Re: GROUP BY

From: V.J. Kumar <vjkmail_at_gmail.com>
Date: Sat, 19 May 2007 16:52:15 +0200 (CEST)
Message-ID: <Xns99356EC0B6AE5vdghher@194.177.96.26>

Lennart <erik.lennart.jonsson_at_gmail.com> wrote in news:f2n1on$m8d$1 @registered.motzarella.org:

> V.J. Kumar wrote:
> [...]

>>> SELECT 1
>>> FROM r
>>> GROUP BY ();
>>> 
>>> returns a single tuple even if r is empty.
>> 
>> What SQL would that be? 

>
> The following feature outside Core SQL-99 is used:
>
> T431, "Extended grouping capabilities"
>
> I believe this is the same feature as where group by grouping sets,
> rollup and cube are defined.

What have 'extended grouping capabilities' got to do with the claim that the simple 'group by' miraculously creates a tuple out of nothing ? It does not, either in the implementations I referred to or in the '92 standard. Neither does it in '99, btw ! Also 'select 1 from t1 group by grouping sets ()' is syntactically incorrect in both implementations.

>
> /Lennart
>
> PS, Mimer (or whatever the are called these days) has a sql validator
> where one can test conformance against different versions of sql:
>
> http://developer.mimer.com/validator/index.htm
>
> DS.
>
> [...]
>
Received on Sat May 19 2007 - 09:52:15 CDT