On Update (trigger hint)

[MaRCeLO PeReiRA]

Hi guys,

Please, give me some advices on how to do the
following:

I have the following table:

CREATE TABLE products (
id SERIAL,
description TEXT,
lastupdate date
);

Well, I would like to update the column "lastupdate"
with the value "now()" on every UPDATE executed on a
row of this table.

Do I have to create a function to do it? Can you help
me?

Regards,

Marcelo

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[Michael Vester]

MaRCeLO PeReiRA wrote:

Hi guys,

Please, give me some advices on how to do the
following:

I have the following table:

CREATE TABLE products (
id SERIAL,
description TEXT,
lastupdate date
);

Well, I would like to update the column "lastupdate"
with the value "now()" on every UPDATE executed on a
row of this table.

Do I have to create a function to do it? Can you help
me?

Regards,

Marcelo

<snip>

/* Your function */
CREATE FUNCTION set_lastchg() RETURNS opaque AS '
BEGIN
NEW.lastupdate = now();
RETURN NEW;
END;
'LANGUAGE 'plpgsql';

/* and the triggers that will use it, All my main tables have a
lastupdate column and a trigger to execute set_lastchg()
whenever the row is changed */

CREATE TRIGGER lastclubchg_trig
BEFORE INSERT OR UPDATE ON club FOR EACH
ROW EXECUTE PROCEDURE set_lastchg();

CREATE TRIGGER lastownerchg_trig
BEFORE INSERT OR UPDATE ON owner FOR EACH
ROW EXECUTE PROCEDURE set_lastchg();

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