SPARQL-如何仅获得最新实体

Question

在我的三重商店中，我有一个具有属性架构：版本和架构：datecreated的schema：Creativework的集合。 现在，我想获得所有架构：创意工作，但只有最新的架构。 我的示例：

PREFIX schema: <https://schema.org/> 
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> 
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
SELECT DISTINCT *
WHERE { 
    ?subject rdf:type schema:CreativeWork .     
    ?subject schema:identifier ?identifier .
    ?subject schema:version ?version .
    ?subject schema:dateCreated ?dateCreated .
    OPTIONAL {?subject schema:about/schema:name ?name .}
    FILTER( ?identifier = "46d8b7abfec44865a567ea04e385661b" ) .
} LIMIT 10

如何仅查询最新版本？

可执行示例： https：//api.triplipliplipliplipliplipliplydb.com/s/rllq4v-jgs

注意：filter（？didentifier =“ 46D8B7ABFEC44865A567EA04E385661B”）。只是为了使其更容易。

Answer 1

Unformeduser的查询运作良好：

PREFIX schema: <https://schema.org/> 
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> 
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
SELECT DISTINCT * 
{
  {
    SELECT ?identifier (max(?dateCreated) as ?latestDate) 
    WHERE {     
      ?subject rdf:type schema:CreativeWork .       
      ?subject schema:identifier ?identifier .     
      ?subject schema:dateCreated ?dateCreated . 
    } group by ?identifier
  }     
  ?subject schema:identifier ?identifier .     
  ?subject schema:version ?version .    
  ?subject schema:dateCreated ?latestDate .     
  OPTIONAL {?subject schema:about/schema:name ?name . } 
} LIMIT 100