I think your right about MySQL not supporting foreign keys. It's not to hard to provide the code to support the referential integrity in your app - but it takes time. Since MySQL 4 now supports SP's maybe you can place the code to RI in a SP.

I haven't had time to check out your app but will later.

In the three tier app you are suggestioning to disconnect? So very time the client app needs data you re-open the connection? Isn't the opening and closing very costly in performance?

John