unsaved-value="any"

cfgar · **Posted:** Thu Mar 04, 2004 9:55 am

Hello all,
Is it a good decision put always

Code:

unsaved-value="any"

when

Code:

?

if i not set to any, saveOrUpdate not works with transiant objets.

thanks in advance,
C

emmanuel · **Posted:** Fri Mar 05, 2004 4:45 am

usaved-value="any" means saveOrUpdate = save

cfgar · **Posted:** Fri Mar 05, 2004 5:10 am

Ok, my doubt is if when generator class="assigned" then i have to set ALWAYS unsaved-value="any"???

For instance:

Code:

  <class name="Plugin" table="plugin">
    <id name="pluginId" column="plugin_id" type="long" 
          unsaved-value="any">
      <generator class="assigned"/>
    </id>
    <set
        name="traducciones"
        lazy="true"
        inverse="true"
        cascade="all"
    >
      <key column="plugin_id"/>
       <one-to-many class="Traduccion"/>
    </set>
  </class>

  <class name="Traduccion" table="traduccion">
    <id name="traduccionId" column="traduccion_id" type="long" 
          unsaved-value="any">
      <generator class="assigned"/>
    </id>
    <property name="ingles" type="string"/>
    <property name="castellano" type="string"/>
    <many-to-one name="plugin" column="plugin_id"
        class="Plugin" not-null="true"/>
  </class>

if i save (or saveOrupdate) a plugin then Hibernate don't knows if have to save (sql insert) or update (sql update) traduccion, because pk is not null (assigned).

then, generator class="assigned" implies unsaved-value="any"???

thanks,
C

michael · **Posted:** Fri Mar 05, 2004 5:17 am

unsaved-value is only considered on cascades and saveOrUpdate(), not on save() or update()

fridoo · **Posted:** Fri Mar 05, 2004 6:31 am

As far as I can grab it, saveOrUpdate is useless when using assigned id's. Why does hibernate not do the following in saveOrUpdate:
- check if an object with the requested id is already loaded (it would be the object passed to saveOrUpdate),
- if not, check if the object exists in the database
- if still not found, do a save (insert), otherwise, do an update

Frido

jlawmi · **Joined:** Mon Nov 24, 2003 6:36 pm **Posts:** 105

If you have an assigned identifier, the simplest thing for hibernate to know whether to issue an update vs an insert, is to use a seperate field with a date as <timestamp>
or <version> element in your mapping. If you have a last_updated field or something like that in your java object.

Check out <version> <timestamp> in the docs.

I wouldn't want hibernate to have the overhead of checking the db first for every object in my collection that might be new/existing.

Of course, I like to avoid the use of assigned altogehter if possible!

James

emmanuel · **Posted:** Fri Mar 05, 2004 11:06 pm

fridoo wrote:

As far as I can grab it, saveOrUpdate is useless when using assigned id's. Why does hibernate not do the following in saveOrUpdate:
- check if an object with the requested id is already loaded (it would be the object passed to saveOrUpdate),
- if not, check if the object exists in the database
- if still not found, do a save (insert), otherwise, do an update

Frido

This is highly inefficient ! And business PK sucks generally.
But as James pointed out, the <version unsaved-value=""> is precious in such cases.

OT: I'm afraid, however that people using assigned id don't use optimistic locking either :(

gavin · **Posted:** Fri Mar 05, 2004 11:08 pm

You can do whatever you like in Interceptor.isUnsaved() .... but don't go to the database, thats crazy!