>There is one problem I see with that. You have to keep the SQL as generic as possible, which means it can't take advantage of things like Stored Procs and other performance advantages one platform may have over another. I prefer to write specific code for the platform and have the same API to each.

We have a strategy that we store the SQL statements in a table and depending on the backend could have different SQL statements. We try to keep away from stored procedures as much as possible, but even in this case we could abstract away from backend specific implementations