Re: update only if single row

It is supposed to update multiple rows.

It is supposed to update all rows which have an email
address matching the pattern ~* 'rvro', except rows
where there are other rows with the same email address.

Troy



>
>
> Except for one minor detail.  It updates multiple rows!
>
> At 02:39 AM 4/07/00 -0700, you wrote:
> >Excellent solution.
> >
> >You can use oid as the unique attribute.
> >
> > UPDATE contact SET bounce = 1 WHERE email ~* 'rvro' AND email NOT IN
> >  (SELECT c1.email FROM contact c1, contact c2
> >   WHERE c1.oid != c2.oid AND c1.email = c2.email);
> >
> >Troy
> >>
> >> Hi
> >>
> >> FB> select * from contact where email ~* 'rvro';
> >> FB> if I get a single row in the result then I enter:
> >> FB> update contact set bounce=1 where  email ~* 'rvro';
> >>
> >> FB> Can I combine this into a single SQL statement with the following
> >> FB> requirements:
> >> FB> 1) the update is only performed if a single row is selected
> >> FB> 2) I only enter the selection string ('rvro' in this case) once in the
> >> FB> command?
> >>
> >> Assume that pk is PRIMARY KEY (or UNIQUE attribute) of relation contact.
> >>
> >> UPDATE contact SET bounce = 1 WHERE email ~* 'rvro' AND NOT email IN
> >>  (SELECT c1.email FROM contact c1, contact c2
> >>   WHERE c1.pk != c2.pk AND c1.email = c2.email);
> >>
> >> LPK Station                            mailto:kl@84105.aanet.ru
>