- From: Andy Seaborne <andy.seaborne@epimorphics.com>
- Date: Mon, 23 Aug 2010 12:02:13 +0100
- To: Axel Polleres <axel.polleres@deri.org>
- CC: SPARQL Working Group <public-rdf-dawg@w3.org>
On 23/08/10 11:51, Axel Polleres wrote:
>> > But: observation: agg06.rq
>> >
>> > ------------------------------------------
>> > PREFIX :<http://www.example.org>
>> >
>> > SELECT ?P (COUNT(*) AS ?C)
>> > WHERE { ?S ?P ?O }
>> > HAVING (COUNT(*)> 0 )
>> > ------------------------------------------
>> > uses non-group key variable ?P in the SELECT line.
>> >
> thanks, that wad wrong, should've been without the ?P in the select.
>
>> > In ARQ, this results in, effectively, a new ?P (it's a different scope -
>> > the use in the group is hidden because only variable from the group key
>> > are in-scope and the mention of ?P in the SELECT line is a new,
>> > different ?P and is hence unbound).
> Wouldn't we rather want this to be a syntax error (don't remember in detail, but I think we discussed this, need to check)
Could be (IIRC we'd suggested this as a warning if an impl chooses) - in
ARQ ?P can be resued (e.g. select expression:
SELECT (SAMPLE(?P) as ?P) (COUNT(*) AS ?C)
{...}
If we wish to make it an error, then we really ought to specify the
condition to check (e.g. give an algorithm).
Leaving it as-is is fine as well.
Andy
Received on Monday, 23 August 2010 11:02:50 UTC