Is querying the pagerank value on DBpedia no longer available? - sparql

Question

Since the Virtuoso version is updated recently, when I try to use the query below on the public DBpedai SPARQL endpoint. The result is empty.
PREFIX rdf:<http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX dbo:<http://dbpedia.org/ontology/>
PREFIX vrank:<http://purl.org/voc/vrank#>
SELECT ?s ?v
FROM <http://dbpedia.org>
FROM <http://people.aifb.kit.edu/ath/#DBpedia_PageRank>
WHERE {
?s rdf:type dbo:University.
?s vrank:hasRank/vrank:rankValue ?v.
}
ORDER BY DESC(?v) LIMIT 50
Thank you!

Answer 1

There is also the option to query the Wikidata endpoint via query federation and map the result to DBpedia URIs:
PREFIX wd: <http://www.wikidata.org/entity/>
PREFIX wdt: <http://www.wikidata.org/prop/direct/>
PREFIX vrank: <http://purl.org/voc/vrank#>
PREFIX owl: <http://www.w3.org/2002/07/owl#>
PREFIX schema: <http://schema.org/>
SELECT * WHERE {
{
SELECT DISTINCT ?uni (URI(REPLACE(str(?article), "https://en.wikipedia.org/wiki", "http://dbpedia.org/resource")) as ?dbpedia) WHERE {
SERVICE <https://query.wikidata.org/sparql> {
?uni wdt:P31/wdt:P279* wd:Q3918.
?article schema:about ?uni .
?article schema:inLanguage "en" .
?article schema:isPartOf <https://en.wikipedia.org/> .
}
}
}
OPTIONAL {
?uni vrank:pagerank ?rank.
}
} ORDER BY desc(?rank) LIMIT 50
Just run the HDT file with the Wikidata PageRank scores locally as explained on https://github.com/athalhammer/danker-hdt-docker. The result is cleaner (no resources such as dbpedia:Physics in the result set) and the query runs in < 3 seconds.