Oracle-L: RE: comparing null values

From: Koivu, Lisa <Lisa.Koivu_at_efairfield.com>
Date: Thu, 30 Jan 2003 11:26:45 -0800
Message-ID: <F001.0053F645.20030130112645@fatcity.com>

Gary I think this goes back to the classic definition of NULL. NULL means "unknown value". Therefore you can't say anything definite about the value. So it is not equal to anything or like anything, period. It is "IS NULL" from a SQL perspective.

HTH -----Original Message-----
Sent: Thursday, January 30, 2003 12:42 PM To: Multiple recipients of list ORACLE-L

Can anyone explain why it is that I seem unable to use 'like' and 'not like'

on columns containing null values. (I am unable to find information regarding this on MetaLink.)

For example:

SQL> select * from tester2;

COL1 COL2 WHATEVER
---- ---- --------
1 1 STUFF
2 2 STUFF
3 3
4 4

SQL> select * from tester2 where whatever not like '%STU%'; no rows selected

My question is why does this not return the 3 & 4 columns?

MSN 8 helps eliminate e-mail viruses. Get 2 months FREE*. http://join.msn.com/?page=features/virus

--

Please see the official ORACLE-L FAQ: http://www.orafaq.net
--

Author: Gary Jackson
INET: fred_fred_1_at_hotmail.com

Fat City Network Services    -- 858-538-5051 http://www.fatcity.com
San Diego, California        -- Mailing list and web hosting services
---------------------------------------------------------------------

To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).

--

Please see the official ORACLE-L FAQ: http://www.orafaq.net
--

Author: Koivu, Lisa
INET: Lisa.Koivu_at_efairfield.com

Fat City Network Services    -- 858-538-5051 http://www.fatcity.com
San Diego, California        -- Mailing list and web hosting services
---------------------------------------------------------------------