SPARQL-Star x Query using Context Meta-information (RDF-Star)

Utilizando o recurso de RDF-Star onde cada tripla pode ser anotada com predicado e valor

Testes via Apache Jena Fuseki no desktop

Instalação

JDK

https://medium.com/@fadirra/setting-up-jena-fuseki-with-update-in-windows-10-2c8a2802ee8f

Download para WIndows
Unzip
Cria a pasta data

cmd
cd C:\Users\.....\apache-jena-fuseki-4.3.2
fuseki-server --loc=data --update /meta_info

http://localhost:3030/index.html

DATASET

Testes

SPARQL EndPoint /meta_info/update


PREFIX ns: <http://example.org/ns#>
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>

INSERT DATA {ns:c1 rdf:type ns:Country; ns:name 'Germany';  ns:language 'German'; ns:continent 'Europe'; ns:population 83000000 };
INSERT DATA {ns:c2 rdf:type ns:Country; ns:name 'France'; ns:language 'French'; ns:continent 'Europe'; ns:population 67000000 };
INSERT DATA {ns:c3 rdf:type ns:Country; ns:name 'United Kingdom'; ns:language 'English'; ns:continent 'Europe'; ns:population: 66000000 };

INSERT DATA {ns:p1 rdf:type ns:Person; ns:name 'John' };
INSERT DATA {ns:p2 rdf:type ns:Person; ns:name 'Harry'};
INSERT DATA {ns:p3 rdf:type ns:Person; ns:name 'Anna'};

INSERT DATA {ns:p1 ns:LIVING_IN ns:c1};
INSERT DATA {<<ns:p1 ns:LIVING_IN ns:c1>>  ns:date_of_start 2014};
INSERT DATA {ns:p1 ns:WORKING_IN ns:c2};
INSERT DATA {<<ns:p1 ns:WORKING_IN ns:c2>>  ns:date_of_start 2014};

INSERT DATA {ns:p1 ns:LIVING_IN ns:c3};
INSERT DATA {<<ns:p1 ns:LIVING_IN ns:c3>>  ns:date_of_start 2014};
INSERT DATA {ns:p1 ns:WORKING_IN ns:c3};
INSERT DATA {<<ns:p1 ns:WORKING_IN ns:c3>>  ns:date_of_start 2014};

INSERT DATA {ns:p3 ns:LIVING_IN ns:c1};
INSERT DATA {<<ns:p3 ns:LIVING_IN ns:c1>>  ns:date_of_start 2016};
INSERT DATA {ns:p3 ns:WORKING_IN ns:c3};
INSERT DATA {<<ns:p3 ns:WORKING_IN ns:c3>>  ns:date_of_start 2014};
INSERT DATA {ns:p1 ns:FRIENDS_WITH ns:p2};
INSERT DATA {<<ns:p1 ns:FRIENDS_WITH ns:p2>>  ns:date_of_start 2011};
INSERT DATA {ns:p3 ns:FRIENDS_WITH ns:p1};
INSERT DATA {<<ns:p3 ns:FRIENDS_WITH ns:p1>>  ns:date_of_start 2012};
INSERT DATA {ns:p3 ns:FRIENDS_WITH ns:p2};
INSERT DATA {<<ns:p3 ns:FRIENDS_WITH ns:p2>>  ns:date_of_start 2014};

--

SPARQL EndPoint /meta_info/query


PREFIX ns: <http://example.org/ns#>
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>

# View quads
SELECT ?s ?p ?o ?g {
  # default graph
  { ?s ?p ?o . }
  UNION
  # named graphs
  { GRAPH ?g { ?s ?p ?o . }  }
}

