[plt-scheme] No ODBC for DrScheme?

Hi all,
I'm learning R6RS Scheme and I would like to use it in some simple
program at work. I need to connect to some databases (mainly Informix
and MSSQL) through ODBC but I could not find an ODBC library. I
googled a lot but it seems that such library does not exists, am I
blind or is it real? It would be strange that no one needs it...
It seems that Spark Scheme, built on top of MzScheme, has a built-in
database and also a generic ODBC interface (see
http://spark-scheme.wikispot.org/SQL_%26_ODBC). Maybe it's possible to
use its libraries?

Thank you for your help