<?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="learn.hibernate">   
   <class name="ClassA" table="A">   
     <id name="aId" type="long" column="a_id" />
     <property name="aProperty" column="a_prop" />
     <set name="bSet"
          lazy="true"
          inverse="true"
          cascade="all-delete-orphan">
       <key>
          <column name="a_id" />
       </key>
       <one-to-many class="learn.hibernate.ClassB"/>
      </set>
   </class>
</hibernate-mapping>

<?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="learn.hibernate">
   <class name="ClassB" table="B">
      <composite-id>
         <key-property name="bIdOne" column="b_id" />
         <key-property name="bIdTwo" column="a_id" />
      </composite-id>
      <property name="bProperty" column="b_prop" />
      <many-to-one name="aObject"
                   class="learn.hibernate.ClassA"
                   column="a_id"
                   insert="false" update="false"/>
   </class>
</hibernate-mapping>