Chuck,
>Instead, I will query SQL before the delete - if data exists in other tables, display a friendly message if the bizobj lives on a form. That way the delete method never takes place. Question: Would this be a good candidate for a business rule?
You may just want to place the check in the business object's PreDeleteHook().
Regards,
Kevin McNeish
Eight-Time .NET MVP
VFP and iOS Author, Speaker & Trainer
Oak Leaf Enterprises, Inc.
Chief Architect, MM Framework
http://www.oakleafsd.com