如何从 SPARQL 查询访问土地注册处住宅类型

我正在尝试使用 SPARQL 查询从英国土地登记处检索住宅类型。

API 显示它被称为“属性类型”，并显示有四种类型：独立式、公寓式、半独立式、联排式。 API在这里：http://landregistry.data.gov.uk/def/common?_page=1.

查询是：

PREFIX xsd:     <http://www.w3.org/2001/XMLSchema#>
PREFIX rdf:     <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX rdfs:    <http://www.w3.org/2000/01/rdf-schema#>
PREFIX owl:     <http://www.w3.org/2002/07/owl#>
PREFIX lrppi:   <http://landregistry.data.gov.uk/def/ppi/>
PREFIX skos:    <http://www.w3.org/2004/02/skos/core#>
PREFIX lrcommon: <http://landregistry.data.gov.uk/def/common/>

SELECT ?propertytype ?paon ?saon ?street ?town ?county ?locality ?district ?postcode ?    amount ?date
WHERE
{    
SERVICE <http://landregistry.data.gov.uk/landregistry/sparql>
{ 
    ?transx  lrppi:pricePaid ?amount .
    ?transx   lrppi:transactionDate ?date .
    ?transx   lrppi:propertyAddress ?addr.

    ?addr lrcommon:district "MALVERN HILLS"^^xsd:string .

    OPTIONAL {?addr lrcommon:county ?county .}
    OPTIONAL {?addr lrcommon:paon ?paon .}
    OPTIONAL {?addr lrcommon:saon ?saon .}
    OPTIONAL {?addr lrcommon:street ?street .}
    OPTIONAL {?addr lrcommon:town ?town .}
    OPTIONAL {?addr lrcommon:locality ?locality .}
    OPTIONAL {?addr lrcommon:postcode  ?postcode .}
}
}
ORDER BY ?postcode ?amount
LIMIT 1000

这将检索我期望的数据（为了速度限制为 1000），但我想提取显示其是否为独立式、梯田式等的数据。

非常感谢任何帮助！

答案

你只需要添加三元组

?transx lrppi:propertyType ?propertytype .

您的查询。例如，这是一个基于您的查询：

PREFIX xsd:     <http://www.w3.org/2001/XMLSchema#>
PREFIX rdf:     <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX rdfs:    <http://www.w3.org/2000/01/rdf-schema#>
PREFIX owl:     <http://www.w3.org/2002/07/owl#>
PREFIX lrppi:   <http://landregistry.data.gov.uk/def/ppi/>
PREFIX skos:    <http://www.w3.org/2004/02/skos/core#>
PREFIX lrcommon: <http://landregistry.data.gov.uk/def/common/>

SELECT ?propertytype ?paon ?saon ?street ?town ?county ?locality ?district ?postcode ?amount ?date
WHERE {
    ?transx lrppi:pricePaid ?amount ;
            lrppi:transactionDate ?date ;
            lrppi:propertyAddress ?addr ;
            lrppi:propertyType ?propertytype .

    ?addr lrcommon:district "MALVERN HILLS"^^xsd:string .

    OPTIONAL {?addr lrcommon:county ?county .}
    OPTIONAL {?addr lrcommon:paon ?paon .}
    OPTIONAL {?addr lrcommon:saon ?saon .}
    OPTIONAL {?addr lrcommon:street ?street .}
    OPTIONAL {?addr lrcommon:town ?town .}
    OPTIONAL {?addr lrcommon:locality ?locality .}
    OPTIONAL {?addr lrcommon:postcode  ?postcode .}
}
ORDER BY ?postcode ?amount
LIMIT 10

您可以将其复制并粘贴到终点并得到结果。 （不幸的是，似乎没有办法直接链接到结果。）

寻找答案

我是这样的found该财产。这endpoint有一些示例查询，其中之一是“列出正在使用的 RDF 类型”：

PREFIX rdf:      <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX rdfs:     <http://www.w3.org/2000/01/rdf-schema#>

# Get labels for types used in the data.
SELECT  ?type ?name
WHERE {
    ?type rdfs:label ?name .
     FILTER EXISTS {  ?something rdf:type ?type . }
}

