On 04/14/10 08:33, Feixiong Li wrote:
Hi , guys ,
I am newbie for sql, I have a problem when using max() function, I need
get null when there are null in the value list, or return the largest
value as usual, who can do this?
i.e. max([1,2,3,4,5]) => 5
max([1,2,3,4,5,null]) => null
if u want a function, not an aggregate
then u have the
greatest(...)
except it does not return null on null input
(i was really surprised with this completely perverted behavior
(very unusual for postgres), but it is a fact)
if u want to cheat u may just
coalesce() each input argument
then nullif() a result of the greatest() function
(if only u have enough space in a reference range to room the one
special value instead of null)
--
Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-sql
