NHibernate - mapping connection-table & back-references - nhibernate

Question

Hey,
I have to map the following entities:
class Document
{
public int DocumentId { get; set; }
public DocumentList ContainingList { get; set; }
}
class DocumentList
{
public int DocumentListId { get; set; }
public DateTime LastUpdateTime { get; set; }
public IList<Doucment> Documents { get; set; }
}
With the constraint that only one DocumentList can own a specific document (altough a collection-table exists here).
Mapping has to rely on the following tables (which cannot be changed, for the sake of simplicity):
TB_DOC
------
DOC_ID (int, PK)
DOC_CONTENT (blob)
TB_DOC_LIST
-----------
DOC_LIST_ID (int, PK)
DOC_LIST_UPDATE_TIME (datetime)
TB_LIST_AND_DOCS
----------------
DOC_LIST_ID
DOC_ID
So the mapping i tohught of would be like this:
enter code here
<class name="DocumentList" table="TB_DOC_LIST">
<id name="DocumentListId">
<column name="DOC_LIST_ID"/>
<generator class="assigned" />
</id>
<property name="LastUpdateTime" column="DOC_LIST_UPDATE_TIME ">
<set name="Documents" table="TB_LIST_AND_DOCS">
<key column="DOC_ID"></key>
<one-to-many class="Document" />
</set>
</class>
and:
<class name="Document" table="TB_DOC">
<id name="DocumentId">
<column name="DOC_ID"/>
<generator class="assigned" />
</id>
[ ??? ] - property to reference the "owner" document list
</class>
Now, following the known patterns, i can't figure out how should the back-link from Document to the DocumentList be mapped, since i have a "weired| one-to-many relation here, broken by a third table.
I also don't want a Document object to reference an IList to solve this with back-referencing many-to-many, since each Document has only one such "owner" DocumentList.
Any elegant idea? what am i mispercepting here?

Answer 1

cant test it right now, but a join could be used to get the reference id.
<class name="Document" table="TB_DOC">
<id name="DocumentId">
<column name="DOC_ID"/>
<generator class="assigned" />
</id>
<join table="TB_LIST_AND_DOCS">
<key column="DOC_ID"/>
<many-to-one class="DocumentList">
<column name="DOC_LIST_ID" />
</many-to-one>
</join>
</class>