SPARQL - Forsidegrimstad.uia.no/janpn/IKT437/2016/slides/pdf/SPARQL_2.pdf · S P O Apache Jena...

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SPARQL

Part

II

Jan Pettersen Nytun, UiA

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First a small SPARQL example


Jan Pettersen Nytun, UIA, page 3

Ask:SELECT ?who WHERE { :JamesDean :playedIn ?what .

?what :directedBy ?who . }

Answer: :GeorgeStevens, :EliaKazan, :NicholasRay, :FredGuiol

[4]:

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OP More Meaningful Variable Names


[4]:

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Installing Your Own SPARQL Endpoint


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OP Apache Jena Fuseki

• SPARQL server / SPARQL endpoint enables users to query a knowledge base via the SPARQL language

• Has a user interface for server monitoring and administration.

• Provides the SPARQL 1.1 protocols for query and update.


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OP TDB

• Fuseki is tightly integrated with TDB to provide a robust, transactional persistent storage layer.

• TDB is a component of Jena for RDF storage and query. It support the full range of Jena APIs. TDB can be used as a high performance RDF store on a single machine.


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OP Downloadhttps://jena.apache.org/download/


https://jena.apache.org/download/

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OP Starting FusekiWeb Application


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Using YourSPARQL Endpoint


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You may copy the text on next slide into a ttl-file (OWL in Turtle format)

and upload it.

@prefix : <http://www.uia.no/film_ontology#> .

@prefix owl: <http://www.w3.org/2002/07/owl#> .

@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .

@prefix xml: <http://www.w3.org/XML/1998/namespace> .

@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .

@base <http://www.uia.no/film_ontology> .

<http://www.uia.no/film_ontology> rdf:type owl:Ontology .

:Film rdf:type owl:Class .

:Human rdf:type owl:Class .

:Man rdf:type owl:Class ; rdfs:subClassOf :Human .

:Woman rdf:type owl:Class ; rdfs:subClassOf :Human .

:playedIn rdf:type owl:ObjectProperty .

:Giant rdf:type :Film , owl:NamedIndividual .

:EastOfEden rdf:type :Film , owl:NamedIndividual .

:CarrollBaker rdf:type :Woman , owl:NamedIndividual ; :playedIn :Giant .

:ElizabethTaylor rdf:type :Woman , owl:NamedIndividual ; :playedIn :Giant .

:JoVanFleet rdf:type :Woman , owl:NamedIndividual ; :playedIn :EastOfEden .

:JulieHarris rdf:type :Woman , owl:NamedIndividual ; :playedIn :EastOfEden .

:MercedesMcCambridge rdf:type :Woman , owl:NamedIndividual ; :playedIn :Giant .

:RockHudson rdf:type :Man , owl:NamedIndividual ; :playedIn :Giant .

:JamesDean rdf:type :Man , owl:NamedIndividual ; :playedIn :EastOfEden , :Giant .

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The postfix of the file must be correct (must be ttl if Turtle)


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Etc. …


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OP Insert Data


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Find the women that played in the same movies as James Dean.

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Given the following graph, find the women that played in the same movies as James Dean.

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OP Prefixes

prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>

prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#>

prefix owl: <http://www.w3.org/2002/07/owl#>

prefix xsd: <http://www.w3.org/2001/XMLSchema#>

prefix : <http://www.uia.no/film_ontology#>


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SELECT ?actress ?movie WHERE { :JamesDean :playedIn ?movie .

?actress :playedIn ?movie . ?actress rdf:type :Woman }

[4]:

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OP


In Protégé:

page 27

In Fuseki

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Defining Graphs in Fuseki


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2.1.4 Specifying an RDF Dataset

A SPARQL query is executed against an RDF Dataset.

The RDF Dataset for a query may be specified either via the default-graph-uri

and named-graph-uri parameters in the SPARQL Protocol or in the SPARQL

query string using the FROM and FROM NAMED keywords.

[https://www.w3.org/TR/sparql11-protocol/]:

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OP You may add GRAPH when uploading file


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OP

prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#>prefix owl: <http://www.w3.org/2002/07/owl#>prefix xsd: <http://www.w3.org/2001/XMLSchema#>prefix : <http://www.uia.no/film_ontology#>

SELECT ?actress ?movie WHERE { GRAPH <http://localhost:3030/Testing/data/JPNGRAPHH>

{:JamesDean :playedIn ?movie . ?actress :playedIn ?movie . ?actress rdf:type :Woman }

}


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Find all actors.

