetch from db). So, my question is : how I can keep in sync the database and the java entity state in case of children and reverse relation, in any case (previously lazy-loaded or not) ? :'( Thanks in advance. -- Aeris