JPQL: Receiving a Collection in a Constructor Expression

Question

I\'m using JPQL and want to receive some normal parameters and a collection in a Constructor Expression to directly create the DTO-objects. But if the Collection is empty, I

Answer 1

I had a similar problem and tried "Object" in DTO constructor as James suggested, but a child object is passed in and it seems that it is only the first child instead of the expected List/Array of children.

I ended up with a "normal" query creating all the DTOs in a for loop.

TypedQuery query = em.createQuery("SELECT p FROM Parent p", Parent class);
        List list = query.getResultList();
        List result = new ArrayList<>();
        for (Parent p : list)
        {
            DTO dto = new DTO();
            //set dto props and fill collection
            result.add(obj);
        }
        return result;