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Re: another aggregates test case...

From: Lee Feigenbaum <lee@thefigtrees.net>
Date: Tue, 08 Jun 2010 09:20:23 -0400
Message-ID: <4C0E4397.8060205@thefigtrees.net>
To: Axel Polleres <axel.polleres@deri.org>
CC: SPARQL Working Group <public-rdf-dawg@w3.org>
I would expect this query to be an error, yes.

I'd also be happy to define an aggregate query as any query in which:

1. A GROUP BY clause is present, OR
2. An aggregate is included in the query projection

Lee

On 6/8/2010 9:07 AM, Axel Polleres wrote:
> Student of mine pointed me to a somewhat corner test case:
>
> PREFIX rdf:<http://www.w3.org/1999/02/22-rdf-syntax-ns#>
> PREFIX rdfs:<http://www.w3.org/2000/01/rdf-schema#>
> PREFIX dcterms:<http://purl.org/dc/terms/>
> PREFIX foaf:<http://xmlns.com/foaf/0.1/>
> PREFIX mpp:<http://imp.deri.ie/ontology/moviePostProcessing#>
>
> SELECT *
> FROM NAMED<http://imp.deri.ie/vff/ppa/projects>
> FROM NAMED<http://imp.deri.ie/vff/ppa/people>
> WHERE {
>
>   ?project rdf:type foaf:Project ;
>            rdfs:label ?title .
>   ?person rdf:type mpp:Person ;
>            rdfs:label ?personName ;
>            foaf:currentProject ?project .
> }
> GROUP BY ?project
>
> Actually, I *think* this should be syntactically invalid, as per:
> "In aggregate queries and sub-queries only expressions which have been used as GROUP BY expressions, or aggregated expressions (i.e. expressions where all variables appear inside an aggregate) can be projected."
>
> interestingly, the formulation - strictly speaking - doesn't say what an aggregate query is, but GROUP BY without aggregtate doesn't make a lot of sense anyways, except that it should have the same effect as DISTINCT, right(?), but we still don't want to allow in the presence of GROUP BY some non-grouped/aggregated things to be projected, I assume.
>
> Axel
>
Received on Tuesday, 8 June 2010 13:47:32 GMT

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