屬性提取值隨SPARQL

Question

我想用SPARQL獲得科目rdf:value具有以下資源：http://purl.org/dc/terms/LCSH

<dcterms:subject> 
    <rdf:Description rdf:nodeID="N4192a7fb1dd6438c94649f7afd192f09"> 
     <rdf:value>United States. Declaration of Independence</rdf:value> 
     <dcam:memberOf rdf:resource="http://purl.org/dc/terms/LCSH"/> 
    </rdf:Description> 
</dcterms:subject> 
<dcterms:subject> 
    <rdf:Description rdf:nodeID="N887b24b564624253b374ee7c95f0ed51"> 
     <rdf:value>United States -- History -- Revolution, 1775-1783 -- Sources</rdf:value> 
     <dcam:memberOf rdf:resource="http://purl.org/dc/terms/LCSH"/> 
    </rdf:Description> 
</dcterms:subject> 
<dcterms:subject> 
    <rdf:Description rdf:nodeID="N1b3ed5adb91b4b0c8aa1215180fdfa96"> 
     <rdf:value>JK</rdf:value> 
     <dcam:memberOf rdf:resource="http://purl.org/dc/terms/LCC"/> 
    </rdf:Description> 
</dcterms:subject> 
<dcterms:subject> 
    <rdf:Description rdf:nodeID="Nc5deb6e74cc6462fbeeb8c1871983f09"> 
     <dcam:memberOf rdf:resource="http://purl.org/dc/terms/LCC"/> 
     <rdf:value>KF</rdf:value> 
    </rdf:Description> 
</dcterms:subject> 

有沒有一種方法來提取rdf:resource，並用它來篩選的主題？

Answer 1

的RDF/XML片斷是不完整的，所以我們不能寫一個完美的查詢，但你會想是這樣的：

select ?value { 
    ?x dcterms:subject ?subject . 
    ?subject rdf:value ?value . 
    ?subject dcam:memberOf <http://purl.org/dc/terms/LCSH> . 
} 

如果你想，一個有點短，你可以這樣做：

select ?value { 
    ?x dcterms:subject [ 
     rdf:value ?value ; 
     dcam:memberOf <http://purl.org/dc/terms/LCSH> ] 
} 

如果你真的只在乎的東西，有RDF：價值特性，並LCSH的成員，你可以跳過第一個三乾脆：

select ?value { 
    ?x rdf:value ?value ; 
     dcam:memberOf <http://purl.org/dc/terms/LCSH> 
}