Since you ask - always avoid "macros". Always calculate with code and then update.

>I have an inventory app, want to switch the back-end to MySQL, someone suggested me not to use calculated fields (eg: stock_OnHand) and replaced them with calculation by the fly.
>
>(I have stock_OnHand field to record the balance, while his idea is throw away this field, just keep the transactions, anytime need it, calculated them with SQL statement).
>
>I'm not sure about this, before I do a big change to my app, I would like to ask for second opinion, is this the way to do with MySQL?
>
>regards,
>
>Jerry