<?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 default-access="field">
  <class name="uk.ac.warwick.sbr.AbstractPageImpl"
         proxy="uk.ac.warwick.sbr.Page"
         table="PAGE"
         dynamic-insert="true"
         dynamic-update="true">
    <id name="id"
        column="id"
        type="java.lang.String"
        unsaved-value="null">
        <generator class="org.hibernate.id.UUIDHexGenerator"/>
    </id>
    <one-to-one name="lock"
                cascade="all-delete-orphan"
                class="uk.ac.warwick.sbr.LockImpl"/>
  </class>

  <!-- Lock is only used as part of Page. -->
  <class name="uk.ac.warwick.sbr.LockImpl"
         proxy="uk.ac.warwick.sbr.Lock"
         lazy="true"
         table="PAGE_LOCK">
    <id name="id"
        column="id"
        type="java.lang.String">
        <generator class="foreign">
          <param name="property">page</param>
        </generator>
    </id>
    <one-to-one name="page" class="uk.ac.warwick.sbr.AbstractPageImpl" constrained="true"/>
    <property name="lockedBy" column="LOCKED_BY"/>
    <property name="lockedSince" column="LOCKED_TIME"/>
  </class>
</hibernate-mapping>

        page.setLock(null);
        ((LockImpl)lock).setPage(null);
        anotherSession.flush();

        page = (HtmlPage) anotherSession.load(HtmlPageImpl.class, page.getId());
        lock = page.getLock();
        assertNull("lock still attached to page", lock);

        List allLocks = anotherSession.createSQLQuery(
                "select {lock.*} from page_lock lock"
                )
                .addEntity("lock", LockImpl.class)
                .list();
        assertTrue("orphan row exists", allLocks.isEmpty());
    }