<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0">
 
  <class name="SiteOptionsParent" table="SiteOptions">
    <id name="OptionID" type="Int32">
      <generator class="identity" />
    </id>
    <property name="OptionText" type="String(128)"/>
    <bag name="SiteOptionsList" lazy="false" order-by="?????????">
      <key column="ParentOptionID"/>
      <one-to-many class="SiteOptionsRel"/>
    </bag>
  </class>
 
  <class name="SiteOptionsRel" table="SiteOptionRel">
    <id name="RowID" type="Int32">
      <generator class="identity" />
    </id>
    <property name="ParentOptionID" type="Int32" />
    <many-to-one name="Child" column="ChildOptionID" class="SiteOptionChild" unique="true" />
  </class>

  <class name="SiteOptionChild" table="SiteOptions">
    <id name="OptionID" type="Int32">
      <generator class="identity" />
    </id>
    <property name="OptionText" type="String(128)" />
  </class>
 
</hibernate-mapping>

return session.CreateCriteria(typeof(SiteOptionsRel))
    .Add(Expression.Eq("SiteOptionsParent", siteOptionsParent))
    .CreateCriteria(typeof(SiteOptionsChild))
        .AddOrder(Order.Asc("OptionText"))
    .List();