Could you post DDL, sample data in the form of INSERT INTO statements and expected results based on that sample data.
I'm not sure if you have the best design idea according to the relational theory.
Luis C.
General Disclaimer:
Are you seriously taking the advice and code from someone from the internet without testing it? Do you at least understand it? Or can it easily kill your server?
How to post data/code on a forum to get the best help: Option 1 / Option 2