Question: How many airlines are members of the Star Alliance?
SPARQL:
PREFIX dbo: <http://dbpedia.org/ontology/>
PREFIX dbp: <http://dbpedia.org/ontology/>
PREFIX res: <http://dbpedia.org/resource/>
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> 
SELECT COUNT(DISTINCT ?uri)
WHERE { 
        ?uri rdf:type dbo:Airline . 
        ?uri dbp:alliance res:Star_Alliance .
}