query_wikidata function

Send one or more SPARQL queries to WDQS

Makes a POST request to Wikidata Query Service SPARQL endpoint.

query_wikidata(sparql_query, format = "tibble", ...)

Arguments

• sparql_query: SPARQL query (can be a vector of queries)
• format: tibble (default) returns a pure character data frame, simple returns a pure character vector, while smart fetches JSON-formatted data and returns a tibble with datetime columns converted to POSIXct
• \dots: Additional parameters to supply to [httr::POST]

Returns

A tibble or vector. Note: QID values will be returned as QIDs, rather than URLs.

Query limits

There is a hard query deadline configured which is set to 60 seconds. There are also following limits: - One client (user agent + IP) is allowed 60 seconds of processing time each 60 seconds - One client is allowed 30 error queries per minute See query limits section in the WDQS user manual for more information.

Examples

# R's versions and release dates:
sparql_query <- 'SELECT DISTINCT
  ?softwareVersion ?publicationDate
  WHERE {
    BIND(wd:Q206904 AS ?R)
    ?R p:P348 [
      ps:P348 ?softwareVersion;
      pq:P577 ?publicationDate
    ] .
}'
query_wikidata(sparql_query)

## Not run:

# "smart" format converts all datetime columns to POSIXct
query_wikidata(sparql_query, format = "smart")
## End(Not run)