Prime ministers from Wikidata

wd_prime_ministers.rq

PREFIX bd: <http://www.bigdata.com/rdf#>
PREFIX p: <http://www.wikidata.org/prop/>
PREFIX q: <http://www.wikidata.org/prop/qualifier/>
PREFIX v: <http://www.wikidata.org/prop/statement/>
PREFIX wd: <http://www.wikidata.org/entity/>
PREFIX wikibase: <http://wikiba.se/ontology#>

SELECT DISTINCT ?countryLabel ?primeMinisterLabel
WHERE {
  ?country p:P31 ?countryStatement . 
  ?countryStatement v:P31 wd:Q6256 . # Find all countries
  FILTER NOT EXISTS {
    ?countryStatement q:P582 ?x . # Filter out countries with dissolution date
  }
  ?country p:P6 ?primeMinisterStatement .
  ?primeMinisterStatement v:P6 ?primeMinister . # Find prime minister for each country
  FILTER NOT EXISTS {
    ?primeMinisterStatement q:P582 ?x . # Filter out prime ministers, whose term ended
  }
  SERVICE wikibase:label {
    bd:serviceParam wikibase:language "cs,en" . # Add Czech labels (fallback on English ones)
  }
}