Hello Akshaya Gawand, thank you very much for the reproducers.

Looks like the error in Hibernate 6 is caused by the @Id annotations on the InProcessRefSeqNoId class that is used as @IdClass that cause the foreign key constraint to be generated with a wrong order of columns. Simply removing those annotations, which by the way are not needed since it’s already an @IdClass so they have no effect, should solve your problem.

Let me know if that works for you so I can close the issue.