Cascade, child object's id is not updated

sowelie · **Joined:** Wed Dec 17, 2008 12:10 pm **Posts:** 47

I am working with a parent object which has a Map collection map with child objects like this:

<map cascade="all-delete-orphan" catalog="SomeCatalog" inverse="true"
name="revisions" sort="unsorted" table="SomeTable">
<key column="PageFK"/>
<index column="Revision" type="int"/>
<one-to-many class="SomeType" not-found="ignore"/>
</map>

My problem is that as you can see I'm cascading the save to the child objects. They are being saved properly, but they id is not being updated on the child objects. So, until I open a new session and re-get the collection, anything that was added has an id of zero. Any thoughts?

nordborg · **Posted:** Tue Mar 03, 2009 4:54 am

Might be a problem with the id mapping of the child object. Can you post it as well?

sowelie · **Joined:** Wed Dec 17, 2008 12:10 pm **Posts:** 47

Here's the ID mapping of the child object:

<id name="id" type="java.lang.Integer">
<column name="SomeObjectID"/>
<generator class="identity"/>
</id>

nordborg · **Posted:** Tue Mar 03, 2009 9:47 am

The mapping seems to be ok. Are you using Session.merge() to update the parent object? merge() creates copies and doesn't modify existing objects.

Quote:

... anything that was added has an id of zero

Hmmm.... are you sure the id is '0' and not 'null'? What is the value of the child id before you add it to the the collection?

In the mapping you have type="java.lang.Integer", which suggests that unsaved items should have a 'null' id. If you use '0' I am not really sure what is going to happen. I would expect Hibernate to complain about multiple objects using the same id... but if Hibernate tries to insert an object with id=0 the database may actually generate a new >0 id. Since Hibernate doesn't allow id's to change the child id would still be 0.

sowelie · **Joined:** Wed Dec 17, 2008 12:10 pm **Posts:** 47

Ah, I see. I am using Session.saveOrUpdate(). Also, prior to being saved the value of the id is zero. In my data objects I'm using the primitive type int. Is there a way to use the primitive type int in the mapping?

mmerder · **Posted:** Tue Mar 03, 2009 11:32 am

Try to add unsaved-value="0" to your id-mapping.

sowelie · **Joined:** Wed Dec 17, 2008 12:10 pm **Posts:** 47

Alright, I will try that. I will have to create a test case because I changed the way I was working with the example I posted above. This application is constantly changing ;). Thanks for your help!!

nordborg · **Posted:** Tue Mar 03, 2009 2:15 pm

sowelie · **Joined:** Wed Dec 17, 2008 12:10 pm **Posts:** 47

This did not work. It is still zero after the parent object has been saved. Is there anything else you can think of?

sowelie · **Joined:** Wed Dec 17, 2008 12:10 pm **Posts:** 47

Here are the full mappings:

Parent:

Code:

<hibernate-mapping package="somePackage">
 <class catalog="SomeCatalog" name="Page" table="Pages">
  <id name="id" type="java.lang.Integer">
   <column name="PageID"/>
   <generator class="identity"/>
  </id>
  <many-to-one class="Folder" fetch="select" name="folder">
   <column name="FolderFK" not-null="false"/>
  </many-to-one>
  <many-to-one class="Layout" fetch="select" name="layout">
   <column name="LayoutFK" not-null="true"/>
  </many-to-one>
  <many-to-one class="Template" fetch="select" name="template">
   <column name="TemplateFK" not-null="true"/>
  </many-to-one>
  <many-to-one class="Site" fetch="select" name="site">
   <column name="SiteFK" not-null="true"/>
  </many-to-one>
  <property generated="never" lazy="false" name="name" type="string">
   <column length="50" name="Name" not-null="true"/>
  </property>
  <property generated="never" lazy="false" name="url" type="string">
   <column length="200" name="Url"/>
  </property>
  <map cascade="all-delete-orphan" catalog="SomeCatalog" inverse="true"
   name="revisions" sort="unsorted" table="SomeTable">
   <key column="PageFK"/>
   <index column="Revision" type="int"/>
   <one-to-many class="PageRevision" not-found="ignore"/>
  </map>
  <property generated="never" lazy="false" name="title" type="string">
   <column length="200" name="Title"/>
  </property>
  <property generated="never" lazy="false" name="metaDescription" type="string">
   <column name="MetaDescription"/>
  </property>
  <many-to-one class="User" name="lockedBy">
   <column name="LockedBy"/>
  </many-to-one>
 </class>
</hibernate-mapping>

Child:

Code:

<hibernate-mapping package="com.verani.common.cms">
 <class catalog="CMS" name="PageRevision" table="PageRevisions">
  <id column="PageRevisionID" name="id" type="int" unsaved-value="0">
   <generator class="native"/>
  </id>
  <many-to-one class="com.verani.common.cms.Page" fetch="select" name="page">
   <column name="PageFK" not-null="true"/>
  </many-to-one>
  <property generated="never" lazy="false" name="revision" type="int">
   <column name="Revision" not-null="true"/>
  </property>
  <property generated="never" lazy="false" name="published" type="boolean">
   <column name="IsPublished" not-null="true"/>
  </property>
  <property generated="never" lazy="false" name="date" type="timestamp">
   <column length="19" name="Date" not-null="true"/>
  </property>
  <many-to-one class="com.verani.common.backPage.User" column="UserFK"
   lazy="proxy" name="user"/>
  <set cascade="all,delete-orphan" catalog="CMS" inverse="true"
   name="fields" sort="unsorted" table="PageFields">
   <key column="PageRevisionFK"/>
   <one-to-many class="com.verani.common.cms.PageField"/>
  </set>
  <property generated="never" lazy="false" name="committed" type="boolean">
   <column name="IsCommitted"/>
  </property>
 </class>
</hibernate-mapping>

mmerder · **Posted:** Wed Mar 04, 2009 3:59 am

Do you also set the parent of the child-objects like child.setParent(parent)? You need to do this, as you have mapped the association as inverse in parent, so the child is the owner of it.

Also something that makes me wonder: In your parent mapping the class name is just "Page", but in your child you map it as "com.verani.common.cms.Page" try to use the same name on both sides.

sowelie · **Joined:** Wed Dec 17, 2008 12:10 pm **Posts:** 47

Thanks for your help. I think that may be it, I might not be setting the parent in the child object. Also, I was trying to remove all of the package names to simplify the mapping files haha.

sowelie · **Joined:** Wed Dec 17, 2008 12:10 pm **Posts:** 47

Ah, nuts. I confirmed that I am actually setting the parent. I'm really baffled as to why this is happening? The parent itself has its id set properly when it is created, just not the child.

sowelie · **Joined:** Wed Dec 17, 2008 12:10 pm **Posts:** 47

I see why it is happening. The cascade isn't being triggered by Session.saveOrUpdate. It's only being triggered once I execute a query or use the criteria API. So basically, the insert has not run for the child object yet, even though I've saved the parent object. Is this expected behavior?

mmerder · **Posted:** Wed Mar 04, 2009 11:21 am

Did you flush the session or commit the transaction?