Hibernate native query creation returns empty result

I have this method in my DAO class:

public List<Protocolo> buscarProtocolos(int situacao){

    List<Protocolo> protocolos = null;
    protocolosPorSitucao = null;
    String sql = "select * from hibernatedb.protocolo where situacao_id = ?";

    em = HibernateManager.getEntityManager();
    protocolosPorSitucao = em.createNativeQuery(sql, Protocolo.class);
    protocolosPorSitucao.setParameter(1, situacao);

    em.getTransaction().begin();
    logger.info("Buscando protocolos por situacao : "+ situacao);
    protocolos = (List<Protocolo>) protocolosPorSitucao.getResultList();
    logger.info("Protocolos encontrados: "+protocolos.size());
    em.getTransaction().commit();
    em.close();

    return protocolos;
}

      

        
        
        
      

    

This query select * from hibernatedb.protocolo where situacao_id = 1

returns one row when executed in pgAdmin3, but hibernate returns 0 rows. Here's the log generated from hibernation:

Hibernate: select * from hibernatedb.protocolo where situacao_id = ?
0

      

        
        
        
      

    

This means hibernate returned 0 results because my list is empty.

Where is the error in this code?

PS: when creating NativeQueries, I also need to install the database. Is this because NativeQuery ignores configs set in persistence.xml

?