Message-ID: <00f001bff876$cc57f8d0$74b5f8c2@wkst6>
From: "=?iso-8859-1?B?QW5kcukgTuZzcw==?=" <andre.nass@student.uib.no>
To: <pgsql-sql@postgresql.org>
References: <200007272216.AAA28690@hot.jw.home>
Subject: Re: Conditional rule?
Date: Fri, 28 Jul 2000 11:32:46 +0200
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----- Original Message -----
>     No. The rule
>
>         CREATE RULE newsrule AS ON INSERT TO news
>             WHERE new.publishtime NOTNULL DO
>             INSERT INTO news_unpublished VALUES (new.id);
>
>     should  do  the  job  perfectly.  Maybe  you want to have the
>     following rules too:

The following happens:
rules=# insert into news (title, time) values('Hei', now());
ERROR:  <unnamed> referential integrity violation - key referenced from
news_unpublished not found in news

Seems the data is inserted into news_unpublished first, thereby violating
the constraint I have defined for the news_id field (see below). After
removing the constraint a second problem arose; the id created for news
(serial) was 4, while the id inserted into news_unpublished was 3. So far a
trigger procedure seems to be the best solution.

>         CREATE RULE newsrule4 AS ON DELETE TO news
>             WHERE old.publishtime NOTNULL DO
>             DELETE FROM news_unpublished WHERE news_unpublished.id =
old.id;

This is also achieved by the following right? (id is the primary key for
news):
create table news_unpublished (
  news_id int references news on delete cascade
);


André Næss