title: NHibernate - Composite-Id on relation - Where ID of parent is not same composite
body: <p>Say I have these table in an Oracle database</p>
  
  <p>Person:<br>
  PersonId &lt;- PK ID (int, from sequence)<br>
  PersonFirstNameID &lt;-- int<br>
  PersonLastNameID &lt;-- int<br>
  PersonSecurityID &lt;-- int  </p>
  
  <p>PersonDetails<br>
  PersonFirstNameID -CompositeKey<br>
  PersonLastNameID -CompositeKey<br>
  PersonSecurityID -CompositeKey<br>
  PersonDetailKey<br>
  PersonDetailValue<br>
  PersonDetailRisk  </p>
  
  <p>Now I want to model the one to many relation from Person to PersonDetails in NHibernate.</p>
  
  <p>How can I do this?  I've tried setting up a component representing the composite Id and feeding this into the one to many via the property ref however this generate SQL with duplicate columns and throws the following:
  System.ArgumentException: Identifier type mismatch; Found: Expected:</p>
  
  <p>The NHibernate documentation talks only about doing this when the composite Id is the same on both.. </p>
  
  <p>Yes... Its not my DB schema, its a legacy DB and access is very limited.</p>