Re: get first and last row in one sql as two columns

Поиск
Список
Период
Сортировка
От Dickson S. Guedes
Тема Re: get first and last row in one sql as two columns
Дата
Msg-id 20150903105106.GB6274@dba01
обсуждение исходный текст
Ответ на get first and last row in one sql as two columns  (Tom Smith <tomsmith1989sk@gmail.com>)
Ответы Re: get first and last row in one sql as two columns
Список pgsql-general
On Wed, Sep 02, 2015 at 07:14:40PM -0400, Tom Smith wrote:
> Hi:
>
> I need to get the first and last tow in one sql like below
>
> select first(col1), last(col1) from table order by col1

Have you tried the window functions [1] last_value and first_value?

You could use something like:

SELECT first_value(col1) over (order by col1),
       last_value(col1)  over (order by col1)
FROM table;

It should be as simple as that, or I miss your point.


[1] http://www.postgresql.org/docs/current/static/functions-window.html


[]s
--
Dickson S. Guedes
@guediz - http://github.com/guedes

Вложения

В списке pgsql-general по дате отправления:

Предыдущее
От: Martín Marqués
Дата:
Сообщение: Re: error on online backup using pg_basebackup tool
Следующее
От: Tom Smith
Дата:
Сообщение: Re: get first and last row in one sql as two columns