Re: Selecting tree data

Поиск
Список
Период
Сортировка
От Pat Maddox
Тема Re: Selecting tree data
Дата
Msg-id 810a540e0710261107i65292263q51934fbad70f46ed@mail.gmail.com
обсуждение исходный текст
Ответ на Re: Selecting tree data  (Michael Glaesemann <grzm@seespotcode.net>)
Ответы Re: Selecting tree data  (brian <brian@zijn-digital.com>)
Список pgsql-general
On 10/26/07, Michael Glaesemann <grzm@seespotcode.net> wrote:
>
> On Oct 26, 2007, at 10:56 , Pat Maddox wrote:
>
> > A bunch of options so far...but there's really no way to do this with
> > standard SQL?
>
> What do you mean by "standard SQL"? Trees aren't inherently relational.

Right now my table looks like this:

posts
  id
  body
  parent_id
  root_id
  created_at

so if I've got the records

(1, 'post 1', NULL, 1, '4pm')
(2, 'post 2', NULL, 2, '8pm')
(3, 'post 3', 1, 1, '6pm')
(4, 'post 4', 1, 1, '5pm')
(5, 'post 5', 4, 1, '6pm')
(6, 'post 6', NULL, 1, '5pm')

I'd like to do a select and get them all in this order:

(1, 'post 1', NULL, 1, '4pm')
(4, 'post 4', 1, 1, '5pm')
(5, 'post 5', 4, 1, '6pm')
(3, 'post 3', 1, 1, '6pm')
(6, 'post 6', NULL, 1, '5pm')
(2, 'post 2', NULL, 2, '8pm')

And reverse sorted would be:

(2, 'post 2', NULL, 2, '8pm')
(6, 'post 6', NULL, 1, '5pm')
(1, 'post 1', NULL, 1, '4pm')
(3, 'post 3', 1, 1, '6pm')
(4, 'post 4', 1, 1, '5pm')
(5, 'post 5', 4, 1, '6pm')

Does that make sense?

Pat

В списке pgsql-general по дате отправления:

Предыдущее
От: Rainer Bauer
Дата:
Сообщение: Re: 8.2.3: Server crashes on Windows using Eclipse/Junit
Следующее
От: Matthew Hixson
Дата:
Сообщение: Re: change format of logging statements?