- From: Peter Waher <Peter.Waher@clayster.com>
- Date: Tue, 19 Jun 2012 15:55:05 +0000
- To: "public-rdf-dawg-comments@w3.org" <public-rdf-dawg-comments@w3.org>
- Message-ID: <1693EFE1FD641C42A0D542FCBC732DE69627D4A1@EX3.YODA.UTOPIA.LOCAL>
Hello I have some questions regarding the use of [] is queries in the test cases. To me, the following test case (aggregates/agg-groupconcat-01, GROUP_CONCAT 1) is not correctly defined. Have I misunderstood something, or is this a known error, or does the short form [] match anything, and not only blank nodes? Manifest: (Notice it has been approved) :agg-groupconcat-01 rdf:type mf:QueryEvaluationTest ; mf:name "GROUP_CONCAT 1" ; mf:feature sparql:group_concat ; dawgt:approval dawgt:Approved; dawgt:approvedBy <http://www.w3.org/2009/sparql/meeting/2010-09-07#resolution_2> ; mf:action [ qt:query <agg-groupconcat-1.rq> ; qt:data <agg-groupconcat-1.ttl> ] ; mf:result <agg-groupconcat-1.srx> Data: @prefix : <http://www.example.org/> . :s :p1 "1", "22" . :s :p2 "aaa", "bb", "c" . Query: PREFIX : <http://www.example.org/> ASK { {SELECT (GROUP_CONCAT(?o) AS ?g) WHERE { [] :p1 ?o }} FILTER(?g = "1 22" || ?g = "22 1") } To my eyes (and in our implementation) this returns false. But the test case states it should evaluate to true: <?xml version="1.0"?> <sparql xmlns="http://www.w3.org/2005/sparql-results#"> <head/> <boolean>true</boolean> </sparql> To me, this pattern in the query shouldn't match any pattern at all in the data (:s is not a blank node, but an iri): [] :p1 ?o However, if I change this pattern in the query to ?x :p1 ?o then the query evaluates to true in my implementation. According to the specification, [] should match a blank node (not just anything): http://www.w3.org/TR/sparql11-query/#QSynBlankNodes So, which is correct? * Should [] in a query be able to match any type of term? o Is this described in the specification, or does the specification need to be updated? o How does this relate to compatibility with SPARQL 1.0 queries? * Should the query in the test case be updated? * Have I misunderstood something else? Thanks in advance, Peter Waher
Received on Tuesday, 19 June 2012 15:55:39 UTC