Yet another SPARQL 1.1 brief introduction

Yet another SPARQL 1.1
brief introduction
Victor Saquicela Galarza, Almudena Gonzalez, and Boris Villazón-Terrazas
bvillazon@expertsystem.com
@boricles
Slides available at: http://www.slideshare.net/boricles/

SPARQL 1.1
• W3C Recommendation 21 March 2013
• New features in Query language:
- Aggregate functions: COUNT, SUM, MIN, MAX, AVG,
GROUP_CONCAT, and SAMPLE.
- Subqueries: Nest the results of a query within another query
- Negation: Check the absence of triples in a graph
- Expressions in SELECT: Introduce new variables in the SELECT clause
- Property paths: Search graphs through structures that involve
arbitrary-length paths
- Assignment: BIND keyword and expressions in SELECT and
GROUP_BY
- Short form for CONSTRUCT
- Expanded functions and operators: EXISTS, NOT EXISTS, SUBSTR,
etc.2

Other SPARQL 1.1 specifications
• Update
Language extension to express updates to an RDF graph/store
• Protocol
Changes related to the update operation
• Service description
Discover a SPARQL endpoint's capabilities and summary information of its data
• Graph Store HTTP Protocol
Update and fetch RDF graph content from a Graph Store over HTTP in the REST style
• Entailment Regimes
Define the semantics of SPARQL queries for some entailment frameworks: OWL
flavors, RDFS, RIF
• Federation Extensions
Take a query and provide solutions based on information from many different
sources
• Query Result JSON, CSV, TSV
3

ToC
• Update
• Federated queries
• Basic property paths
4

Some preliminary useful queries
SELECT DISTINCT ?g WHERE { GRAPH ?g { ?s ?p ?o } }
Query to get the current graphs of my triplestore:
5
SELECT *
FROM <http://mygraph/>
WHERE {
?s ?p ?o
}
Query to get everything from a particular graph

A simple SPARQL INSERT query
#graph http://linkeddata.ec/graph/tutorial/example1
PREFIX lde: <http://linkeddata.ec/resource/>
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
WITH <http://linkeddata.ec/graph/tutorial/example1>
INSERT { lde:myname foaf:name "boráclito" }
Data before:
Query:
6
@prefix foaf: <http://xmlns.com/foaf/0.1/> .
<http://linkeddata.ec/resource/myname> foaf:name "boráclito" .
Data after:

A simple SPARQL DELETE query
DELETE { lde:myname foaf:name "boráclito" }
Data before:
Query:
7
Data after:

Another way to INSERT a triple
INSERT DATA {
GRAPH <http://linkeddata.ec/graph/tutorial/example1>
{<http://linkeddata.ec/resource/myname> foaf:name "boráclito" . }
}
Data before:
Query:
8
Data after:

Another way to DELETE a triple
DELETE DATA {
{<http://linkeddata.ec/resource/myname> foaf:name "boráclito" . }
}
Data before:
Query:
9
Data after:

Inserting triples
INSERT DATA {
{<http://linkeddata.ec/resource/team1> foaf:name "Ecuador" .
<http://linkeddata.ec/resource/team2> foaf:name "Bolivia" .
<http://linkeddata.ec/resource/team3> foaf:name "España" .
}
}
Data before:
Query:
10
<http://linkeddata.ec/resource/team1> foaf:name "Ecuador" .
Data after:

DELETE with WHERE clause
DELETE
{ ?s foaf:name ?name .
}
WHERE {
?s foaf:name ?name .
FILTER(REGEX(?name,"E"))
}
Data before:
Query:
11
Data after:

Renaming a particular object
12
DELETE { ?s foaf:name "Bolivia" }
INSERT { ?s foaf:name "Ecuador" }
WHERE
{
?s foaf:name "Bolivia"
}
Data before:
Query:
Data after:

Inserting triples
#graph http://linkeddata.ec/graph/tutorial/people
INSERT DATA {
GRAPH <http://linkeddata.ec/graph/tutorial/people>
{ lde:victor a foaf:Person .
lde:victor foaf:name "Victor Saquicela" .
lde:victor foaf:mbox <mailto:victor.saquicela@ucuenca.edu.ec> .
lde:mauri a foaf:Person .
lde:mauri foaf:name "Mauricio Espinoza" .}
}
Data before:
Query:
13
#graph http://linkeddata.ec/graph/tutorial/people
@prefix lde: <http://linkeddata.ec/resource/> .
lde:victor a foaf:Person .
lde:mauri a foaf:Person .
lde:mauri foaf:name "Mauricio Espinoza" .
Data after:

Copy triples of name and email from one named graph to another
#graph http://linkeddata.ec/graph/tutorial/addresses
INSERT
{ GRAPH <http://linkeddata.ec/graph/tutorial/addresses>
{
?person foaf:name ?name .
?person foaf:mbox ?email
} }
WHERE
{ GRAPH <http://linkeddata.ec/graph/tutorial/people>
{
?person foaf:name ?name .
OPTIONAL { ?person foaf:mbox ?email }
} }
Data before:
Query:
14
#graph http://linkeddata.ec/graph/tutorial/addresses
@prefix lde: <http://linkeddata.ec/resource/> .
lde:mauri foaf:name "Mauricio Espinoza" .
Data after:

