I found a bug, or at least a serious problem:
When the index column in a many-to-many relation with a sorted list is named 'Order', then NHibernate crashes when loading collections from this relation.

The reason is that in my mapping file I have to put in [Order] because Order is a SQL keyword. Upon loading the collection NHibernate uses the string [Order] to lookup the field index in a SqlDataReader, which fails miserably with a IndexOutOfBoundsException.

With the build 1.0.2 (downloaded today) the exception happens in file Driver\NHybridDataReader.cs in line 362, GetOrdinal(name). And yes, I'm very proud that I debugged this problem myself :-)

Now, it'd be questionable if I should use column names that are keywords. However, nothing in NHibernate is preventing me from doing that. So I'll leave it to the community to determine whether this is a bug or I have a crappy DB design ;-)

Take care, Christoph

I forgot to mention:
I built NHibernate using .Net 1.1 and run it against a SQL2005 database. Don't know if it's any different with SQL2000.

Here is what my mapping for many-to-many looks like:

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0">

<class name="DataAccess.DomainModel.FaultEntry, DataAccess" table="Fault">
<id name="ID" column="ID" access="field.pascalcase-m-underscore" type="System.Guid">
<generator class="assigned" />
</id>

<list name="Diagnoses" table="FaultDiagnosis" cascade="all">
<key column="FaultID" />
<index column="[Order]"/>
<many-to-many column="DiagnosisID" class="DataAccess.DomainModel.DiagnosisEntry, DataAccess"/>
</list>
</class>
</hibernate-mapping>

Try enclosing the Order token in back-ticks (`) in your mapping file, rather than square brackets. This tells NHibernate the token is a SQL keyword and to treat it appropriately.