ORDER BY Not Working in JPQL Query

Question

I have the following method that returns a HashMap based on a Users Department and Building. I want to ORDER BY ASC based on the user name

private HashMap<Long, String> getCriticalPde(long departmentId, long buildingId) {
    HashMap<Long, String> map = new HashMap<Long, String>();
    Query query = emf
        .createEntityManager()
        .createQuery(
            "SELECT parent FROM Table1 parent WHERE parent.id NOT IN "
            + "(SELECT chldQry.userId FROM Table2 chldQry "
            + "WHERE chldQry.departmentId = :departmentId "
            + "AND chldQry.buildingId = :buildingId)"
            + "ORDER BY parent.userName ASC");
        query.setParameter("departmentId", departmentId);
        query.setParameter("buildingId", buildingId);
        List<User> list= (List <User>) query.getResultList();
        for (User user : userList) {
            map .put(user.getId(), user.getName());
        }
    return map;
}

However when my map is returned it remains ordered by UserId. This script does ORODER BY correctly when ran in Toad/Squirrel/etc. Any ideas?

Answer 1

You are loosing the order because you are using a HashMap, which does not guaratee the order of iteration. Try using a LinkedHashMap instead, it will preserve the original order.

Answer 2

The order by definately works, what doesn't is the HashMap . Hashmaps don't preserve insert order. Use a LinkedHashMap instead

Answer 3

You are retrieving an ordered resultlist and then storing in in an UNordered hashmap. Use an ordered collection to store the users.