Thanks, morning coffee hasn't kicked in. This worked out well. select user_id, max(tweet_createdat) from tweets group by user_id having datediff(now(),max(tweet_createdat)) > 7;
I forgot when to use the where and when to use the having clause. -----Original Message----- From: Michael Dykman [mailto:mdyk...@gmail.com] Sent: Sunday, November 08, 2009 8:35 AM To: John Meyer Cc: mysql@lists.mysql.com Subject: Re: Finding users who haven't posted in a week the function max(), among others, makes no sense in the absence of a GROUP BY clause. try adding "GROUP BY user_id" - michael dykman On Sun, Nov 8, 2009 at 9:40 AM, John Meyer <johnme...@pueblocomputing.com> wrote: > I want to get a list of all users who haven't posted in a week. But when I > use the following function. > > > > select user_id, max(tweet_createdat) from tweets where > datediff(now(),max(tweet_createdat)) > 7; > > > > > > Is producing the error: > > > > Invalid use of group function > > > > > > -- - michael dykman - mdyk...@gmail.com "May you live every day of your life." Jonathan Swift Larry's First Law of Language Redesign: Everyone wants the colon. No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.425 / Virus Database: 270.14.52/2484 - Release Date: 11/08/09 07:37:00 -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql?unsub=arch...@jab.org
