Question

public enum ReportStatus { 
    SUCCCEED, FAILED;
}

public class Work {
    @ElementCollection
    @Enumerated(EnumType.STRING)
    List<ReportStatus> reportStatuses;
}

Given the following structure, I’d like to perform a query to find all the work filtered by reportStatuses. It works fine with the following hql syntax :

public List<Long> queryHQL() {
    final String query = "SELECT w.id FROM Work w JOIN w.reportStatuses s WHERE s in (:rs)";

    final List<ReportStatus> reportStatuses = new ArrayList<ReportStatus>();
    reportStatuses.add(ReportStatus.FAILED);

    return this.entityManager.createQuery(query).setParameter("rs", reportStatuses).getResultList();
}

But I’d like to use the criteria API (jpa2), and can’t figure out how to do it. Here is my closest try I think :

public List<Long> query() {
    final List<ReportStatus> reportStatuses = new ArrayList<ReportStatus>();
    reportStatuses.add(ReportStatus.FAILED);

    final CriteriaBuilder builder = this.entityManager.getCriteriaBuilder();

    final CriteriaQuery<Long> criteriaQuery = builder.createQuery(Long.class);
    final Root<Work> workModel = criteriaQuery.from(Work.class);

    final ListJoin<Work, ReportStatus> status = workModel.joinList("reportStatuses");

    final Predicate predicate = status.in(reportStatuses);

    criteriaQuery.where(predicate);
    criteriaQuery.select(workModel.<Long> get("id"));

    return this.entityManager.createQuery(criteriaQuery).getResultList();
}

I’ve also tried with the hibernate criteria API, but as the jpa2 one I’ve failed to find the correct the syntax.

Answer 1

I would use following CriteriaQuery syntax for doing the same thing.

EntityManager em = entityManagerFactory.createEntityManager();

final List<ReportStatus> reportStatuses = new ArrayList<ReportStatus>();
reportStatuses.add(ReportStatus.FAILED);

final CriteriaBuilder builder = em.getCriteriaBuilder();

final CriteriaQuery<Long> criteriaQuery = builder.createQuery(Long.class);
final Root<Work> _work = criteriaQuery.from(Work.class);

/*final ListJoin<Work, ReportStatus> status = _work.joinList("reportStatuses");
final Predicate predicate = status.in(reportStatuses);
criteriaQuery.where(predicate);*/

final Expression<List<ReportStatus>> _status = _work.get(Work_.reportStatuses);
_status.in(reportStatuses);

criteriaQuery.select(_work.get(Work_.id));

List<Long> list =  em.createQuery(criteriaQuery).getResultList();

UPDATE

Thanks, but we do not use the
generated metamodel. So unfortunately
I can’t try with your answer. 🙁

If you don’t use Metamodel, just replace _work.get(Work_.reportStatuses) with _work.get("reportStatuses"). It’ll work. 🙂