Subtle problem with indexed lists

sbtourist · **Joined:** Fri Nov 18, 2005 9:54 am **Posts:** 4

Hello all,

I have a very subtle problem with one-to-many bidirectional associations based on indexed lists, using Hibernate 3.0.5

I've mapped my association following the instructions given in this document: http://www.hibernate.org/193.html

So, this is my parent mapping:

Code:

<list cascade="all-delete-orphan" inverse="false" lazy="true"
  name="requiredDocuments">
           <cache usage="read-write"/>
           <key column="enrollmentRequest"/>
           <index column="displayOrder"/>
           <one-to-many class="com.foo.EnrollmentRequestDocument"/>
</list>

And this is my child mapping:

Code:

<many-to-one cascade="none" insert="false" lazy="proxy"
  name="enrollmentRequest" not-null="false" update="false"/>

Finally, this is my "add" method in the parent class:

Code:

public void addDocument(EnrollmentRequestDocument document) {
        document.setEnrollmentRequest(this);
        this.requiredDocuments.add(document);
}

Notice that in the child mapping I had to write not-null="FALSE" because if I set it to TRUE I get a not-null constraint violation when inserting.

However, this doesn't work. The foreign key in the child is not set, nor is set the index column during saving.

Am I missing something relevant?

Thanks in advance,

Sergio B.

anthony · **Posted:** Fri Nov 18, 2005 11:39 am

if your association is bidirectionnal, why inverse=false?

Next, the reference guide says:
A bidirectional association allows navigation from both "ends" of the association. Two kinds of bidirectional association are supported:

one-to-many

set or bag valued at one end, single-valued at the other

sbtourist · **Joined:** Fri Nov 18, 2005 9:54 am **Posts:** 4

anthony wrote:

if your association is bidirectionnal, why inverse=false?

Because it is implemented as an indexed collection, a list, which, according to http://www.hibernate.org/193.html, cannot be managed in inverse fashion.

Recall:

Quote:

Hibernate 3 allows you to use indexed collections in a bidirectional association without workaround, just use this mapping:

Parent
<list inverse="false"/>
</list>

Child
<many-to-one insert="false" update="false"/>

To summarize, you need to let the collection be the owner side.

Is this maybe wrong?

Thank you for your interest,

Regards,

Sergio B.

anthony · **Posted:** Fri Nov 18, 2005 12:01 pm

oh sorry i forgot this was possible with H3.

This should work... strange

Code:

public void addDocument(EnrollmentRequestDocument document) {
    what if document.getEnrollmentRequest != null ?
you must remove the document from its old EnrollmentRequest
    document.setEnrollmentRequest(this);
    this.requiredDocuments.add(document);
} 

sbtourist · **Joined:** Fri Nov 18, 2005 9:54 am **Posts:** 4

anthony wrote:

This should work... strange

Yes, very strange ... no idea?

anthony wrote:

Code:

public void addDocument(EnrollmentRequestDocument document) {
    what if document.getEnrollmentRequest != null ?
you must remove the document from its old EnrollmentRequest
    document.setEnrollmentRequest(this);
    this.requiredDocuments.add(document);

This doesn't matter because never happens due to business requirements.

Any help?

Regards,

Sergio B.

anthony · **Posted:** Fri Nov 18, 2005 12:19 pm

please show id mapping file tags and Hibernate API calls

sbtourist · **Joined:** Fri Nov 18, 2005 9:54 am **Posts:** 4

anthony wrote:

please show id mapping file tags and Hibernate API calls

Id mappings are simple:

Code:

<id column="id" name="id" unsaved-value="null">
   <generator class="native"/>
</id>

And I cannot show you Hibernate API calls because I'm using the HibernateDAOSupport class provided by the Spring framework.

Regards,

Sergio B.

RichMacDonald · **Posted:** Sat Nov 19, 2005 12:08 am

Try using <list-index> instead of <index>.

I'd like to see more of the mapping definition, the generated SQL for the table definitions, and the constraint violation message. Turn on the debugger and post the results.

You have to be careful with index columns and not-null values in order to get the correct constraint definitions. In particular, Hibernate does not support list-to-list, but that doesn't appear to be what you're attempting.