Publishing linked data from relational databases
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Transcript of Publishing linked data from relational databases
Iván Ruiz Rube Departamento de Lenguajes y Sistemas Informáticos
Universidad de Cádiz
09/11/2011 1
Publishing Linked Data
from relational databases
Jornadas de Software Libre y Web 2.0
Roadmap
The evolution of the Web
Linked Open Data
Exposing databases with D2R Server
Case study: The VOA3R Project
Conclusions
09/11/2011 2 Jornadas de Software Libre y Web 2.0
THE EVOLUTION OF THE WEB
PUBLISHING LINKED DATA FROM RELATIONAL DATABASES
09/11/2011 3 Jornadas de Software Libre y Web 2.0
World Wide Web
Most important infrastructure for the
distribution of information.
Rich and broad information: text, images,
videos, slides, etc.
Web navigators support HTML, JS, CSS
and other formats.
Navigation based on hyperlinks.
09/11/2011 4 Jornadas de Software Libre y Web 2.0
Web based on documents
09/11/2011 5 Jornadas de Software Libre y Web 2.0
Web Evolution
09/11/2011 6
Web 1.0 Web 2.0 Web 3.0
Jornadas de Software Libre y Web 2.0
Web 1.0
Beginnings of the
Web
Static pages
Limited use of
standards
Lack of interaction
with the user
09/11/2011 7 Jornadas de Software Libre y Web 2.0
Web 2.0
Higher bandwidth
Standards
Rich User Interface
Accessibility
Usability
Social networks
09/11/2011 8 Jornadas de Software Libre y Web 2.0
Web 3.0
3D virtual
environments
The Internet of
Things
Domotics
Cloud Computing
Semantic Web
09/11/2011 9 Jornadas de Software Libre y Web 2.0
Semantic Web
09/11/2011 10
“I have a dream for the Web (in which computers) become
capable of analyzing all the data on the Web….”
“…the day-to-day mechanisms of trade, bureaucracy and
our daily lives will be handled by machines talking to
machines.”
1Tim Berners-Lee
Jornadas de Software Libre y Web 2.0
LINKED OPEN DATA
PUBLISHING LINKED DATA FROM RELATIONAL DATABASES
09/11/2011 11 Jornadas de Software Libre y Web 2.0
Information Age
Huge amount of
information
A large number of
information
systems
Big challenges: ◦ Data integration
◦ Data analysis
09/11/2011 12 Jornadas de Software Libre y Web 2.0
Need for open data
Improvement of
organizational
transparency
Public data
Foster the
research
Promote the
development of
third-party system
09/11/2011 13 Jornadas de Software Libre y Web 2.0
Linked Open Data
“A method of publishing structured data so that it can be
interlinked and become more useful.
…it extends web pages to share information in a way that can
be read automatically by computers.”1
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1Tim Berners-Lee
Resource Description Format
http://publisher.org/Papers/
Paper12345
09/11/2011 15 Jornadas de Software Libre y Web 2.0
Resource Description Format
2008
year
Linked Data -
The Story So Far
title
http://publisher.org/Papers/
Paper12345
09/11/2011 16 Jornadas de Software Libre y Web 2.0
Resource Description Format
author
publishedIn
2008
http://publisher.org/Journals/
JournalSWIS
year
Linked Data -
The Story So Far
title
http://w3.org/People/
Berners-Lee
http://publisher.org/Papers/
Paper12345
09/11/2011 17 Jornadas de Software Libre y Web 2.0
Resource Description Format
author
publishedIn
2008
http://publisher.org/Journals/
JournalSWIS
year
http://w3c.org
director
Linked Data -
The Story So Far
title
http://w3.org/People/
Berners-Lee
http://publisher.org/Papers/
Paper12345
09/11/2011 18 Jornadas de Software Libre y Web 2.0
http://xmlns.com/foaf/
Person
type
RDF (sintaxis)
09/11/2011 19
<http://publisher.org/Papers/Paper12345>
title "Linked Data - The Story So Far";
year "2008-01-01";
author <http://w3.org/People/Berners-Lee>;
publishedIn <http://publisher.org/Journal/JournalSWIS> .
<rdf:Description rdf:about="http://publisher.org/Papers/Paper12345">
<title>Linked Data - The Story So Far</title>
<year>2008-01-01</year>
<author rdf:resource="http://w3.org/People/Berners-Lee" />
<publishedIn rdf:resource="http://publisher.org/Journal/JournalSWIS" />
</rdf:Description>
Jornadas de Software Libre y Web 2.0
Ontologies (vocabularies)
09/11/2011 20
“An ontology is an explicit and formal specification of a shared
conceptualization1“
1Tom Gruber
Jornadas de Software Libre y Web 2.0
Linked Data Cloud
09/11/2011 21 Jornadas de Software Libre y Web 2.0
EXPOSING DATABASES WITH D2R SERVER
PUBLISHING LINKED DATA FROM RELATIONAL DATABASES
09/11/2011 22 Jornadas de Software Libre y Web 2.0
How is your data currently stored?
