Hibernate: 
    select
        formation0_.FORMATION_ID as FORMATION1_0_0_,
        formation0_.FORMATION_THEME as FORMATION3_0_0_,
        formation0_.DATE_DEBUT as DATE4_0_0_,
        formation0_.duree as duree0_0_,
        formation0_.lieu_id as lieu6_0_0_,
        formation0_.nbEntreprises as nbEntrep7_0_0_,
        formation0_.niveauPersonalisationSupports as niveauPe8_0_0_,
        formation0_.type_formation as type2_0_0_ 
    from
        FORMATIONS formation0_ 
    where
        formation0_.FORMATION_ID=?
Hibernate: 
    select
        formation0_.FORMATION_ID as FORMATION1_0_0_,
        formation0_.FORMATION_THEME as FORMATION3_0_0_,
        formation0_.DATE_DEBUT as DATE4_0_0_,
        formation0_.duree as duree0_0_,
        formation0_.lieu_id as lieu6_0_0_,
        formation0_.nbEntreprises as nbEntrep7_0_0_,
        formation0_.niveauPersonalisationSupports as niveauPe8_0_0_,
        formation0_.type_formation as type2_0_0_ 
    from
        FORMATIONS formation0_ 
    where
        formation0_.FORMATION_ID=?
Exception in thread "main" org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session: [com.objis.demohibernate.complexe.FormationInter#3]
	at org.hibernate.engine.StatefulPersistenceContext.checkUniqueness(StatefulPersistenceContext.java:613)
	at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.performUpdate(DefaultSaveOrUpdateEventListener.java:307)
	at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsDetached(DefaultSaveOrUpdateEventListener.java:246)
	at org.hibernate.event.def.DefaultUpdateEventListener.performSaveOrUpdate(DefaultUpdateEventListener.java:56)
	at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:93)
	at org.hibernate.impl.SessionImpl.fireUpdate(SessionImpl.java:592)
	at org.hibernate.impl.SessionImpl.update(SessionImpl.java:580)
	at org.hibernate.impl.SessionImpl.update(SessionImpl.java:572)
	at com.objis.demohibernate.DemoHibernate.demoMerge(DemoHibernate.java:152)
	at com.objis.demohibernate.DemoHibernate.main(DemoHibernate.java:29)