Wikidata:SPARQL dotazovací služba

This page is a translated version of the page Wikidata:SPARQL query service and the translation is 35% complete.

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Co je SPARQL

SPARQL (vyslovujeme „sparkle“) je dotazovací jazyk RDF, tj. sémantický dotazovací jazyk pro databáze. Od září 2015 Wikidata poskytují SPARQL koncový bod včetně výkonného webového grafického uživatelského rozhraní. Se SPARQL můžete extrahovat jakýkoli druh dat pomocí dotazu složeného z logických kombinací trojic.

GUI SPARQL dotazovací služby je zde: https://query.wikidata.org
SPARQL koncový bod: https://query.wikidata.org/bigdata/namespace/wdq/sparql?query={SPARQL}

Učíme se SPARQL

Presentation "SPARQL and Wikidata intro" by shonagon- École de Bibliothécaires Documentalistes (French) (2016-04-04)

Nápověda

Ostatní materiály

SPARQL in 11 minutes Basic Introduction-Video
SPARQL Tutorial
2016 SPARQL Workshop
Querying Wikidata with SPARQL for Absolute Beginners, 2 hour tutorial
Wikidata:SPARQL tutorial
Wikidata:SPARQL query service/query optimization
Wikidata:SPARQL query service/query limits
{{Item documentation}} and other generic queries templates

Interfacing

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 ([2]) that plots Wikidata content on a world map in R. (Andra Waagmeester, [3])
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 to practice 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 Wikidata's wikibase. Run, test, download the data as xml, json, csv or tsv. Has advanced user-friendly features such as : word hovering too see a term's meaning, code optimization, etc.
Wikimedia Commons Query Service (WCQS)	`https://commons-query.wikimedia.org/sparql`	Run SPARQL Queries upon Wikimedia Commons wikibase.
LinguaLibre Query Service (LLQS)	`https://lingualibre.org/sparql`	Run SPARQL Queries upon LinguaLibre's wikibase. Run, test, download the data as json, xml, csv or tsv.

Statistiky

Další informace

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