Hi Christof,
Not MySQL, but I have done it for SQLite3 database. You can find the details of the implementation and the source code from here:
http://onkyo.u-aizu.ac.jp/index.php/software/hrir/
I wonder how difficult would be to make a generic DB driver, an object that connects to any DB, performs SQL send to its input and returns the results in its outlet. Sounds like fun…
Cheers,
Julian.