Data structure
dbpedia:Mount_Etna rdf:type umbel-sc:Volcano ;
rdfs:label "Etna" ;
p:location dbpedia:Italy .
dbpedia:Mount_Baker rdf:type umbel-sc:Volcano ;
p:location dbpedia:United_States.
dbpedia:Beerenberg rdf:type umbel-sc:Volcano ;
rdfs:label ”Beerenberg“@en ;
p:location dbpedia:Norway
问题
哪些火山位于挪威或者是意大利
Query
SELECT ?v WHERE { ?v rdf:type umbel-sc:Volcano .
{ ?v p:location dbpedia:Italy }
UNION
{ ?v p:location dbpedia:Norway }
}
返回
dbpedia:Mount_Etna，
dbpedia:Beerenberg；
