Hello, Can any of you explain me why, when i do this request : select count(*) from OBJET as t1 left join COLLECTION as t2 ON t1.numColl = t2.numColl where t2.numSupp = 0; I've got an error saying : Field numObj not found note that numObj is the Key of table OBJET... Thank's -- Best regards, SixK mailto:[EMAIL PROTECTED] --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php