Skip site navigation (1) Skip section navigation (2)

Re: Is it possible to redirect an update/insert/delete to a different table?

From: Andreas Kretschmer <akretschmer(at)spamfence(dot)net>
To: pgsql-sql(at)postgresql(dot)org
Subject: Re: Is it possible to redirect an update/insert/delete to a different table?
Date: 2005-11-20 16:42:34
Message-ID: 20051120164234.GB2832@kaufbach.delug.de (view raw or flat)
Thread:
Lists: pgsql-sql
Andy Ballingall <andy(at)areyoulocal(dot)co(dot)uk> schrieb:

> Hello Jaime,
> 
> I'm still not quite clear.
> 
> Say I have a number of different updates on a table 'apples' in my code,
> including:
> 
> UPDATE apples set pips=6 and color='yellow' where id=3;
> UPDATE apples set size=10 where id=6;
> 
> What would a rule look like which, when *any* update is attempted on the
> apples table, will instead apply the update to a different table - 'pears'.

Try it.

test=# create table apples (id int, name1 text, name2 text);
CREATE TABLE
test=# create table pears (id int, name1 text, name2 text);
CREATE TABLE
test=# create rule apples_pears_update as on update to apples do instead
update pears set name1= NEW.name1, name2=NEW.name2 where id=NEW.id ;
CREATE RULE
test=# insert into apples values (1, 'a', 'a');
INSERT 0 1
test=# insert into pears values (1, 'a', 'a');
INSERT 0 1
test=#
test=# update apples set name1='b' where id = 1;
UPDATE 1
test=# select * from pears ;
 id | name1 | name2
----+-------+-------
  1 | b     | a
(1 row)

test=# update apples set name2='c' where id = 1;
UPDATE 1
test=# select * from pears ;
 id | name1 | name2
----+-------+-------
  1 | a     | c
(1 row)

test=# update apples set name1='e', name2='e' where id = 1;
UPDATE 1
test=# select * from pears ;
 id | name1 | name2
----+-------+-------
  1 | e     | e
(1 row)



> 
> -----Original Message-----

Please, no top-posting.


HTH, Andreas
-- 
Really, I'm not out to destroy Microsoft. That will just be a completely
unintentional side effect. (Linus Torvalds)
Kaufbach, Saxony, Germany, Europe.              N 51.05082°, E 13.56889°

In response to

Responses

pgsql-sql by date

Next:From: Andreas KretschmerDate: 2005-11-20 17:01:36
Subject: Re: Is it possible to redirect an update/insert/delete to a different table?
Previous:From: Andy BallingallDate: 2005-11-20 16:37:54
Subject: Re: Is it possible to redirect an update/insert/delete to a different table?

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group