Problem with SERVICE calls to Wikidata

[epoz]

When doing a query to Wikidata as a SERVICE, an error is raised by WDQS: Error 405 Method Not Allowed returned by https://query.wikidata.org/

We need to look into what HTTP method is used by oxigraph when doing SERVICE queries.

This is an example query:

PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX schema: <http://schema.org/>
PREFIX nfdicore: <https://nfdi.fiz-karlsruhe.de/ontology/>
PREFIX n4c: <https://nfdi4culture.de/id/>
PREFIX gnd: <https://d-nb.info/gnd/>
PREFIX htd: <https://portal.hoftheater-detmold.de/index.html#HoftheaterDetmold:>
PREFIX wdtn: <http://www.wikidata.org/prop/direct-normalized/>

SELECT *
WHERE {
  n4c:E5305 schema:dataFeedElement ?hofTheaterDataFeedItem .
  ?hofTheaterDataFeedItem schema:item ?hofTheaterItem.
  ?hofTheaterItem schema:keywords ?keyword .
  n4c:E5313 schema:dataFeedElement ?rismDataFeedItem.
  ?rismDataFeedItem schema:item ?rismItem.
  ?rismItem schema:keywords ?keyword.

  SERVICE <https://query.wikidata.org/> {
    ?wikidataID ?property ?keyword .
    OPTIONAL {?wikidataID wdtn:P214 ?viafID .}
    OPTIONAL {?wikidataID wdtn:P5504 ?rismID .}
    OPTIONAL {?wikidataID wdtn:P950 ?nationalLibrarySpainID .}
    OPTIONAL {?wikidataID wdtn:P227 ?gndID .}
    OPTIONAL {?wikidataID wdtn:P244 ?libraryCongressID .}
  }
}