Re: Return LEFT JOINed tables when one has no matching column

Поиск
Список
Период
Сортировка
От Harald Fuchs
Тема Re: Return LEFT JOINed tables when one has no matching column
Дата
Msg-id pueit91q5g.fsf@srv.protecting.net
обсуждение исходный текст
Ответ на Return LEFT JOINed tables when one has no matching column  (Madison Kelly <linux@alteeve.com>)
Ответы Re: Return LEFT JOINed tables when one has no matching column  (Madison Kelly <linux@alteeve.com>)
Список pgsql-general
In article <4A425379.90907@alteeve.com>,
Madison Kelly <linux@alteeve.com> writes:

> SELECT
>     a.tbl1_name,
>     b.tbl2_date,
>     c.tbl3_value AS some_value
> FROM
>     table_1 a
> LEFT JOIN
>     table_2 b ON (a.tbl1_id=b.tbl2_tbl1_id)
> LEFT JOIN
>     table_3 c ON (a.tbl1_id=c.tbl3_tbl1_id)
> WHERE
>     c.tbl3_variable='some_variable'
> AND
>     a.tbl1_id=123;

>   I want the data from table_1 and table_2 to return and table_3 to
> return NULL when there is no matching
> c.tbl3_variable='some_variable'. Is this possible?

Move "c.tbl3_variable='some_variable'" from WHERE to c's ON clause.

В списке pgsql-general по дате отправления:

Предыдущее
От: Eduardo Morras
Дата:
Сообщение: Re: WAL and master multi-slave replication
Следующее
От: Jorge Vidal - Disytel
Дата:
Сообщение: Re: 8.4 RC1 on ubuntu 9.04 jaunty, problems after install