3.1.3
PostgreSQL 8.1.2

Game<-(1:N)->Round
Round<-(N:M)->Person

I will add Role for each Person( A person only has one Role in one Round)
So I define a class:

<class name="PersonRole" table="person_role">

<composite-id name="compId" class="PersonRoleCompositeID">
<key-property name="roundId" column="round_id"></key-property>
<key-property name="personId" column="person_id"></key-property>
</composite-id>

<many-to-one name="round" class="Round" column="round_id" insert="false" update="false"/>
<many-to-one name="person" class="Person" column="person_id" insert="false" update="false"/>

<many-to-one name="role" class="Role" column="role_id" not-null="true"/>

</class>

public class PersonRole {

private PersonRoleCompositeID compId;

private Round round;

private Person person;

private Role role;
...
...
}

How could I add into Round class?
Thanks.

I would rather create class PersonRoundLink and have role property there. In the case we will be dealing with simple ternary type of relationships

http://www.hibernate.org/hib_docs/v3/re ... ns-ternary