SPARQL 1.1 Update (2013-03-05)

SPARQL is ...
● A standard query language for RDF
– And now with update of RDF stores
● Product of W3C Process
● Submissions
● “members”
● Working groups
● Consensus (amongst the active participants)
● Widely implemented

History 1.0
● SPARQL 1.0
– Timescale: 2004 – 2008
● 2 years late
– Lots of choices for starting points
– Controversies
● Syntax
● Named graphs
● Algebra

SPARQL 1.0 Example
@prefix person: <http://example/person/> .
@prefix foaf: <http://xmlns.com/foaf/0.1/> .

person:A foaf:name "Alice" .
person:A foaf:mbox <mailto:alice@example.net> .
person:B foaf:name "Bob" .

PREFIX person: <http://example/person/>
PREFIX foaf: <http://xmlns.com/foaf/0.1/>

SELECT ?n ?mailbox
WHERE
{ person:A foaf:mbox ?mailbox ;
foaf:name ?n . }

----------------------------------------
| n | mailbox |
========================================
| "Alice" | <mailto:alice@example.net> |
----------------------------------------

SPARQL 1.0 Example
@prefix dc: <http://purl.org/dc/elements/1.1/> .
@prefix stock: <http://example.org/stock#> .

stock:book1 dc:title "SPARQL Query Language Tutorial" .
stock:book2 dc:title "SPARQL Query Language (2nd ed)" .
stock:book3 dc:title "Moving from SQL to SPARQL" .
stock:book4 dc:title "Applying XQuery" .

PREFIX dc: <http://purl.org/dc/elements/1.1/>
PREFIX stock: <http://example.org/stock#>

SELECT ?book ?title
{
?book dc:title ?title .
FILTER (regex(?title, "SPARQL"))
}

--------------------------------------------------
| book | title |
==================================================
| stock:book3 | "Moving from SQL to SPARQL" |
| stock:book2 | "SPARQL Query Language (2nd ed)" |
| stock:book1 | "SPARQL Query Language Tutorial" |
--------------------------------------------------

SPARQL 1.0
● Experimentation for new features started
before the first standard was published
– But you can't wait until “completely complete”
● Issues
– Counting
– Standard function library
– Hard-to-use negation
– Query only, no update
– Only a “note” about a JSON output

History 1.1
● SPARQL 1.1
– Timescale : 2009 – 2013
● 2 years late …
– Controversies
● Negation
● Property paths
● Graphs … REST ...

SPARQL 1.1
●
SPARQL 1.1 Query
● SPARQL 1.1 Update
●
SPARQL 1.1 Protocol
● SPARQL 1.1 Graph Store Protocol
●
SPARQL 1.1 Service Description
● SPARQL 1.1 Federated Query
●
SPARQL 1.1 Query Results JSON Format
● SPARQL 1.1 Query Results CSV and TSV Formats
●
SPARQL Query Results XML Format
●
SPARQL 1.1 Entailment Regimes

SPARQL 1.1
The important bits (IMO)
● SPARQL 1.1 Query
– Subqueries, aggregation
– negation
– property paths
– remote query
● SPARQL 1.1 Update
● SPARQL 1.1 Graph Store Protocol

SPARQL 1.1 Query Examples
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>

SELECT ?name
{
{ SELECT ?x (count(*) AS ?count)
{ ?x foaf:knows ?y . }
GROUP BY ?x
HAVING (?count = 3)
}
?x foaf:name ?name .
}


SELECT ?x
{ ?x rdf:type foaf:Person .
FILTER NOT EXISTS { ?x foaf:name ?name }
}

Property Paths and Inference
Class inference
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX : <http://example/>

SELECT ?s {
?s rdf:type ?T .
?T rdfs:subClassOf* :SomeClass .
}

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

SELECT * {
?s ?p ?o .
?p rdfs:subPropertyOf* :property .
}

SPARQL 1.1 Update
● Fine grain graph manipulations
– Act on a “graph store”
– Add and remove graphs
– Act on the contents of graphs
– Quad centric
● LOAD, DROP, CREATE
● INSERT, DELETE
– Data and patterns
● One request is multiple operations

Data Operations

DELETE DATA { <http://example/abc> foaf:name "DEF" . } ;

INSERT DATA { <http://example/abc> foaf:name "ABC" . } ;

Pattern Operations : DELETE-INSERT
Pattern → Delete triples → Insert triples

PREFIX vc: <http://www.w3.org/2006/vcard/ns#>

DELETE { ?p vc:fn ?x }
INSERT { ?p foaf:name ?x }
WHERE
{
?p vc:fn ?x .
?p foaf:knows <http://example/#me> }
}

SPARQL 1.1 Graph Store Protocol
● Simple way to manage a store (RDF Dataset)
● GET, PUT, POST, DELETE
● Naming
– Same server
http://server/store/graph1
– Different server
http://server/store?graph=http://example/g1
http://server/store?graph=http%3A//example/g1
http://server/store?default

RESTful(ish) operation
curl -T D.ttl --header 'Content-type: text/turtle'
http://server.com/store?graph=http%3A//example/g1

PUT /store?graph=http%3A//example/g1 HTTP/1.1
Host: server.com
Content-type: text/turtle

@prefix : <http://example/> .

:subject :pred1 1 ;

:pred2 “hello” .

Digression: RDF 1.1
● Work-in-progress
● Incremental
● Turtle, TriG, N-Triples, N-Quads
● RDF Datasets (as SPARQL?)
● Related: JSON-LD

JSON-LD
● Links and semantics for the JSON ecosystem
● Adds a "context" to map JSON to RDF
● RDF → JSON-LD → RDF is lossless
{
"@context": "http://json-ld.org/contexts/person.jsonld",
"@id": "http://example.org/alice.foaf#me",
"name": "Alice Hacker",
"homepage": "http://example.org/alice",
}

@prefix foaf: <http://xmlns.com/foaf/0.1/> .

<http://example.org/alice.foaf#me>
foaf:name "Alice Hacker" ;
foaf:homepage <http://example.org/alice> .

http://jena.apache.org/
Title:(asf_logo.eps)
Creator:Adobe Illustrator(R) 8.0
CreationDate:(10/20/99) (11:38 AM)

Apache Jena
● Full Apache Project since May 2012
● SPARQL 1.1
– Query
– Update
– Protocol
– Graph Store Protocol

Fuseki – SPARQL Server
● SPARQL server
● RDF native database
– ACID transactions
– Query timeout
● Deployed live

Data Management
● Web UI
● curl / wget
● SOH (SPARQL over HTTP)
– Scripts
– s-get, s-put, s-post, s-delete, s-query, s-update

Online
● http://www.sparql.org/
– Fuseki running on Apache project hardware
● Services
– SPARQL query validator
– SPARQL update validator
– RDF data validator
– IRI validator

SPARQL 1.1 Update (2013-03-05)

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