hi,

I really don't get it:

Assume I want to model a simple parent/child one to many association on a single class. A Person can have multibe SubPersons and a single SuperPerson.

Person.hbm:
<set
name="subPeople"
lazy="true"
inverse="false"
cascade="none"
>

<key
column="SUPER_PERSON_FK"
/>

<one-to-many
class="PersonStub"
/>
</set>

<many-to-one
name="superPerson"
class="PersonStub"
cascade="none"
outer-join="auto"
update="true"
insert="true"
column="SUPER_PERSON_FK"
/>

My problem is:
<code>
hibSession = hibFactory.openSession();
Person super = (Person) hibSession.load(Person.class, "A");
Person sub = (Person) hibSession.load(Person.class, "B");

sub.setSuperPerson(super);

if (sub.getSuperPerson().equlas(super))
logger.debug("that works fine");
if (!super.getSubPerson().contains(sub))
logger.debug("and that does not!");

hibSession.close();
</code>


When closing and opening a new Session it works fine!
What am I doing wrong? Do I have to set inverse to true? (caus' hibReference sais: "Changes made only to the inverse end of the association are not persisted.") Do I have to use cascade=updateOrSave?

I REALLY don't get it, can anyone explain cascade/inverse to me?

thnak you
marie

If you want to associate the objects, you of course have to set both sides of the association manually!

How should this

ever work, that is just java.

You have to do:

well, mhh, yes, sounds logical.

maybe i hoped that hibernate is intelligent enough to compensate my missing one :()
no, honest: after I call hibSession.save(...) I assumed that all objects were up to date. but setting both sides of the relation is maybe the easiest way. but the following problem arises: if I have a new entity and I call save() on the associated, existing entity, an Exception (unsaved entity, or s.th.) is thrown. thiswhy I wanted to avoid setting both sides.

Ok, sure, answer is: call save() on the new created entity first, but I can't. Assume the following:

static loadValues(): alters data of an entity, maybe creates a new object, maybe creates a new associated object.

save(): calls hibSession.save() on the existing entity (this), and than save() of all associated objects.

a) If loadValues() creates a new object, save() has to call hibSession.save(this) first and than hibSession.save(all associated objects).
but:
b) If loadValues() creates a new associated objects, save() has to call hibSession.save(all associated objects) first!
c) maybe both are newly created!

If I would not have to set both sides, I could call this.save() without having troubles with "unsaved entities", because the relation would not have been set explicitly.
Yes, I no, if hibernat would do manage both-side setting, I propably would have the same problem.

maybe the solution is s.th. completly diffrent (I read your tutorial (good one, thank you for that!) but I've not found a section dealing with it:)
I know, there is a possibility to alter data without persisting it and keep it over multible session. I am doing the above because I only want to save, if a user presses a save-button, because he could alter the (multi-page spanning) data and than press cancel.

dennoch vielen dank
marie

You need to work with the inverse and cascade attributes. Have you read http://www.hibernate.org/hib_docs/reference/html/parent-child.html and http://www.hibernate.org/155.html ?

Probably I don't get your problem correctly, if you want send me an email (in german :)

solved.
Indeed, the problem was the inverse-attribute. I set it to true and set BOTH sides of the relation.
the document http://www.hibernate.org/155.html helped alot

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