Some examples of the criteria API (JPA 2.0)

When I wrote my examples on how to use JavaFX and JPA 2.0 (part II and III), I made some other tries using Criteria API.

Of course, these examples use the table and the entity described in "Examples using JPA 2.0"

Example using like and a JPA parameter

In JPQL

String param = "Arc%";

        Query query = em.createQuery(
             "select m from Music m where m.artisteName like :param");
        query.setParameter("param", param);
        List<Music> musics = query.getResultList();

        for (Music music : musics){
            System.out.println(music);
        }

Equivalent with Criteria API

String param = "Arc%";

        CriteriaBuilder cb = em.getCriteriaBuilder();
        CriteriaQuery<Music> query = cb.createQuery(Music.class);

        Root<Music> music3 = query.from(Music.class);
        query.where(cb.like(music3.<String>get("artisteName"),
                            cb.parameter(String.class, "param")));

        TypedQuery<Music> tq = em.createQuery(query);
        tq.setParameter("param", param);
        List<Music> musics = tq.getResultList();

        for (Music music : musics){
            System.out.println(music);
        }

Example of criteria API using count

In JPQL

String param = "Archive";

        Query query = em.createQuery(
             "select count(m) from Music m where m.artisteName = :artisteNameParam");
        query.setParameter("artisteNameParam", param);
        Long count1 = (Long)query.getSingleResult();

        System.out.println("count : "+count1);

Equivalent with Criteria API

String param = "Archive";

        CriteriaBuilder cb = em.getCriteriaBuilder();
        CriteriaQuery<Long> query = cb.createQuery(Long.class);

        Root<Music> music = query.from(Music.class);
        query.select(cb.count(music));
        query.where(cb.equal(music.<String>get("artisteName"),
                             cb.parameter(String.class,"artisteNameParam")));

        TypedQuery<Long> tq = em.createQuery(query);
        tq.setParameter("artisteNameParam", param);

        Long count = tq.getSingleResult();

        System.out.println("count : "+count);

Example of criteria using distinct

In JPQL

String param = "Arc%";

        Query query = em.createQuery(
             "select distinct m.artisteName from Music m where m.artisteName like :param");
        query.setParameter("param", param);
        List<String> artistes= query.getResultList();

        for (String artiste : artistes){
            System.out.println(artiste);
        }

Equivalent with Criteria API

String param = "Arc%";

        CriteriaBuilder cb = em.getCriteriaBuilder();
        CriteriaQuery<String> query = cb.createQuery(String.class);

        Root<Music> music = query.from(Music.class);
        query.select(music.<String>get("artisteName"));
        query.distinct(true);

        query.where(cb.like(music.<String>get("artisteName"),
                            cb.parameter(String.class, "param")));

        TypedQuery<String> tq = em.createQuery(query);
        tq.setParameter("param", param);

        List<String> artistes = tq.getResultList();


        for (String artiste : artistes){
            System.out.println(artiste);
        }