Hibernate createQuery(".....")的几种不同用法

String category = "abc";//顺便写

 

//第一种:
            Query query = em.createQuery("from Product as p where p.category = ?1"); 
            query.setParameter(1, category);
//第二种:
            Query query = session.createQuery("from test.Product product whereproduct.category=?");
            query.setString(0, category);


//第三种:
         Query query = em.createQuery("from Product as p wherep.category = :category");
           query.setParameter("category", category);

//第4种:
         Query query = em.createQuery("select p  from Product p where p.id in (:ids)");
           query.setParameter("ids", category);