Re: [HACKERS] Little Suggestion for 6.6

On Wed, 30 Jun 1999, Daniele Orlandi wrote:

>
>
> The Hermit Hacker wrote:
> >
> > > tacacs=> SELECT * FROM users,counters WHERE users.username=counters.username
> > > AND username='foobar';
> > > ERROR: Column 'username' is ambiguous
> > >
> > > ...username is NOT ambiguous...
> >
> > Of course it is...which username do you want to match on, users.username
> > or counters.username?
>
> IMHO it's the same, since they have to be equal...
>
> Pardon me if I'm not seeing something obvious :^)

If I understand things (which could be pushing it), the join that is being
attempted (simplistically) gets broken down as something like:

a) find all usernames in users that exist in counters
b) find all usernames in ?? that equals foobar
c) find all a AND b

Very simplistic, mind you...

IN the above sample, b can't be resolved, since you don't tell it which
table to search for the username...

Marc G. Fournier ICQ#7615664 IRC Nick: Scrappy
Systems Administrator @ hub.org
primary: scrappy(at)hub(dot)org secondary: scrappy(at){freebsd|postgresql}.org