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

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.

Web based on documents

Web Evolution

09/11/2011 6

Web 1.0 Web 2.0 Web 3.0

Web 1.0

Beginnings of the

Static pages

Limited use of

standards

Lack of interaction

with the user

Web 2.0

Higher bandwidth

Standards

Rich User Interface

Accessibility

Usability

Social networks

Web 3.0

3D virtual

environments

The Internet of

Things

Domotics

Cloud Computing

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

LINKED OPEN DATA

Information Age

Huge amount of

information

A large number of

information

systems

Big challenges: ◦ Data integration

◦ Data analysis

Need for open data

Improvement of

organizational

transparency

Public data

Foster the

research

Promote the

development of

third-party system

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

09/11/2011 Jornadas de Software Libre y Web 2.0 14

1Tim Berners-Lee

Resource Description Format

http://publisher.org/Papers/

Paper12345

Linked Data -

The Story So Far

Paper12345

author

publishedIn

http://publisher.org/Journals/

JournalSWIS

Linked Data -

The Story So Far

http://w3.org/People/

Berners-Lee

Paper12345

author

publishedIn

http://publisher.org/Journals/

JournalSWIS

http://w3c.org

director

Linked Data -

The Story So Far

http://w3.org/People/

Berners-Lee

Paper12345

http://xmlns.com/foaf/

Person

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>

</rdf:Description>

Ontologies (vocabularies)

09/11/2011 20

“An ontology is an explicit and formal specification of a shared

conceptualization1“

1Tom Gruber

Linked Data Cloud

EXPOSING DATABASES WITH D2R SERVER

How is your data currently stored?

How to publish Linked Data?

Annotation

◦ Manual

◦ Collaborative

◦ (Semi-)automatic

Exposure

◦ RDF Triple Store

◦ HTML+RDF (RDFa)

◦ RDF Wrappers

◦ SQL2RDF

JournalSemanticWeb

The Story

So Far

Berners-Lee LinkedData

Web Application Architecture

09/11/2011 25

Relational

Database Application Server

User Interface

Web Application Architecture using

D2R Server

09/11/2011 26

Relational

Database

Application

Server

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

Server

Application

Server

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

Server

Application

Server

Exposing and Consuming Linked

Internet Navigator

URL: http://mashup.org File Favourites Help

mashup

Server Relational

Database

Installing D2R

Using D2R

~/d2rserver$> generate-mapping

-o MAPPING.n3

-d com.mysql.jdbc.Driver

-u USER -p PASSWORD

jdbc:mysql://localhost:3306/DATABASE

09/11/2011 31

~/d2rserver$> d2r-server MAPPING.n3

Database model example

Vocabularies

09/11/2011 33

#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#> .

Database Connection

09/11/2011 34

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";

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 <> ''“ .

http://dataset.org/organizations/

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 “ .

cerif:headcount

Exposing 1:N relations

09/11/2011 37

map:OrganisationUnits_Name a d2rq:PropertyBridge;

d2rq:property cerif:name;

d2rq:join "ORG_NAME.ORGID = ORGANISATIONS.ID";

d2rq:column "ORG_NAME.NAME“ .

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:property cerif:members;

d2rq:join "ORG_PERS.ORGID = ORGANISATIONS.ID";

d2rq:join "ORG_PERS.PERSID = PERSON.ID";

d2rq:refersToClassMap map:Person .

http://dataset.org/people/

InvestigadorXYZ

cerif:members

CASE STUDY: THE VOA3R PROJECT

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.

VOA3R Portal

Organization’s Data in VOA3R

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> ;

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> .

Organization’s Data via D2R

SPARQL Client

CONCLUSIONS

Conclusions

Web based on documents Web based on

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

Iván Ruiz Rube ivan.ruiz@uca.es

09/11/2011 50

Publishing Linked Data from

relational databases

thanks

Publishing linked data from relational databases

Technology

Transcript of Publishing linked data from relational databases

Object relational and extended relational databases

- Triplify Light-Weight Linked Data Publication from Relational Databases

Object-relational Databases Extend relational databases with OO features 1.

Creating Linked Data from Relational Databases

Relational Databases

DBS201: Relational Databases

Extending Relational Databases

Relational Databases and MySQL. Relational Databases Relational databases model data by storing rows and columns in tables. The power of the relational.

Publishing Relational Databases as Linked Data

Object-Relational Databases

ISO6 Relational Databases

From relational databases to linked data:R for the … · From relational databases to linked data:R for the semantic web Jose Quesada, Max Planck Institute, Berlin. Who this talk

Non-Relational Databases

ULB4.3 Relational databases VS Non relational databases 4.3.1 Relational databases Relation databases are also known as relational database management systems (RDBMS) or SQL databases,

Relational databases vs Non-relational databases

Nested Relational Databases

Basic Relational Databases

Databases - Relational Algebra

Relational Database Features Management Databaseptw/teaching/DBM/non-relational.pdf · Non-Relational Databases Object-oriented and object-relational databases No SQL databases Relational

Mapping Relational Databases to Linked Data