JPA association without foreign key

Question

Is it possible to set up a ManyToOne association without JPA creating a foreign key in the database?

The tables are owned by another system and are populated asynchr

Answer 1

The fact that ConstraintMode.NO_CONSTRAINT is ignored looks like a bug in Hibernate 4 due to be fixed in 5.

https://hibernate.atlassian.net/browse/HHH-8805

The comments on that and indeed this post here:

Multiple relationships with single mapping table without generating foreign keys by Hibernate

suggest adding the deprecated (hibernate rather than JPA) annotation

@ForeignKey( name = "none" )

to the relationship should work.