[hibernate-issues] [JIRA] (HHH-16575) Batch fetch with FlushMode COMMIT overrides/discards dirtied ManyToOne property

Jones ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=557058%... ) *created* an issue Hibernate ORM ( https://hibernate.atlassian.net/browse/HHH?atlOrigin=eyJpIjoiYjI5MzBhZGE1... ) / Bug ( https://hibernate.atlassian.net/browse/HHH-16575?atlOrigin=eyJpIjoiYjI5Mz... ) HHH-16575 ( https://hibernate.atlassian.net/browse/HHH-16575?atlOrigin=eyJpIjoiYjI5Mz... ) Batch fetch with FlushMode COMMIT overrides/discards dirtied ManyToOne property ( https://hibernate.atlassian.net/browse/HHH-16575?atlOrigin=eyJpIjoiYjI5Mz... ) Issue Type: Bug Affects Versions: 6.2.2 Assignee: Unassigned Components: query-hql Created: 09/May/2023 10:14 AM Priority: Critical Reporter: Jones ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=557058%... ) @Entity @Table(name = "ENTITY_A" ) public class EntityA { @Id @GeneratedValue(strategy = GenerationType.AUTO) @Column(name = "ID" ) Integer id; @Column(name = "FOO" ) Integer foo; @JoinColumn(name = "CURRENT_ENTITY_B" ) @ManyToOne EntityB currentEntityB; // not needed for bug report // @OneToMany(mappedBy = "entityA" ) // List<EntityB> listOfEntitiesB = new ArrayList<>(); } @Entity @Table(name = "ENTITY_B" ) public class EntityB { @Id @GeneratedValue(strategy = GenerationType.AUTO) @Column(name = "ID" ) Integer id; @JoinColumn(name = "ENTITY_A" ) @ManyToOne EntityA entityA; } @Override protected void configure(Configuration configuration) { super.configure(configuration); configuration.setProperty(AvailableSettings.SHOW_SQL, Boolean.TRUE.toString()); configuration.setProperty(AvailableSettings.FORMAT_SQL, Boolean.TRUE.toString()); configuration.setProperty(AvailableSettings.DEFAULT_BATCH_FETCH_SIZE, "10" ); configuration.setProperty(HibernateHints.HINT_FLUSH_MODE, FlushMode.COMMIT.name()); } @Test public void hhhXXXXTest() throws Exception { Integer currentBId; try (Session s = openSession()) { Transaction tx = s.beginTransaction(); EntityA entityA1 = new EntityA(); EntityB entityB1 = new EntityB(); entityB1.entityA = entityA1; entityA1.currentEntityB = entityB1; s.persist(entityA1); s.persist(entityB1); s.flush(); entityA1.foo = 123; EntityB entityB2 = new EntityB(); entityB2.entityA = entityA1; entityA1.currentEntityB = entityB2; s.persist(entityB2); currentBId = entityB2.id; List<EntityA> entitiesA = s.createQuery( "select a from EntityA a" , EntityA.class).getResultList(); assertThat(entitiesA).hasSize(1); tx.commit(); } try (Session s = openSession()) { List<EntityA> entitiesA = s.createQuery( "select a from EntityA a" , EntityA.class).getResultList(); assertThat(entitiesA).hasSize(1); assertThat(entitiesA.get(0).foo).isEqualTo(123); assertThat(entitiesA.get(0).currentEntityB.id).isEqualTo(currentBId); } } of course, disabling batch fetch or switching to default flush mode would avoid the issue. The problem happens because the first query loads the EntityA.currentEntityB in a batch load which will use EntityB.entityA to override the parentInstance property. Failing test scenario to be attached ( https://hibernate.atlassian.net/browse/HHH-16575#add-comment?atlOrigin=ey... ) Add Comment ( https://hibernate.atlassian.net/browse/HHH-16575#add-comment?atlOrigin=ey... ) Get Jira notifications on your phone! Download the Jira Cloud app for Android ( https://play.google.com/store/apps/details?id=com.atlassian.android.jira.... ) or iOS ( https://itunes.apple.com/app/apple-store/id1006972087?pt=696495&ct=Em... ) This message was sent by Atlassian Jira (v1001.0.0-SNAPSHOT#100225- sha1:b79b7f6 )