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help / color / mirror / Atom feedFrom: Andreas Joseph Krogh <andreas@visena.com>
To: Pavel Stehule <pavel.stehule@gmail.com>
Cc: pgsql-sql@postgresql.org
Subject: Re: Update columns in the same table in a deferred constraint trigger
Date: Tue, 29 Jul 2014 12:49:52 +0200 (CEST)
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På tirsdag 29. juli 2014 kl. 12:40:21, skrev Pavel Stehule <
pavel.stehule@gmail.com <mailto:pavel.stehule@gmail.com>>: 2014-07-29 12:36
GMT+02:00 Andreas Joseph Krogh<andreas@visena.com <mailto:andreas@visena.com>>:
På tirsdag 29. juli 2014 kl. 12:27:32, skrev Pavel Stehule <
pavel.stehule@gmail.com <mailto:pavel.stehule@gmail.com>>: 2014-07-29 12:21
GMT+02:00 Andreas Joseph Krogh<andreas@visena.com <mailto:andreas@visena.com>>:
På tirsdag 29. juli 2014 kl. 12:12:17, skrev Pavel Stehule <
pavel.stehule@gmail.com <mailto:pavel.stehule@gmail.com>>: 2014-07-29 12:05
GMT+02:00 Andreas Joseph Krogh<andreas@visena.com <mailto:andreas@visena.com>>:
På tirsdag 29. juli 2014 kl. 12:01:48, skrev Pavel Stehule <
pavel.stehule@gmail.com <mailto:pavel.stehule@gmail.com>>: 2014-07-29 11:59
GMT+02:00 Andreas Joseph Krogh<andreas@visena.com <mailto:andreas@visena.com>>:
På tirsdag 29. juli 2014 kl. 11:56:17, skrev Pavel Stehule <
pavel.stehule@gmail.com <mailto:pavel.stehule@gmail.com>>: Hi 2014-07-29
11:52 GMT+02:00 Andreas Joseph Krogh<andreas@visena.com
<mailto:andreas@visena.com>>: Hi all. I have this simple schema: create
table fisk(
name varchar primary key,
autofisk varchar
); I want to update the column "autofisk" on commit based the value of
"name", so I created this trigger: CREATE OR REPLACE FUNCTION fisk_tf()
returns TRIGGER AS $$
BEGIN
raise notice 'name %', NEW.name <http://NEW.name;;
NEW.autofisk = NEW.name <http://NEW.name; || CURRENT_TIMESTAMP::text;
RETURN NEW;
END;
$$ LANGUAGE plpgsql; CREATE CONSTRAINT TRIGGER fisk_t AFTER INSERT OR
UPDATE ON fisk DEFERRABLE INITIALLY DEFERRED It should be BEFORE INSERT OR
UPDATE trigger He he, yes - I know that will work, but I need the trigger to
be run as a constraint-trigger, on commit, after all the data is populated in
other tables and this table. It is not possible - Postgres can change data
only before writing Is there a work-around, so I in the trigger can issue for
example: update fisk set autofisk = NEW.name <http://NEW.name; ||
CURRENT_TIMESTAMP::text where name = NEW.name; without it also triggering the
trigger? theoretically yes - you can disable triggers via ALTER TABLE DISABLE
TRIGGER
but then the code will be unmaintainable. Anything else is better than
dependency in triggers. You should to think about different solution.
Sometimes triggers can be replaced by functions directly called from
applications instead DML statements. I have tried this but the commit never
returns, I think because it recursively triggers the trigger again for that
modification. Will temporarily disabeling the trigger inside the trigger (in
a transaction) work? I really afraid of this strategy I see, so it boils
down to this being impossible at the moment. I really want this to be at the
DML-level so any modification done also updates the "autofisk"-column. Are
there any plans to make this work, that being modifying the same table in a
trigger running on it where the modification (comming form statements inside
the trigger-functino) like what I'm trying will not trigger the trigger? you
can use a auxiliary column with information where are from a UPDATE. This
information should be used for breaking recursion. But it is not a good
solution. You do some too complex.
Why you need it? Pavel How would I use this auxiliary column? As I
understand the WHERE-condition in the trigger-definition is not deferred, and
evaled only once, or is this not what you propose? Can you make an example of
how to use such an auxiliary-column? The reason I need this is that I will
concat information from different tables based on information in the table the
trigger is installed on. This information is to be updated in a column in the
same table of type "tsvector" and used for searching later. I want the
tsvector-column to be in the same table to be able to have a multicolumn index
and avoid unnecessary JOIN'ing. I am thinking so correct solution for this
solution is using a function instead trigger or redesign a schem I need this
function to be called whenever *any* modification (insert or update) is done on
the main table, how do I accomplish that without using a trigger? Thanks. --
Andreas Joseph Krogh CTO / Partner - Visena AS Mobile: +47 909 56 963
andreas@visena.com <mailto:andreas@visena.com> www.visena.com
<https://www.visena.com; <https://www.visena.com;
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To: pgsql-sql@postgresql.org
Cc: andreas@visena.com, pavel.stehule@gmail.com
Subject: Re: Update columns in the same table in a deferred constraint trigger
In-Reply-To: <VisenaEmail.41.cf32d343dc3f42c4.14781bc3e5e@tc7-on>
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