Prevent update on cross-refrence table Hibernate

[zabet tyan]

Hi

I have the following problem:

I have an Activity class that maps to table activity.


I have a Profile class that maps to profile table. Everytime the profile is updated I create a ProfileHistory object and save it in profile_history table.

The history should never be modified.

Now in special cases I want to associate the Activity with ProfileHistory in activity_profile_history_xref table which only saves the id of the activity and profile_history:

activity_profile_history_xref table:
activity_id
profile_history_id

Here is the related hbm file in Activity :

 <set cascade="save-update" name="matchedProfiles" inverse="false"
lazy="false" table="activity_profile_history_xref">
<key>
<column name="activity_id" not-null="true" />
</key>
<many-to-many
entity-name="some.test.ProfileHistory">
<column name="profile_history_id" not-null="true" />
</many-to-many>
</set>

Now here is the problem:

profileHistory has an attribute Facility. ProfileHistory objects could be pointing to the same Facility object.

Hence when I retrieve multiple profileHistory objects that point to the same Facility object and associate them to Activity and then save the Activity object, I get

a different object with the same identifier value was already associated with the session [for Facility object]


And the problem is that hibernate is trying to update the profileHistory, while nothing has changed on the profileHistory side ( I can tell from the hibernate sql statements).

Is there a way to force hibernate to just update the Activity object?

So far my only solution was to do something like this:

for (ProfileHistory p : profileHistories)
{
Query q = HibernateUtil
.getCurrentSession()
.createSQLQuery(
"insert into activity_profile_history_xref values (:activityId, :profileHistoryId)");
q.setLong("activityId", activity.getId);
q.setLong("profileHistoryId", p.getId());
q.executeUpdate();
}

Could someone suggest a better way?


Thanks in advance.

[zabet tyan]

I used merge() and everything seems ok now. But the question remains...why does hibernate update something that hasn't changed?!