--

SELECT ?s ?p ?o ?g { GRAPH ?g { ?s ?p ?o . }  }

--

SELECT ?s ?p ?o { ?s ?p ?o . }  

Exemplo do resultado em XML

    <result>
      <binding name="s">
        <triple>
          <subject>
            <uri>http://example.org/ns#p1</uri>
          </subject>
          <predicate>
            <uri>http://example.org/ns#WORKING_IN</uri>
          </predicate>
          <object>
            <uri>http://example.org/ns#c3</uri>
          </object>
        </triple>
      </binding>
      <binding name="p">
        <uri>http://example.org/ns#date_of_start</uri>
      </binding>
      <binding name="o">
        <literal datatype="http://www.w3.org/2001/XMLSchema#integer">2014</literal>
      </binding>
    </result>

Exemplo do resultado em JSON

      {
        "s": {
          "type": "triple" ,
          "value": {
            "subject":  { "type": "uri" , "value": "http://example.org/ns#p1" } ,
            "predicate": { "type": "uri" , "value": "http://example.org/ns#LIVING_IN" } ,
            "object":   { "type": "uri" , "value": "http://example.org/ns#c1" }
          }
        } ,
        "p": { "type": "uri" , "value": "http://example.org/ns#date_of_start" } ,
        "o": { "type": "literal" , "datatype": "http://www.w3.org/2001/XMLSchema#integer" , "value": "2014" }
      } ,
      
--

SELECT ?s ?p ?c ?t
{ ?c rdf:type  ns:Country; ns:name 'United Kingdom'.
  <<?s ?p ?c>> ns:date_of_start 2014 .
  BIND(<< ?s ?p ?c>> AS ?t)}

--

SELECT ?p_name ?f_name ?o ?t
WHERE {
    ?p rdf:type ns:Person; ns:name ?p_name.
    ?f ns:name ?f_name.
    <<?p ns:FRIENDS_WITH ?f>>  ns:date_of_start ?o.
    BIND(<<?p ns:FRIENDS_WITH ?f>> AS ?t)
    FILTER (?o > 2010) .
}

--

SELECT ?p_name ?f_name ?o ?t2
WHERE {
    ?p rdf:type ns:Person; ns:name ?p_name.
    ?f2 ns:name ?f_name.
    <<?p ns:FRIENDS_WITH ?f1>>  ns:date_of_start ?o1.
    <<?p ns:FRIENDS_WITH ?f2>>  ns:date_of_start ?o2.
    BIND(<<?p ns:FRIENDS_WITH ?f2>> AS ?t2)
    FILTER (?o2 > ?o1) .
}

Resultado em JSON

{ "head": {
    "vars": [ "p_name" , "f_name" , "o" , "t2" ]
  } ,
  "results": {
    "bindings": [
      {
        "p_name": { "type": "literal" , "value": "Anna" } ,
        "f_name": { "type": "literal" , "value": "Harry" } ,
        "t2": {
          "type": "triple" ,
          "value": {
            "subject":  { "type": "uri" , "value": "http://example.org/ns#p3" } ,
            "predicate": { "type": "uri" , "value": "http://example.org/ns#FRIENDS_WITH" } ,
            "object":   { "type": "uri" , "value": "http://example.org/ns#p2" }
          }
        }
      }
    ]
  }
}
--

SELECT ?p1_name ?p2_name ?p3_name ?p4_name ?o ?t2
WHERE {
    ?p1 rdf:type ns:Person; ns:name ?p1_name.
    ?p2 rdf:type ns:Person; ns:name ?p2_name.
    ?p3 rdf:type ns:Person; ns:name ?p3_name.
    ?p4 rdf:type ns:Person; ns:name ?p4_name.
    <<?p1 ns:FRIENDS_WITH ?p3>>  ns:date_of_start ?o.
    <<?p2 ns:FRIENDS_WITH ?p4>>  ns:date_of_start ?o.
    BIND(<<?p ns:FRIENDS_WITH ?f2>> AS ?t2)
    FILTER (?p1 != ?p2) .
}

