Lawrence,
>I wonder if there is a way to use a relation (like VFP SET RELATION TO) and I'm going to explore that today.
ADO.NET has DataRelation objects that allow you to specify relationships between DataTables in a DataSet. I highly recommmend a book "ADO.NET Core Reference" by MS Press...it has a lot to say about these sorts of issues.
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