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The result contains two occurrences of JamesDean!

prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#>prefix owl: <http://www.w3.org/2002/07/owl#>prefix xsd: <http://www.w3.org/2001/XMLSchema#>prefix : <http://www.uia.no/film_ontology#>

SELECT ?actor WHERE {

?actor :playedIn ?movie .}

actor1 :CarrollBaker2 :ElizabethTaylor3 :JamesDean4 :MercedesMcCambridge5 :RockHudson6 :JamesDean7 :JoVanFleet8 :JulieHarris

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Avoid duplicatesby using DISTINCT


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OP Ordering of the SPARQL statement triples

• Semantically the order is insignificant.

• In regard to efficiency:

–Typically the queries are processed in top-to-bottom order…

– Order triples in a query so that the first triples gives fewest matches, e.g., by have the triples with fewest new variables first.


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New ontology for the next slides.

You may copy the text on next slide into a ttl-file and upload it.

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@prefix : <http://www.uia.no/janpettersennytun/ontologies/family#> .

@prefix owl: <http://www.w3.org/2002/07/owl#> .

@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .

@prefix xml: <http://www.w3.org/XML/1998/namespace> .

@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .

@base <http://www.uia.no/janpettersennytun/ontologies/family> .

<http://www.uia.no/janpettersennytun/ontologies/family> rdf:type owl:Ontology .

:hasBrother rdf:type owl:ObjectProperty .

:hasParent rdf:type owl:ObjectProperty .

:hasSister rdf:type owl:ObjectProperty .

:hasUncle rdf:type owl:ObjectProperty .

:birthday rdf:type owl:DatatypeProperty ; rdfs:range xsd:dateTime .

:diedOn rdf:type owl:DatatypeProperty ; rdfs:range xsd:dateTime .

:hasName rdf:type owl:DatatypeProperty ; rdfs:range xsd:string .

:CityMan rdf:type owl:Class ; rdfs:subClassOf :Man .

:Man rdf:type owl:Class ; rdfs:subClassOf :Person .

:Person rdf:type owl:Class .

:Woman rdf:type owl:Class ; rdfs:subClassOf :Person .

:Ester rdf:type :Woman ,

owl:NamedIndividual ;

:hasName "Ester"^^xsd:string ;

:hasBrother :Olav ,

:Sigmund .

:Jan rdf:type :Man ,


:birthday "1957-12-16T04:30:00"^^xsd:dateTime ;

:hasName "Jan"^^xsd:string ;

:hasParent :Sigmund .

:Kirsten rdf:type :Woman ,


:birthday "1956-05-12T14:00:00"^ x̂sd:dateTime ;

:hasName "Kirsten"^^xsd:string ;


:Olav rdf:type :Man ,


:hasName "Olav"^̂ xsd:string ;

:hasSister :Ester ;

:hasBrother :Sigmund .

:Rolf rdf:type :Man ,


:hasName "Rolf"^̂ xsd:string .

:Sigmund rdf:type :Man ,


:birthday "1933-08-21T15:00:00"^ x̂sd:dateTime ;

:diedOn "1980/07/14T21:32:52"̂ ^xsd:dateTime ;

:hasName "Sigmund"^^xsd:string ;

:hasBrother :Rolf .

:Sigrund rdf:type :Woman ,


:birthday "1952-07-21T15:00:007"^̂ xsd:dateTime ;

:hasName "Sigrund"^^xsd:string ;


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Use SPARQL and get all parents.


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OP

PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>

PREFIX owl: <http://www.w3.org/2002/07/owl#>

PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>

PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>

PREFIX : <http://www.uia.no/janpettersennytun/ontologies/family#>

SELECT ?parent

WHERE { ?child :hasParent ?parent }


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Avoid duplicate listingsof parents in result.


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Avoid duplicatesof parents in result.


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Find all the properties of Jan together with their

values.


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OP Find all properties with values of Jan


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Find all persons born afterthe beginning of 1940


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OP But first find all persons.






SELECT DISTINCT ?person

WHERE { ?person rdf:type :Person }


OBS! The result set is empty!!

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OP Find all men are easy!







WHERE { ?person rdf:type :Man}


The result is all men:

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OP Find all persons, i.e., find all members of Person and the subclasses of Person







WHERE { ?person rdf:type ?class .

?class rdfs:subClassOf* :Person }


SPARQL 1.1 includes a transitive operator: *[4]: If we include a * after a property name, then the triple matches any number of chained occurrences of the same property.

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OP Find all persons and their birthdays






SELECT DISTINCT ?person ?birthday


?class rdfs:subClassOf* :Person .

?person :birthday ?birthday }

Jan Pettersen Nytun, UIA, page 49(Persons without a birthday will not be found.)

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OP

Find all persons born after beginning of 1940 by using FILTER.


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OP Find all persons born after beginning of 1940

PREFIX : <http://www.uia.no/janpettersennytun/ontologies/family#>PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>PREFIX owl: <http://www.w3.org/2002/07/owl#>PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>SELECT DISTINCT ?person

WHERE { ?person rdf:type ?class .?class rdfs:subClassOf* :Person .?person :birthday ?birthday .

