Question

是否可以使用SPARQL查询定义资源（来自DBpedia）？我希望在(Conceptual) Clustering methods for the Semantic Web: issues and applications (slides 10–11)中显示类似TBox和ABox的内容。例如，对于DBpedia资源Stephen King，我希望：

Stephen_King：人⊓作家⊓男⊓......（最具体的课程）

Answer 1

您可以使用如下所示的查询来询问Stephen King所属的类，这些类没有子类，其中Stephen King也是一个实例。这似乎与“最具体的类”的想法完全一致。但是，因为（据我所知）没有任何理由附加到DBpedia SPARQL端点，可能存在可以推断的子类关系但是没有明确的存在于数据中。

select distinct ?type where { 
   dbr:Stephen_King a ?type .
  filter not exists { 
    ?subtype ^a  dbr:Stephen_King ;
             rdfs:subClassOf ?type .
  }
}

SPARQL results

实际上，由于每个类本身都是rdfs:subClassOf，因此您可能希望在该查询中添加另一行，以排除?subtype和?type相同的情况：

select distinct ?type where { 
   dbr:Stephen_King a ?type .
  filter not exists { 
    ?subtype ^a  dbr:Stephen_King ;
             rdfs:subClassOf ?type .
    filter ( ?subtype != ?type )
  }
}

SPARQL results

如果您确实需要像这些幻灯片中显示的那样的结果字符串，可以使用values将变量绑定到dbr:Stephen_King，然后使用一些分组和字符串连接来获得更好看的内容（有点）：

select
  (concat( ?person, " =\n", group_concat(?type; separator=" AND\n")) as ?sentence)
where { 
  values ?person {  dbr:Stephen_King }
  ?type ^a ?person .
  filter not exists { 
    ?subtype ^a ?person ;
             rdfs:subClassOf ?type .
    filter ( ?subtype != ?type )
  }
}
group by ?person

SPARQL results

http://dbpedia.org/resource/Stephen_King =
http://dbpedia.org/class/yago/AuthorsOfBooksAboutWritingFiction AND
http://dbpedia.org/ontology/Writer AND
http://schema.org/Person AND
http://xmlns.com/foaf/0.1/Person AND
http://dbpedia.org/class/yago/AmericanSchoolteachers AND
http://dbpedia.org/class/yago/LivingPeople AND
http://dbpedia.org/class/yago/PeopleFromBangor,Maine AND
http://dbpedia.org/class/yago/PeopleFromPortland,Maine AND
http://dbpedia.org/class/yago/PeopleFromSarasota,Florida AND
http://dbpedia.org/class/yago/PeopleSelf-identifyingAsAlcoholics AND
http://umbel.org/umbel/rc/Artist AND
http://umbel.org/umbel/rc/Writer AND
http://dbpedia.org/class/yago/20th-centuryNovelists AND
http://dbpedia.org/class/yago/21st-centuryNovelists AND
http://dbpedia.org/class/yago/AmericanHorrorWriters AND
http://dbpedia.org/class/yago/AmericanNovelists AND
http://dbpedia.org/class/yago/AmericanShortStoryWriters AND
http://dbpedia.org/class/yago/CthulhuMythosWriters AND
http://dbpedia.org/class/yago/HorrorWriters AND
http://dbpedia.org/class/yago/WritersFromMaine AND
http://dbpedia.org/class/yago/PeopleFromDurham,Maine AND
http://dbpedia.org/class/yago/PeopleFromLisbon,Maine AND
http://dbpedia.org/class/yago/PostmodernWriters

检索大多数特定类的实例

1 个答案: