Question

Say I have a basic table, products, with 3 fields, productname, cost, and costnotax.

Is it possible to automatically fill in the costnotax field by subtracting a percentage from the cost field?

Answer 1

Yes – simply something like this to calculate what the original cost was if you’ve got, say, 6% tax

UPDATE mytable SET costnotax=cost/1.06

However, there’s little point in storing it when you can select it just as easily

SELECT cost, cost/1.06 AS costnotax FROM mytable;