09/11/2011 Jornadas de Software Libre y Web 2.0 23
How to publish Linked Data?
Annotation
◦ Manual
◦ Collaborative
◦ (Semi-)automatic
Exposure
◦ RDF Triple Store
◦ HTML+RDF (RDFa)
◦ RDF Wrappers
◦ SQL2RDF
09/11/2011 Jornadas de Software Libre y Web 2.0 24
2008
JournalSemanticWeb
W3C
The Story
So Far
Berners-Lee LinkedData
Web Application Architecture
09/11/2011 25
Relational
Database Application Server
User Interface
Jornadas de Software Libre y Web 2.0
Web Application Architecture using
D2R Server
09/11/2011 26
Relational
Database
Application
Server
Jornadas de Software Libre y Web 2.0
Web Application Architecture using
D2R Server
09/11/2011 27
<http://cris.org:/resource/projects/Organic>
a cerif:Project ;
rdfs:label "Multilingual Federation of Learning
Repositories"@en-uk ;
cerif:acronym "Organic.Edunet" ;
cerif:endDate "2010-09-30"^^xsd:date ;
cerif:internalIdentifier
"ff808181300cf99e01300d1a355f0003"
cerif:isLinkedByOrganisationUnit
Relational
Database
D2R
Server
Application
Server
Jornadas de Software Libre y Web 2.0
Web Application Architecture using
D2R Server
09/11/2011 28
<http://cris.org:/resource/projects/Organic>
a cerif:Project ;
rdfs:label "Multilingual Federation of Learning
Repositories"@en-uk ;
cerif:acronym "Organic.Edunet" ;
cerif:endDate "2010-09-30"^^xsd:date ;
cerif:internalIdentifier
"ff808181300cf99e01300d1a355f0003"
cerif:isLinkedByOrganisationUnit
Relational
Database
D2R
Server
Application
Server
Jornadas de Software Libre y Web 2.0
Exposing and Consuming Linked
Data
Internet Navigator
URL: http://mashup.org File Favourites Help
mashup
D2R
Server Relational
Database
09/11/2011 29 Jornadas de Software Libre y Web 2.0
Installing D2R
09/11/2011 30 Jornadas de Software Libre y Web 2.0
Using D2R
~/d2rserver$> generate-mapping
-o MAPPING.n3
-d com.mysql.jdbc.Driver
-u USER -p PASSWORD
jdbc:mysql://localhost:3306/DATABASE
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~/d2rserver$> d2r-server MAPPING.n3
Jornadas de Software Libre y Web 2.0
Database model example
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Vocabularies
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#Built-in vocabularies
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
#Specific vocabularies
@prefix foaf: <http://xmlns.com/foaf/0.1/> .
@prefix dc: <http://purl.org/dc/elements/1.1/> .
@prefix dcterms: <http://purl.org/dc/terms/> .
@prefix bibo: <http://purl.org/ontology/bibo/> .
@prefix geo: <http://www.w3.org/2003/01/geo/wgs84_pos#> .
@prefix cerif: <http://eurocris.org/cerif#> .
Jornadas de Software Libre y Web 2.0
Database Connection
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map:database a d2rq:Database;
# Main settings
d2rq:jdbcDriver "com.mysql.jdbc.Driver";
d2rq:jdbcDSN "jdbc:mysql://localhost:3306/DATABASE";
d2rq:username "USER";
d2rq:password "PASSWORD";
# Other settings
jdbc:autoReconnect "true";
jdbc:zeroDateTimeBehavior "convertToNull";
d2rq:allowDistinct "true";
jdbc:keepAlive "3600"; # value in seconds
jdbc:keepAliveQuery "SELECT 1";
.
Jornadas de Software Libre y Web 2.0
Exposing RDF Resources
09/11/2011 35
map:OrganisationUnits a d2rq:ClassMap;
d2rq:dataStorage map:database;
d2rq:class cerif:Organization;
d2rq:uriPattern "organizations/@@ORGANISATIONS.ACRONYM@@";
d2rq:condition "ORGANISATIONS.ACRONYM <> ''“ .
Jornadas de Software Libre y Web 2.0
http://dataset.org/organizations/
UCA
http://eurocris.org/cerif/
Organization
rdf:type
Exposing literal properties
09/11/2011 36
map:OrganisationUnits_Headcount a d2rq:PropertyBridge;
d2rq:belongsToClassMap map:OrganisationUnits;
d2rq:property cerif:headcount;
d2rq:column "ORGANISATIONS.HEADCOUNT “ .
