Version property with many-to-many association?

fdelisle · **Posted:** Thu May 06, 2004 11:49 am

I have a association table for a many to many relation. This table contains extra fields.

So I have the following tables / objects:

Person
id
name

PersonLanguage
personId
languageId
speaked
written
updateCount

Language
id
code

The mapping, from the Person.hbm.xml file, looks like this:

Code:

<set name="languages" table="Person_Language">
    <key column="Version_Id"/>
    <composite-element class="PersonLanguage">
        <property name="guiOnly" column="speaked" type="boolean"/>
        <property name="guiDefault" column="written" type="boolean"/>
        <many-to-one name="language" class="Language" column="Language_Id" outer-join="false"/> 
    </composite-element> 
</set>

The problem is that I'm using optimistic locking with a version property. In our current (and established) database schema, we have a version column for the association table

Person_Language
update_count

However, I can't specify a <version> tag in a <composite-element> tag.

How can I map a version property for optimistic locking residing in an association table?

christian · **Posted:** Thu May 06, 2004 11:53 am

You can't. Use a database trigger to update the version in that table and don't map it, Hibernate doesn't need it.

fdelisle · **Posted:** Thu May 06, 2004 12:29 pm

Unbelievable!!!

1. I submitted my question
2. I printed the JBoss Training form to be part of the training in NY (2 pages)
3. I came back at my desk and had already an answer

Awesome! heheh

Thanks!

fdelisle · **Posted:** Tue Jun 08, 2004 8:55 pm

I'm now using a class (and a mapping) even for join-table (tables used to associate 2 entities using a many-to-many relation).

Since mapped, it may have a version property as any other entities.

I consider the relation as being an entity by itself.

Thanks