use hibernate 2.1.3:


have a mapping as follows (with some simplification):

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping SYSTEM "http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">
<hibernate-mapping auto-import="false">
<class
name="PersistentAlarm" table="ALR">
<id name="id" type="long">
<generator class="sequence">
<param name="sequence">ALR_SEQ</param>
<param name="table">ALR_UIDTABLE</param>
<param name="column">ALR0000_HIVALUECOLUMN</param>
</generator>
</id>

<property name="eventtime" length="7" type="calendar">
<column name="eventtime" index="index_eventtime"/>
</property>
<property name="additionaltext" length="2047" type="string">
<column name="additionaltext" index="index_additionaltext"/>
</property>
<set name="additionalinformation" table="PROPERTY" inverse="true" cascade="none" outer-join="true">
<key column="entry_id"/>
<one-to-many class="PersistentAlarm"/>
</set>
</class>
</hibernate-mapping>


in addition i have set "hibernate.use_outer_join" to "true" globally for hibernate.


use hibernate Query interface to get items and their children.

Query q = sess.createQuery("from ALR alarm");
q.setFirstResult(20);
q.setMaxResults(10);
List alarms = q.list();


hibernate will select the master table (ALR) at first then select the slave table (PROPERTY)
by every result record in the master table. It generates many SQL commands. it doesn't use
the outer-join as i thought to fetch the stuffs in one SQL command!


can i configure hibernate to select master and slave table altogether using outer-join and
then auto split the results into correct java classes?


many thanx!

-- bs

Use left join fetch in your HQL.