Database schema adapter library/framework/application

Greetings,

We have a web service which pulls information from our partners and we want for it be as easy as possible for them to integrate the webservice with their existing systems. We expect most of our partners will store the data in a database so this is what we are concentrating on, but since each database will have differing data schema, we don't have a 'one size fits all' solution.

Ideally we would like for them to be able to install an application on their server where they can configure the data mapping from their database columns to our web service schema and exposes an API that our web service can connect to.

I gather this is a fairly typical scenario, so rather then developing a solution from scratch is there a framework available we could possibly make use of to go some way to achieving this?

Alan,