one-to-one save an already saved object

emmanuel · **Posted:** Tue Dec 23, 2003 11:47 am

I'm having some trouble whith Hibernate 2.0.3

Here is the case.
I have a mono-directional one-to-one relationship with a foreign generator.
I save the non mapped side object in one session, close it
Then I save the mapped side object and hibernate recreate a new non-mapped side object. I can't understand why.
Here are some materials

Code:

session = sf.openSession();
Transaction tx = session.beginTransaction();
Dumb dumb = new Dumb();
session.save(dumb);
tx.commit();
session.close();
Long oldDumbId = dumb.getId(); //copy id
        
//new session        
session = sf.openSession();
tx = session.beginTransaction();
Dumber dumber = new Dumber();
dumber.setDumb(dumb);
session.save(dumber);
tx.commit();
session.close();
assertEquals(oldDumbId, dumb.getId()); //this fail, actually a new dumb is inserted in DB with a new id

the previous code with session.saveOrUpdate(dumb); before session.save(dumber); works.

Here is the mapping

Code:

<hibernate-mapping>
  <class name="sample.Dumb" table="dumb">

    <id name="id" column="id" type="long" unsaved-value="null">
      <generator class="sequence">
        <param name="sequence">SEQ_DEFAULT</param>
      </generator>
    </id>
  </class>
</hibernate-mapping>

<hibernate-mapping>
  <class name="sample.Dumber" table="dumber">

    <id name="id" column="id" type="long" unsaved-value="null">
      <generator class="foreign">
        <param name="property">dumb</param>
      </generator>
    </id>
   <one-to-one class="sample.Dumb" constrained="true" name="dumb"/>
  </class>
</hibernate-mapping>

Is this the expected behavior ? Why hibernate does not execute a saveOrUpdate() on dumb instead of save() when saving dumber ?

gavin · **Posted:** Wed Dec 31, 2003 6:45 am

Submit to JIRA.

emmanuel · **Posted:** Wed Dec 31, 2003 11:44 am

I dug the subject and found that it was solved in the 2.1 familly (using getEntityIdentifierIfNotUnsaved() in the foreign generator instead of brutal save()).
This is a minor and very rare issue, I don't know if it's useful to backport the 2.1 fix.

alex.shn · **Joined:** Mon Jan 12, 2004 3:25 pm **Posts:** 9

I have the same situation except my direction needs to go the other way.
So I would have a mapping like:

Code:

<hibernate-mapping> 
  <class name="sample.Dumb" table="dumb"> 

    <id name="id" column="id" type="long" unsaved-value="null"> 
      <generator class="sequence"> 
        <param name="sequence">SEQ_DEFAULT</param> 
      </generator> 
    </id> 

    <one-to-one class="sample.Dumber" constrained="false"  name="dumber" cascade="all" /> 

  </class> 
</hibernate-mapping> 

<hibernate-mapping> 
  <class name="sample.Dumber" table="dumber"> 

    <id name="id" column="id" type="long" unsaved-value="null"> 
      <generator class="foreign"> 
        <param name="property">dumb</param> 
      </generator> 
    </id> 
  </class> 
</hibernate-mapping>

the foreign generator does not make sense anymore, but I was wondering how would I go about setting this relation?
How would I tell hibernate to fill the id of the Dumber?

Does anyone have a clue?

Thanks,
Alex.[/quote]

michael · **Posted:** Mon Jan 12, 2004 4:46 pm

Use foreign generator in Dumb, and sequence in Dumber I'd say

alex.shn · **Joined:** Mon Jan 12, 2004 3:25 pm **Posts:** 9

Makes sense, but my assocation is 1 (Dumb) to 0..1 (Dumber) and solution you suggest will break in case there are 0 Dumber for a Dumb.

Any other suggestions?

Thanks,
Alex.

emmanuel · **Posted:** Mon Jan 12, 2004 9:20 pm

Set a bi-dir

alex.shn · **Joined:** Mon Jan 12, 2004 3:25 pm **Posts:** 9

that is what I did for now,
but I really only need one direction

it is quite strange, a simple thing like
this is hard to describe. I guess I can
complain to the "authorities" :-)

Thanks,
Alex.