SPARQL Web Service

Features:

construct a new RDF graph on the fly using describe/construct/select/ask operator
run SPARQL on an RDF graph with Pellet OWL DL reasoning support
REST web service interface

Process sparql query

REST Service Interface Description

Base service URI: http://onto.rpi.edu/sw4j/sparql

parameter	meaning
queryURL	the URL of sparql query
output	(optional) output syntax : RDF/XML, N3, SPARQL/XMl, SPARQL/JSON . Default output: RDF/XML for describe/construction; TEXT/PLAIN for other queries
usePellet	(optional) run OWL DL inference on the dataset before SPARQL query. possible value: "yes", "no" (default)

example usage

return RDF/XML - http://onto.rpi.edu/sw4j/sparql?queryURL=http://onto.rpi.edu/alpha/sparql/test1.sparql
return N3 - http://onto.rpi.edu/sw4j/sparql?queryURL=http://onto.rpi.edu/alpha/sparql/test1.sparql&output=n3
return Text - http://onto.rpi.edu/sw4j/sparql?queryURL=http://onto.rpi.edu/alpha/sparql/test3.sparql
return SPARQL/Xml - http://onto.rpi.edu/sw4j/sparql?queryURL=http://onto.rpi.edu/alpha/sparql/test3.sparql&output=sparql/xml
use Pellet OWL DL inference - http://onto.rpi.edu/sw4j/sparql?queryURL=http://onto.rpi.edu/alpha/sparql/test4.sparql&usePellet=yes

Examples

test1.sparql - a simple SPARQL query for test. see result
test2.sparql - a SPARQL query with many sources for test. see result
test3.sparql - a SPARQL query executed without Pellet Inference for test. see result
test3.sparql - a SPARQL query executed with Pellet Inference for test. see result
test4.sparql - a SPARQL query (with Pellet Inference) which uses GRAPH in pattern for test. see result
test5.sparql - a SPARQL query (with Pellet Inference) which does not use GRAPH in pattern for test. see result
test6.sparql - a SPARQL query (with Pellet Inference) which checks deductive closure. see result
check for missing property value (hasMaker). We need OWL DL inference to find all applicable cardinality restrictions. We use the same SPARQL query - test7.sparql with different option (with/without Pellet Inference).
- Without OWL DL reasoning, we can only find three "owl:hasValue" restrictions being the direct super class of wine:Zinfandel. Therefore, this SPARQL query will not detect missing value issue. see result
- with OWL DL reasoning (on owl:equivalentClass, owl:intersectionOf, and compute transitive closure for rdfs:subClassOf ), we can detect many more cardinality restrictions, including many cardinality restrictions which are orginaly super classes of wine:Wine, as the super class of wine:Zinfandel. Therefore, we are able to tell that hasMaker is required but missing. see result
A more interesting case along this line is the relation between "hasValue" and "Cardinality" restriction. When cardinality=1 and hasValue restriction has been asserted, users typically use such construct to assert default value, and thus omit such description in individuals. Hence we should better avoid reporting missing value issues when cardinality=1 and hasValue restriction can be found. Such semantics is implemented by SPARQL query test8.sparql. By applying this query on instance data , we should expect missing value issue caused by hasMaker but not hasColor because the default value of hasColor has been asserted by "owl:hasValue" in wine ontology (see a fragment of wine ontology). (see result)
test9.sparql, users may use an RDF graph dynamically generated by this service via describe/construct SPARQL query in the FROM clause of another SPARQL query. (see result)

This page is maintained by Li Ding. Page last updated on June 2, 2009