RDF graph from the SPARQL endpoint, the content of which is left to the endpoint to decide, based on what the maintainer deems as useful information. Each of these query forms takes a WHERE block to restrict the query, although, in the case of the DESCRIBE query, the WHERE is optional. SPARQL 1.1 specifies a language for updating the database with several new query forms. Example Another SPARQL query example that models the question "What are all the country capitals in Africa?": PREFIX ex: <http://example.com/exampleOntology#> SELECT ?capital ?country WHERE { ?x ex:cityname ?capital ; ex:isCapitalOf ?y . ?y ex:countryname ?country ; ex:isInContinent ex:Africa . } Variables are indicated by a ? or $ prefix. Bindings for ?capital and the ?country will be returned. When a triple ends with a semicolon, the subject from this triple will implicitly complete the following pair to an entire triple. So for example ex:isCapitalOf ?y is short for ?x ex:isCapitalOf ?y. The SPARQL query processor will search for sets of triples that match these four triple patterns, binding the variables in the query to the corresponding parts of each triple. Important to note here is the "property orientation" (class matches can be conducted solely through class-attributes or properties – see Duck typing) To make queries concise, SPARQL allows the definition of prefixes and base URIs in a fashion similar to Turtle. In this query, the prefix "ex" stands for “http://example.com/exampleOntology#”. Extensions GeoSPARQL defines filter functions for geographic information system (GIS) queries using well-understood OGC standards (GML, WKT, etc.). SPARUL is another extension to SPARQL. It enables the RDF store to be updated with this declarative query language, by adding INSERT and DELETE methods. XSPARQL is an integrated query language combining XQuery with SPARQL to query both XML and RDF data sources at once. Implementations Open source, reference SPARQL implementations RDF4J, formerly Sesame from Eclipse Foundation Jena (framework) from Apache Software Foundation OpenLink Virtuoso See List of SPARQL implementations for more comprehensive coverage, including triplestore, APIs, and other storages that have implemented the SPARQL standard. See also Semantic Integration SPARQL Query Results XML Format SPARQL Syntax Expressions Wikidata References External links W3C Data Activity Blog W3C SPARQL 1.1 Working Group - closed - mailing lists and archives, was RDF Data Access Working Group SPARQL 1.1 Recommendation SPARQL 1.0 Query language (legacy) SPARQL 1.0 Protocol (legacy) SPARQL 1.0 Query XML Results Format (legacy) SPARQL2XQuery Mappings between OWL-RDF/S