Bidirectional Relationship Persistence - orphanRemoval not working as expected

[yankydoo]

Describe the bug

When clearing collections on both sides of a bidirectional relationship within the same transaction without an intermediate persistAndFlush(), relationship entities are not properly removed from the database.

ProjectEntity has

    @OneToMany(mappedBy = "id.sourceProject", cascade = CascadeType.ALL, orphanRemoval = true)
    List<ProjectRelationship> outgoingRelationships = new ArrayList<>();
    @OneToMany(mappedBy = "id.targetProject", cascade = CascadeType.ALL, orphanRemoval = true)
    List<ProjectRelationship> incomingRelationships = new ArrayList<>();

after creating three projects and connecting them (pe1 -> pe2 -> pe3) I use the following code to disconnect pe2 from pe1 and pe3:

        ProjectEntity project = ProjectEntity.findById(pe2Id);
        project.outgoingRelationships.clear();
        // without the following line, it doesnt work
        // project.persistAndFlush();
        project.incomingRelationships.clear();
        project.persist();

Expected behavior

Clearing collections on both sides of a bidirectional relationship within the same transaction without an intermediate persistAndFlush(), should properly remove entities from the database.

Actual behavior

It seems that only for the collection that was cleared last (incomingRelations) the orphanRemoval works as expected.

How to Reproduce?

I created a repo to reproduce the bug: https://github.com/yankydoo/repro-hibernate-extended-many-to-many-orphan-removal/tree/main

Execute the only test to reproduce it

Output of uname -a or ver

No response

Output of java -version

Java version: 21.0.6, vendor: Amazon.com Inc., runtime: /Users/.../Library/Java/JavaVirtualMachines/corretto-21.0.6/Contents/Home

Quarkus version or git rev

3.19.4

Build tool (ie. output of mvnw --version or gradlew --version)

Apache Maven 3.9.9 (8e8579a9e76f7d015ee5ec7bfcdc97d260186937

Additional information

No response

[quarkus-bot]

/cc @gsmet (hibernate-orm)

[lucamolteni]

Thanks for the reproducer

This is a weird behaviour from the cascade removal of the relationship side, I'll investigate and open a bug in Hibernate.

Just a suggestion on the way you're using Hibernate: calling .persist() on a managed-object (that is, an object returned by em.find()) doesn't make sense because it's already persisted, so in a transactional method every changes you're making to the ProjectRelationship objects should be reflected accordingly.

I'd rewritten the test case like this so that you avoid relying on cascading and instead you have full control on what exactly is executed. Note that disconnectProjects doesn't call neither persist or flush anymore, that is how it should worked. I also used getReference instead of find to avoid one select query.

This should work as a workaround

    @Inject
    EntityManager em;

   @Test
    void run() {
        Long pe2Id = createAndConnectProjects();

        disconnectProjects(pe2Id);

        ProjectEntity pe2 = ProjectEntity.findById(pe2Id);
        assertTrue(pe2.incomingRelationships.isEmpty());
        assertTrue(pe2.outgoingRelationships.isEmpty());
    }

    @Transactional
    void disconnectProjects(Long id) {
        ProjectEntity project = em.getReference(ProjectEntity.class, id);
        em.createQuery(
                        "delete from ProjectRelationship pe " +
                                "where pe.id.sourceProject = :entity or " +
                                "pe.id.targetProject = :entity ")
                .setParameter("entity", project)
                .executeUpdate();
    }

[yankydoo]

Thanks a lot for investigating and also thanks for the workaround! Can you please link the issue you created in Hibernate? I'd like to follow it there but I'm unable to find it

[lucamolteni]

Thanks a lot for investigating and also thanks for the workaround! Can you please link the issue you created in Hibernate? I'd like to follow it there but I'm unable to find it

https://hibernate.atlassian.net/jira/software/c/projects/HHH/boards/31?selectedIssue=HHH-19367