rdf - SPARQL 查询以提取 schema.org/Product isSimilarTo 属性

Question

我已经编写了一个如下形式的查询来从 schema.org/Product 中提取数据，但是有一个isSimilarTo与 schema.org/Product 关联的属性可能有多个值，我需要提取isSimilarTo数组中属性的所有值对于每个产品。我怎么能做到这一点？

我正在使用如下类似的查询：

PREFIX schema: <http://schema.org/> 
PREFIX xsd:    <http://www.w3.org/2001/XMLSchema#> 

SELECT ?productName ?modelNumber ?price ?sellerName 
WHERE {
   ?product a schema:Product . 
   ?product schema:name ?productNameVal . 
   # str() to strip any language tags
   BIND(str(?productNameVal) AS ?productName)
   ?product schema:model ?modelNumberVal . 
   BIND(str(?modelNumberVal) AS ?modelNumber)
   ?product schema:offers ?offer . 
   ?offer a schema:Offer . 
   ?offer schema:price ?priceVal . 
   # Remove $ and cast to decimal
   BIND(xsd:decimal(replace(?priceVal,"\\$","")) AS ?price)
   ?offer schema:seller ?seller. 
   # In case there's a level of indirection for seller name
   OPTIONAL {
    ?seller schema:name ?sellerSchemaName . 
   }
   BIND(str(coalesce(?sellerSchemaName,?seller)) AS ?sellerName )
}
ORDER BY ?modelNumber ?price