SPARQL联邦查询-使用从另一个查询中的查询返回的uri

在下面的查询中，我想使用

？uri

变量，该变量标识DBpedia资源，以从DBpedia SPARQL服务获取DBpedia元素，但它不返回任何结果，因为它需要

中的uri

我也试过

//
//班级
//
//
//个人
//
杰克伦敦
http://dbpedia.org/resource/Julius_Caesar
https://www.wikidata.org/wiki/Q1048
http://dbpedia.org/resource/Julius_Caesar
https://www.wikidata.org/wiki/Q1048
数据库百科全书
http://dbpedia.org/page/Julius_Caesar
数据库百科全书
http://dbpedia.org/resource/Julius_Caesar_（播放）
维基数据
https://www.wikidata.org/wiki/Q215750
维基数据
https://www.wikidata.org/wiki/Q1048
数据库百科全书
dbpedia.org/page/William_Shakespeare
维基数据
https://www.wikidata.org/wiki/Q692
http://dbpedia.org/page/Julius_Caesar_（播放）
https://www.wikidata.org/wiki/Q1048
http://dbpedia.org/page/Julius_Caesar_（播放）
https://www.wikidata.org/wiki/Q1048
http://dbpedia.org/page/William_Shakespeare
https://www.wikidata.org/wiki/Q692
http://dbpedia.org/page/William_Shakespeare
https://www.wikidata.org/wiki/Q692

在这个问题和前面的问题中，您模糊了本体（描述中使用的词汇）和实例数据（描述本身）之间的界限。这里，您的查询包括几个额外的

前缀

定义（您只需要

lit:

和

rdf:

）。直接的问题包括：您的数据（如您的另一个问题所示）不包含

lit:dbpediaUri

谓词；存在的URI被类型化为文本，而不是URI；它们可能不是完整的URI（缺少

http://

）；他们可能不会识别实体

/resource/

，但会识别他们的描述

/page/

…我更新了我的问题。我添加了dbpediaUri属性作为字符串变量。现在它直接指向uri。我还在编辑服务部件时添加了查询结果。我希望您需要类似于

？character lit:dbpediaUri？uri的内容。绑定（IRI（？uri）为？real_uri）}

<代码>{？real\u uri rdf:type？type.太好了！它成功了。谢谢。不客气！但是，这种设计很糟糕（如Talled所指出的）。这些标识符应该是uri，而不是文字。分别地，属性应该是对象属性，而不是数据属性。

PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX lit: <http://purl.org/net/cnyt-literature#>

SELECT distinct ?writer ?play ?character ?uri ?type  WHERE {
    {
        ?writer lit:writerOf ?play .
        ?play lit:character ?character .
        ?character lit:dbpediaUri ?uri
    }

    SERVICE <http://dbpedia.org/sparql> {
        ?uri rdf:type ?type
    }   
}
LIMIT 50

<?xml version="1.0"?>
<rdf:RDF xmlns="http://purl.org/net/cnyt-literature#"
     xml:base="http://purl.org/net/cnyt-literature"
     xmlns:literature="http://purl.org/net/cnyt-literature#"
     xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
     xmlns:owl="http://www.w3.org/2002/07/owl#"
     xmlns:xml="http://www.w3.org/XML/1998/namespace"
     xmlns:xsd="http://www.w3.org/2001/XMLSchema#"
     xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#">
    <owl:Ontology rdf:about="http://purl.org/net/cnyt-literature"/>
    <!-- 

    //
    // Object Properties
    //

    <!-- http://purl.org/net/cnyt-literature#character -->

    <owl:ObjectProperty rdf:about="http://purl.org/net/cnyt-literature#character">
        <rdfs:domain rdf:resource="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#Play"/>
        <rdfs:range rdf:resource="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#Human"/>
    </owl:ObjectProperty>

    <!-- http://purl.org/net/cnyt-literature#writerOf -->

    <owl:ObjectProperty rdf:about="http://purl.org/net/cnyt-literature#writerOf">
        <rdfs:domain rdf:resource="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#Writer"/>
        <rdfs:range rdf:resource="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#Play"/>
    </owl:ObjectProperty>

    <!-- http://www.w3.org/2002/07/owl#sameAs -->

    <owl:ObjectProperty rdf:about="http://www.w3.org/2002/07/owl#sameAs">
        <rdfs:domain rdf:resource="http://www.w3.org/2002/07/owl#Thing"/>
        <rdfs:range rdf:resource="http://www.w3.org/2002/07/owl#Thing"/>
    </owl:ObjectProperty>
    <!-- 

    //
    // Data properties
    //

    <!-- http://purl.org/net/cnyt-literature#dbpediaUri -->

    <owl:DatatypeProperty rdf:about="http://purl.org/net/cnyt-literature#dbpediaUri">
        <rdfs:subPropertyOf rdf:resource="http://www.w3.org/2002/07/owl#topDataProperty"/>
    </owl:DatatypeProperty>

