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Q&A Wikidata: How do I ask for the start date of a property in SPARQL?

I have a SPARQL query to Wikidata that returns the names and handles and parties of politicians for whom a Mastodon address is stored at Wikidata. Filtered by nationality and with an output of the ...

1 answer  ·  posted 1y ago by wasuko‭  ·  last activity 5mo ago by Ordoviz‭

Question SPARQL wikidata
#2: Nominated for promotion by user avatar Alexei‭ · 2024-01-28T12:54:56Z (11 months ago)
#1: Initial revision by user avatar wasuko‭ · 2023-12-20T20:56:10Z (about 1 year ago)
Wikidata: How do I ask for the start date of a property in SPARQL?
I have a SPARQL query to Wikidata that returns the names and handles and parties of politicians for whom a Mastodon address is stored at Wikidata. Filtered by nationality and with an output of the name field in the corresponding language.

I would like to extend this so that the start date (P580) of the Mastodon address (P4033) is output in a field in order to be able to sort the result by new members. Does anyone know how to add the question? `joinedfediverse` should tell the start date.

``` 
SELECT ?name ?partyLabel ?mastodon ?joinedfediverse
WHERE {
  ?politician wdt:P31 wd:Q5;                                         # instance of human
             wdt:P106 wd:Q82955;                                     # occupation politician
             wdt:P27 wd:Q183;                                        # country of citizenship Germany
             wdt:P4033 ?mastodon.                                    # Mastodon address
  OPTIONAL {?politician wdt:P580 ?joinedfediverse. }                 # Fediverse joining date
  OPTIONAL {?politician wdt:P39 ?position.                           # position held
            ?position wdt:P279* wd:Q13217683.                        # subclass of member of parliament
            ?position wdt:P1001 ?parliament.}                        # applies to jurisdiction
  OPTIONAL {?politician wdt:P102 ?party.}                            # member of political party
  OPTIONAL {?politician rdfs:label ?name.                            # name
            FILTER(LANG(?name) = "de")}                              # in German language
  SERVICE wikibase:label { bd:serviceParam wikibase:language "de". } # labels in German language
}