CODEWITHSUNDEEP
sparqlsemantic-web
Sina
Sina

Reputation: 1692

How to get this sparqle query to work?

I want to have the following query in Sparql: "social triads involving Barack Obama and two other people who have some connection to the state of Illinois." Where a social triad is a group of three people where there is a link between every pair.

# Find social triads involving Barack Obama and two other people who
# have some connection to the state of Illinois.  A social triad is a
# group of three people where there is a link between every pair.
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX dbpr: <http://dbpedia.org/resource/>
PREFIX dbpo: <http://dbpedia.org/ontology/>
PREFIX dbpprop: <http://dbpedia.org/property/>
PREFIX dbpedia: <http://dbpedia.org/resource/>
PREFIX owl: <http://www.w3.org/2002/07/owl#>
SELECT  distinct ?P1 ?P2
WHERE { 
    ?P1 a dbpo:Person.
    ?P2 a dbpo:Person.
    ?P1 dbpprop:state dbpr:Illinois.
    ?P2 dbpprop:state dbpr:Illinois.
    ?prop a rdf:Property. 

    {?P1 ?prop ?P2} UNION {?P2 ?prop ?P1}.
    {dbpedia:Barack_Obama ?prop ?P1} UNION {?P1 ?prop dbpedia:Barack_Obama}. 
    {dbpedia:Barack_Obama ?prop ?P2} UNION {?P2 ?prop dbpedia:Barack_Obama}. 

  }

However I get no result out of it. How can I get it to work? Moreover I want ?P1 and ?P2 to be different persons. How is it that possible?

Upvotes: 2

Views: 564

Answers (1)

Thomas
Thomas

Reputation: 2193

If I understand you correctly, then this may be what you want:

SELECT  distinct ?P1 ?P2
WHERE { 
  ?P1 a dbpo:Person.
  ?P2 a dbpo:Person.
  ?P1 dbpprop:state dbpr:Illinois.
  ?P2 dbpprop:state dbpr:Illinois.

  # all three are connected via prop
  ?P1 ?prop ?P2, dbpedia:Barack_Obama .
  ?P2 ?prop ?P1, dbpedia:Barack_Obama .
  dbpedia:Barack_Obama ?prop ?P1, ?P2 .

  # P1 and P2 are not the same, and not Barack Obama
  FILTER (?P1 != ?P2)
  FILTER (?P1 != dbpedia:Barack_Obama)
  FILTER (?P2 != dbpedia:Barack_Obama)
}

Note that this queries only for "triads" of people who have the same property ?prop linking them, not triads connected by any property.

Upvotes: 4

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