SPARQL查詢：如何從EARL文檔中獲取行和字符編號？

Question

這可能是一個相當新手的問題，但RDF圖和sparql查詢只是讓我困惑。 這是一個（EARL，評估和報告語言）RDF文件的相關部分，我需要搜索：

<earl:Assertion> 
<earl:subject rdf:nodeID="A1"/> 
<earl:assertedBy rdf:nodeID="A2"/> 
<earl:test rdf:resource="http://www.w3.org/TR/xhtml1/#C_2"/> 
<earl:mode rdf:resource="http://www.w3.org/ns/earl#automatic"/> 
<earl:result> 
    <earl:TestResult> 
    <earl:pointer> 
     <pnt:EquivalentPointers> 
     <pnt:groupPointer> 
      <pnt:LineCharPointer> 
      <pnt:charNumber rdf:datatype="http://www.w3.org/2001/XMLSchema#positiveInteger" 
      >108</pnt:charNumber> 
      <pnt:lineNumber rdf:datatype="http://www.w3.org/2001/XMLSchema#positiveInteger" 
      >9</pnt:lineNumber> 
      </pnt:LineCharPointer> 
     </pnt:groupPointer> 
     <pnt:groupPointer> 
      <pnt:CharOffsetPointer> 
      <pnt:offset rdf:datatype="http://www.w3.org/2001/XMLSchema#positiveInteger" 
      >935</pnt:offset> 
      </pnt:CharOffsetPointer> 
     </pnt:groupPointer> 
     </pnt:EquivalentPointers> 
    </earl:pointer> 
    <earl:outcome rdf:resource="http://www.w3.org/ns/earl#failed"/> 
    <dct:description rdf:datatype="http://www.w3.org/2001/XMLSchema#string" 
    >A space character is missing before '/&gt;'.</dct:description> 
    </earl:TestResult> 
</earl:result> 
</earl:Assertion> 

我想從這個摘錄得到什麼：行號（和charNumber）的事實，伯爵：結果失敗了，說明。到目前爲止，我所能得到的只是行號，結果卻給出了行號+「^^ http://www.w3.org/2001/XMLSchema#positiveInteger」。我不知道爲什麼會發生這種情況。

感謝您的幫助！

Answer 1

下面的查詢翻出所有失敗的結果，從您的樣品（請注意，我不得不做出一個URI爲pnt:，因爲你沒有說那是什麼，它不是在prefix.cc列出）​​：

prefix pnt: <http://example.org/pnt#> 
prefix earl: <http://www.w3.org/ns/earl#> 
prefix dct: <http://purl.org/dc/terms/> 

select ?result ?desc ?charNo ?lineNo { 
    ?assert a earl:Assertion; 
      earl:result ?result. 

    ?result earl:outcome earl:failed; 
      earl:pointer/pnt:groupPointer ?gpt; 
      dct:description ?desc. 

    ?gpt pnt:charNumber ?charNo; 
     pnt:lineNumber ?lineNo. 
} 

該查詢給出明文以下結果：

$ arq --graph=./src/main/resources/earl.rdf --file=./src/main/resources/earl.sparql 
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ 
| result | desc                        | charNo             | lineNo             | 
==================================================================================================================================================================================================================================== 
| _:b0 | "A space character is\n   missing before '/>'."^^<http://www.w3.org/2001/XMLSchema#string> | "108"^^<http://www.w3.org/2001/XMLSchema#positiveInteger> | "9"^^<http://www.w3.org/2001/XMLSchema#positiveInteger> | 
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ 

你想與XSD類型datatyped的兩個數字，根據您提供的RDF樣品。 ^^裝飾只是使用Turtle語法表示數據類型。你可以清楚地看到這一點，如果我們在JSON選擇輸出，而不是：

$ arq --graph=./src/main/resources/earl.rdf --file=./src/main/resources/earl.sparql --results=json 
{ 
    "head": { 
    "vars": [ "result" , "desc" , "charNo" , "lineNo" ] 
    } , 
    "results": { 
    "bindings": [ 
     { 
     "result": { "type": "bnode" , "value": "b0" } , 
     "desc": { "datatype": "http://www.w3.org/2001/XMLSchema#string" , "type": "typed-literal" , "value": "A space character is\n   missing before '/>'." } , 
     "charNo": { "datatype": "http://www.w3.org/2001/XMLSchema#positiveInteger" , "type": "typed-literal" , "value": "108" } , 
     "lineNo": { "datatype": "http://www.w3.org/2001/XMLSchema#positiveInteger" , "type": "typed-literal" , "value": "9" } 
     } 
    ] 
    } 
}