- From: Lee Feigenbaum <lee@thefigtrees.net>
- Date: Sun, 19 Sep 2010 19:46:51 -0400
- To: Axel Polleres <axel.polleres@deri.org>
- CC: SPARQL Working Group <public-rdf-dawg@w3.org>
Glitter implements that, though I need to update the syntax for SEPARATOR. Lee On 9/19/2010 7:17 PM, Axel Polleres wrote: > It seems DISTINCT might be quite important for GROUP_CONCAT ... > I was just playing with the following use case > > > Data: > @prefix ex:<http://example.org/> . > @prefix foaf:<http://xmlns.com/foaf/0.1/> . > > ex:alice a foaf:Person; foaf:name "Alice Wonderland"; > foaf:nick "Alice", "The real Alice". > > ex:bob a foaf:Person; > foaf:name "Robert Doe", "Robert Charles Doe", "Robert C. Doe"; > foaf:nick "Bob","Bobby","RobC","BobDoe". > > ex:charles a foaf:Person; > foaf:name "Charles Charles"; > foaf:nick "Charlie" . > ============= > > My query should do the following: > pick one sample name per person, plus a concatenated list of nicknames > > query, first version: > > ============= > > PREFIX foaf:<http://xmlns.com/foaf/0.1/> > SELECT ( SAMPLE(?N) as ?Name) > ( GROUP_CONCAT(?M; SEPARATOR = ",") AS ?Nicknames ) > WHERE { ?P a foaf:Person ; > foaf:name ?N ; > foaf:nick ?M . } > GROUP BY ?P > > ============= > > doesn't work, since the nicknames appear repeated... I suppose this is where I'd need DISTINCT, but I couldn't get that > following version running yet with any implementation: > > ============= > PREFIX foaf:<http://xmlns.com/foaf/0.1/> > SELECT ( SAMPLE(?N) as ?Name) > ( GROUP_CONCAT( DISTINCT ?M; SEPARATOR = ",") AS ?Nicknames ) > WHERE { ?P a foaf:Person ; > foaf:name ?N ; > foaf:nick ?M . } > GROUP BY ?P > > ============= > > My expected result for the latter query was something like: > -------------------------------------------------------------------------------------------- > | Name | Nicknames | > ============================================================================================ > | "Robert C. Doe" | "BobDoe,RobC,Bobby,Bob" | > | "Alice Wonderland" | "The real Alice,Alice" | > | "Charles Charles" | "Charlie" | > -------------------------------------------------------------------------------------------- > > Does anybody have that implemented/running yet? > > best, > Axel >
Received on Sunday, 19 September 2010 23:47:29 UTC