i have 2 classes that iherit from the main class
each class has associations with ohter class (Intervenant).
i wrote my file hbm for the main class (i use joined-subclass..)

public class MyAction implements Serializable {

private Integer id_action = null;
....}
public class MyActionIndividuelle extends MyAction implements Serializable {

private Intervenant intervenant ;
....
}
public class MyActionGroupe extends MyAction implements Serializable {

private Set participants = new HashSet();
private Intervenant responsable ;...}

public class Intervenant implements Serializable {

private Integer id_intervenant = null;
....
private Set actionsgroupe = new HashSet();
private Set actionsindividuelle = new HashSet();
private Set actionsGResponsable = new HashSet();}

the problem is:
when i use

Query query = session.createQuery(
"select elements(interv.actionsindividuelle) from com.cosoftware.Intervenant interv join interv.actionsindividuelle as indiv where indiv.id_action=2 and interv.id_intervenant=1 ");
return query.list();

in a class IntervenantManager that not retrieve the right information from DB (Mysql)

Thanks for all helps.