SPARQL Query Language for RDF - The Diigo Meta page

• 24 Sep 15
  

  Sofia Papastamkou
• 25 Oct 14
  

  jahnhane

  sparql rdf

• 17 Jul 14
  

  chloe hwang
• 16 Feb 14
  

  Sergey Skubyev

  SemanticWeb

• 03 Jan 14
  

  Nathalie Nosny

  outils sparql w3c rdf semantisation

• 19 Nov 13
  

  Dhanushanth Pushparajah
• 13 Nov 13
  

  Allard Strijker

  RDF is a directed, labeled graph data format for representing information in the Web. RDF is often used to represent, among other things, personal information, social networks, metadata about digital artifacts, as well as to provide a means of integration over disparate sources of information. This specification defines the syntax and semantics of the SPARQL query language for RDF.

  sparql rdf w3c Linked data metadata open

• 10 Nov 13
  

  wasifbaig
  • RDF is a directed, labeled graph data format for representing information   in the Web
  • Query patterns generate an unordered collection of solutions
  • These solutions are then treated as a sequence (a solution sequence), initially in no specific order;  any sequence modifiers are then applied to create another sequence
  • The ORDER BY clause establishes the order of a solution sequence
  • Following the ORDER BY clause is a sequence of order comparators, composed of an expression and an optional order modifier (either ASC() or DESC())
  • The "<" operator (see the Operator Mapping and 11.3.1 Operator Extensibility) defines  the relative order of pairs of numerics, simple literals, xsd:strings, xsd:booleans  and xsd:dateTimes
  • A plain literal is lower than an RDF literal with type xsd:string of the same lexical form
  • The solution sequence can be transformed into one involving only a subset of  the variables. For each solution in the sequence, a new solution is formed using  a specified selection of the variables using the SELECT query form
  • A solution sequence with no DISTINCT or REDUCED query modifier  will preserve duplicate solutions
  • The DISTINCT solution modifier eliminates duplicate solutions
  • duplicates are eliminated before either limit or offset is applied
  • OFFSET causes the solutions generated to start after the specified  number of solutions. An OFFSET of zero has no effect
  • LIMIT clause puts an upper bound on the number of solutions returned
  • A LIMIT of 0 would cause no results to be returned. A limit may not be negative
  • SPARQL has four query forms
  • SELECT

     

    Returns all, or a subset of, the variables bound in a query pattern match.

     

    CONSTRUCT

     

    Returns an RDF graph constructed by substituting variables in a set of triple   templates.

     

    ASK

     

    Returns a boolean indicating whether a query pattern matches or not.

     

    DESCRIBE

     

    Returns an RDF graph that describes the resources found.
  • The CONSTRUCT query form returns a single RDF graph specified by  a graph template. The result is an RDF graph formed by taking each query solution  in the solution sequence, substituting for the variables in the graph template,  and combining the triples into a single RDF graph by set union
  • The graph template can contain  triples with no variables (known as ground or explicit triples)
  • A template can create an RDF graph containing blank nodes. The blank node labels  are scoped to the template for each solution
  • Applications can use the ASK form to test whether or not a query  pattern has a solution. No information is returned about the possible query solutions,  just whether or not a solution exists
  • The DESCRIBE form returns a single result RDF graph containing RDF  data about resources.

  19 more annotations...

• 18 Feb 13
  

  pauline charbonnier

  sparql web sémantique spécification

• 22 Jan 13
  

  Laurence Baba

  RDF SPARQL

• 09 Dec 12
  

  Christopher Günther
  • specification defines the remote protocol
  • basic graph pattern
  • each of the subject, predicate and object may be a variable
  • the SELECT clause
  • WHERE clause
  • Each solution gives one way in which the selected variables can be bound  to RDF terms so that the query pattern matches the data
  • The result set gives  all the possible solutions
  • This following query has no solution because "cat" is not the   same RDF literal as "cat"@en
  • The CONSTRUCT query form returns an RDF graph

  7 more annotations...

• 23 Nov 12
  

  Eric Rodriguez

  sparql w3c rdf

• 22 Nov 12
  

  Cesar Palma

  web semantica

• 19 Oct 12
  

  An SQL type language for operating on tree structures. Might be usable with NoSQL databases

  sparql bigdata nosql

• 21 Jul 12
  

  biiber

  w3c sparql

• 13 Jul 12
  

  Sub Proletarian

  sparql rdf w3c

• 05 Jul 12
  
  • FILTER regex(str(?mbox), "@work.example")
• 03 Jul 12
  

  Jean-Marie Favre

  sparql query language rdf documentation

• 26 May 12
  

  kevinyik
  • 6.2 Constraints  in Optional Pattern Matching
  • 6.3 Multiple Optional Graph  Patterns
• 04 Apr 12
  

  J. Felix Ontañón

  semanticweb sparql

• 16 Feb 12
  

  standards

• 26 Aug 11
  

  yasuhiro nishioka

  sparql rdf semanticweb w3c query reference xml semantic zootool_imported

• 08 Jul 11
  

  adrian b82

  SPARQL w3c

• 19 Jun 10
  

  dancecodes

  sparql rdf semanticweb w3c query xml reference semantic select 2read example lvl9 me:icio

• 20 Feb 09
  

  Magnus K

  syntax and semantics of the SPARQL query language for RDF

  semanticweb semantic rdf w3c reference sparql query recommendation

• 12 Dec 08
  

  Mopuffus Lumkins

  Ontology sparql rdf semanticweb w3c XML reference semantic web query

• 09 Sep 08
  

  jrmota

  ia semanticweb sparql delicious

• 10 Jul 08
  

  Marcirio Chaves

  SPARQL rdf semantic-web W3C

• 21 Mar 08
  

  steampickle

  semanticweb w3c

• 07 Feb 08
  

  jon

  federation sparql for:jipdigao

• 28 Jan 08
  

  rsolt34

  sparql rdf w3c query xml semantic

• 19 Jan 08
  

  ivernaloo

  w3c

• 18 Jan 08
  

  J Irving

  SPARQL rdf w3c semanticweb query xml reference web

• 27 Aug 07
  

  Pru Mitchell

  standards.edna rdf vocabularies

• 19 Jan 07
  

  mikeyp

  SPARQL rdf

• 25 Apr 06
  

  Martin Homik

  rdf sparql w3c query semanticweb

• 25 Dec 05
  

  willierogers

  language programming protocol rdf reference search semantic W3C semweb semanticWeb xml query

• 18 Oct 05
  

  Andrae Muys

  rdf prog language reference docs kowari tech delicious

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