Re: [hibernate-dev] Bidirectional one-to-one, both sides are owners, using @PrimaryKeyJoinColumn

Hi Gail, The mapping is IMO invalid. For removal etc. to work properly, the direction needs to be deducible. However, I’ve observed this mapping as a workaround for supporting lazy loading on either side of the association, prior to our fixes in 5.4 with HHH-12842 [1] . The mapping works in my experience, but with quirks that are to be expected. With Hibernate 5.4 there is no reason to map this at all: if the association is non-optional and non-nullable, also the non-owning side of the association can be lazy loaded. Kind regards, Jan-Willem [1] https://github.com/hibernate/hibernate-orm/pull/2612 On 15 Jan 2020, at 05:18, Gail Badner <gbadner@redhat.com<mailto:gbadner@redhat.com>> wrote: Hi, Does Hibernate support having both entities involved in a one-to-one association own its side of the association when using @PrimaryKeyJoinColumn? My guess is that this is not supported by Hibernate. I just want to confirm. For example: @Entity public class Employee { @EmbeddedId private CompositeKey id; @OneToOne(optional = false) @PrimaryKeyJoinColumns({ @PrimaryKeyJoinColumn(name = "ID1", referencedColumnName = "ID1"), @PrimaryKeyJoinColumn(name = "ID2", referencedColumnName = "ID2"), }) }) private EmployeeInfo employeeInfo; ... } @Entity public class EmployeeInfo { @EmbeddedId private CompositeKey id; @OneToOne(optional = false) @PrimaryKeyJoinColumns({ @PrimaryKeyJoinColumn(name = "ID1", referencedColumnName = "ID1"), @PrimaryKeyJoinColumn(name = "ID2", referencedColumnName = "ID2"), }) }) private Employee employee; ... } In this particular case, the foreign keys have been deleted, so it's possible to load and delete these entities. An attempt to insert an entity on either side results in: org.hibernate.PropertyValueException: not-null property references a null or transient value When converted to use @MapsId and @JoinColumns instead, Hibernate throws: org.hibernate.MappingException: cyclic dependency in derived identities Please let me know... Thanks, Gail _______________________________________________ hibernate-dev mailing list hibernate-dev@lists.jboss.org<mailto:hibernate-dev@lists.jboss.org> https://lists.jboss.org/mailman/listinfo/hibernate-dev