[Hibernate-devel] How to map nested many-to-one relationship?

[Patrick S. <psa...@co...>]

Hi Guys,
I've recently got back onto my hibernate project
and like it _very_ much.
I am having a little difficulty nesting a class
in another - perhaps someone can easily pinpoint
where I'm going wrong.

In a nutshell, there is a one-to-many relationship from
class productSpecifcation to class panelSpecification.

I want to model this using a nested collection.
When I retrieve a ProductSpecification object I want to 
get the corresponding panelSpecification objects also.

Question: What have I got wrong with my mapping file?
Also, I don't understand the use of the <element> tag
in the declaration of my <list>. The docs are a bit
vague on this.

Though the manual is detailed, I reckon a few more
examples of common things done would answer 95% of newbie questions.

I am using version 1.0rc2 .
Any tips much appreciated.

Thanks,
Patrick.

======================== Mapping file==================
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD//EN"
	"file://localhost//usr/local/hibernate-1.0rc2/src/cirrus/hibernate/hibernate-mapping.dtd">
<hibernate-mapping>

       <class name="com.psaunders.project.ProductSpecification"
              table="product_specification"
	      select="all">

              <id name="productTypeId" column="product_type_id" type="long">
                    <generator class="sequence"/>
              </id>

              <property name="longDesc" column="long_desc"/>
              <property name="shortDesc" column="short_desc"/>

              <list role="panels" table="panel_specification" lazy="false" cascade="none" >
                  <key     column="product_type_id" type="long" />
                  <index   column="product_type_id" type="long"/>
                  <element column="id" type="long"/>

              </list>

              <collection name="panelName" column="panel_name" role="panels" />
              <collection name="productTypeId" column="product_type_id" role="panels" />
              <collection name="zOrder" column="z_order" role="panels" />

       </class>

       <class name="com.psaunders.project.PanelSpecification"
              table="panel_specification"
	      select="all">

	        <id name="id" column="uid" type="long">
                    <generator class="sequence"/>
            </id>

            <property name="productTypeId" column="product_type_id"/>
            <property name="panelName" column="panel_name"/>
            <property name="zOrder"    column="z_order"/>
        </class>

</hibernate-mapping>
=================================================

========== DDL for schema ================
drop table panel_specification
drop table product_specification
drop sequence hibernate_sequence
create table panel_specification (panel_name VARCHAR(255), product_type_id INT4, uid INT8 not null, z_order INT4, primary key (uid))
create table product_specification (long_desc VARCHAR(255), product_type_id INT8, short_desc VARCHAR(255), primary key 
(product_type_id))
alter table panel_specification add constraint panel_specificationFK0 foreign key (product_type_id) references product_specification
create index panel_specificationIDX1 on panel_specification (product_type_id)
========================================