Re: What kind of JOIN, if any?

Поиск
Список
Период
Сортировка
От Serge Fonville
Тема Re: What kind of JOIN, if any?
Дата
Msg-id 680cbe0e0909170814r2829321cr68c4add34997dcca@mail.gmail.com
обсуждение исходный текст
Ответ на What kind of JOIN, if any?  (Paul M Foster <paulf@quillandmouse.com>)
Список pgsql-general
Hi,
 
I'd look into outer joins
 
 
I can do *part* of this with various JOINs, but the moment I specify
userid = 'paulf', I don't get the rows with NULLs
 
If you want all fields from one table and only those matching from another use outer join
 
HTH
 
Regards,
 
Serge Fonville

On Thu, Sep 17, 2009 at 4:29 PM, Paul M Foster <paulf@quillandmouse.com> wrote:
Folks:

I can't find a way to do this purely with SQL. Any help would be
appreciated.

Table 1: urls

id | url
--------------
1  | alfa
2  | bravo
3  | charlie
4  | delta

Table 2: access

userid | url_id
---------------
paulf  | 1
paulf  | 2
nancyf | 2
nancyf | 3

The access table is related to the url table via url_id = id.

Here's what I want as a result of a query: I want all the records of the
url table, one row for each record, plus the userid field that goes with
it, for a specified user (paulf), with NULLs as needed, like this:

userid | url
-------------
paulf  | alfa
paulf  | bravo
      | charlie
      | delta

I can do *part* of this with various JOINs, but the moment I specify
userid = 'paulf', I don't get the rows with NULLs.

Again, any help would be appreciated.

Paul

--
Paul M. Foster

--
Sent via pgsql-general mailing list (pgsql-general@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general

В списке pgsql-general по дате отправления:

Предыдущее
От: Paul M Foster
Дата:
Сообщение: What kind of JOIN, if any?
Следующее
От: Sam Mason
Дата:
Сообщение: Re: What kind of JOIN, if any?