Wikidados:Serviço de consulta SPARQL

O que é SPARQL

SPARQL (pronunciado como sparkle) é uma linguagem de consulta RDF, isto é, uma linguagem de consulta semântica para as bases de dados. Desde setembro de 2015 que a Wikidados proporciona um ponto de acesso SPARQL que inclui um uma GUI (Interface do Utilizador Gráfica) da Web poderosa. Com SPARQL pode extrair qualquer tipo de dados, com uma consulta composta por combinações lógicas de triplas.

• A GUI do serviço de consulta SPARQL está aqui: https://query.wikidata.org
• Ponto de acesso SPARQL: https://query.wikidata.org/bigdata/namespace/wdq/sparql?query={SPARQL}

Aprender SPARQL

"Introdução ao SPARQL e à Wikidata", por shonagon - École de Bibliothécaires Documentalistes (francês)

Portal de ajuda

• Portal de ajuda sobre o serviço de consultas de Wikidata
• Wikidados:Serviço de consulta SPARQL/consultas
  • Wikidados:Serviço de consulta SPARQL/consultas/exemplos
    • Wikidata:SPARQL query service/queries/examples/advanced
    • Wikidata:SPARQL query service/queries/examples/human
    • Wikidata:SPARQL query service/queries/examples/maintenance
    • Wikidata:SPARQL query service/queries/examples
• Queries from Wikidata status update weekly summaries

Outros materiais

• SPARQL in 11 minutes (video, English)
• SPARQL Tutorial at the Apache Jena website (English)
• 2016 SPARQL Workshop presented by the Wikimedia Foundation (English)
• Pesquisas na Wikidata com SPARQL para iniciados, tutorial de 2 horas (inglês)
• Wikidata:SPARQL tutorial (várias línguas)
• Query optimization
• Query limits
• {{Item documentation}} and other generic queries templates

Interface

SPARQL queries can be submitted directly to the SPARQL endpoint with GET request to https://query.wikidata.org/bigdata/namespace/wdq/sparql?query={SPARQL} or the endpoint's alias https://query.wikidata.org/sparql?query={SPARQL}. The result is returned as XML by default, or as JSON if either the query parameter format=json or the header Accept: application/sparql-results+json are provided. See the user manual for more detailed information. RDF data can alternatively be accessed via a Linked Data Fragments[1] interface at https://query.wikidata.org/bigdata/ldf.

• R package WikidataQueryServiceR which queries the WDQS SPARQL endpoint and returns data.frames
• R script (https://gist.github.com/andrawaag/2b8c831ab4dd70b16cf2) that plots Wikidata content on a world map in R. (Andra Waagmeester, https://lists.wikimedia.org/pipermail/wikidata/2015-September/007080.html)
• Python example, how to make a plot of causes of death for U.S. Presidents
• An example of using SPARQLWrapper library to query WDQS in Python: https://people.wikimedia.org/~bearloga/notes/wdqs-python.html
• An example using the Apache Jena command line tools. (This is useful e.g. for very large SPARQL statements with +2000 lines which WDQS UI currently cannot handle properly because of the parsing, or e.g., for scripting a batch of queries to run every week (via cron) and report the results by email)

• https://wdq2sparql.toolforge.org/w2s.php Convert WDQ (previous tool to query Wikidata) queries syntax to SPARQL (by Stas Malyshev)
• Generate plots for results by cutting-and-pasting queries to http://demo.seco.tkk.fi/visu – some examples by User:Pyb: U.S. States by date of creation, Burial counts for Père Lachaise cemetery by year, Dates of birth of 2000 centenarians

Wikimedia SPARQL query services

On Wikidata, the WDQS allows practicing SPARQL queries creation in an intuitive way.

Human interface	Machine's endpoint	Description
Wikidata Query Service (WDQS)	https://query.wikidata.org/sparql	Run SPARQL Queries upon the Wikidata Wikibase instance. Run, test, download the data as XML, JSON, CSV, or TSV. Has advanced user-friendly features such as: word hovering to see a term's meaning, code optimization, etc.
Wikimedia Commons Query Service (WCQS)	https://commons-query.wikimedia.org/sparql	Run SPARQL Queries upon the Wikimedia Commons Wikibase instance.
LinguaLibre Query Service (LLQS)	https://lingualibre.org/sparql	Run SPARQL Queries upon the LinguaLibre Wikibase instance. Run, test, download the data as XML, JSON, CSV, or TSV.

Estatísticas

• WDQS Metrics Dashboard
• Federation report

Recursos adicionais

• Special:ListDatatypes - covers approximate prefixes and explanation of some values
• Help:Dates - additional notes about dates
• Wikidata:SPARQL query service/Documentation - a hub for documents about the WDQS, organized under the Diátaxis framework
• SPARQL 1.1 W3C Recommendation
• Blazegraph wiki - Blazegraph is the query engine used by the Wikidata SPARQL query service. The wiki provides useful insights.
• Alternative endpoints