query-411ed731d52b151a9cec8c1eaaf30bba

rq turtle/ttl

Filtering only truthy nodesI want a properties that are both truthy and have an English language qualifier, but struggle to get both. I have

Use at

PREFIX wikibase: <http://wikiba.se/ontology#>
PREFIX wdt: <http://www.wikidata.org/prop/direct/>
PREFIX wd: <http://www.wikidata.org/entity/>
PREFIX ps: <http://www.wikidata.org/prop/statement/>
PREFIX pq: <http://www.wikidata.org/prop/qualifier/>
PREFIX p: <http://www.wikidata.org/prop/>
PREFIX bd: <http://www.bigdata.com/rdf#>
SELECT DISTINCT ?issuer ?issuerLabel ?register ?URLprefix WHERE {
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en-GB,en". }
  {
    SELECT DISTINCT ?issuer ?register ?URLprefix WHERE {
      ?register p:P31 ?statement0.
      ?statement0 (ps:P31/(wdt:P279*)) wd:Q18618628. # cultural heritage
      ?register wdt:P17 wd:Q145.

      ?register p:P1630 [ps:P1630 ?URLprefix; pq:P407 wd:Q1860].  
      #?register wdt:P1630 ?URLprefix. 
      #FILTER (lang(?URLprefix) = "en")
      OPTIONAL {?register wdt:P2378 ?issuer} 
    }
  }
}

Query found at

graph TD classDef projected fill:lightgreen; classDef literal fill:orange; classDef iri fill:yellow; v3("?URLprefix"):::projected v4("?issuer"):::projected v1("?register"):::projected v2("?statement0") a1((" ")) a2((" ")) c4(["en-GB,en"]):::literal c2(["bd:serviceParam"]):::iri c8(["wd:Q18618628"]):::iri c10(["wd:Q145"]):::iri c13(["wd:Q1860"]):::iri subgraph s1["http://wikiba.se/ontology#label"] style s1 stroke-width:4px; c2 --"wikibase:language"--> c4 end v1 --"p:P31"--> v2 v2 --"p:statement/P31"--> a1 a1 --"p:direct/P279"--> c8 v1 --"p:direct/P17"--> c10 a2 --"p:statement/P1630"--> v3 a2 --"p:qualifier/P407"--> c13 v1 --"p:P1630"--> a2 subgraph optional0["(optional)"] style optional0 fill:#bbf,stroke-dasharray: 5 5; v1 -."p:direct/P2378".-> v4 end