Question

我在处理数字数据类型时遇到SPARQL问题。

我有一个本体论（http://cabas.ugr.es/ontology/ugr），其中我定义了一对属性，代表了特定性别的学生人数：

<http://cabas.ugr.es/ontology/ugr#hombres>
                     a owl:DatatypeProperty, owl:FunctionalProperty, rdf:Property ;
  rdfs:label
    "hombres"@es,
    "men"@en ;
  rdfs:comment
    "Número de estudiantes hombres."@es,
    "Number of male students."@en ;
  rdfs:range xsd:nonNegativeInteger ;
  rdfs:isDefinedBy <http://cabas.ugr.es/ontology/ugr#> ;
  owl:sameAs <http://cabas.ugr.es/ontology/ugr#hombres> ;
  owl:inverseOf <http://cabas.ugr.es/ontology/ugr#mujeres> ;
  ns1:term_status "stable" .

<http://cabas.ugr.es/ontology/ugr#mujeres>
                     a owl:DatatypeProperty, owl:FunctionalProperty, rdf:Property ;
  rdfs:label
    "mujeres"@es,
    "women"@en ;
  rdfs:comment
    "Número de estudiantes mujeres."@es,
    "Number of female students."@en ;
  rdfs:range xsd:nonNegativeInteger ;
  rdfs:isDefinedBy <http://cabas.ugr.es/ontology/ugr#> ;
  owl:sameAs <http://cabas.ugr.es/ontology/ugr#mujeres> ;
  owl:inverseOf <http://cabas.ugr.es/ontology/ugr#hombres> ;
  ns1:term_status "stable" .

我在Virtuoso（http://cabas.ugr.es:8890/sparql）上安装了SPARQL端点，我在其中输入以下查询：

PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX ugr: <http://cabas.ugr.es/ontology/ugr#>

SELECT ?X ?titulacion ?rama ?hombres ?mujeres
WHERE {
  ?X ugr:Titulación ?titulacion .
  ?X ugr:RamaConocimiento ?rama .
  ?X ugr:hombres ?hombres .
  ?X ugr:mujeres ?mujeres
}

（与this link对应）

它返回所有记录，但字段＆＃34; hombres＆＃34; 和＆＃34; mujeres＆＃34; 将它们返回给我，就好像它一样是字符串而不是数字值，因此例如，不可能应用像FILTER (?hombres > 500)这样的过滤器。知道我错了什么吗？

顺便说一句，可以通过以下链接访问本体和具有值的资源：

本体：
- 龟格式：
  - http://cabas.ugr.es/ontology/ugr
  - http://cabas.ugr.es/ontology/ugr.ttl
- RDF / XML格式：
  - http://cabas.ugr.es/ontology/ugr.rdf
资源：
- 龟格式：
  - http://cabas.ugr.es/resources/MatriculasGrado1516
  - http://cabas.ugr.es/resources/matriculas_grado_1516.ttl
- RDF / XML格式：
  - http://cabas.ugr.es/resources/matriculas_grado_1516.rdf

Answer 1

In order to treat the numbers as numbers, you need to define them as such.

Right now you define them as strings:

<http://cabas.ugr.es/resources/MatriculasGrado1516#21>
  ns0:hombres "91" ;
  ns0:mujeres "68" .

To define them as integers, you need to set their type to xsd:integer:

<http://cabas.ugr.es/resources/MatriculasGrado1516#21>
  ns0:hombres "91"^^xsd:integer ;
  ns0:mujeres "68"^^xsd:integer .

Strings can also be cast to integer in queries, if needed. For example:

FILTER(xsd:integer(?hombres) > 500)

由SPARQL作为字符串返回的数字属性

1 个答案: