Re: Constraint problems

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От GB Clark
Тема Re: Constraint problems
Дата
Msg-id 20020927145652.4c82624e.postgres@vsservices.com
обсуждение исходный текст
Ответ на Re: Constraint problems  (Stephan Szabo <sszabo@megazone23.bigpanda.com>)
Список pgsql-sql
On Fri, 27 Sep 2002 11:29:34 -0700 (PDT)
Stephan Szabo <sszabo@megazone23.bigpanda.com> wrote:

> On Fri, 27 Sep 2002, GB Clark wrote:
> 
> > CREATE TABLE sysusers (
> > user_id            INTEGER DEFAULT nextval('sysusers_user_id_seq')
> >                     UNIQUE NOT NULL PRIMARY KEY,
> > username            text NOT NULL UNIQUE,
> > password            text NOT NULL,
> >
> > createby            text NOT NULL DEFAULT 'syscreate',
> >
> > status            char(1) DEFAULT 'A' CHECK (status in ('A', 'I')),
> > comment1            text,
> > comment2            text,
> > tstamp            timestamp DEFAULT CURRENT_TIMESTAMP
> > );
> >
> > CREATE UNIQUE INDEX username_unique_idx ON sysusers (username);
> >
> > INSERT INTO sysusers (username, password, createby) VALUES ('syscreate', 'testing', 'syscreate');
> >
> > ALTER TABLE sysusers ADD CONSTRAINT createby_test CHECK (createby in (username));
> 
> This is only going to check the value of username in the current row.
> 
> Why not use a foreign key from createby to username?
> 
Thanks!  The FK was just what I was looking for.  I had not relized that I could
do a current table reference in a FK declaration.

Thanks,

GB

-- 
GB Clark II             | Roaming FreeBSD Admin
gclarkii@VSServices.COM | General Geek           CTHULU for President - Why choose the lesser of two evils?


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