NHibernate: mapping bidirectional one-to-many with IList semantics - nhibernate

Question

Here are the relevant pieces. This is a parent object:
public class Article
{
public virtual IList<ArticleRevision> Revisions { get; set; }
}
<list name="Revisions" cascade="all" inverse="true" table="ArticleRevision">
<cache usage="read-write" />
<key column="ArticleID" not-null="true" />
<index column="Number" type="int32" />
<one-to-many class="ArticleRevision" />
</list>
This is a child:
public class ArticleRevision
{
public virtual Article Article { get; set; }
}
<many-to-one name="Article" column="ArticleID" not-null="true" />
Now, I create an instance of Article, add one ArticleRevision to Article.Revisions collection, set ArticleRevision.Article to reference the Article instance and shove it to the database:
INSERT
INTO
ArticleRevision
(Content, Keywords, CreatedAt, SiteID, ArticleID, CreatedByUserID, ID)
VALUES
(#p0, #p1, #p2, #p3, #p4, #p5, #p6);
No Number column gets inserted.
How do I correctly map a bidirectional one-to-many collection with list semantics in NHibernate?

Answer 1

From the NHibernate documentation:
Please note that NHibernate does not
support bidirectional one-to-many
associations with an indexed
collection (list, map or array) as the
"many" end, you have to use a set or
bag mapping.

Answer 2

As far as I know, All of ORM frameworks state that when you have a bi-directional relationship, you should define one side, in which your ORM will rely on when updating the state of your bi-directional relationship. Otherwise, you can get side effects such as
Inconsistent mapping
Violation of constraints
Among other stuffs
In your case, the column ArticleID can be managed by both ends of the relationship. Because of that, you should mark one side as inverse="true", which should be placed in the many side when you have a #OneToMany relationship.
However, you can achieve the same behavior by disabling the property ArticleRevision.Article, by setting its mapping as
<many-to-one name="Article" column="ArticleID" insert="false" update="false" />
Using insert="false" update="false", you are saying: NHibernate, does not care about me, in which, as a result, NHibenate you simply ignore it. Now, discard inverse="false" in the property Article.Revisions, and you will get your answer.
UPDATE:
Remove not-null="true" from your key column because it is updated right after ArticleRevision. As a consequence, you will get a constraint violation otherwise.