Re: Help with join syntax sought

Поиск
Список
Период
Сортировка
От James B. Byrne
Тема Re: Help with join syntax sought
Дата
Msg-id 43368.216.185.71.24.1242767790.squirrel@webmail.harte-lyne.ca
обсуждение исходный текст
Ответ на Re: Help with join syntax sought  (Andy Colson <andy@squeakycode.net>)
Ответы Re: Help with join syntax sought  (Andy Colson <andy@squeakycode.net>)
Список pgsql-general
On Tue, May 19, 2009 17:02, Andy Colson wrote:

>
> so: select max(name), type from food group by type
> works cuz we only get one name (the max name) back for each type.
>
> or: select name, type from food group by type, name
> which in our example is kinda pointless, but still, give us the
> distinct
> items for "type, name".

Thanks.  I think I am beginning to see this.  So, if there are more
than one type for a given currency code and I do not select and
group by type then the having count(whatever) = 1 means that these
rows are not selected either.  Is that correct?


--
***          E-Mail is NOT a SECURE channel          ***
James B. Byrne                mailto:ByrneJB@Harte-Lyne.ca
Harte & Lyne Limited          http://www.harte-lyne.ca
9 Brockley Drive              vox: +1 905 561 1241
Hamilton, Ontario             fax: +1 905 561 0757
Canada  L8E 3C3


В списке pgsql-general по дате отправления:

Предыдущее
От: "James B. Byrne"
Дата:
Сообщение: Re: Help with join syntax sought
Следующее
От: "Pal, Dipali (UMKC-Student)"
Дата:
Сообщение: Direct I/O and postgresql version