    <!-- http://purl.org/net/cnyt-literature#name -->

    <owl:DatatypeProperty rdf:about="http://purl.org/net/cnyt-literature#name">
        <rdfs:domain rdf:resource="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#Human"/>
        <rdfs:domain rdf:resource="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#Literary_Work"/>
        <rdfs:domain rdf:resource="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#Politician"/>
        <rdfs:domain rdf:resource="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#Writer"/>
        <rdfs:range rdf:resource="http://www.w3.org/2001/XMLSchema#string"/>
    </owl:DatatypeProperty> 

    <!-- http://purl.org/net/cnyt-literature#source -->

    <owl:DatatypeProperty rdf:about="http://purl.org/net/cnyt-literature#source"/>

    <!-- http://purl.org/net/cnyt-literature#wikidataUri -->

    <owl:DatatypeProperty rdf:about="http://purl.org/net/cnyt-literature#wikidataUri"/>

    <!-- http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#uri -->

    <owl:DatatypeProperty rdf:about="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#uri"/>

    <!-- http://www.w3.org/2002/07/owl#sameAs -->

    <owl:DatatypeProperty rdf:about="http://www.w3.org/2002/07/owl#sameAs"/>

    //
    // Classes
    //

    <!-- http://purl.org/net/cnyt-literature#Novel -->

    <owl:Class rdf:about="http://purl.org/net/cnyt-literature#Novel">
        <rdfs:subClassOf rdf:resource="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#Literary_Work"/>
    </owl:Class>
    <!-- http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#ExternalItem -->

    <owl:Class rdf:about="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#ExternalItem"/>

    <!-- http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#Human -->

    <owl:Class rdf:about="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#Human"/>
    <!-- http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#Literary_Work -->

    <owl:Class rdf:about="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#Literary_Work"/>

    <!-- http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#Play -->

    <owl:Class rdf:about="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#Play">
        <rdfs:subClassOf rdf:resource="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#Literary_Work"/>
    </owl:Class>



    <!-- http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#Politician -->

    <owl:Class rdf:about="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#Politician">
        <rdfs:subClassOf rdf:resource="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#Human"/>
    </owl:Class>

    <!-- http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#Writer -->

    <owl:Class rdf:about="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#Writer">
        <rdfs:subClassOf rdf:resource="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#Human"/>
    </owl:Class>



    //
    // Individuals
    //

    <!-- http://purl.org/net/cnyt-literature#JackLondon -->

    <owl:NamedIndividual rdf:about="http://purl.org/net/cnyt-literature#JackLondon">
        <rdf:type rdf:resource="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#Writer"/>
        <writerOf rdf:resource="http://purl.org/net/cnyt-literature#WhiteFang"/>
        <name rdf:datatype="http://www.w3.org/2001/XMLSchema#string">Jack London</name>
    </owl:NamedIndividual>

    <!-- http://purl.org/net/cnyt-literature#JuliusCaesar -->

    <owl:NamedIndividual rdf:about="http://purl.org/net/cnyt-literature#JuliusCaesar">
        <rdf:type rdf:resource="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#Politician"/>
        <dbpediaUri rdf:datatype="http://www.w3.org/2001/XMLSchema#string">http://dbpedia.org/resource/Julius_Caesar</dbpediaUri>
        <wikidataUri rdf:datatype="http://www.w3.org/2001/XMLSchema#string">https://www.wikidata.org/wiki/Q1048</wikidataUri>
        <owl:sameAs rdf:datatype="http://www.w3.org/2001/XMLSchema#string">http://dbpedia.org/resource/Julius_Caesar</owl:sameAs>
        <owl:sameAs rdf:datatype="http://www.w3.org/2001/XMLSchema#string">https://www.wikidata.org/wiki/Q1048</owl:sameAs>
    </owl:NamedIndividual>

    <!-- http://purl.org/net/cnyt-literature#JuliusCaesarDbpedia -->

    <owl:NamedIndividual rdf:about="http://purl.org/net/cnyt-literature#JuliusCaesarDbpedia">
        <rdf:type rdf:resource="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#ExternalItem"/>
        <source rdf:datatype="http://www.w3.org/2001/XMLSchema#string">dbpedia</source>
        <literature1:uri rdf:datatype="http://www.w3.org/2001/XMLSchema#string">http://dbpedia.org/page/Julius_Caesar</literature1:uri>
    </owl:NamedIndividual>


    <!-- http://purl.org/net/cnyt-literature#JuliusCaesarPlayDbpedia -->

    <owl:NamedIndividual rdf:about="http://purl.org/net/cnyt-literature#JuliusCaesarPlayDbpedia">
        <rdf:type rdf:resource="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#ExternalItem"/>
        <source rdf:datatype="http://www.w3.org/2001/XMLSchema#string">dbpedia</source>
        <literature1:uri rdf:datatype="http://www.w3.org/2001/XMLSchema#string">http://dbpedia.org/resource/Julius_Caesar_(play)</literature1:uri>
    </owl:NamedIndividual>
    <!-- http://purl.org/net/cnyt-literature#JuliusCaesarPlayWikidata -->

