From my little and personal experience, if you search for an object on your repo, for example by Id or Name the named query method returns an object of type T, but if no results are found from your repo, it will return null. Methods that can return more than one element, will produce an … Read more
Change your code likes this; int count = ((Number)em.createNamedQuery(“Charakteristika.findAllCount”).getSingleResult()).intValue(); System.out.println(count);
As mentioned in a different answer to the question referenced previously, the following HQL construct works for me: select o from Product o WHERE :value is null or o.category = :value if :value is passed in as null, all Products are returned. See also Optional or Null Parameters Note that this won’t work in some … Read more
You can’t have the % in the NamedQuery, but you can have it in the value you assign the parameter. As in: String city = “needle”; query.setParamter(“city”, “%” + city + “%”);
I’m not sure for JPA 1.0 but you can pass a Collection in JPA 2.0: String qlString = “select item from Item item where item.name IN :names”; Query q = em.createQuery(qlString, Item.class); List<String> names = Arrays.asList(“foo”, “bar”); q.setParameter(“names”, names); List<Item> actual = q.getResultList(); assertNotNull(actual); assertEquals(2, actual.size()); Tested with EclipseLInk. With Hibernate 3.5.1, you’ll need to … Read more