--

SELECT ?p1_name ?p2_name ?c1_name ?c2_name ?o ?t2
WHERE {
    ?p1 rdf:type ns:Person; ns:name ?p1_name.
    ?p2 rdf:type ns:Person; ns:name ?p2_name.
    ?c1 rdf:type ns:Country; ns:name ?c1_name.
    ?c2 rdf:type ns:Country; ns:name ?c2_name.
    <<?p1 ns:LIVING_IN ?c1>>  ns:date_of_start ?o.
    <<?p2 ns:LIVING_IN ?c2>>  ns:date_of_start ?o.
    BIND(<<?p2 ns:LIVING_IN ?c2>> AS ?t2)
    FILTER (?c1 != ?c2) .
}

--

SELECT DISTINCT ?s1_name ?rel1 ?o1_name ?s2_name ?rel2 ?o2_name ?o
WHERE {
    ?s1 ns:name ?s1_name.
    ?s2 ns:name ?s2_name.
    ?o1 ns:name ?o1_name.
    ?o2 ns:name ?o2_name.
    <<?s1 ?rel1 ?o1>>  ns:date_of_start ?o.
    <<?s2 ?rel2 ?o2>>  ns:date_of_start ?o.
      BIND(<<?s1 ?rel1 ?o1>> AS ?t1)
    BIND(<<?s2 ?rel2 ?o2>> AS ?t2)
    FILTER (?t1 != ?t2) .
}

--

SELECT ?p1_name ?p2_name ?since ?t
WHERE {
    ?p1 ns:FRIENDS_WITH+ ?p2.
    ?p1 rdf:type ns:Person; ns:name ?p1_name.
    ?p2 rdf:type ns:Person; ns:name ?p2_name.
    <<?p1 ns:FRIENDS_WITH ?p2>>  ns:date_of_start ?since.
      BIND(<<?p1 ns:FRIENDS_WITH ?p2>> AS ?t)
    FILTER (?since > 2010) .
}

--


SPARQL EndPoint /meta_info/update

PREFIX ns: <http://example.org/ns#>
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>

INSERT DATA {<<ns:p1 ns:FRIENDS_OF ns:p2>>  ns:date_of_start 2018};
INSERT DATA {<<ns:p3 ns:FRIENDS_OF ns:p1>>  ns:date_of_start 2019} ;
INSERT DATA {<<ns:p3 ns:FRIENDS_OF ns:p2>>  ns:date_of_start 2017} ;
INSERT DATA {ns:p1 ns:FRIENDS_OF ns:p2};
INSERT DATA {ns:p3 ns:FRIENDS_OF ns:p1};
INSERT DATA {ns:p3 ns:FRIENDS_OF ns:p2};

SPARQL EndPoint /meta_info/query


PREFIX ns: <http://example.org/ns#>
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>

SELECT ?since ?t
WHERE {
    ns:p3 ns:FRIENDS_OF+ ns:p2.
    <<?p1 ns:FRIENDS_OF ?p2>>  ns:date_of_start ?since.
      BIND(<<?p1 ns:FRIENDS_OF ?p2>> AS ?t)
    FILTER (?since > 2016) .
}

SELECT ?since ?t
WHERE {
    ns:p3 ns:FRIENDS_OF+ ns:p2.
    <<?p1 ns:FRIENDS_OF ?p2>>  ns:date_of_start ?since.
      BIND(<<?p1 ns:FRIENDS_OF ?p2>> AS ?t)
    FILTER (?since > 2017) .
}

As consultas do tipo property path em SPARQL e SPARQL-Star retornam apenas os nós inicial e final de um caminho e não permitem variáveis ​​em expressões regulares para os predicados dos caminhos. Dessa forma, as consultas de caminho não retornam todos os nós intermediários em cada caminho. Adicionalmente um caminho de triplas RDF não pode ser representado naturalmente no formato de resultados tabulares de SPARQL.Com isso não é possível associar as triplas RDF recuperadas com as triplas RDF-Star associadas aos pares chave/valor dos qualificadores.