我有以下SPARQL查询,请注意选择谓词中的rowcount和查询末尾的group by子句。
我希望查询在每条记录中返回正确的行数,我注意到返回的行数不正确意味着如果有一条记录我得到1或有时2,如果有超过2记录,我仍然得到2,基本上它似乎返回随机值。
我知道因为我的查询有些问题,有人可以让我知道我可能做错了什么吗?我正在使用Apache Jena。
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX pf: <http://jena.hpl.hp.com/ARQ/property#>
PREFIX d: <http://data-vocabulary.org/>
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
PREFIX s: <http://schema.org/>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
PREFIX gr: <http://purl.org/goodrelations/v1#>
SELECT DISTINCT (count(*) AS ?rowCount) ?productName ?offerImage ?offerName ?productCategory ?salePrice ?suggestedRetailPrice ?productImage ?productThumbNail ?productUrl (GROUP_CONCAT(DISTINCT ?productdescription) AS ?productdescriptions) ?productBrand ?productId ?productSku ?productModel ?productMPN ?productManufacturer ?productGtin13 ?productGtin14 ?productGtin8 ?productAvailable ?productUnAvailable ?productUsedCondition ?productNewCondition ?productColor ?productAggregateRatingValue ?productReviewCount
WHERE
{
?p2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> d:Product .
?p2 <http://data-vocabulary.org/Product/offerDetails> ?schOffer .
?schOffer <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> d:Offer .
?schOffer <http://data-vocabulary.org/Offer/price> ?salePrice
OPTIONAL
{ ?schOffer <http://data-vocabulary.org/Offer/name> ?offerName }
OPTIONAL
{ ?p2 <http://data-vocabulary.org/Product/name> ?productName }
OPTIONAL
{ ?schOffer <http://data-vocabulary.org/Offer/image> ?offerImage }
OPTIONAL
{ ?p2 <http://data-vocabulary.org/Product/url> ?productUrl }
OPTIONAL
{ ?p2 <http://data-vocabulary.org/Product/image> ?productImage }
OPTIONAL
{ ?schOffer <http://data-vocabulary.org/Offer/category> ?productCategory }
OPTIONAL
{ ?p2 <http://data-vocabulary.org/Product/description> ?productdescription }
OPTIONAL
{ ?p2 <http://data-vocabulary.org/Product/brand> ?pBrandNode
OPTIONAL
{ ?pBrandNode <http://data-vocabulary.org/Brand/name> ?brandNodeName }
OPTIONAL
{ ?pBrandNode <http://data-vocabulary.org/Organization/name> ?brandNodeName }
BIND(str(coalesce(?brandNodeName, ?pBrandNode)) AS ?productBrand)
}
OPTIONAL
{ ?p2 <http://data-vocabulary.org/Product/manufacturer> ?pManufacturerNode
OPTIONAL
{ ?pManufacturerNode <http://data-vocabulary.org/manufacturer/name> ?manufacturerNodeName }
BIND(str(coalesce(?manufacturerNodeName, ?pManufacturerNode)) AS ?productManufacturer)
}
OPTIONAL
{ ?p2 <http://schema.org/Product/aggregateRating> ?pAggregateRating
OPTIONAL
{ ?pAggregateRating <http://schema.org/AggregateRating/ratingValue> ?productAggregateRatingValue }
OPTIONAL
{ ?pAggregateRating <http://schema.org/AggregateRating/reviewCount> ?productReviewCount }
}
OPTIONAL
{ ?p2 <http://data-vocabulary.org/Product/productID> ?productId }
OPTIONAL
{ ?p2 <http://data-vocabulary.org/Product/sku> ?productSku }
OPTIONAL
{ ?p2 <http://data-vocabulary.org/Product/itemCondition> ?productNewCondition .
?productNewCondition <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> s:NewCondition
}
OPTIONAL
{ ?p2 <http://data-vocabulary.org/Product/itemCondition> ?productUsedCondition .
?productUsedCondition <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> s:UsedCondition
}
OPTIONAL
{ ?p2 <http://data-vocabulary.org/Product/gtin13> ?productGtin13 }
OPTIONAL
{ ?p2 <http://data-vocabulary.org/Product/gtin14> ?productGtin14 }
OPTIONAL
{ ?p2 <http://data-vocabulary.org/Product/gtin8> ?productGtin8 }
OPTIONAL
{ ?schOffer <http://data-vocabulary.org/Offer/availability> ?productAvailable
FILTER ( ?productAvailable = s:InStock )
}
OPTIONAL
{ ?schOffer <http://data-vocabulary.org/Offer/availability> ?productUnAvailable
FILTER ( ?productUnAvailable = s:OutOfStock )
}
OPTIONAL
{ ?p2 <http://data-vocabulary.org/Product/model> ?productModel }
OPTIONAL
{ ?p2 <http://data-vocabulary.org/Product/mpn> ?productMPN }
OPTIONAL
{ ?p2 <http://data-vocabulary.org/Product/color> ?productColor }
}
GROUP BY ?productName ?offerImage ?offerName ?productCategory ?salePrice ?suggestedRetailPrice ?productImage ?productThumbNail ?productUrl ?productBrand ?productId ?productSku ?productModel ?productMPN ?productManufacturer ?productGtin13 ?productGtin14 ?productGtin8 ?productAvailable ?productUnAvailable ?productUsedCondition ?productNewCondition ?productColor ?productAggregateRatingValue ?productReviewCount
答案 0 :(得分:1)
这就是说你在一个组中有多个项目的模式。尝试在没有计数和分组的情况下运行,并查看获得2的结果。