From: Markus Schaber <schabios@logi-track.com>
To: PostgreSQL SQL <pgsql-sql@postgresql.org>
Subject: Re: Update instead rules on Views
Date: Tue, 2 Nov 2004 16:42:36 +0100
Message-ID: <20041102164236.639f10c9@kingfisher.intern.logi-track.com> (raw)
In-Reply-To: <20041102162037.306d4d0a@kingfisher.intern.logi-track.com>
References: <20041102130507.2acf486a@kingfisher.intern.logi-track.com>
<20041102162037.306d4d0a@kingfisher.intern.logi-track.com>
Hello,
On Tue, 2 Nov 2004 16:20:37 +0100
Markus Schaber <schabios@logi-track.com> wrote:
> > -- But to remain compatibility with old apps, we also need to manage
> > -- updates to the view, which are to be rewritten as follows:
> > CREATE RULE testview_update_rule
> > AS ON UPDATE TO testview DO INSTEAD
> > UPDATE realdata SET
> > index = NEW.index,
> > data = NEW.data,
> > obsolete=NULL
> > ;
>
> I now got it to work with adding a "WHERE index=NEW.index" to the view.
This seems only to work when I update on the INDEX row. I now modified
the rule to look like:
CREATE RULE testview_update_rule
AS ON UPDATE TO testview DO INSTEAD
UPDATE realdata SET
index = NEW.index,
data = NEW.data,
obsolete=NULL
WHERE index = OLD.index;
This seems to work now for arbitrary columns, provided that index is an
unique row.
When I have a table that looks like
index | data | obsolete
-------+-------+----------
2 | test |
3 | blubb |
1 | nono |
3 | hallo |
and I issue
viewtest=# update testview set data='blob' where data='hallo';
I get:
UPDATE 2
and it really updated 2 rows.
As far as I understand now, I need a primary key in the underyling table
as the qualification from the original statemet is applied to the view
results, and not propagated to the underlying table.
Thanks,
Markus
--
markus schaber | dipl. informatiker
logi-track ag | rennweg 14-16 | ch 8001 zürich
phone +41-43-888 62 52 | fax +41-43-888 62 53
mailto:schabios@logi-track.com | www.logi-track.com
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To: pgsql-sql@postgresql.org
Cc: schabios@logi-track.com
Subject: Re: Update instead rules on Views
In-Reply-To: <20041102164236.639f10c9@kingfisher.intern.logi-track.com>
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