79 Matching Annotations
  1. Nov 2022
  2. Oct 2022
  3. Sep 2022
  4. Aug 2022
  5. Jul 2022
  6. Jun 2022
    1. Servizi

      Forse evidenzierei di già la possibilità di usare standard come SPARQL per accedere ai dati. Mentre per accedere ai dati in CSV (o dati su database) ho necessità di creare delle interfacce ad-hoc

  7. May 2022
    1. 4.1 RDF/XML Service Description


      Given the HTTP request:

      GET /sparql/ HTTP/1.1 Host: www.example

      the SPARQL service responds with an RDF/XML encoded

      service description (no content negotiation or RDFa

      encoding is used):

      HTTP/1.1 200 OK Date: Fri, 09 Oct 2009 17:31:12 GMT Server: Apache/1.3.29 (Unix) PHP/4.3.4 DAV/1.0.3 Connection: close Content-Type: application/rdf+xml

      <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:sd="http://www.w3.org/ns/sparql-service-description#" xmlns:prof="http://www.w3.org/ns/owl-profile/" xmlns:void="http://rdfs.org/ns/void#"> <sd:Service> <sd:endpoint rdf:resource="http://www.example/sparql/"/> <sd:supportedLanguage rdf:resource="http://www.w3.org/ns/sparql-service-description#SPARQL11Query"/> <sd:resultFormat rdf:resource="http://www.w3.org/ns/formats/RDF_XML"/> <sd:resultFormat rdf:resource="http://www.w3.org/ns/formats/Turtle"/> <sd:feature rdf:resource="http://www.w3.org/ns/sparql-service-description#DereferencesURIs"/> <sd:defaultEntailmentRegime rdf:resource="http://www.w3.org/ns/entailment/RDFS"/> <sd:extensionFunction> <sd:Function rdf:about="http://example.org/Distance"/> </sd:extensionFunction> <sd:defaultDataset> <sd:Dataset> <sd:defaultGraph> <sd:Graph> <void:triples rdf:datatype="http://www.w3.org/2001/XMLSchema#integer">100</void:triples> </sd:Graph> </sd:defaultGraph> <sd:namedGraph> <sd:NamedGraph> <sd:name rdf:resource="http://www.example/named-graph"/> <sd:entailmentRegime rdf:resource="http://www.w3.org/ns/entailment/OWL-RDF-Based"/> <sd:supportedEntailmentProfile rdf:resource="http://www.w3.org/ns/owl-profile/RL"/> <sd:graph> <sd:Graph> <void:triples rdf:datatype="http://www.w3.org/2001/XMLSchema#integer">2000</void:triples> </sd:Graph> </sd:graph> </sd:NamedGraph> </sd:namedGraph> </sd:Dataset> </sd:defaultDataset> </sd:Service> </rdf:RDF> ```

    1. ```sparql PREFIX rdfs: http://www.w3.org/2000/01/rdf-schema# PREFIX i: http://learningsparql.com/ns/instrument/ PREFIX s: http://learningsparql.com/ns/schema/ PREFIX b: http://www.bobdc.com/ns/beatles/

      SELECT ?britishGroup WHERE { ?bassist b:favoriteBritishGroup ?britishGroup . SERVICE https://dydra.com/bobdc/beatles-musicians/sparql { SELECT ?bassist WHERE { ?song a s:Song ; rdfs:label "The Long And Winding Road" ; i:bass ?bassist . } } } ```

    1. ```sparql PREFIX rdf: http://www.w3.org/1999/02/22-rdf-syntax-ns# PREFIX skos: http://www.w3.org/2004/02/skos/core# PREFIX schema: http://schema.org/ prefix owl: http://www.w3.org/2002/07/owl# prefix rdfs: http://www.w3.org/2000/01/rdf-schema#

      CONSTRUCT { http://schema.org/ a skos:ConceptScheme ; skos:hasTopConcept schema:Thing . ?child a skos:Concept ; skos:broaderTransitive ?parent ; skos:broader ?ancestors ; skos:prefLabel ?label ; skos:definition ?desc ; skos:inScheme ?ext . ?parent skos:narrowerTransitive ?child . ?ancestors skos:narrower ?child .<br /> } WHERE { ?child rdfs:subClassOf ?parent . ?child rdfs:subClassOf+ ?ancestors . OPTIONAL { ?child rdfs:label ?label } OPTIONAL { ?child rdfs:comment ?desc } OPTIONAL { ?child schema:isPartOf ?ext } } ```

  8. Mar 2022
  9. Feb 2022
    1. Zusätzlich bietet die Abfragesprache SPARQL die Möglichkeit,RDF-kodierte semantische Daten strukturiert abzufragen, wobei bereits (beschränkter)Gebrauch der Möglichkeit logischer Schlussfolgerungen gemacht werden kann.

      SPARQL = Abfragesprache von RDF



    1. sql use "http://triplr.org/sparyql/sparql.xml" as sparql; select * from sparql where query="PREFIX foaf: <http://xmlns.com/foaf/0.1/> SELECT $nick $name FROM <http://www.dajobe.org/foaf.rdf> WHERE { $x a foaf:Person . $x foaf:nick $nick . $x foaf:name $name }" and service="http://sparql.org/sparql"

    1. ```xml <iq to='crschmidt@crschmidt.net/sparql' type='get' id='2'> <query xmlns='http://www.w3.org/2005/09/xmpp-sparql-binding'> SELECT ?a WHERE { ?a &http://xmlns.com/foaf/0.1/nick> "crschmidt". } </query> </iq>

      <iq to='crschmidt@crschmidt.net/sparql' type='result' id='2' from='crschmidt@crschmidt.net/sparql'> <query xmlns='http://www.w3.org/2005/09/xmpp-sparql-binding'> <meta /> <sparql xmlns='http://www.w3.org/2001/sw/DataAccess/rf1/result'> <head> <variable name='a'/> </head> <results> <result> </result> <result> </result> <result> </result> </results> </sparql> </query> </iq> ```

  10. Jan 2022
  11. Dec 2021
  12. May 2021
    1. Note that variables cannot appear in the predicate position.
  13. Jun 2020
  14. Jan 2020
  15. Nov 2019
  16. Jun 2019
    1. SPARQ

      SPARQL is an RDF query language—that is, a semantic query language for databases—able to retrieve and manipulate data stored in Resource Description Framework format



  17. Nov 2018
    1. Now you know how to search for all works of art, or all buildings, or all human settlements: the magic incantation wdt:P31/wdt:P279*, along with the appropriate class. This uses some more SPARQL features that I haven’t explained yet, but quite honestly, this is almost the only relevant use of those features, so you don’t need to understand how it works in order to use WDQS effectively. If you want to know, I’ll explain it in a bit, but you can also just skip the next section and memorize or copy+paste wdt:P31/wdt:P279* from here when you need it.

      wdt:P31/wdt:P279* = magic incantation for Wikidata SPARQL to mean "instance of or subclass of"

  18. Oct 2018