exist-sparql
Integrates SPARQL and RDF indexing through the Jena TDB libraries into eXist-db.
Compile and install
If you installed the app through the package manager you only need to do step 5 and restart.
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clone the github repository: https://github.com/ljo/exist-sparql.git
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You may then either build with Apache Maven (preferred) or Apache Ant.
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To build with Apache Maven:
mvn clean compile package -
or, to build with Apache Ant:
ant
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upload the xar file found in
target/into eXist-db using the dashboard -
enable the Index module in conf.xml, by adding one module declaration under "indexer/modules":
<module id="rdf-index" class="org.exist.indexing.rdf.TDBRDFIndex"/>- Restart eXist-db.
Overview
Currently there is one function with the signature sparql:query($sparql-query as xs:string) as node() available. See the usage example below.
Usage example
xquery version "3.0";
import module namespace sparql="http://exist-db.org/xquery/sparql" at
"java:org.exist.xquery.modules.rdf.SparqlModule";
declare namespace rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#";
let $rdftest-coll := xmldb:create-collection("/db", "rdftest")
let $rdftest-conf-coll := xmldb:create-collection("/db/system/config/db", "rdftest")
let $rdf-conf :=
<collection xmlns="http://exist-db.org/collection-config/1.0">
<index xmlns:xs="http://www.w3.org/2001/XMLSchema">
<rdf />
</index>
</collection>;
let $rdf-xml-1 :=
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:myhouse="myhouse://">
<rdf:Description rdf:about="myhouse://table">
<rdf:type rdf:resource="myhouse://furniture" />
<myhouse:room rdf:resource="kitchen" />
<myhouse:count>1</myhouse:count>
</rdf:Description>
</rdf:RDF>;
let $rdf-xml-2 :=
<rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:myhouse="myhouse://">
<rdf:Description rdf:about="myhouse://chair">
<rdf:type rdf:resource="myhouse://furniture" />
<myhouse:room rdf:resource="kitchen" />
<myhouse:count>2</myhouse:count>
</rdf:Description>
<rdf:Description rdf:about="myhouse://window">
<myhouse:count>3</myhouse:count>
</rdf:Description>
</rdf:RDF>
let $dummy1 := xmldb:store($rdftest-conf-coll, "collection.xconf", $rdf-conf)
let $dummy2 := (xmldb:store($rdftest-coll, "myhouse1.rdf", $rdf-xml-1),
xmldb:store($rdftest-coll, "myhouse2.rdf", $rdf-xml-2))
let $query1 := ("PREFIX myhouse: <myhouse://>
SELECT ?x
WHERE { ?x a myhouse:furniture }
ORDER BY ?x")
(: ("myhouse://chair", "myhouse://table") :)
let $query2 := ("PREFIX myhouse: <myhouse://>
SELECT ?x ?c
WHERE { ?x myhouse:count ?c ; a myhouse:furniture }
ORDER BY ASC(?c)")
(: ("myhouse://table", "1", "myhouse://chair", "2") :)
let $query3 := ("PREFIX myhouse: <myhouse://>
SELECT ?x ?r
WHERE { ?x myhouse:room ?r }
ORDER BY ASC(?c)")
(: ("myhouse://chair", "kitchen", "myhouse://table", "kitchen") :)
let $queries := ($query1, $query2, $query3)
return
for $query in $queries
(: return sparql:query($query)//text() :)
return sparql:query($query)//sr:uri