From: pgsql-sql-owner@postgresql.org [mailto:pgsql-sql-owner@postgresql.org] On Behalf Of Marcin Krawczyk Sent: Mittwoch, 8. Dezember 2010 14:20 To: Pavel Stehule Cc: pgsql-sql@postgresql.org Subject: Re: [SQL] conditional aggregates
Yeah I know but I'm having problems creating sfunc fuction for the aggregate.
> Hi list, > Can anyone advise me on creating an aggregate that would take additional > parameter as a condition ? For example, say I have a table like this > id;value > 1;45 > 2;13 > 3;0 > 4;90 > I'd like to do something like this > SELECT min_some_cond_aggregate(value,0) FROM table > to get the minimal value from table greater than 0, in this case 13. > I can't do SELECT min(value) FROM table WHERE value > 0 as this will mess my > other computations. My current solution involves a function operating on the > output of array_accum from the docs, but I'm looking for more elegant > solution. > Is this possible at all ? I'm running 8.1. > > regards > mk >
