On 20/09/11 09:25, Kjell Rilbe wrote:

> ...

> I was under the impression that the query parser would recognize that
> the two expressions are identical. That's actually how it works in SQL
> Server 2008. In fact, there you HAVE to use that syntax; you CANNOT
> refer to the select list's column alias in the group by clause. I wasn't
> aware that SQL Server and Firebird are different in this respect.
Ditto Oracle. You must repeat the selected expression in the group by
clause, you cannot use an alias or a column position. Having said that,
I much prefer the Firebird method!

> ...

>> You will get the groups in order anyway, so you don't actually need the
>> ORDER BY clause.
> But this is just an implementation artefact, isn't it? Not something
> that's actually defined in the language?
Again, in Oracle, it is not necessarily true that a group by implies the
same order by. It used to - up to version 9i if I remember correctly -
but not any longer.


Just an observation.


Cheers,
Norm.

--
Norman Dunbar
Dunbar IT Consultants Ltd

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