> If you need it to work, I'm afraid you're out of luck. Think about > what a IN (x,y,z) means. It's basically the same as a = x or a = y > or a = z. So wifi_list IN (NULL) is like wifi_list = NULL, > which is never true.
Thanks for the reply Paul, and I get that NULL is a special case value, but if "wifi_list IS NULL" works, then why doesn't "wifi_list = NULL"? Logically they seem to be the same, is "IS" only used for NULL values or something? Or in other words, it would make sense to me that I should be able to say "wifi_list IS 3" instead of an = sign. > -----Original Message----- > From: Paul DuBois [mailto:[EMAIL PROTECTED] > Sent: Thursday, June 03, 2004 7:56 PM > > At 18:32 -0700 6/3/04, Daevid Vincent wrote: > >How come this one works: > > > >SELECT wifi_list, IFNULL(wifi_list, 0) as wifi_list_new, > >FROM wifi_table LEFT JOIN Swordfish.scanner ON scanner.scanner_id = > >wifi_table.scanner_id LEFT JOIN wifi_wlist_table ON wifi_table_mac = mac > >WHERE last_seen >= CURRENT_DATE AND wifi_list IS NULL; > > > >This one works too > > > >SELECT wifi_list, IFNULL(wifi_list, 0) as wifi_list_new, > >FROM wifi_table LEFT JOIN Swordfish.scanner ON scanner.scanner_id = > >wifi_table.scanner_id LEFT JOIN wifi_wlist_table ON wifi_table_mac = mac > >WHERE last_seen >= CURRENT_DATE HAVING wifi_list_new IN (0,1,2); > > > >But this one doesn't... I *need* this to work: > > >SELECT wifi_list, IFNULL(wifi_list, 0) as wifi_list_new, > >FROM wifi_table LEFT JOIN Swordfish.scanner ON scanner.scanner_id = > >wifi_table.scanner_id LEFT JOIN wifi_wlist_table ON wifi_table_mac = mac > >WHERE last_seen >= CURRENT_DATE AND wifi_list IN (NULL); -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
