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From:Peter Lauri Date:December 6 2006 10:28am
Subject:RE: SUM() of 1 and NULL is 1 ?
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IF(SUM(IF(Jan IS NULL, 0, Jan))>0, SUM(IF(Jan IS NULL, 0, Jan)), NULL)

This was just a guess :)



-----Original Message-----
From: C.R.Vegelin [mailto:cr.vegelin@stripped] 
Sent: Wednesday, December 06, 2006 11:58 AM
To: mysql@stripped
Subject: SUM() of 1 and NULL is 1 ?

Hi List,

I need to SUM() on months from a table like:
CREATE TABLE `data`
( `Jan` float default NULL,
...
) ENGINE=MyISAM; # V 5.0.15

Months may have NULL values, like:
INSERT INTO data (Jan) VALUES (1), (NULL);

However, when I use SELECT SUM(Jan) AS Jan,
the returned value is 1 in stead of NULL.
How to get a result NULL when in such a case ?

TIA, Cor

Thread
SUM() of 1 and NULL is 1 ?C.R.Vegelin6 Dec
  • RE: SUM() of 1 and NULL is 1 ?Peter Lauri6 Dec
  • Re: SUM() of 1 and NULL is 1 ?ViSolve DB Team6 Dec
  • Re: SUM() of 1 and NULL is 1 ?ViSolve DB Team6 Dec
  • Re: SUM() of 1 and NULL is 1 ?Remo Tex7 Dec
Re: SUM() of 1 and NULL is 1 ?C.R.Vegelin6 Dec
  • Re: SUM() of 1 and NULL is 1 ?Martijn Tonies6 Dec
  • Re: SUM() of 1 and NULL is 1 ?Peter Brawley6 Dec