I'm looking for a thin, generic layer (probably written in PHP) that sits between a database (probably MySQL) and web service clients (which could be anything). I imagine there would be config files of some sort that tell it how to map web service requests to database queries (or other DB commands). It would also need to handle authentication and authorization, of course.
I've done some googling but failed to find anything that fits the bill. Can anyone suggest something like this?