<class name="HotelRoom">
   <id name="code" type="long" column="code" unsaved-value="null">
      <generator class="native" />
    </id>
    <property name="ord" type="long"/>
    <property name="name" type="string" length="60"/>
    <property name="ident" type="string" length="20"/>
    <property name="description" type="string" length="60"/>
    <many-to-one name="hotel" column="hotel" unique="false"/>
    <property name="minAdults" type="int"/>
    <property name="maxAdults" type="int"/>
    <set name="childrensDisscount" inverse="true" lazy="true" order-by="hotelRoom" cascade="all">
       <key>
          <column name="hotelRoom"/>
          <column name="numAdults"/>
          <column name="numChildren"/>
       </key>
        <one-to-many class="HotelRoomWithChildrenDisscount"/>
    </set>
</class>

<class name="HotelRoomWithChildrenDisscount">
   <composite-id>
      <key-many-to-one name="hotelRoom" class="es.parsec.parsys.hotel.HotelRoom" column="hotelRoom"/>
      <key-property name="numAdults" type="int"/>
      <key-property name="numChildren" type="int"/>
   </composite-id>
</class>

public class HotelRoom
{
   private Long code;
   private long ord;
   private String name;
   private String ident;
   private String description;
   private Hotel hotel;
   private int minAdults;
   private int maxAdults;
   
   private Set childrensDisscount;
/** Getters and setters.......

public HotelRoomWithChildrenDisscount addNewHotelRoomWithChildrenDisscount()
   {
      HotelRoomWithChildrenDisscount hRoomWithChDisscount = new HotelRoomWithChildrenDisscount();
      hRoomWithChDisscount.setHotelRoom(this);
      
      getChildrensDisscount().add(hRoomWithChDisscount);
      
      return hRoomWithChDisscount;
   }
}

public class HotelRoomWithChildrenDisscount  implements Serializable
{
   
   private HotelRoom hotelRoom;
   private Integer numAdults;
   private Integer numChildren;

/** Getters and setters.......

}

<property name="minAdults" type="int"/>