SPARQLVariable["var"]
represents a variable with label "var" in a SPARQL query.
SPARQLVariable
SPARQLVariable["var"]
represents a variable with label "var" in a SPARQL query.
Details and Options
- SPARQLVariable["x"] is used in SPARQL graph patterns and expressions to distinguish a variable with label "x" from a string literal "x".
- The SPARQLVariable wrapper is optional in places where only variables can appear.
- A SPARQLVariable can appear in any position of an RDFTriple .
- An RDFTriple that contains a SPARQLVariable is also known as a triple pattern.
Examples
open all close allBasic Examples (1)
Needs["GraphStore`"]Given an RDFStore about people:
store = GraphStore`RDFStore[{GraphStore`RDFTriple[URL["http://example.org/sophia"],
URL["http://xmlns.com/foaf/0.1/firstName"], "Sophia"],
GraphStore`RDFTriple[URL["http://example.org/sophia"], URL["http://xmlns.com/foaf/0.1/lastName"],
"Rodríguez"]}, Association[]];Query all persons together with their first name:
foaf[s_] := URL["http://xmlns.com/foaf/0.1/" <> s];store//SPARQLSelect[{
RDFTriple[SPARQLVariable["person"], foaf["firstName"], SPARQLVariable["first"]]
}]Get the first and last name:
store//SPARQLSelect[{
RDFTriple[SPARQLVariable["person"], foaf["firstName"], SPARQLVariable["first"]],
RDFTriple[SPARQLVariable["person"], foaf["firstName"], SPARQLVariable["last"]]
}]Possible Issues (1)
Needs["GraphStore`"]Given an RDFStore about people:
store = GraphStore`RDFStore[{GraphStore`RDFTriple[URL["http://example.org/sophia"],
URL["http://xmlns.com/foaf/0.1/firstName"], "Sophia"],
GraphStore`RDFTriple[URL["http://example.org/sophia"], URL["http://xmlns.com/foaf/0.1/lastName"],
"Rodríguez"]}, Association[]];Define a pattern that matches the first and last name:
foaf[s_] := URL["http://xmlns.com/foaf/0.1/" <> s];firstLastPatt = {
RDFTriple[SPARQLVariable["person"], foaf["firstName"], SPARQLVariable["first"]],
RDFTriple[SPARQLVariable["person"], foaf["lastName"], SPARQLVariable["last"]]
};The strings "first" and "last" in the "concat" function are interpreted as literals:
store//SPARQLSelect[firstLastPatt -> {
"name" -> SPARQLEvaluation["concat"]["first", " ", "last"]
}]To refer to the variables use the SPARQLVariable wrapper:
store//SPARQLSelect[firstLastPatt -> {
"name" -> SPARQLEvaluation["concat"][SPARQLVariable["first"], " ", SPARQLVariable["last"]]
}]See Also
Related Guides
Text
Wolfram Research (2019), SPARQLVariable, Wolfram Language function, https://reference.wolfram.com/language/GraphStore/ref/SPARQLVariable.html.
CMS
Wolfram Language. 2019. "SPARQLVariable." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/GraphStore/ref/SPARQLVariable.html.
APA
Wolfram Language. (2019). SPARQLVariable. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/GraphStore/ref/SPARQLVariable.html
BibTeX
@misc{reference.wolfram_2026_sparqlvariable, author="Wolfram Research", title="{SPARQLVariable}", year="2019", howpublished="\url{https://reference.wolfram.com/language/GraphStore/ref/SPARQLVariable.html}", note=[Accessed: 19-August-2026]}
BibLaTeX
@online{reference.wolfram_2026_sparqlvariable, organization={Wolfram Research}, title={SPARQLVariable}, year={2019}, url={https://reference.wolfram.com/language/GraphStore/ref/SPARQLVariable.html}, note=[Accessed: 19-August-2026]}