MySQL 5: Does it matter what order my GROUP BY fields are in?

Question

Peeps,

I have a few aggregate/calculated fields in my MySQL query. My GROUP BY clause is dynamically generated, depending on what options a user selects in a web form. Curious if the order of fields listed in the GROUP BY clause can have any impact on the calculations (things like SUMs, AVERAGEs, etc)

Thanks!

Answer 1

It WILL matter if you are using WITH ROLLUP, otherwise, it should not.