query_wikidata {WikidataR}

Send one or more SPARQL queries to WDQS

Description

Makes a POST request to Wikidata Query Service SPARQL endpoint.

Usage

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'

...

Additional parameters to supply to [httr::POST]

Value

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](https://www.mediawiki.org/wiki/Wikidata_Query_Service/User_Manual#Query_limits) 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)