该查询的结果包括

---------------------------------------------------------------------------------------------------------------------------------------------
| type                                                                           | name                                                     |
=============================================================================================================================================
| <http://landregistry.data.gov.uk/def/common/PropertyTypeConcept>               | "Property type concept"@en                               |
---------------------------------------------------------------------------------------------------------------------------------------------

既然我们现在讨论类型<http://landregistry.data.gov.uk/def/common/PropertyTypeConcept>我们可以询问它的实例：

PREFIX rdf:      <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX rdfs:     <http://www.w3.org/2000/01/rdf-schema#>

SELECT  ?x 
WHERE { ?x a <http://landregistry.data.gov.uk/def/common/PropertyTypeConcept> }
LIMIT 10 

----------------------------------------------------------------
| x                                                            |
================================================================
| <http://landregistry.data.gov.uk/def/common/detached>        |
| <http://landregistry.data.gov.uk/def/common/semi-detached>   |
| <http://landregistry.data.gov.uk/def/common/flat-maisonette> |
| <http://landregistry.data.gov.uk/def/common/terraced>        |
----------------------------------------------------------------

现在我们可以看到什么与其中之一相关，以及通过哪些属性相关。例如

PREFIX rdf:      <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX rdfs:     <http://www.w3.org/2000/01/rdf-schema#>

SELECT  ?x ?y
WHERE { ?x ?y <http://landregistry.data.gov.uk/def/common/detached> }
LIMIT 10 

----------------------------------------------------------------------------------------------------------------------------------------------------------------------
| x                                                                                                         | y                                                      |
======================================================================================================================================================================
| <http://landregistry.data.gov.uk/data/ppi/transaction/C7AE071D-242D-4825-9162-97BBF3B71840/2009-02-27233> | <http://landregistry.data.gov.uk/def/ppi/propertyType> |
| <http://landregistry.data.gov.uk/data/ppi/transaction/D0CDBC03-5147-4D93-BCE5-176AF007E391/2009-02-10191> | <http://landregistry.data.gov.uk/def/ppi/propertyType> |
| <http://landregistry.data.gov.uk/data/ppi/transaction/E37CAA33-CEF5-4162-8E07-918394B3C8AF/2009-02-00643> | <http://landregistry.data.gov.uk/def/ppi/propertyType> |
| <http://landregistry.data.gov.uk/data/ppi/transaction/E37CAA33-CEF5-4162-8E07-918394B3C8AF/2009-03-32825> | <http://landregistry.data.gov.uk/def/ppi/propertyType> |
| <http://landregistry.data.gov.uk/data/ppi/transaction/22276002-0030-4748-A7F6-C20F125DAC1C/2009-02-47264> | <http://landregistry.data.gov.uk/def/ppi/propertyType> |
| <http://landregistry.data.gov.uk/data/ppi/transaction/FA525F65-CC8E-4617-A682-F8B267319445/2009-02-38989> | <http://landregistry.data.gov.uk/def/ppi/propertyType> |
| <http://landregistry.data.gov.uk/data/ppi/transaction/3BFA438C-47AE-4B47-87AD-5DC365977619/2009-02-37729> | <http://landregistry.data.gov.uk/def/ppi/propertyType> |
| <http://landregistry.data.gov.uk/data/ppi/transaction/A5BED22B-F54B-4459-9BF9-18920B8CDBAA/2009-02-21721> | <http://landregistry.data.gov.uk/def/ppi/propertyType> |
| <http://landregistry.data.gov.uk/data/ppi/transaction/DDAAE7E0-B07F-49FF-AAB6-A2B96D8D4DE3/2009-02-11020> | <http://landregistry.data.gov.uk/def/ppi/propertyType> |
| <http://landregistry.data.gov.uk/data/ppi/transaction/5168D986-FAA2-42E8-B2C8-A04981C8BD0F/2009-02-09080> | <http://landregistry.data.gov.uk/def/ppi/propertyType> |
----------------------------------------------------------------------------------------------------------------------------------------------------------------------

我们看到我们想要的属性是<http://landregistry.data.gov.uk/def/ppi/propertyType>，可以缩短为lrppi:propertyType使用您定义的前缀。它似乎将交易与财产类型相关联，并且由于您查询中的交易是?transx, we add

?transx lrppi:propertyType ?propertyType