Re: CHECK constraint

Поиск
Список
Период
Сортировка
От paul butler
Тема Re: CHECK constraint
Дата
Msg-id 0f5683353140d33PCOW058M@blueyonder.co.uk
обсуждение исходный текст
Ответ на CHECK constraint  (Ben Clewett <B.Clewett@roadrunner.uk.com>)
Ответы Re: CHECK constraint  (Ben Clewett <B.Clewett@roadrunner.uk.com>)
Список pgsql-novice
Date sent:          Thu, 13 Mar 2003 14:35:40 +0000
From:               Ben Clewett <B.Clewett@roadrunner.uk.com>
Copies to:          pgsql-novice@postgresql.org
Subject:            [NOVICE] CHECK constraint

Ben,
Would foreign keys not be the simplest solution?

CREATE TABLE foo(

id int4 NOT NULL,
FOREIGN KEY (id) REFERENCES bar(id) ON DELETE CASCADE ON UPDATE CASCADE NOT DEFERRABLE INITIALLY IMMEDIATE,

)
In SQL standards, I belive a SELECT query is valid in a check constraint:

CREATE TABLE foo (
    a INT CHECK ( a IN ( SELECT b FROM bar WHERE .... ) )
}


> However, this seems not to be the case (yet) in PostgreSQL.
>
> Should I do this with Triggers instead?  Are there any other elegent
> methods of doing the same?


Ben


---------------------------(end of broadcast)---------------------------
TIP 2: you can get off all lists at once with the unregister command
    (send "unregister YourEmailAddressHere" to majordomo@postgresql.org)

В списке pgsql-novice по дате отправления:

Предыдущее
От: Ben Clewett
Дата:
Сообщение: CHECK constraint
Следующее
От: Bruno Wolff III
Дата:
Сообщение: Re: Version Number