Some operations over graphs
LOAD
<http://terrazas.name/villazon/boris/data/TwitterAccounts.nt>
INTO GRAPH <http://linkeddata.ec/graph/data-test>
Load
15
CLEAR GRAPH <http://linkeddata.ec/graph/data-test>
Clear

ToC
• Update
16

Federated Queries - Motivation
17
DBpedia
LinkedMDB
Query both datasets in an integrated way

What is exactly Federated SPARQL
Query?
18
Image taken from Flick https://www.flickr.com/photos/fadirra/5915787567/

Federated SQL queries within DBMS?
19
• Not so difficult if we are using the same
DBMS vendor
- MySQL to MySQL
- Oracle to Oracle
- PostgreSQL to PostgreSQL
• If we are dealing with different DBMS vendor
- Build wrappers

Federated SPARQL Query Syntax
20
SPARQL_ENDPOINT_URL_A
SELECT *
FROM <http://example.com/graph/mygraph>
WHERE {
?s ?q ?w .
SERVICE <SPARQL_ENDPOINT_URL_B> {
SELECT *
FROM <http://localhost:8890/isoco> {
?t ?q ?o .
}
}
}
SPARQL_ENDPOINT_URL_A
SERVICE <….> { SELECT * FROM …. WHERE { ….} }
SPARQL_ENDPOINT_URL_B
Results

Federated Queries examples
21
SPARQL endpoint 1
lab-1-1.ttl
SPARQL endpoint 2
lab-1-2.ttl
SPARQL endpoint 3
DBpedia

Federated query example 1
SELECT *
FROM <http://linkeddata.ec/graph/federado>
WHERE {
?s ?q ?w .
SERVICE <http://172.16.147.92:8890/sparql/> {
SELECT * FROM <http://localhost:8890/isoco2> {
?t ?q ?o .
}
}
}
Query:
22

SELECT *
WHERE {
?s ?q ?w .
SELECT * FROM <http://localhost:8890/isoco> {
?t ?q ?o .
}
}
}
Query:
23

SELECT *
WHERE {
?s ?q ?w .
?t ?q ?o .
}
}
SERVICE <http://dbpedia.org/sparql/> {
SELECT * FROM <http://dbpedia.org>{
<http://dbpedia.org/resource/Cochabamba> ?h ?k .
}
}
}
Query:
24

SELECT *
WHERE {
<http://lab.isoco.net/resource/agonzalez>
<http://vocab.isoco.net/lab/birthPlace> ?c .
<http://lab.isoco.net/resource/agonzalez> foaf:currentProject ?p
SERVICE <http://172.16.147.144:8890/sparql> {
<http://lab.isoco.net/resource/agonzalez> foaf:currentProject ?o .
}
}
?c ?h ?k .
}
}
}
Query:
25

SELECT *
WHERE {
?s <http://vocab.isoco.net/lab/birthPlace> ?c .
?s foaf:currentProject ?p
?s foaf:currentProject ?o .
}
}
?c ?h ?k .
}
}
}
Query:
26

ToC
• Update
27

Example 1
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX vocab: <http://vocab.isoco.net/>
INSERT DATA {
GRAPH <http://data.isoco.net/graph/test-subclassof> {
vocab:Person rdf:type rdfs:Class .
vocab:Professor rdf:type rdfs:Class .
vocab:AssistantProfessor rdf:type rdfs:Class .
vocab:Professor rdfs:subClassOf vocab:Person .
vocab:AssistantProfessor rdfs:subClassOf vocab:Professor .
<http://data.isoco.net/people/Penny> rdf:type vocab:Professor .
<http://data.isoco.net/people/Leonard> rdf:type vocab:AssistantProfessor .
}
}
Query:
28
INSERT

Example 1
SELECT *
FROM <http://data.isoco.net/graph/test-subclassof>
WHERE {
<http://vocab.isoco.net/AssistantProfessor> rdfs:subClassOf+ ?s }
Query:
29
SUPERCLASSES
s
http://vocab.isoco.net/Professor
http://vocab.isoco.net/Person
Results:

Example 1
SELECT *
FROM <http://data.isoco.net/graph/test-subclassof>
WHERE {
?a rdf:type ?type .
?type rdfs:subClassOf* <http://vocab.isoco.net/Person> }
Query:
30
INSTANCES
a type
http://data.isoco.net/people/Leonard http://vocab.isoco.net/AssistantProfessor
http://data.isoco.net/people/Penny http://vocab.isoco.net/Professor
Results:

Contacts
Thank you
Boris Villazon-Terrazas
bvillazon@expertsystem.com
www.expertsystem.com

Yet another SPARQL 1.1 brief introduction

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