Hi All, Sorry, I got a autoreply from [EMAIL PROTECTED] I was not able to understand the autoreply and thought that the mail bouced. Please ignore my duplicate mail.
Thanks again, Harish -----Original Message----- From: Roger Baklund [mailto:[EMAIL PROTECTED] Sent: Monday, January 31, 2005 6:15 PM To: mysql Cc: Michael Stassen Subject: Re: Need a query to get the difference of two tables Michael Stassen wrote: > > Roger Baklund wrote: [...] >> select a.address >> from a >> left join b on b.iid=a.id >> where b.iid is null; > > > That's not equivalent, because it leaves out a condition. I think it > should be > > SELECT a.address > FROM a > LEFT JOIN b ON a.id = b.iid AND b.message='y' > WHERE b.iid IS NULL; You are of course right, thank you! :) ...and the important thing here is to put this extra condition in the ON clause, not in the WHERE clause. -- Roger -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED] -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
