Message-ID: <005501c26007$e2aa3bc0$4201a8c0@beeblebrox>
From: "Michael Paesold" <mpaesold@gmx.at>
To: "PostgreSQL Server" <postgres@rsd.it>, <pgsql-sql@postgresql.org>
References: 
 <Pine.LNX.4.44.0209191747250.31615-100000@sunrise2.radiostudiodelta.it>
Subject: Re: Table Copy.
Date: Thu, 19 Sep 2002 20:10:46 +0200
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Alex wrote:
> HI!
> 
> I'm new to postgres. I need to have a table as a copy of another one.
> 
> Example:
> 
> CREATE TABLE one (
>         fileda INTEGER,
>         filedb INTEGER,
>         filedc INTEGER );
> 
> CREATE TABLE two (
>         fileda INTEGER,
>         filedb INTEGER,
>         filedc INTEGER );
> 
> As on insert to table one I should get the same insert on table two.
> As on delete to table one I should get the same delete on table two.
> As on update to table one I should get the same update on table two.
> 
> Can someone provide the examples i can study ?

You could do it with RULEs. Here is an example how you would do the DELETE.

CREATE RULE copy_one_to_two AS
  ON DELETE TO one
  DO
    DELETE FROM two
    WHERE two.fileda=OLD.fileda
      AND two.filedb=OLD.filedb
      AND two.filedc=OLD.filedc;

You should change the where clause if you have a primary key on that table.
I am presuming fileda/filedb/filedc are unique in combination...
Read the section of the docs about RULEs for INSERT and UPDATE examples.

Regards,
Michael Paesold