Re: SQL feature requests

Kevin Grittner wrote:
>>>> On Thu, Aug 23, 2007 at 3:01 PM, in message <11856(dot)1187899268(at)sss(dot)pgh(dot)pa(dot)us>,
> Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> The only argument I've
>> heard that carries much weight with me is that it eases porting from
>> other DBMS's that allow this. Are there any others besides Oracle?
>
>> select * from (select f1 from t)
>
> In Sybase:
>
> com.sybase.jdbc2.jdbc.SybSQLException: The derived table expression is missing a correlation name. Check derived table syntax in the Reference Manual.
> Error code: 11753
> SQL state: ZZZZZ

The really funny thing is that pgsql, mysql and at least sybase
*explicitly* dissallow the no-alias case. Which shows that
.) This seems to be common source of confusion and errors.
.) Aliasless-Subqueries wouldn't lead to ambigous grammras in those databases.
Otherwise, you'd expect to get some more generic syntax error, and not
the very explicit "No alias, but expected one".

I agree with Tom - knowing *why* the standard committee disallows that syntax -
and why everybody except oracle chose to agree with it would be quite interesting.

greetings, Florian Pflug