query-f69f3aed79e48eb572c24698b4de1d18

rq turtle/ttl

Trouble connecting the qualifier to a propertyHi, I'm trying to retrieve data for a given University and I want to plot the number of students over the years. I selected a university by its ROR_ID there exists data from 2011 to 2019. Unfortunately, I always get no return values as soon as I try to add the qualifier P585 as the moment in time when the number of students actually was real.

Use at

PREFIX wikibase: <http://wikiba.se/ontology#>
PREFIX wdt: <http://www.wikidata.org/prop/direct/>
PREFIX pq: <http://www.wikidata.org/prop/qualifier/>
PREFIX bd: <http://www.bigdata.com/rdf#>
SELECT ?itemLabel ?students ?year  WHERE {
  ?item wdt:P6782 "024z2rq82";
    wdt:P2196 ?students.
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
  OPTIONAL { ?students pq:P585 ?year. }
}

Query found at

graph TD classDef projected fill:lightgreen; classDef literal fill:orange; classDef iri fill:yellow; v1("?item") v2("?students"):::projected v3("?year"):::projected c5(["bd:serviceParam"]):::iri c7(["en"]):::literal c2(["024z2rq82"]):::literal v1 --"wdt:P6782"--> c2 v1 --"wdt:P2196"--> v2 subgraph s1["http://wikiba.se/ontology#label"] style s1 stroke-width:4px; c5 --"wikibase:language"--> c7 end subgraph optional0["(optional)"] style optional0 fill:#bbf,stroke-dasharray: 5 5; v2 -."pq:P585".-> v3 end