在RDF域中链接对象到主题

Question

我有这个RDF文件:

<rdf:RDF
    xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
    xmlns:j.0="http://relation/"
    xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"> 
  <rdf:Description rdf:about="soggetto">
    <j.0:Nome>Vercelli</j.0:Nome>
    <j.0:Regione>Piemonte</j.0:Regione>
  </rdf:Description>
  <rdf:Description rdf:about="Piemonte">
    <rdfs:label>Piemonte</rdfs:label>
  </rdf:Description>
  <rdf:Description rdf:about="Regione">
    <rdfs:label>Regione</rdfs:label>
    <rdf:type rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Property"/>
  </rdf:Description>
  <rdf:Description rdf:about="Vercelli">
    <rdfs:label>Vercelli</rdfs:label>
  </rdf:Description>
  <rdf:Description rdf:about="Nome">
    <rdfs:label>Nome</rdfs:label>
    <rdf:type rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Property"/>
  </rdf:Description>
</rdf:RDF>

我想将Piemonte和Vercelli对象(在"soggetto"主题中)与Piemonte和Vercelli主题联系起来，并且我想将Regione和Nome谓词(在"soggetto"主题中)与Regione和Nome主题联系起来。

对我来说，Vercelli主语等于Vercelli宾语，Piemonte主语等于Piemonte宾语，Regione谓词等于Regione主语，Nome谓词等于Nome主语。

我怎样才能做到这一点?我能用rdf:type谓词使维切利的宾语等于维切利的主语吗?或者是否存在其他属性?

Answer 1

我认为您真正要问的是如何使用资源作为某些主题的对象，而不是碰巧具有类似内容的字符串。首先，让我们在数据中添加一个xml:base和一个xmlns，这样它就更可预测了:

<rdf:RDF
    xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
    xmlns:j.0="http://stackoverflow.com/q/24084473/1281433/relations/"
    xml:base="http://stackoverflow.com/q/24084473/1281433/"
    xmlns="http://stackoverflow.com/q/24084473/1281433/"
    xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"> 
  <rdf:Description rdf:about="soggetto">
    <j.0:Nome>Vercelli</j.0:Nome>
    <j.0:Regione>Piemonte</j.0:Regione>
  </rdf:Description>
  <rdf:Description rdf:about="Piemonte">
    <rdfs:label>Piemonte</rdfs:label>
  </rdf:Description>
  <rdf:Description rdf:about="Regione">
    <rdfs:label>Regione</rdfs:label>
    <rdf:type rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Property"/>
  </rdf:Description>
  <rdf:Description rdf:about="Vercelli">
    <rdfs:label>Vercelli</rdfs:label>
  </rdf:Description>
  <rdf:Description rdf:about="Nome">
    <rdfs:label>Nome</rdfs:label>
    <rdf:type rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Property"/>
  </rdf:Description>
</rdf:RDF>

现在，使用Turtle/N3序列化比使用RDF/XML要容易得多，所以让我们看一下Turtle中的相同数据:

@prefix :      <http://stackoverflow.com/q/24084473/1281433/> .
@prefix rdf:   <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs:  <http://www.w3.org/2000/01/rdf-schema#> .
@prefix j.0:   <http://stackoverflow.com/q/24084473/1281433/relations/> .
:Nome   a           rdf:Property ;
        rdfs:label  "Nome" .
:Regione  a         rdf:Property ;
        rdfs:label  "Regione" .
:Vercelli  rdfs:label  "Vercelli" .
:soggetto  j.0:Nome  "Vercelli" ;
        j.0:Regione  "Piemonte" .
:Piemonte  rdfs:label  "Piemonte" .

更容易看到数据的结构，并知道如何修复它。它听起来像是，而不是说

:soggetto  j.0:Nome  "Vercelli" ;
        j.0:Regione  "Piemonte" .

您希望将:soggetto区域作为资源:Piemonte，您可以简单地通过使用:Piemonte而不是"Piemonte"来实现。那么在Turtle和RDF/XML中，您的数据将是

@prefix :      <http://stackoverflow.com/q/24084473/1281433/> .
@prefix rdf:   <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs:  <http://www.w3.org/2000/01/rdf-schema#> .
@prefix j.0:   <http://stackoverflow.com/q/24084473/1281433/relations/> .
:Nome   a           rdf:Property ;
        rdfs:label  "Nome" .
:Regione  a         rdf:Property ;
        rdfs:label  "Regione" .
:Vercelli  rdfs:label  "Vercelli" .
:soggetto  j.0:Nome  "Vercelli" ;
        j.0:Regione  :Piemonte .
:Piemonte  rdfs:label  "Piemonte" .

<rdf:RDF
    xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
    xmlns="http://stackoverflow.com/q/24084473/1281433/"
    xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
    xmlns:j.0="http://stackoverflow.com/q/24084473/1281433/relations/">
  <rdf:Property rdf:about="http://stackoverflow.com/q/24084473/1281433/Regione">
    <rdfs:label>Regione</rdfs:label>
  </rdf:Property>
  <rdf:Property rdf:about="http://stackoverflow.com/q/24084473/1281433/Nome">
    <rdfs:label>Nome</rdfs:label>
  </rdf:Property>
  <rdf:Description rdf:about="http://stackoverflow.com/q/24084473/1281433/soggetto">
    <j.0:Nome>Vercelli</j.0:Nome>
    <j.0:Regione>
      <rdf:Description rdf:about="http://stackoverflow.com/q/24084473/1281433/Piemonte">
        <rdfs:label>Piemonte</rdfs:label>
      </rdf:Description>
    </j.0:Regione>
  </rdf:Description>
  <rdf:Description rdf:about="http://stackoverflow.com/q/24084473/1281433/Vercelli">
    <rdfs:label>Vercelli</rdfs:label>
  </rdf:Description>
</rdf:RDF>