Викиданные:Сервис запросов SPARQL
Что такое SPARQL
SPARQL (произносится "спаркл") — это язык запросов RDF, то есть язык семантических запросов для баз данных. Викиданные предоставляют эндпойнт SPARQL, включая мощный веб-GUI, с сентября 2015. С помощью SPARQL вы можете извлечь любые виды данных, использовав запрос, составленный из логических комбинаций триплетов.
- GUI сервиса запросов SPARQL находится здесь: https://query.wikidata.org
- SPARQL-эндпойнт: https://query.wikidata.org/bigdata/namespace/wdq/sparql?query={SPARQL}
Изучение SPARQL
Справочный портал
- портал справки Wikidata Query Service
- Wikidata:SPARQL query service/queries
- Queries from Wikidata status update weekly summaries
Other materials
- 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
| Human interface | Machine's endpoint | Description |
|---|---|---|
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. | |
https://commons-query.wikimedia.org/sparql
|
Run SPARQL Queries upon Wikimedia Commons wikibase. | |
https://lingualibre.org/sparql
|
Run SPARQL Queries upon LinguaLibre's wikibase. Run, test, download the data as json, xml, csv or tsv. |
Статистика
Further resources
- 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