I think the idea is feasble but would it possible to have this work with a MYSQL db? or maybe should it just wok with a text file.
It is possible to do what you are talking about but i am not sure though with a mysql database i would use SQL-Server if you can. I have heard of people using mysql but have also heard it is very difficult to get it to work right. Again these are things that i have heard not actually done. Hope that helps.
Also i wouldnt use a text document for security reasons. It is also considered bad practice to store information like that in a text document.