At 08:56 PM 6/29/99 -0300, The Hermit Hacker wrote:
>On Wed, 30 Jun 1999, Daniele Orlandi wrote:
>
>>
>> I don't know what SQL standards say about this, but in:
>>
>> 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?
He's saying that the expression can be resolved because
their values are equal, so it doesn't matter which username
you match on.
Which means he thinks that expression semantics rather than
scoping/parsing/type rules ought to determine what is
and what is not an ambiguous expression. Which is...well...
just wrong :)
- Don Baccus, Portland OR <dhogaza@pacifier.com> Nature photos, on-line guides, and other goodies at
http://donb.photo.net