Re: max and sum function

Поиск
Список
Период
Сортировка
От Greg Stark
Тема Re: max and sum function
Дата
Msg-id 87y932kxv8.fsf@stark.dyndns.tv
обсуждение исходный текст
Ответ на Re: max and sum function  ("Waruna Geekiyanage" <waruna@nirmani.com>)
Список pgsql-php
"Waruna Geekiyanage" <waruna@nirmani.com> writes:

> 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);

select int4larger(int4larger(max(one),max(two)),max(three)) from table group by id;

I'm a bit stumped why it seems I have to use "int4larger" and just "larger"
doesn't work like with most functions. There must be a right way to do it
without hard coding the datatype.

--
greg

В списке pgsql-php по дате отправления:

Предыдущее
От: apz
Дата:
Сообщение: Re: make form list with option select
Следующее
От: Ray Hunter
Дата:
Сообщение: Re: make form list with option select