Hi,

I have created a table containing two types of objects: BatchInfo and Batch objects. The Batch class is a subclass of BatchInfo.

I want to insert a Batch object into the table, and thereafter retreive it as a BatchInfo object. Is it possible ?
Thanks.

My xml file:
--------------------------------------
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping
PUBLIC "-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">

<hibernate-mapping>


<class name="BatchInfo" table="batch">
<id name="id" column="id" type="long">
<generator class="sequence">
<param name="sequence">batch_sequence</param>
</generator>
</id>
<discriminator column="subclass"/>
<property name="owner" column="owner"/>
<property name="name" column="name"/>
<property name="description" column="description"/>
<property name="format" column="format"/>
<property name="timeEstimate" column="timeEstimate"/>
<property name="lastUsedDate" column="lastUsedDate"/>
<property name="createdDate" column="createdDate"/>

<subclass name="Batch" discriminator-value="batch" >

<property name="samples" column="samples"/>
</subclass>
</class>

</hibernate-mapping>

yes, see 11.6. Polymorphic queries

Yes,

But it will return a list of instances of the Batch class and not instances of the BatchInfo class.

I want to be able to get a list of BatchInfo objects, which are build from the Batch objects in the table.

/Lorenzen

well just query "from Batch" and your result is automatically a BatchInfo because it extends it!!

Afaik Hibernate 2.xx does not handle loading lightweight version of heavyweight object.


Did you try using native query?

Query sqlQuery = session.createSQLQuery(
"select {bi.*} from batch {bi}",
"bi",
BatchInfo.class);
sqlQuery.list();


try it and let us know if it works.

Are you expecting to have instances of BatchInfo or it is going to be sort of abstract class?

Lukasz