accumulated statistics

I need accumulated hits statistics from my web appl. and it was looks easy
to implement.

Quick scenario:

1. create table hits (msg_id int4 not null primary key, hits int4);
2. in cgi script
update hits set hits=hits+1 where msg_id = $msg_id;

But this will not works if there are no row with msg_id,
so I need to insert row before. I could do this in application
but I suspect it could be done with rules.

before I dig into rules programming I'd like to know if somebody
has already have similar rule or is there another way to do this
in postgres. I'd prefer fast solution.

Regards,

Oleg

_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
Internet: oleg(at)sai(dot)msu(dot)su, http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83