- From: Andy Seaborne <andy.seaborne@epimorphics.com>
- Date: Thu, 23 Sep 2010 08:36:26 +0100
- To: Axel Polleres <axel.polleres@deri.org>
- CC: SPARQL Working Group <public-rdf-dawg@w3.org>
On 22/09/10 06:59, Axel Polleres wrote:
> I have a small question about the Definition of "Group" in the query draft:
>
> "Group((),Ω) = { 1 -> Ω }"
>
> ... shouldn't that be:
>
> "Group((),Ω) = { () -> Ω }"
>
> i.e., what is the 1 supposed to mean?
The 1 is any key. When the set of groups keys is the empty, which
happnes for
SELECT (count(*) AS ?c) { ?s ?p ?o }
then there needs to be a key value for the group.
It could be said to be slightly more sense to be (1), not 1, as it's a
list when then the key isn't empty. The key just needs to be unique,
and here, there is only one key so it's arbitrary.
Andy
>
> Thanks for clarification,
> Axel
>
>
>
>
Received on Thursday, 23 September 2010 07:37:02 UTC