Hibernate检查集合中相同的所有元素

Question

I have two entities ie Person and Activity. Activity has property status and Person entity contains collection of activities. I'd like to get a list of persons that have all activities with status 'Done'.

   Criteria crit = s.createCriteria(Person.class);
   crit.createAlias("activities", "act").add(Restrictions.eq("act.status","Done"));

But this return all object with at least one activity with status done. I 'd like to retrive list of person with all activities status set to Done. Can anyone help me?

Answer 1

Think in negate it. Retrieve those whose have activities and none is in state different of Done . Then you can simply add the maxResults() or list.get(0) (Bear in mind that might contain no person).

Answer 2

// open hibernate session
Query query = session.createQuery("Select p from Persons p inner join p.activities a where a.status = :code");
query.setParameter("code", "Done");
List results = query.list();

// close session

for (int i = 0; i < results.size(); ){
  Person person = results.get(i);
  List<Activity> activities = person.getActivities();
  for (int j = 0; j < activities.size(); j++){
    if (!activities.code.equals("Done")){
      results.remove(i);
      break;
    } // end if
  } // end for j
  i++;
} // end for i

This should do the trick. Note that if you have lazy load, you may need to add "fetch" keyword in your Hibernate query. Here is a useful link for joins: http://docs.jboss.org/hibernate/orm/3.3/reference/en/html/queryhql.html#queryhql-joins

Answer 3

Here is how you can do it with Criteria :

Criteria crit = s.createCriteria(Person.class);

DetachedCriteria sub = DetachedCriteria.forClass(Person.class);
sub.createAlias("activities","act");
sub.add(Restrictions.ne("act.status","Done"));
sub.setProjection(Projections.property("id");

crit.add(Property.forName("id").notIn(sub);

Kinda late but I hope I can help someone who still struggles with this as I did.