This isn't for sql, for sql view some of the sql tutorials, documentation, or plugin examples. I wrote an example last year using the older version of sql access, Hawk wrote information on how to use the newer SQL data access.
SQL Information, Code Examples, and Tutorials By:
BAILOPAN
Hawk552
TheNewt
I recommend learning SQLx from Hawk's thread there. Mine's is the older version, and BAIL's there is an update to the API, not really a tutorial.