Re: conditional aggregates
| От | Marc Mamin |
|---|---|
| Тема | Re: conditional aggregates |
| Дата | |
| Msg-id | C4DAC901169B624F933534A26ED7DF31034BB97C@JENMAIL01.ad.intershop.net обсуждение исходный текст |
| Ответ на | Re: conditional aggregates (Marcin Krawczyk <jankes.mk@gmail.com>) |
| Ответы |
Re: conditional aggregates
|
| Список | pgsql-sql |
something like ?
Select min (case when X > 0 then X end)
HTH,
Marc Mamin
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.
regards
mk
2010/12/8 Pavel Stehule <pavel.stehule@gmail.com>
Hello
use a CASE statement
http://www.postgresql.org/docs/7.4/static/functions-conditional.html
Regards
Pavel Stehule
2010/12/8 Marcin Krawczyk <jankes.mk@gmail.com>:
> 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
>
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