IF(SUM(IF(Jan IS NULL, 0, Jan))>0, SUM(IF(Jan IS NULL, 0, Jan)), NULL)
This was just a guess :)
From: C.R.Vegelin [mailto:cr.vegelin@stripped]
Sent: Wednesday, December 06, 2006 11:58 AM
Subject: SUM() of 1 and NULL is 1 ?
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 ?