SPARQL正则表达式不匹配

Question

我希望在标题中没有"The Lord of the rings"字符串的情况下获得所有电影.我在链接电影数据库SPARQL端点尝试了这个,但它不起作用.怎么了？

PREFIX m: <http://data.linkedmdb.org/resource/movie/>
SELECT DISTINCT *  WHERE {
   ?film dc:title ?titulo_pelicula.
   FILTER NOT EXISTS { 
      FILTER (regex(?titulo_pelicula, "The Lord of the Rings","i")) . 
   }
}

Answer 1

首先,你应该澄清你的意思"不起作用."首先,我认为你的意思是它没有返回任何结果,但当我在端点运行时,我意识到你是实际上得到一个关于错误的相当明确的错误消息:

Parse error: 
PREFIX owl: <http://www.w3.org/2002/07/owl#>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
PREFIX oddlinker: <http://data.linkedmdb.org/resource/oddlinker/>
PREFIX map: <file:/C:/d2r-server-0.4/mapping.n3#>
PREFIX db: <http://data.linkedmdb.org/resource/>
PREFIX dbpedia: <http://dbpedia.org/property/>
PREFIX skos: <http://www.w3.org/2004/02/skos/core#>
PREFIX dc: <http://purl.org/dc/terms/>
PREFIX movie: <http://data.linkedmdb.org/resource/movie/>
PREFIX m: <http://data.linkedmdb.org/resource/movie/>
SELECT DISTINCT *  WHERE {
   ?film dc:title ?titulo_pelicula.
   FILTER NOT EXISTS { 
      FILTER (regex(?titulo_pelicula, "The Lord of the Rings","i")) . 
   }
}

Lexical error at line 16, column 14.  Encountered: " " (32), after : "NOT"

当你到达时,你有一个解析错误NOT.端点基于RDF的原始SPARQL查询语言而不是SPARQL 1.1查询语言.最初的SPARQL没有NOT EXISTS.

这很容易解决.首先,识别filter采用表达式并仅保留表达式计算结果为true的结果.regex(?titulo_pelicula, "The Lord of the Rings","i")当正则表达式与标题匹配时,过滤器表达式返回true,并且您正在寻找返回false的情况,因此您只需要用它来否定它!.(!运算符与XPath函数相同not.映射在SPARQL建议的11.3运算符映射中定义.)您需要这样的查询:

PREFIX m: <http://data.linkedmdb.org/resource/movie/>
SELECT DISTINCT *  WHERE {
   ?film dc:title ?titulo_pelicula.
   FILTER (!regex(?titulo_pelicula, "The Lord of the Rings","i")) . 
}

SPARQL结果