> I heard SDF3 is based on Sqlite technology. I've seen ODBC drivers for
> Sqlite but I don't think they work with SDF3.
Although I also see the utility in an OLEDB/ODBC driver for SDF3 (or
more usefully, making SDF3 files accessible as SQLite) in the meantime
you can run queries against SDF3 files using either MapGuide or FDO
The MapGuide FeatureService has some good examples: