Meaning of inverse=true

flam70 · **Joined:** Thu Oct 02, 2003 8:02 am **Posts:** 45

I have a class Utilisateur and class Evenement with a one-to-many association with the following code :

Code:

class Utilisateur 
{ 
      //... 
      Set evenements; 
      //... 
} 

class Evenement 
{ 
      //... 
      Utilisateur user;
} 

The mapping file is :
<class name="com.cfort.calendrier.Evenement" table="evenement">
<id name="id" column="id">
<generator class="hilo"/>
</id>
<property name="moment" type="string" length="12"/>
<property name="debut" type="string" length="10"/>
<property name="fin" type="string" length="10"/>
<property name="titre" type="string" length="40"/>
<property name="description" type="string" length="200"/>
</class>
<class name="com.cfort.utilisateur.Utilisateur" table="utilisateur" >
<id name="identifiant" column="identifiant" type="string" length="20">
<generator class="assigned"/>
</id>
<property name="dateAbonnement" type="date"/>
<property name="datePaiement" type="date"/>
<property name="modeReglement">
<column name="modeReglement" sql-type="varchar(30)"/>
</property>
<property name="nbPoints" type="integer"/>
<set name="evenements">
<key column="utilisateur_numero"/>
<one-to-many class="com.cfort.calendrier.Evenement"/>
</set>

</class>

What does it mean if i modify the code in the mapping file by :
<set name="evenements" inverse="true">
<key column="utilisateur_numero"/>
<one-to-many class="com.cfort.calendrier.Evenement"/>
</set>

I read the documentation but i don't understand the explanations of inverse="true"

Thanks

nickvajberg · **Joined:** Tue Oct 21, 2003 8:15 am **Posts:** 186

Quote:

I read the documentation but i don't understand the explanations of inverse="true"

Most people don't

Quote:

What does it mean if i modify the code in the mapping file by :

I guess it means you can't persistently add Utilisateur's to evenements.

christian · **Posted:** Thu Nov 20, 2003 7:30 am

No, _you_ don't. The other 20.000 do.

nickvajberg · **Joined:** Tue Oct 21, 2003 8:15 am **Posts:** 186

Quote:

No, _you_ don't. The other 20.000 do.

Well, with flam70 we're two. And I'm pretty sure the other 20.000 was confused too.

christian · **Posted:** Thu Nov 20, 2003 8:11 am

http://www.hibernate.org/Documentation/ ... nverseTrue

nickvajberg · **Joined:** Tue Oct 21, 2003 8:15 am **Posts:** 186

Quote:

inserts work fine because I set <many-to-one not-null="true"

non-null="true" means the column cannot be null, right?

-----------------

Nice article! But a few points to fix:

Quote:

The side having inverse="false" (default value) has this responsability...

Typo.

Quote:

This is not recommanded.

Typo.

Quote:

is set during the child save : this is of the child responsability.

Typo.

Quote:

This is not recommanded.

Typo.

Quote:

This is ineficient considering

Typo.

Quote:

But I avoid it for sample purpose.

What's a sample purpose?

Quote:

after this tutorial, I will be soooo easy ;-)

Good to hear that you will be soooo easy ;-)

christian · **Posted:** Thu Nov 20, 2003 8:44 am

You realize there is an "EDIT" button on the top of this page?

nickvajberg · **Joined:** Tue Oct 21, 2003 8:15 am **Posts:** 186

No, there's no EDIT button. If it were - I'd click it.

And yes, I'm logged in.

emmanuel · **Posted:** Thu Nov 20, 2003 9:26 am

nickvajberg wrote:

Quote:

inserts work fine because I set <many-to-one not-null="true"

non-null="true" means the column cannot be null, right?

You're right. Actually I'm not sure this attribute is used by the core of hibernate (only tools ?). And I may be wrong guessing hibernate needs not-null on many-to-one to insert in the proper order. Experts needed.

nickvajberg wrote:

Nice article! But a few points to fix

Well thanks, you were the guy who pushed me to write it ;-)
I'm not a native English speaker, it explains the typos : I fixed then.

nickvajberg wrote:

Quote:

But I avoid it for sample purpose.

What's a sample purpose?

I changed to : I didn't do it to keep this explanation easier to understand and avoid concepts mismatch.

gavin · **Posted:** Thu Nov 20, 2003 10:54 am

Quote:

Well thanks, you were the guy who pushed me to write it ;-)

Dude, you are an absolute hero, for doing stuff like this and for helping out so much in the forum at the moment. We really appreciate your efforts.

peace

Gavin

emmanuel · **Posted:** Thu Nov 20, 2003 1:36 pm

gavin wrote:

We really appreciate your efforts.

Thanks, I appreciate.
Keep improving this fabulous tool and I'll be happy ;-)