Question

In short: A user has many “not clients” (these are the clients the user cannot serve). User is associated to multiple clients through a join table.

User class: https://gist.github.com/dd99690fcaaba2c834d6

Client class: https://gist.github.com/10de71bcd1914ded5fb9

DAO: https://gist.github.com/dd4a369d60a05460d0c0

the “notClients” attribute in User is always null, can anyone help me understand why?

Answer 1

In short, because you’re not including it in your select query. Not sure why you’re writing out SQL queries and using the bean transformer? That’s a very strange way to use hibernate. In the end it means what you’re getting back is not a hibernate managed entity. It’s just an object with the specific stuff that you selected mapped onto it.

The “normal”/”correct” way to use hibernate would be something like this:

private User getUser(int id, String userType)
{
    User result;

    session = HibernateUtil.getWilsonsSessionFactory().getCurrentSession();
    session.beginTransaction();

    Query query = session.createQuery("select u from User u 
                                       where u.id = :id and u.role = :role");
    query.setParameter("id", id);
    query.setParameter("role", userType);

    result = (User)query.uniqueResult();

    session.getTransaction().commit();

    return result;  
}

Then what you get back is an Hibernate entity that will have all its mapped properties populated.

(would not personally use uniqueResult in that way either, but I am willing to admit that is largely a style preference.)