You need to tell the xSQL plugin where to find your database files. If XBMC is running on a different machine from VoxCommando, then you either need to locate the .db files via a network share, or you need to copy the .db files to the computer running VoxCommando.
The other option is to get an updated version of the xJson plugin which allows for an alternative way to get the info. When you are running XBMC on a another machine, this is a better method, but it is not yet part of the official release.
Also, of course your XBMC must be set up correctly with all your media properly scanned to the library.