rdf - 通过正则表达式查询主题或谓词

Question

鉴于此RDF:

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE rdf:RDF [<!ENTITY rdf 'http://www.w3.org/1999/02/22-rdf-syntax-ns#'>
<!ENTITY rdfs 'http://www.w3.org/2000/01/rdf-schema#'>
<!ENTITY xsd 'http://www.w3.org/2001/XMLSchema#'>]>

<rdf:RDF xmlns:xsd="http://www.w3.org/2001/XMLSchema#" 
         xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
         xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
  <rdf:Description rdf:about="Fadi" xml:startTime="00:01:38" xml:endTime="00:01:39">
    <ns0:eat xmlns:ns0="http://example.org/">Apple</ns0:eat>
  </rdf:Description>
</rdf:RDF>

当我执行此SPARQL查询时

SELECT *
WHERE {
  ?s ?p ?o . 
  FILTER (regex(?o, 'Apple','i'))
}

我得到主题和谓词:

s: http://example.org/Fadi , p: http://example.org/eat .

但是当我执行

SELECT *
WHERE {
  ?s ?p ?o .
  FILTER (regex(?s, 'Fadi','i'))
}

要么

SELECT *
WHERE {
  ?s ?p ?o .
  FILTER (regex(?s, 'http://example.org/Fadi','i'))
}

我什么都没有。如何查询主语或谓语？
如何查询startTime和endTime？

Answer 1

？s是一个URI，而正则表达式适用于字符串。使用 str 函数来获取字符串:

FILTER (regex(str(?s), 'Fadi','i'))