FILTER( ?birthday > "1940-01-01T00:00:01"^^xsd:dateTime)}


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OP Find me all landlocked countries with a

population greater than 15 million.[http://www.w3.org/2009/Talks/0615-qbe/]



PREFIX type: <http://dbpedia.org/class/yago/>

PREFIX prop: <http://dbpedia.org/property/>

SELECT ?country_name ?population

WHERE { ?country a type:LandlockedCountries ;

rdfs:label ?country_name ;

prop:populationEstimate ?population .

FILTER (?population > 15000000) . }

• FILTER constraints use boolean conditions to filter out unwanted query results.

• rdfs:label is a common predicate for giving a human-friendly label to a resource.

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Find all persons born 1940-1955


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OP Find all persons born 1940-1955PREFIX : <http://www.uia.no/janpettersennytun/ontologies/family#>







?class rdfs:subClassOf* :Person .

?person :birthday ?birthday .

FILTER( ?birthday > "1940-01-01T00:00:01"^^xsd:dateTime)

FILTER( ?birthday < "1955-12-31T23:59:59"^^xsd:dateTime) }











SELECT ?subject

WHERE { ?subject rdfs:subClassOf* :Person}

Match::Person – :Woman rdfs:subClassOf :Person – :Man rdfs:subClassOf :Person –:CityMan rdfs:subClassOf :Man rdfs:subClassOf :Person

Gives result: :Person, :Woman, :Man and :CityManJan Pettersen Nytun, UIA, page 55

Transitive operator –one more example










SELECT ?subject

WHERE { ?subject rdfs:subClassOf+ :Person}

Match::Woman rdfs:subClassOf :Person - :Man rdfs:subClassOf :Person –:CityMan rdfs:subClassOf :Man rdfs:subClassOf :Person

Gives result: :Woman, :Man and :CityManJan Pettersen Nytun, UIA, page 56

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How to get the friends of your friends?


Existing triples:

@prefix : <http://whatever.org/whatever#>

:jane :friend :frank .

:frank : friend :sarah .

:sarah : friend :steve .

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OP My friends are your friends!


@prefix : <http://rdfdata.org/whatever#>

:jane :friend :frank .

:frank : friend :sarah .

:sarah : friend :steve .

PREFIX : <http://rdfdata.org/whatever#>

SELECT ?person

WHERE {

:jane :friend+ ?person .

}

Result:-------------| person |========| :frank || :sarah || :steve |-------------

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How to list the names of all men together with death date – leave

death date blank if missing?


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OPProblem:

List the names of all men together with their death date...

[4]: Every triple in the graph pattern must match in the data set in order for the match to succeed; if any triple fails to match, then no row appears in the result set at all.

page 60

The following dos not work, it only list the men with a death date!

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OPUsing Optional Matches To Solve

The Problem


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OP MINUS ExampleMINUS removes patterns from the result set that match the patterns specified by the MINUS construct.

Get all people (assumed) alive:

PREFIX : <http://www.uia.no/janpettersennytun/ontologies/family#>PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>PREFIX owl: <http://www.w3.org/2002/07/owl#>PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>SELECT DISTINCT ?person

WHERE { ?person rdf:type ?class .?class rdfs:subClassOf* :Person .MINUS {?person :diedOn ?d} }


I did not get UNSAID or NOT EXISTS to work in the Protégé SPARQL plugin, but MINUS worked.

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OP Yes/No QueriesIt is possible to ask Yes/No questions of a

graph by using the ASK construct.


[3]:

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OP

Is anybody dead, i.e., do anybody have a death date?


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OP






ASK { ?person :diedOn ?deathday }


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OP References


[1] Book: David Poole and Alan Mackworth, Artificial Intelligence: Foundations of Computational Agents, Cambridge University Press, 2010, http://artint.info/

[2] http://www.w3.org/TR/swbp-n-aryRelations/

[3] SPARQL 1.1 Query Language, W3C Recommendation 21 March 2013,http://www.w3.org/TR/2013/REC-sparql11-query-20130321/

[4] Semantic Web for the Working Ontologist, Second Edition: Effective Modeling in RDFS and OWL, May 20, 2011, by Dean Allemang, James Hendler

[5] Appreciating SPARQL CONSTRUCT more, Bob DuCharme's weblog, http://www.snee.com/bobdc.blog/2009/09/appreciating-sparql-construct.html

http://artint.info/

http://www.w3.org/TR/swbp-n-aryRelations/

http://www.w3.org/TR/2013/REC-sparql11-query-20130321/

http://www.snee.com/bobdc.blog/2009/09/appreciating-sparql-construct.html

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