“you have to use GROUP BY for it to work as expected.” Not in this case you don’t. There’s no value in the SELECT to group by. From: Maria-discuss [mailto:maria-discuss-bounces+rhys.campbell=tradingscreen.com@lists.launchpad.net] On Behalf Of Guillaume Lefranc Sent: 19 June 2015 10:03 To: Benoit Panizzon Cc: maria-discuss@lists.launchpad.net Subject: Re: [Maria-discuss] Bug in MAX() function? Hi Benoit, MAX() is an aggregate function, you have to use GROUP BY for it to work as expected. e.g. select MAX(mail_out_anon+mail_out_auth) FROM domaincounters GROUP BY timefunction; Hope this helps -Guillaume 2015-06-19 10:59 GMT+02:00 Benoit Panizzon <benoit.panizzon@imp.ch<mailto:benoit.panizzon@imp.ch>>: Hi all I stumbled over that problem, while trying to graph mail traffic.. I have two different counters for emails sent with authentication and without. Aggregated per hour. I would like to total the both values per row, to create a graph of outgoing emails per hour. MariaDB [maildb]> select mail_out_anon,mail_out_auth from domaincounters; +---------------+---------------+ | mail_out_anon | mail_out_auth | +---------------+---------------+ | 8 | 58 | | 8 | 48 | | 4 | 63 | | 9 | 53 | | 2 | 36 | | 0 | 12 | | 3 | 2 | | 0 | 2 | | 0 | 6 | | 0 | 2 | | 0 | 9 | | 0 | 44 | | 14 | 63 | | 0 | 96 | | 7 | 43 | | 4 | 61 | | 2 | 43 | | 2 | 66 | | 0 | 86 | | 6 | 77 | | 6 | 55 | | 0 | 63 | | 6 | 48 | | 2 | 52 | +---------------+---------------+
select mail_out_anon+mail_out_auth as mail_out_total from domaincounters;
+-----------------------------+ | mail_out_anon+mail_out_auth | +-----------------------------+ | 70 | | 56 | | 67 | | 62 | | 38 | | 12 | | 5 | | 2 | | 6 | | 2 | | 9 | | 44 | | 77 | | 96 | | 50 | | 65 | | 45 | | 68 | | 86 | | 83 | | 61 | | 63 | | 54 | | 54 | +-----------------------------+ Now I need the max value of that addition to auto-scale the graph. MariaDB [maildb]> select MAX(mail_out_anon+mail_out_auth) +----------------------------------+ | MAX(mail_out_anon+mail_out_auth) | +----------------------------------+ | 187 | +----------------------------------+ What did MariaDB count here? I was expecting a value 96 which is the largest value of all the additions. Also trying various ways of first using GREATEST() always returns a way to high value. Is it a bug, or did I do something wrong? Mit freundlichen Grüssen Benoit Panizzon -- I m p r o W a r e A G - ______________________________________________________ Zurlindenstrasse 29 Tel +41 61 826 93 07 CH-4133 Pratteln Fax +41 61 826 93 02 Schweiz Web http://www.imp.ch ______________________________________________________ _______________________________________________ Mailing list: https://launchpad.net/~maria-discuss Post to : maria-discuss@lists.launchpad.net<mailto:maria-discuss@lists.launchpad.net> Unsubscribe : https://launchpad.net/~maria-discuss More help : https://help.launchpad.net/ListHelp