    <owl:NamedIndividual rdf:about="http://purl.org/net/cnyt-literature#JuliusCaesarPlayWikidata">
        <rdf:type rdf:resource="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#ExternalItem"/>
        <source rdf:datatype="http://www.w3.org/2001/XMLSchema#string">wikidata</source>
        <literature1:uri rdf:datatype="http://www.w3.org/2001/XMLSchema#string">https://www.wikidata.org/wiki/Q215750</literature1:uri>
    </owl:NamedIndividual>

    <!-- http://purl.org/net/cnyt-literature#JuliusCaesarWikidata -->

    <owl:NamedIndividual rdf:about="http://purl.org/net/cnyt-literature#JuliusCaesarWikidata">
        <rdf:type rdf:resource="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#ExternalItem"/>
        <source rdf:datatype="http://www.w3.org/2001/XMLSchema#string">wikidata</source>
        <literature1:uri rdf:datatype="http://www.w3.org/2001/XMLSchema#string">https://www.wikidata.org/wiki/Q1048</literature1:uri>
    </owl:NamedIndividual>
    <!-- http://purl.org/net/cnyt-literature#WhiteFang -->

    <owl:NamedIndividual rdf:about="http://purl.org/net/cnyt-literature#WhiteFang">
        <rdf:type rdf:resource="http://purl.org/net/cnyt-literature#Novel"/>
    </owl:NamedIndividual>



    <!-- http://purl.org/net/cnyt-literature#WilliamShakespeareDbpedia -->

    <owl:NamedIndividual rdf:about="http://purl.org/net/cnyt-literature#WilliamShakespeareDbpedia">
        <rdf:type rdf:resource="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#ExternalItem"/>
        <source rdf:datatype="http://www.w3.org/2001/XMLSchema#string">dbpedia</source>
        <literature1:uri rdf:datatype="http://www.w3.org/2001/XMLSchema#string">dbpedia.org/page/William_Shakespeare</literature1:uri>
    </owl:NamedIndividual>

    <!-- http://purl.org/net/cnyt-literature#WilliamShakespeareWikidata -->

    <owl:NamedIndividual rdf:about="http://purl.org/net/cnyt-literature#WilliamShakespeareWikidata">
        <rdf:type rdf:resource="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#ExternalItem"/>
        <source rdf:datatype="http://www.w3.org/2001/XMLSchema#string">wikidata</source>
        <literature1:uri rdf:datatype="http://www.w3.org/2001/XMLSchema#string">https://www.wikidata.org/wiki/Q692</literature1:uri>
    </owl:NamedIndividual>


    <!-- http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#JuliusCaesarPlay -->

    <owl:NamedIndividual rdf:about="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#JuliusCaesarPlay">
        <rdf:type rdf:resource="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#Play"/>
        <character rdf:resource="http://purl.org/net/cnyt-literature#JuliusCaesar"/>
        <dbpediaUri rdf:datatype="http://www.w3.org/2001/XMLSchema#string">http://dbpedia.org/page/Julius_Caesar_(play)</dbpediaUri>
        <wikidataUri rdf:datatype="http://www.w3.org/2001/XMLSchema#string">https://www.wikidata.org/wiki/Q1048</wikidataUri>
        <owl:sameAs rdf:datatype="http://www.w3.org/2001/XMLSchema#string">http://dbpedia.org/page/Julius_Caesar_(play)</owl:sameAs>
        <owl:sameAs rdf:datatype="http://www.w3.org/2001/XMLSchema#string">https://www.wikidata.org/wiki/Q1048</owl:sameAs>
    </owl:NamedIndividual>



    <!-- http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#WilliamShakespeare -->

    <owl:NamedIndividual rdf:about="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#WilliamShakespeare">
        <rdf:type rdf:resource="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#Writer"/>
        <writerOf rdf:resource="http://www.semanticweb.org/cnytync/ontologies/2017/6/literature#JuliusCaesarPlay"/>
        <dbpediaUri rdf:datatype="http://www.w3.org/2001/XMLSchema#string">http://dbpedia.org/page/William_Shakespeare</dbpediaUri>
        <wikidataUri rdf:datatype="http://www.w3.org/2001/XMLSchema#string">https://www.wikidata.org/wiki/Q692</wikidataUri>
        <owl:sameAs rdf:datatype="http://www.w3.org/2001/XMLSchema#string">http://dbpedia.org/page/William_Shakespeare</owl:sameAs>
        <owl:sameAs rdf:datatype="http://www.w3.org/2001/XMLSchema#string">https://www.wikidata.org/wiki/Q692</owl:sameAs>
    </owl:NamedIndividual>
</rdf:RDF>



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