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Home -> Community -> Mailing Lists -> Oracle-L -> RE: comparing null values
the NULL can be looked as field never ever used.
a field that is looked as never ever used cannot match something or it's complement. this filed only matches NULL.
btw: investigate into CODD's laws if you can spend some time.
apologies for any typos overlooked
kr
m.r.reger
>>> wiwaniec_at_novalistech.com 01/30/03 22:15 PM >>>
While I agree that it could return the rows, I also understand the system
side.
Null is nothing so it can not be compared to anything else, even another
null. It is something like:
"I don't know whether it is like '%STU%' or not because it is nothing - I don't know what nothing is"
Witold
-----Original Message-----
Jackson
Sent: 30 January 2003 3:27 PM
To: Multiple recipients of list ORACLE-L
Why is this?? If I know that value X has no value, I certainly know that value X is not like '%STU%' ?????
>From: "Whittle Jerome Contr NCI" <Jerome.Whittle_at_scott.af.mil>
>To: <ORACLE-L_at_fatcity.com>
>CC: <fred_fred_1_at_hotmail.com>
>Subject: RE: comparing null values
>Date: Thu, 30 Jan 2003 13:15:33 -0600
>
>Gary,
>
>Null has no value. It can't be like or not like anything. If you want to
>see the null you'll need to add OR IS NULL to your Where clause.
>
>Jerry Whittle
>ASIFICS DBA
>NCI Information Systems Inc.
>jerome.whittle_at_scott.af.mil
>618-622-4145
>
> > -----Original Message-----
> > From: Gary Jackson [SMTP:fred_fred_1_at_hotmail.com]
> >
> > 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?
> >
-- 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: Witold Iwaniec INET: wiwaniec_at_novalistech.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: Markus Reger INET: reger_at_mdw.ac.at 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).Received on Fri Jan 31 2003 - 01:49:02 CST
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