Alexander Schwartz ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=6267ec4... ) *created* an issue Hibernate ORM ( https://hibernate.atlassian.net/browse/HHH?atlOrigin=eyJpIjoiMjExYTEyOTEz... ) / Bug ( https://hibernate.atlassian.net/browse/HHH-16368?atlOrigin=eyJpIjoiMjExYT... ) HHH-16368 ( https://hibernate.atlassian.net/browse/HHH-16368?atlOrigin=eyJpIjoiMjExYT... ) UnsupportedOperationException: compare() not implemented for EntityType ( https://hibernate.atlassian.net/browse/HHH-16368?atlOrigin=eyJpIjoiMjExYT... ) Issue Type: Bug Affects Versions: 6.2.0.CR4 Assignee: Unassigned Components: hibernate-core Created: 24/Mar/2023 10:29 AM Priority: Major Reporter: Alexander Schwartz ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=6267ec4... ) An example from migrating from H5 to H6 for Keycloak. This happens with Hibernate 6.2.CR4, and used to work with Hibernate 5: * In Quarkus, the default is hibernate.order_updates is set to true in FastBootMetadataBuilder * Given updating two entities with a compsite key / IdClass which references its parent entity, it tries to compare the EntityKey, which fails in H6, but worked in H5 * On flush, the comparison fails with the exception shown below when Hibernate tries to sort the updates There is a reproducer here: https://github.com/ahus1/hibernate-test-case-templates/tree/is-HHH-xxxx-c... ( https://github.com/ahus1/hibernate-test-case-templates/tree/is-HHH-xxxx-c... ) Discussed on the Zulip chat here: https://hibernate.zulipchat.com/#narrow/stream/132096-hibernate-user ( https://hibernate.zulipchat.com/#narrow/stream/132096-hibernate-user ) java.lang.UnsupportedOperationException: compare() not implemented for EntityType at org.hibernate.type.EntityType.compare(EntityType.java:255) at org.hibernate.type.ComponentType.compare(ComponentType.java:215) at org.hibernate.type.Type.compare(Type.java:222) at org.hibernate.action.internal.EntityAction.compareTo(EntityAction.java:160) at org.hibernate.action.internal.EntityAction.compareTo(EntityAction.java:28) at org.hibernate.engine.spi.ExecutableList.add(ExecutableList.java:225) at org.hibernate.engine.spi.ActionQueue.addAction(ActionQueue.java:311) at org.hibernate.engine.spi.ActionQueue.addAction(ActionQueue.java:353) at org.hibernate.event.internal.DefaultFlushEntityEventListener.scheduleUpdate(DefaultFlushEntityEventListener.java:252) at org.hibernate.event.internal.DefaultFlushEntityEventListener.onFlushEntity(DefaultFlushEntityEventListener.java:143) at org.hibernate.event.service.internal.EventListenerGroupImpl.fireEventOnEachListener(EventListenerGroupImpl.java:127) at org.hibernate.event.internal.AbstractFlushingEventListener.flushEntities(AbstractFlushingEventListener.java:221) at org.hibernate.event.internal.AbstractFlushingEventListener.flushEverythingToExecutions(AbstractFlushingEventListener.java:90) at org.hibernate.event.internal.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:38) at org.hibernate.event.service.internal.EventListenerGroupImpl.fireEventOnEachListener(EventListenerGroupImpl.java:127) at org.hibernate.internal.SessionImpl.doFlush(SessionImpl.java:1412) at org.hibernate.internal.SessionImpl.flush(SessionImpl.java:1398) at org.hibernate.bugs.ORMUnitTestCase.hhh123Test(ORMUnitTestCase.java:115) ( https://hibernate.atlassian.net/browse/HHH-16368#add-comment?atlOrigin=ey... ) Add Comment ( https://hibernate.atlassian.net/browse/HHH-16368#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#100219- sha1:ac3e918 )