为什么我的 Ontlgoy 中的某些类没有在我的 SPARQL 查询中返回？

如何解决为什么我的 Ontlgoy 中的某些类没有在我的 SPARQL 查询中返回？

我很困惑为什么我收到的结果太少（预期为 256，返回 224）。当我运行下面的代码时，一切都完全按照我的意愿返回，除了我错过了本体中位于最高级别或低于最高级别的所有类。我不明白我在查询中哪里过于“严格”，以至于这些类没有在表中返回。它们也都有父类（无论是本体的最顶层类“顶级概念”，还是枚举类型类之类的东西，无论哪种方式，仍然应该找到叶子。感谢我的代码可能的提示或指针无意中过滤掉了这些类。

SELECT disTINCT ?leaf ?parentclasses
WHERE {
GRAPH <>
#a leaf is the lowest level class: A class that does not have a subclass
{
    {
        {
            #I want anything which is a class
            {
                ?leaf rdf:type owl:Class.
            }
            #i also want the subclass of any superclass if that exists
            {
                ?leaf rdfs:subClassOf ?superclass .
            }
            #squeezed to specific section of OTL.
            filter strstarts(str(?leaf),"URIgoeshere")
            #Only keep the results that do not have a preflabel
            OPTIONAL {
                ?leaf skos:prefLabel ?subclasslabel.
                
            }
            #make sure the subclasslabel is in dutch
            #filter( langMatches(lang(?subclasslabel),"nl") )
            
            #give me the label of the superclass
            OPTIONAL {
                ?superclass skos:prefLabel ?superclasslabel.
            }
            #make sure it's in dutch
            FILTER (lang(?superclasslabel) = "nl")
            #if it exists,give me also the superclass of the superclass creating a supersuperclass
            {
                ?superclass rdfs:subClassOf ?supersuperclass.
                #give me the label of the supersuperclass
                OPTIONAL {
                    ?supersuperclass skos:prefLabel ?supersuperclasslabel.
                }
                #make sure it's in dutch
                FILTER (lang(?supersuperclasslabel) = "nl")
                #keep the leafs that are NOT The values whereby the subclass is not empty. (double negative for removing leafs where the subclass has a subclass below it)
                FILTER NOT EXISTS {
                    ?subclass rdfs:subClassOf ?leaf 
                    FILTER (?subclass != owl:nothing ) 
                }
                #concatenate the two parentclass variables into one    
                BIND(concat(str(?superclasslabel),str("-"),str(?supersuperclasslabel) ) as ?parentclasses) 
            }
        }
    }
}

}

这是一个与我的数据库结构相同的 ttl 文件：https://file.io/jjwkAWbK4jrF

解决方法

以下是我对问题的最终解决方案。它比我预期的要复杂，但它确实有效。

问题是查询不接受这些没有父类的类。在某些联合情况下，这可以涵盖 0 个父类、1 个父类或 2 个父类。

SELECT DISTINCT ?leaf ?parentclasses
WHERE {
GRAPH <>
#a leaf is the lowest level class: A class that does not have a subclass
{{{{{
                    
                   
                    
        #I want anything which is a class
        {?leaf rdf:type owl:Class.}
                    
#squeezed 
        filter strstarts(str(?leaf),"graph")           
        #keep the leafs that are NOT The values whereby the subclass is not empty. 
 (double negative for removing leafs where the subclass has a subclass below it)
            FILTER NOT EXISTS {?subclass rdfs:subClassOf ?leaf 
            FILTER (?subclass != owl:Nothing ) }
 }              
                {
         {?leaf rdfs:subClassOf ?superclass .}
               
 #grab dutch label if available
optional {
?superclass skos:prefLabel ?superclassnllabel .
filter( langMatches(lang(?superclassnllabel),"nl") )
}

# take either as the label,but dutch over empty
                bind( coalesce( ?superclassnllabel,replace(str(? 
superclass),"^[^#]*#","" ) ) as ?superclasslabel )
            
                {
                    
                {?superclass rdfs:subClassOf ?supersuperclass.}
                

        #grab dutch label if available
 
?supersuperclass skos:prefLabel ?supersuperclassnllabel .
                    filter( langMatches(lang(?supersuperclassnllabel),"nl") )



 # take either as the label,but dutch over empty
                    bind( coalesce( ?supersuperclassnllabel,replace(str(? 
 supersuperclass),"" ) ) as ?supersuperclasslabel )
                BIND(concat(str(?superclasslabel),str(" - "),str(? 
supersuperclasslabel) ) as ?parentclasses)
                }
                union
                {
                    
                    {?superclass ?p ?o.filter(!isblank(?superclass))}
                    FILTER NOT EXISTS {?superclass rdfs:subClassOf ?supersuperclass}
                        BIND(concat(str(?superclasslabel),str("Top 
Concept") ) as ?parentclasses) 
                #concatenate the two parentclass variables into one    
                
                }


        
            }
            }
            
            union
            {
                   #figure this out,WHY IS IT HERE? 
                {?leaf rdf:type owl:Class .filter(!isblank(?leaf))}
                FILTER strstarts(str(?leaf),"graph") 
                FILTER NOT EXISTS {?leaf rdfs:subClassOf ?superclass}
                FILTER NOT EXISTS {?subclass rdfs:subClassOf ?leaf 
                FILTER (?subclass != owl:Nothing ) }
                BIND (str("Top Class")  as ?parentclasses )
                   
                
                }

            }}}}