SELECT MAX(aa.res) from ((select sum(col1) as res from table group by id)
UNION
(select sum(col2) as res from table group by id)
UNION
(select sum(col3) as res from table group by id)) AS aa;
----- Original Message -----
From: "ryanne cruz" <ryanne.cruz@up.edu.ph>
To: <pgsql-php@postgresql.org>
Sent: Sunday, 23 March, 2003 9:47 AM
Subject: Re: [PHP] max and sum function
hi list.
does anyone here knows of a function that is similar to the sum function but
involves more than one column? for example, i have a table with columns id,
col1, col2 and col3. i want to get the max value from the three columns
gruped
by an id.
what i came up with is something like this:
max1=select max(one) from (select sum(col1) as one from table group by id);
max2=select max(two) from (select sum(col2) as two from table group by id);
max3=select max(three) from (select sum(col3) as three from table group by
id);
then i compare the 3 max values and get the maximum of the 3.
is there an easier way to do this?
thanks.
ryanne
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