Hi Peter,
You might want to take a look at the MS SQLXML 3.0 toolkit. I have been using the beta tools for a while and switched to version 3 when it was released to manufacturing about a month ago. It appears to be very stable.
I have developed a data class that implements SQLXML using the SQLXML OLE DB provider supplied with the toolkit. You supply the data tier with an XML request, it provides an XML reply.
Take a close look at the use of mapping schemas. To me, this is one of the neatest tools to come along in quite a while. They are essentially SQL view generators. Mapping schemas allow you to map table columns to XML document elements and establish relationships between tables.
You can then query the database using XPath or SQL queries to retrieve data and use Updategrams to make changes. Datasets from multiple sources can be retrieved in one pass to the server.
I didn't find the learning curve too steep, but the documentation (as always) leaves a lot of unanswered questions that you just have to solve on your own. All-in-all, I think SQLXML is a great tool.
Regards,
Bob Tracy
Never engage in a battle of wits if you're only half armed.