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Message-ID: <45EDA139.6070103@archonet.com>
Date: Tue, 06 Mar 2007 17:13:29 +0000
From: Richard Huxton <dev@archonet.com>
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To: Ezequias Rodrigues da Rocha <ezequias.rocha@gmail.com>
Cc: PostgreSQL <pgsql-sql@postgresql.org>
Subject: Re: Inc
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Ezequias Rodrigues da Rocha wrote:
> Hi list,
> 
> There is any function to increment with 1 some field.
> 
> For example. I have a table with a field that on each update it
> incrementes a field that is allways configured to 0 before the
> starting of updates.

Something like:

CREATE FUNCTION my_autoinc() RETURNS TRIGGER AS $$
BEGIN
     NEW.counter := NEW.counter + 1;
     RETURN NEW;
END;
$$ LANGUAGE plpgsql;

CREATE TRIGGER my_counter_trig BEFORE UPDATE ON my_table
FOR EACH ROW EXECUTE PROCEDURE my_autoinc();

-- 
   Richard Huxton
   Archonet Ltd