The referenced attributes *are* key attributes .. just a subset of the key. So ... odd mapping ... but I don't think it is included in the "optional" category for JPA 2.x.
Stephen On 05/30/2018 03:39 PM, Sanne Grinovero wrote: > Hi Gail, > > I would not consider it a bug to not have documented that we don't > support some non-mandatory feature. > > And it's still optional in JPA 2.2, so I think we're good. > > Thanks, > Sanne > > > > On 30 May 2018 at 19:45, Gail Badner <gbad...@redhat.com> wrote: >> Hi Vlad, >> >> Thanks for your answer. There are definitely better ways to model this >> association. >> >> WRT the second example, where the referenced columns are a subset of the PK >> columns -- I understand there are better ways to model this. >> >> In particular, since the subset of PK columns needs to be unique (since >> they are the referenced columns of a @JoinColumn), there is no reason for >> any other columns to be in the PK. >> >> My question is more about what the JPA spec says about whether this should >> be supported. >> >> Regards, >> Gail >> >> >> >> >> >> On Wed, May 30, 2018 at 12:47 AM, Vlad Mihalcea <mihalcea.v...@gmail.com> >> wrote: >> >>> Hi, >>> >>> For the OneToMany with @JoinColumn, the user can workaround this >>> limitation by just using the @ManyToOne on the child side on any column >>> they want >>> and turning the unidirectional association into a bidirectional one. I >>> remember I tested it and it worked just fine. >>> >>> For the OneToMany with @JoinTable, the only workaround would be if they >>> map the join table as an entity and use the @ManyToOne on the columns they >>> want >>> the association to be based on. >>> >>> Since unidirectional associations don't perform that well, I'm not sure >>> whether it's worth adding support for these use cases. >>> >>> Vlad >>> >>> On Wed, May 30, 2018 at 9:32 AM, Gail Badner <gbad...@redhat.com> wrote: >>> >>>> Unidirectional OneToMany associations using @JoinColumn that reference >>>> columns that are not PK columns is not currently supported. >>>> >>>> The JPA 2.1 documentation for @JoinTable says: >>>> >>>> "Support for referenced columns that are not primary key columns of the >>>> referenced table is optional. Applications that use such mappings will not >>>> be portable." >>>> >>>> I don't see anything in the user doc that explicitly states that Hibernate >>>> does not support this. >>>> >>>> Is this considered a bug? >>>> >>>> Also, what about a unidirectional OneToMany using a @JoinColumn that >>>> references some, but not all, of primary key columns? Hibernate does not >>>> support that either. Should Hibernate support it since they are primary >>>> key >>>> columns? >>>> >>>> Thanks, >>>> Gail >>>> _______________________________________________ >>>> hibernate-dev mailing list >>>> hibernate-dev@lists.jboss.org >>>> https://lists.jboss.org/mailman/listinfo/hibernate-dev >>>> >>> >> _______________________________________________ >> hibernate-dev mailing list >> hibernate-dev@lists.jboss.org >> https://lists.jboss.org/mailman/listinfo/hibernate-dev > _______________________________________________ > hibernate-dev mailing list > hibernate-dev@lists.jboss.org > https://lists.jboss.org/mailman/listinfo/hibernate-dev _______________________________________________ hibernate-dev mailing list hibernate-dev@lists.jboss.org https://lists.jboss.org/mailman/listinfo/hibernate-dev
