SPARQL (pronounced "sparkle", a recursive acronym for SPARQL Protocol and RDF Query Language) is an RDF query language, that is, a query language for databases, able to retrieve and manipulate data stored in Resource Description Framework format.^[1][2] It was made a standard by the RDF Data Access Working Group (DAWG) of the World Wide Web Consortium, and considered as one of the key technologies of semantic web. On 15 January 2008, SPARQL 1.0 became an official W3C Recommendation ^[3][4].

SPARQL allows for a query to consist of triple patterns, conjunctions, disjunctions, and optional patterns.^[5]

Implementations for multiple programming languages exist.^[6] "SPARQL will make a huge difference" according to Sir Tim Berners-Lee in a May 2006 interview.^[7]

There exist tools that allow one to connect and semi-automatically construct a SPARQL query for a SPARQL endpoint, for example ViziQuer.^[8] In addition, there exist tools that translate SPARQL queries to other query languages, for example to SQL^[9] and to XQuery^[10].

Benefits[link]

SPARQL allows users to write unambiguous queries. For example, the following query returns names and emails of every person in the dataset: <source lang="sql"> PREFIX foaf: <http://xmlns.com/foaf/0.1/> SELECT ?name ?email WHERE {

 ?person a foaf:Person.
 ?person foaf:name ?name.
 ?person foaf:mbox ?email.

} </source>

This query can be distributed to multiple SPARQL endpoints (services that accept SPARQL queries and return results), computed, and results gathered, a procedure known as federated query.

Query forms[link]

The SPARQL language specifies four different query variations for different purposes.

SELECT query

Used to extract raw values from a SPARQL endpoint, the results are returned in a table format.

CONSTRUCT query

Used to extract information from the SPARQL endpoint and transform the results into valid RDF.

ASK query

Used to provide a simple True/False result for a query on a SPARQL endpoint.

DESCRIBE query

Used to extract an RDF graph from the SPARQL endpoint, the contents of which is left to the endpoint to decide based on what the maintainer deems as useful information.

Each of these query forms takes a WHERE block to restrict the query although in the case of the DESCRIBE query the WHERE is optional.

Example[link]

Another SPARQL query example that models the question "What are all the country capitals in Africa?": <source lang="sql"> PREFIX abc: <http://example.com/exampleOntology#> SELECT ?capital ?country WHERE {

 ?x abc:cityname ?capital ;
    abc:isCapitalOf ?y .
 ?y abc:countryname ?country ;
    abc:isInContinent abc:Africa .

} </source>

Variables are indicated by a "?" or "$" prefix. Bindings for ?capital and the ?country will be returned.

The SPARQL query processor will search for sets of triples that match these four triple patterns, binding the variables in the query to the corresponding parts of each triple. Important to note here is the "property orientation" (class matches can be conducted solely through class-attributes or properties - see Duck typing)

To make queries concise, SPARQL allows the definition of prefixes and base URIs in a fashion similar to Turtle. In this query, the prefix "abc" stands for “http://example.com/exampleOntology#”.

SPARQL/Update[link]

SPARUL, or SPARQL/Update, is an extension to the SPARQL query language that provides the ability to add, update, and delete RDF data held within a triple store.

SPARQL implementations[link]

This list shows triplestore, APIs, and other storages that have implemented the SPARQL query language.

• 4store
• AllegroGraph
• ARC2
• ARQ
• BigData
• BrightstarDB
• Corese
• D2R Server
• Dydra
• Hercules
• Intellidimension Semantics Platform 2.0
• Jena
• KAON2
• Knowledge Explorer
• Mulgara
• OntoBroker
• Ontotext OWLIM
• Open Anzo
• OpenLink Virtuoso
• Oracle DB Enterprise Ed.
• Parliament
• Pellet
• RAP
• RDF API for PHP
• RDF-3X
• RDF::Query
• Redland / Redstore
• SPARQL Engine
• SemWeb.NET
• Sesame 2
• Stardog
• StrixDB
• Twinql
• Web Query
• IBM DB2^[11]

References[link]

External links[link]

• W3C SPARQL Working Group, was RDF Data Access Working Group
• SPARQL Query language
• SPARQL Protocol
• SPARQL Query XML Results Format
• SPARQL Tutorial
• SPARQL Examples

Todd Williams
Williams pitching for the Baltimore Orioles in 2007.
Free agent
Relief pitcher
Born: (1971-02-13) February 13, 1971 (age 41) Syracuse, New York
Bats: Right	Throws: Right
MLB debut
April 29, 1995 for the Los Angeles Dodgers
Career statistics (through 2007)
Win-Loss	12-14
Earned run average	4.33
Strikeouts	116
Teams
Los Angeles Dodgers (1995) Cincinnati Reds (1998) Seattle Mariners (1999) New York Yankees (2001) Baltimore Orioles (2004-2007)

Todd Michael Williams (born February 13, 1971 in Syracuse, New York) is a former Major League Baseball relief pitcher. He last pitched for the Long Island Ducks of the independent Atlantic League in 2008, and is currently a free agent. He attended Onondaga Community College.

Drafted in the 54th round of the 1990 amateur draft, Williams played three seasons in the minors before making his MLB debut on April 29, 1995, for the Dodgers. On September 8, 1995, Williams was traded to the Oakland Athletics for Matt McDonald. On January 16, 1997, he was released by the Athletics and signed with the Cincinnati Reds on February 3.

On July 22, 1999, Williams was traded to the Seattle Mariners for Kerry Robinson. The Mariners released Williams on November 16, 2000; he signed with the New York Yankees on January 3, 2001. A free agent at the end of the season, Williams signed with his original team, the Dodgers, but was released in spring training. On May 3, 2002, he signed with the Montreal Expos and became a free agent after the season. He signed with the Tampa Bay Devil Rays on December 23, 2002. On December 8, 2003, Williams signed with the Texas Rangers, but was released on June 14, 2004.

On June 23, 2004, Williams signed with the Baltimore Orioles, where he would play for the next four years and make his first appearance in the majors since 2001 with the Yankees. Williams was a valuable member of the Orioles bullpen for the next three years as he posted ERAs of 2.87, 3.30, and 4.74 in 29, 72, and 62 appearances, respectively. In 2007, he struggled with an ERA of 7.53 before being released by the Orioles on June 17. He played in the minors for the Colorado Rockies for the rest of the year. On May 22, 2008, Williams signed with the Long Island Ducks of the Atlantic League.

On December 13, 2007, Williams was one of many athletes mentioned in the detailed Mitchell Report by Senator George Mitchell in which he was alleged to have used performance-enhancing drugs. Kirk Radomski claimed he sold Winstrol to Williams once in 2001.

External links[link]

• Career statistics and player information from MLB, or ESPN, or Baseball-Reference, or Fangraphs, or The Baseball Cube

v t e 2000 Olympic Champions Baseball – United States Brent Abernathy Kurt Ainsworth Pat Borders Sean Burroughs John Cotton Gookie Dawkins Adam Everett Ryan Franklin Chris George Shane Heams Marcus Jensen Mike Kinkade Rick Krivda Doug Mientkiewicz Mike Neill Roy Oswalt Jon Rauch Anthony Sanders Bobby Seay Ben Sheets Brad Wilkerson Todd Williams Ernie Young Tim Young Manager Tommy Lasorda