nHibernate Collections issue ( check your mapping file for property type mismatches)

Question

I'm getting the following error: Unable to cast object of type 'NHibernate.Collection.Generic.PersistentGenericSet to type 'Iesi.Collections.Generic.SortedSet.

Invalid mapping information specified for type [Type], check your mapping file for property type mismatches".

Here's my set definition:

<set name="ProcessTrackerDetails" lazy="true" access="field.camelcase-underscore" 
                sort="natural" cascade="all" inverse="true">
  <key column="ProcessTrackerDetailsID"/>
  <one-to-many class="ProcessTrackerDetail"></one-to-many>
</set>

And heres the code:

private Iesi.Collections.Generic.SortedSet<ProcessTrackerDetail> _processTrackerDetails = new SortedSet<ProcessTrackerDetail>();

Suggestions?

Answer 1

NHibernate requires interfaces. Try to use ISet<ProcessTrackerDetail> instead of SortedSet<ProcessTrackerDetail>

Answer 2

Change your code to define _processTrackerDetails using the ISet interface.

private ISet<ProcessTrackerDetail> _processTrackerDetails = 
    new SortedSet<ProcessTrackerDetail>();

You can still assign it to a SortedSet, but I am not sure that it does much when lazy loaded as NHibernate will use it's ISet implementation to do the lazy loading. The sort="natural" in your mapping should take care of the sort order.