TypedQuery<x> returns vector of Object[] instead of list of x-type object

Question

I have a method:

public List<Timetable> getTimetableTableForRegion(String id) {
        List<Timetable> timetables;
        TypedQuery<Timetable> query = em_read.createQuery("SELECT ..stuff.. where R.id = :id", Timetable.class).setParameter("id", Long.parseLong(id));
        timetables = query.getResultList();

        return timetables;
    }

which returns this:

so, what am I missing in order to return a list of Timetable's?

Answer 1

ok, so, ..stuff.. part of my JPQL contained an inner join to other table. Even through in SELECT there were selected fields just from one table, which was used as type - Timetable, Eclipslink was unable to determine if this fields are part of that entity and instead of returning list of defined entity returned list of Object[].

So in conclusion: Use @OneToMany/@ManyToOne mappings (or flat table design) and query just for ONE table in your JPQL to be able to typize returned entities.

Answer 2

Not sure it might be something is looking for, but I had similar problem and converted Vector to ArrayList like this:

    final ArrayList<YourClazz> results = new ArrayList<YourClazz>();;
    for ( YourClazzkey : (Vector<YourClazz>) query.getResultList() )
    {
        results.add(key);
    }

Answer 3

i have faced the same problem. and my entity has no one to one or one to many relationship. then also jpql was giving me queryresult as vector of objects. i changed my solution to query to criteria builder. and that worked for me. code snippet is as below:

    CriteriaBuilder builder = this.entityManager.getCriteriaBuilder();
    CriteriaQuery<Timetable> criteria = builder.createQuery(Timetable.class);
    Root<Enumeration> root = criteria.from(Timetable.class);
    criteria.where(builder.equal(root.get("id"), id));
    List<Timetable> topics = this.entityManager.createQuery(criteria)   .getResultList();
    return topics;