Create a function that updates the record with and timestamps

In response to Chris Barnes :

I would like to have postgres update the last_modified column with the
current_date on an update of the record.

I am not sure if there is a very simple way of doing this?

Or, do I need to create a function and a trigger to call the row and update
with new data and set the last_modified to current_date?

Yes, that's the way, a TRIGGER on UPDATE for each row. I think, the doc
contains an example.

Andreas
--
Andreas Kretschmer
Kontakt: Heynitz: 035242/47150, D1: 0160/7141639 (mehr: -> Header)
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I see examples for updating tables using a function, but I would like to pull the row requested and modify the last_modified column with current_date and push the modified data back into the same row.

I did see an example of how to use old and new at this at this link, but it is vague.

http://www.faqs.org/docs/ppbook/x20655.htm#TRIGGERFUNCTIONVARIABLES

From: compuguruchrisbarnes@hotmail.com
To: pgsql-general@postgresql.org
Subject: [GENERAL] Create a function that updates the record with and timestamps
Date: Mon, 22 Mar 2010 12:58:49 -0400

I would like to have postgres update the last_modified column with the current_date on an update of the record.

I am not sure if there is a very simple way of doing this?

Or, do I need to create a function and a trigger to call the row and update with new data and set the last_modified to current_date?

Here is the table.

CREATE TABLE price.price_table (
PRICE_DATE DATE,
ID VARCHAR(13),
OPENING NUMERIC(18,6),
CLOSING NUMERIC(18,6),
HIGHEST NUMERIC(18,6),
LOWEST NUMERIC(18,6),
VOLUME BIGINT,
LAST_MODIFIED TIMESTAMP(6) WITHOUT TIME ZONE DEFAULT current_date,
CONSTRAINT PK_PRICE PRIMARY KEY (PRICE_DATE,ID));

Any help would be appreciated.

Cheers,

Chris

Date: Mon, 22 Mar 2010 18:14:00 +0100
From: andreas.kretschmer@schollglas.com
To: pgsql-general@postgresql.org
Subject: Re: [GENERAL] Create a function that updates the record with and timestamps

In response to Chris Barnes :

I would like to have postgres update the last_modified column with the
current_date on an update of the record.

I am not sure if there is a very simple way of doing this?

Or, do I need to create a function and a trigger to call the row and update
with new data and set the last_modified to current_date?

Yes, that's the way, a TRIGGER on UPDATE for each row. I think, the doc
contains an example.

Andreas
--
Andreas Kretschmer
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GnuPG: 0x31720C99, 1006 CCB4 A326 1D42 6431 2EB0 389D 1DC2 3172 0C99

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On Monday 22 March 2010 10:55:36 am Chris Barnes wrote:

I see examples for updating tables using a function, but I would like to
pull the row requested and modify the last_modified column with
current_date and push the modified data back into the same row.

I did see an example of how to use old and new at this at this link, but it
is vague.

http://www.faqs.org/docs/ppbook/x20655.htm#TRIGGERFUNCTIONVARIABLES

Something like this:

CREATE OR REPLACE FUNCTION public.ts_update()
RETURNS trigger AS

$Body$
BEGIN
NEW.ts_update:=timeofday();
RETURN NEW;
END;
$Body$
LANGUAGE 'plpgsql';

--
Adrian Klaver
adrian.klaver@gmail.com

In response to Richard Sickler :

I am not sure if there is a very simple way of doing this?

Or, do I need to create a function and a trigger to call the row and

update

with new data and set the last_modified to current_date?

Yes, that's the way, a TRIGGER on UPDATE for each row. I think, the doc
contains an example.

Andreas

From a novice: I use��� last_updated_at timestamp without time zone NOT NULL
DEFAULT now()

This works only for INSERT, but not for UPDATE.

test=# create table richard (id int, last_updated_at timestamp without time zone NOT NULL DEFAULT NOW());
CREATE TABLE
test=# insert into richard (id) values (1);
INSERT 0 1
test=# select * from richard ;
id | last_updated_at
----+----------------------------
1 | 2010-03-23 06:54:28.656668
(1 row)

test=# select now();
now
-------------------------------
2010-03-23 06:54:42.443224+01
(1 row)

test=# UPDATE richard set id=2 where id=1;
UPDATE 1
test=# select * from richard ;
id | last_updated_at
----+----------------------------
2 | 2010-03-23 06:54:28.656668
(1 row)

As you can see, the last_updated_at isn't up-to-date ;-)

Regards, Andreas
--
Andreas Kretschmer
Kontakt: Heynitz: 035242/47150, D1: 0160/7141639 (mehr: -> Header)
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