RE: comparing null values

From: Pardee, Roy E <roy.e.pardee_at_lmco.com>
Date: Thu, 30 Jan 2003 11:05:54 -0800
Message-ID: <F001.0053F4D5.20030130110554@fatcity.com>

I believe that's expected behavior, arising from the 'null means we don't know *what* the value is--it could be anything' nature of nulls. For all the db knows, those nulls represent unknown values that *are* indeed like '%STU%'. You should get the same result from select * from tester2 where whatever != 'STUFF'.

HTH,
-Roy

Roy Pardee
Programmer/Analyst
SWFPAC Lockheed Martin IT
Extension 8487

-----Original Message-----

Sent: Thursday, January 30, 2003 9:42 AM 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?

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Author: Gary Jackson
  INET: fred_fred_1_at_hotmail.com

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Author: Pardee, Roy E
  INET: roy.e.pardee_at_lmco.com

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