Re: mysql Group by

[Magnus Olsson]

Hi!
To me your SQL-query is not valid. Each item in the select list must be either a column in the group by list or a set function. E.g you want one row and the set-function (MAX) will select one value, but timestamp have different values so the DBMS don't know which value to use.

I don't understand why MySQL lets such a query through. It ought to reply with the same kind of error message you get when you execute the same query but without the group by:

"Mixing of GROUP columns (MIN(),MAX(),COUNT(),...) with no GROUP columns is illegal if there is no GROUP BY clause "

To your query...
I think you can use a correlated subquery:

select port, bytes, timestamp
from test t
where bytes = (select max(bytes) from test where input_interface = t.input_interface);