JPAQuery（jpql）从抽象类到具体类的铺设连接

Question

Maybe simple question :

abstract class Contact

class ContactOffice extends Contact

class ContactUser extends Contact

This is the setup, now I'm trying to search for a specific name of office.

new JPAQuery().from(recipient).innerJoin(recipient.recipient(),QContact.contact)

Now I need to lay a link between Contact and ContactOffice.

I tried :

.innerJoin(recipient.recipient(),QContactOffice.contactOffice._super)

But this gives this output :

  inner join treat(notaRecipient.recipient as ContactOffice) as contactOffice

where he complains about the (

any suggestions would be gratefull.

Answer 1

Apparently seems this issue still a little unexplored, or unimplemented.

The solution I opted for is doing a native query in the Repository.
Advantage is that I have the full query under control and normally this would be the fastest way, as I can also skip the T_CONTACT and directly go to T_CONTACT_USER and T_CONTACT_OFFICE, because the id's are unique.

Edit :

While I first got some good results, I got a problem with the in clause because this native query was actually a subquery and could return more then 2000 objects, and the DB driver doesn't allow this.

But there is also good news .

I made the JpaSubQuery to work, you need to make the path's otherwise you can't query with the BooleanBuilder as mine example later on.

new JPASubQuery().from(recipient)
                    .innerJoin(recipient.nota(), QNota.nota)
                    .leftJoin(recipient.recipient().as(QContactUser.class).user(), QLightUser.lightUser)
                    .leftJoin(recipient.recipient().as(QContactOffice.class).office(), QOffice.office)
                    .leftJoin(recipient.recipient().as(QContactExternal.class).external(), QExternal.external)
                    .where(predicateBuilder).distinct()
                    .list(recipient.nota())));

As you can see I can make the links correct and this is how I search :

predicateBuilder.and(recipient.recipient().as(QContactUser.class).user().firstName.containsIgnoreCase(query.getToUser())
                        .or(recipient.recipient().as(QContactUser.class).user().lastName.containsIgnoreCase(query.getToUser())));

Because now the complete query is going to the DB I don't have to worry about the 2000 limit, only performance issues.
But, if you ever need to link an abstract class or interface with implementation, this is how it could be done.