ODBC to Web Service -- any advice?

Hello-

I’d like to allow 3rd-party access to data in my web app’s database.
However, I don’t want the 3rd party software to have direct SQL access
– for security reasons.

Is it reasonable to make this access via a Web Service and then write an
ODBC adapter to communicate to that Web Service?

There is a lot of documentation for -using- ODBC adapters, but I haven’t
seen much on -writing- one. Does anyone have any leads I could check
out?

Also, ODBC seems more tuned to work with SQLs. Abstracting that into a
Web Service seems a bit awkward. Is there another solution? The
software I’m trying to connect to my database speaks ODBC and ADO.NET.

(After reading, I realize this may be off-topic, though my app is
written in rails. Any suggestions for a better group to ask would be
welcome)

Cheers,
Jake