Jornadas de Software Libre y Web 2.0
http://dataset.org/organizations/
UCA
cerif:headcount
2400
Exposing 1:N relations
09/11/2011 37
map:OrganisationUnits_Name a d2rq:PropertyBridge;
d2rq:belongsToClassMap map:OrganisationUnits;
d2rq:property cerif:name;
d2rq:join "ORG_NAME.ORGID = ORGANISATIONS.ID";
d2rq:column "ORG_NAME.NAME“ .
Jornadas de Software Libre y Web 2.0
http://dataset.org/organizations/
UCA
cerif:name
University of
Cádiz@en
Universidad
de Cádiz@es
cerif:name
Exposing N:M relations
09/11/2011 38
map:OrganisationUnits_Person a d2rq:PropertyBridge;
d2rq:belongsToClassMap map:OrganisationUnits;
d2rq:property cerif:members;
d2rq:join "ORG_PERS.ORGID = ORGANISATIONS.ID";
d2rq:join "ORG_PERS.PERSID = PERSON.ID";
d2rq:refersToClassMap map:Person .
Jornadas de Software Libre y Web 2.0
http://dataset.org/people/
InvestigadorXYZ
http://dataset.org/organizations/
UCA
cerif:members
CASE STUDY: THE VOA3R PROJECT
PUBLISHING LINKED DATA FROM RELATIONAL DATABASES
09/11/2011 39 Jornadas de Software Libre y Web 2.0
Platform based on semantic technologies
to integrate open contents for
researchers.
Manages scientific context:
◦ Organizations
◦ Research Projects
◦ Researcher Profiles
◦ etc.
Publishes its data using D2R Server.
09/11/2011 40 Jornadas de Software Libre y Web 2.0
VOA3R Portal
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Organization’s Data in VOA3R
09/11/2011 42 Jornadas de Software Libre y Web 2.0
Organization’s Data in RDF <http://voa3r.cc.uah.es/dataset/resource/organisationUnits/UAH>
rdf:type cerif:OrganisationUnit ;
rdfs:label "University of Alcala" ;
cerif:acronym "UAH" ;
foaf:homepage <http://www.uah.es> ;
cerif:researchActivities "Ontologies, Linked Data" ;
dcterms:subject <http://aims.fao.org/aos/agrovoc/c_7273> ,
<http://aims.fao.org/aos/agrovoc/c_8070> ;
09/11/2011 43 Jornadas de Software Libre y Web 2.0
Organization’s Data in RDF (II) …
cerif:researchProjects
<http://voa3r.cc.uah.es/dataset/resource/projects/Organic.Edunet> , <http://voa3r.cc.uah.es/dataset/resource/projects/Organic.Lingua> , <http://voa3r.cc.uah.es/dataset/resource/projects/VOA3R> ;
cerif:innerGroups
<http://voa3r.cc.uah.es/dataset/resource/organisationUnits/IERU> ;
cerif:members
<http://voa3r.cc.uah.es/dataset/resource/person/Salvador_Sanchez> , <http://voa3r.cc.uah.es/dataset/resource/person/Miguel_Refusta> , <http://voa3r.cc.uah.es/dataset/resource/person/Luis_Torrico> .
09/11/2011 44 Jornadas de Software Libre y Web 2.0
Organization’s Data via D2R
09/11/2011 45 Jornadas de Software Libre y Web 2.0
SPARQL Client
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CONCLUSIONS
PUBLISHING LINKED DATA FROM RELATIONAL DATABASES
09/11/2011 47 Jornadas de Software Libre y Web 2.0
Conclusions
Web based on documents Web based on
Data.
Linked Data as a way for interchanging data
between different datasets in the Web.
RDF as a standard format to describe data.
D2R allows to publish RDF metadata from
databases (non-intrusive technique).
Main aim: Create new third-party
applications using open linked data from LD
systems. 09/11/2011 48 Jornadas de Software Libre y Web 2.0
References
Linked Data: Evolving the Web into a
Global Data Space
◦ http://linkeddatabook.com/
W3C Linking Open Data Project
◦ http://www.w3.org/wiki/SweoIG/TaskForces/C
ommunityProjects/LinkingOpenData
D2R Server
◦ http://www4.wiwiss.fu-berlin.de/bizer/d2r-
server
09/11/2011 49 Jornadas de Software Libre y Web 2.0
Iván Ruiz Rube [email protected]
09/11/2011 50
Publishing Linked Data from
relational databases
thanks
Jornadas de Software Libre y Web 2.0