对 sparql 查询的结果进行排名

Bob Dudan

我有一个 skos 概念的层次结构和一些由这些概念索引的个人(例如ex:Regina dct:subject ex:Pizza)。

我想找到由某些概念(或更具体的概念)索引的每个人。下面的查询检索比萨饼或自制的每顿饭。(我正在使用concatgroup_concat轻松获得一排膳食的概念)

select ?ind ?name (group_concat(concat(str(?concept),':',?conceptName)) as ?concepts){
  ?ind a ex:Individual.
  ?ind skos:prefLabel ?name.
  ?ind dct:subject ?concept.
  ?concept skos:prefLabel ?conceptName.
  optional{?ind dct:subject [skos:broaderTransitive* ex:Pizza].}
  optional{?ind dct:subject [skos:broaderTransitive* ex:Homemade].}
}
group by ?ind ?name

这很好,但现在我想根据这些结果与我想要的共同概念的数量对这些结果进行排名。所以在我的例子中,我想先吃自制比萨饼,然后才吃比萨饼或自制餐点。
我还想摆脱没有任何我感兴趣的概念的结果。
理想情况下,我还希望由所需概念直接索引的膳食比由更具体的概念索引的膳食具有更高的分数。

我当然可以对结果进行后处理,但我很确定在 sparql 中有一种聪明而有效的方法。任何想法 ?

编辑:根据请求样本数据

@prefix : <http://www.semanticweb.org/owl/owlapi/turtle#> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix xml: <http://www.w3.org/XML/1998/namespace> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix skos: <http://www.w3.org/2004/02/skos/core#> .
@prefix dct: <http://purl.org/dc/terms/>  .
@prefix ex: <http://example.com#> .

ex:FoodScheme a skos:ConceptScheme ;
    skos:prefLabel "The food schema"@en ;
    skos:hasTopConcept ex:Food .

ex:Food a skos:Concept ;
    skos:prefLabel "Food"@en ;
    skos:inScheme ex:FoodScheme .

    ex:Italian a skos:Concept ;
        skos:prefLabel "Italian food"@en ;
        skos:broaderTransitive ex:Food ;
        skos:inScheme ex:FoodScheme .

        ex:Pizza a skos:Concept ;
            skos:prefLabel "Pizza"@en ;
            skos:broaderTransitive ex:Italian ;
            skos:inScheme ex:FoodScheme .

        ex:Pasta a skos:Concept ;
            skos:prefLabel "Pasta"@en ;
            skos:broaderTransitive ex:italian ;
            skos:inScheme ex:FoodScheme .

    ex:Homemade a skos:Concept ;
        skos:prefLabel "Homemade food"@en ;
        skos:broaderTransitive ex:Food ;
        skos:inScheme ex:FoodScheme .

ex:Regina a ex:Meal ;
    skos:prefLabel "Regina"@en ;
    dct:subject ex:Homemade ;
    dct:subject ex:Pizza.

ex:PeppyPaneer a ex:Meal ;
    skos:prefLabel "From Domino's"@en ;
    dct:subject ex:Pizza.

ex:Carbonara a ex:Meal ;
    skos:prefLabel "Pasta a la carbonara"@en ;
    dct:subject ex:Homemade ;
    dct:subject ex:Pasta.

ex:Lasagna a ex:Meal ;
    skos:prefLabel "Lasagna"@en ;
    dct:subject ex:Italian.

自制披萨的预期结果(首先是 Regina,因为它是自制的披萨,不包括 carbonara,因为它既不是自制的也不是披萨。PeppyPaneer 和 Carbonara 的顺序无关紧要,它们应该具有相同的“分数”):

ex:Regina
ex:PeppyPaneer
ex:Carbonara

意大利语的预期结果(首先是烤宽面条,因为它被直接索引为意大利语,而其他则不是):

ex:Lasagna
ex:Carbonara
ex:PeppyPaneer
ex:Regina
不知情的用户

给定一组相关的主题{ ex:Pizza ex:Homemade },我们可以这样做:

询问

PREFIX  ex: <http://example.com#> 
PREFIX  dct:  <http://purl.org/dc/terms/>
PREFIX  skos: <http://www.w3.org/2004/02/skos/core#>

SELECT  ?ind ?name (GROUP_CONCAT(DISTINCT ?conceptStr) AS ?concepts) (COUNT(DISTINCT ?cls) AS ?score)
WHERE
  { ?ind      skos:prefLabel  ?name ;
              dct:subject     ?concept .
    ?concept  skos:prefLabel  ?conceptName
    BIND(concat(str(?concept), ":", ?conceptName) AS ?conceptStr)
    OPTIONAL
      { VALUES ?cls { ex:Pizza ex:Homemade }
        ?ind dct:subject/(skos:broaderTransitive)* ?cls
      }
  }
GROUP BY ?ind ?name
HAVING ( ?score > 0 )
ORDER BY DESC(?score)

输出:

+-----------------+-------------------------+--------------------------------------------------------------------------+-------+
|       ind       |          name           |                                 concepts                                 | score |
+-----------------+-------------------------+--------------------------------------------------------------------------+-------+
|  ex:Regina      | Regina en               | http://example.com#Pizza:Pizza http://example.com#Homemade:Homemade food |     2 |
|  ex:Carbonara   | Pasta a la carbonara en | http://example.com#Pasta:Pasta http://example.com#Homemade:Homemade food |     1 |
|  ex:PeppyPaneer | From Domino's en        | http://example.com#Pizza:Pizza                                           |     1 |
+-----------------+-------------------------+--------------------------------------------------------------------------+-------+

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