Re: Update and trigger

Thanks...but a difference seems to be that the rule is not specific to
update on a particular col but any col of a row getting updated...

Thanks

On Tue, Jun 10, 2008 at 10:21 PM, A. Kretschmer <
andreas(dot)kretschmer(at)schollglas(dot)com> wrote:

> am Tue, dem 10.06.2008, um 18:45:51 -0700 mailte Medi Montaseri folgendes:
> > Hi,
> >
> > I need to increament a counter such as myTable.Counter of type integer
> > everytime myTable.status a boolean column is updated. Can you help me
> complete
> > this...
> >
> > create trigger counter_trigger after update on myTable.counter
> > execute procedure 'BEGIN statement; statement; statement END'
>
> much simpler, use a RULE instead a TRIGGER like my example:
>
> Suppose, i have a table called foo, it contains now:
>
> test=# select * from foo;
> i
> ---
> 1
> 2
> (2 rows)
>
>
> I create a sequence and a RULE:
>
> test=*# create sequence foo_counter;
> CREATE SEQUENCE
> test=*# create or replace rule foo_update as on update to foo do also
> select nextval('foo_counter');
> CREATE RULE
>
>
> And now i do a update on foo:
>
>
> test=*# update foo set i=2;
> nextval
> ---------
> 1
> (1 row)
>
> test=*# update foo set i=3;
> nextval
> ---------
> 2
> (1 row)
>
>
> test=*# select currval('foo_counter');
> currval
> ---------
> 2
> (1 row)
>
>
>
> Andreas
> --
> Andreas Kretschmer
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