我正在使用DBPedia信息框属性和信息框类型从DBPedia导入数据。但是我仍然错过了班级之间的关系。如何以相对简单的方式有效地检索类型层次结构？我考虑过将DBpedia类型映射到Yago类型，然后使用
检索yago类型层次结构是否有更简单或更直接的解决方法？
答案 0 :(得分：2)
您可以使用其中一个API以编程方式执行此操作以使用RDF，也可以使用RDF查询工具（如SPARQL）执行此操作。在这两种情况下，您都需要下载DBpedia ontology（在RDF / XML中序列化的OWL本体）。
使用Jena，您可以将数据加载到Model，然后使用listStatements选择以rdfs:subClassOf作为谓词的语句。请注意，null用作通配符。
import com.hp.hpl.jena.rdf.model.Model;
import com.hp.hpl.jena.rdf.model.ModelFactory;
import com.hp.hpl.jena.rdf.model.RDFNode;
import com.hp.hpl.jena.rdf.model.Statement;
import com.hp.hpl.jena.rdf.model.StmtIterator;
import com.hp.hpl.jena.vocabulary.RDFS;
public class IterateRDFSSubclassTriples {
public static void main(String[] args) {
final Model dbpedia = ModelFactory.createDefaultModel();
dbpedia.read( "/home/taylorj/Downloads/dbpedia_3.9.owl", "RDF/XML" );
final StmtIterator stmts = dbpedia.listStatements(null, RDFS.subClassOf, (RDFNode) null);
while ( stmts.hasNext() ) {
final Statement stmt = stmts.next();
System.out.println( stmt.getSubject() + " is a subclass of " + stmt.getObject() );
}
}
}
这会产生如下输出：
http://dbpedia.org/ontology/FilmFestival is a subclass of http://schema.org/Festival
http://dbpedia.org/ontology/Embryology is a subclass of http://dbpedia.org/ontology/AnatomicalStructure
http://dbpedia.org/ontology/Canal is a subclass of http://dbpedia.org/ontology/Stream
http://dbpedia.org/ontology/Fern is a subclass of http://dbpedia.org/ontology/Plant
http://dbpedia.org/ontology/Architect is a subclass of http://dbpedia.org/ontology/Person
…
您可以运行以下SPARQL查询以从rdfs:subClassOf三元组中提取所有子类和超类：
prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#>
select ?subclass ?superclass where {
?subclass rdfs:subClassOf ?superclass
}
使用Jena的命令行sparql工具，我们找到了541个这样的三元组：
$ sparql --query query.rq --data dbpedia_3.9.owl | head
-----------------------------------------------------------------------------------------------------------------------------------------------
| subclass | superclass |
===============================================================================================================================================
| <http://dbpedia.org/ontology/FilmFestival> | <http://schema.org/Festival> |
| <http://dbpedia.org/ontology/Embryology> | <http://dbpedia.org/ontology/AnatomicalStructure> |
| <http://dbpedia.org/ontology/Canal> | <http://dbpedia.org/ontology/Stream> |
| <http://dbpedia.org/ontology/Fern> | <http://dbpedia.org/ontology/Plant> |
| <http://dbpedia.org/ontology/Architect> | <http://dbpedia.org/ontology/Person> |
...
| <http://dbpedia.org/ontology/LegalCase> | <http://dbpedia.org/ontology/Case> |
| <http://dbpedia.org/ontology/Lymph> | <http://dbpedia.org/ontology/AnatomicalStructure> |
| <http://dbpedia.org/ontology/City> | <http://dbpedia.org/ontology/Settlement> |
-----------------------------------------------------------------------------------------------------------------------------------------------
如果您希望将此数据作为图表，则可以改为使用construct查询，并且您可以使用多种输出格式：
prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#>
construct where {
?subclass rdfs:subClassOf ?superclass
}
$ sparql --query query.rq --data dbpedia_3.9.owl | head -20
@prefix : <http://dbpedia.org/ontology/> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
:PoloLeague rdfs:subClassOf :SportsLeague .
:RacingDriver rdfs:subClassOf :Athlete .
:ResearchProject rdfs:subClassOf :Project .
# ...
$ sparql -out NT --query query.rq --data dbpedia_3.9.owl | head -20
<http://dbpedia.org/ontology/PoloLeague> <http://www.w3.org/2000/01/rdf-schema#subClassOf> <http://dbpedia.org/ontology/SportsLeague> .
<http://dbpedia.org/ontology/RacingDriver> <http://www.w3.org/2000/01/rdf-schema#subClassOf> <http://dbpedia.org/ontology/Athlete> .
<http://dbpedia.org/ontology/ResearchProject> <http://www.w3.org/2000/01/rdf-schema#subClassOf> <http://dbpedia.org/ontology/Project> .
<http://dbpedia.org/ontology/Song> <http://www.w3.org/2000/01/rdf-schema#subClassOf> <http://dbpedia.org/ontology/MusicalWork> .
<http://dbpedia.org/ontology/NetballPlayer> <http://www.w3.org/2000/01/rdf-schema#subClassOf> <http://dbpedia.org/ontology/Athlete> .
<http://dbpedia.org/ontology/Guitar> <http://www.w3.org/2000/01/rdf-schema#subClassOf> <http://dbpedia.org/ontology/Instrument> .
$ sparql -out RDF/XML --query query.rq --data dbpedia_3.9.owl | head -28
<rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:owl="http://www.w3.org/2002/07/owl#"
xmlns:xsd="http://www.w3.org/2001/XMLSchema#"
xmlns="http://dbpedia.org/ontology/"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#">
<rdf:Description rdf:about="http://dbpedia.org/ontology/SpeedwayTeam">
<rdfs:subClassOf>
<rdf:Description rdf:about="http://dbpedia.org/ontology/SportsTeam">
<rdfs:subClassOf>
<rdf:Description rdf:about="http://dbpedia.org/ontology/Organisation">
<rdfs:subClassOf>
<rdf:Description rdf:about="http://dbpedia.org/ontology/Agent">
<rdfs:subClassOf rdf:resource="http://www.w3.org/2002/07/owl#Thing"/>
</rdf:Description>
</rdfs:subClassOf>
</rdf:Description>
</rdfs:subClassOf>
</rdf:Description>
</rdfs:subClassOf>
</rdf:Description>
<rdf:Description rdf:about="http://dbpedia.org/ontology/NoteworthyPartOfBuilding">
<rdfs:subClassOf>
<rdf:Description rdf:about="http://dbpedia.org/ontology/ArchitecturalStructure">
<rdfs:subClassOf>
<rdf:Description rdf:about="http://dbpedia.org/ontology/Place">
<rdfs:subClassOf rdf:resource="http://www.w3.org/2002/07/owl#Thing"/>
</rdf:Description>
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