The mechanics of connecting to a MySQL database are at least part of the MySQL submissions I've made to the Exchange (like the forum and some others). Once you are comfortable with inbound and outbound data from the DB, it will make more sense when you start tapping those Xoops tables.

Xoops (I used to make flash objects for Xoops) uses an associative table structure that is a little more difficult since you have to associate things from more than one table to accomplish any given task (since the php backends it uses has a rather complicated abstraction method...and the worst part is none of it's included backends are useful to the flasher...you end up constructing your own) but it can be done.