Hibernate: "not-null property references a null or transient value" only with HSQL

Hi Guys,

I have an already release software that makes use of Hibernate+Postgre, and now I have to make it compatible ALSO with HSQL.

All in all, I managed to get everything working, except the following issue. I have a Product and a ProductDetail entities. And the latter has a reference to the former and everything works like a charm on Postgre. When I create a product (and proddetails) the Hibernate can save them. But when I use the HSQL, it flops:

not-null property references a null or transient value: xx.xxx.xxxx.product.ProductDetail.product

But the thing is, I've inspected the entity on the line:

HibernateUtil.getSession().saveOrUpdate(entity);

And it is a ProductDetail, and its product field IS NOT EMPTY. It contains a valid Product object. And that is no surprise, as I've already written it works with Postgre.

Any clues?

I think we need your mapping for the entities related to your problem.
Maybe you are trying to save an unsaved entity and you forgot a cascade.

I don't think that's the problem, since it works with Postgres. But here it goes (some parts were ommited due to confidentiality):

ProductDetail.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="xxxxx.product">
<class name="ProductDetail" table="prod_det" schema="public">
        <id name="id" column="cd_prod_det">
            <generator class="native">
                 <param name="sequence">prod_det_cd_prod_det_seq</param>  
            </generator>
        </id>  
        <many-to-one name="specialAddInfo" class="xxxxx.product.SpecialAdditionalInformation" lazy="false" fetch="join">
            <column name="cd_special_add_info" />
        </many-to-one>      
        <many-to-one name="sector" class="xxxxx.equipment.Sector" lazy="false" fetch="join">
            <column name="cd_sector" not-null="true" />
        </many-to-one>
        <many-to-one name="product" class="Product" lazy="false" fetch="join" cascade="all">
            <column name="cd_prod" not-null="true" />
        </many-to-one>
(...)
    </class>
</hibernate-mapping>

Product.hbm.xml