Retrieve the US release date for a movie from Wikidata using Sparql - sparql

Question

I am trying to retrieve the titles and release dates (publication date) for movies using the wikidata.org sparkql endpoint (https://query.wikidata.org/). The titles are listed in different languages, which are filtered in the query below. However, some movies also have several publication dates (e.g. for different countries), e.g. https://www.wikidata.org/wiki/Q217020. I'm not sure how the RDF triple structure is actually used to assign a country to the value of another triple, but specifically, how can I only retrieve the publication date for a movie in the US?
SELECT ?item ?title ?publicationdate
WHERE {
?item wdt:P31 wd:Q11424 ;
rdfs:label ?title ;
wdt:P577 ?publicationdate ;
filter ( lang(?title) = "en" )
}
ORDER BY ?movieid
LIMIT 10
Solution
The solution provided by M.Sarmini works. Apparently, facts such as publication data are stored as n-ary relations, they create a unique symbolic tag that links the resources. The value that P577 links to is just the date, when turned into a string will give the release date, while in reality it is a token that you can link to other qualifiers.

Answer 1

Just add a new variable to hold the place of publication and filter your results to just list US films like this:
PREFIX q: <http://www.wikidata.org/prop/qualifier/>
PREFIX s: <http://www.wikidata.org/prop/statement/>
SELECT distinct ?item ?title ?publicationdate
WHERE {
?item wdt:P31 wd:Q11424;
rdfs:label ?title;
p:P577 ?placeofpublication.
?placeofpublication q:P291 wd:Q30.
?placeofpublication s:P577 ?publicationdate;
filter ( lang(?title) = "en")
}
ORDER BY ?item