使用WikiPageRedirects的sparql [英] sparql using wikiPageRedirects

问题描述

我正在使用sparql查找实体的位置。我有dbpedia-spootlight的网址，想为他们找到位置。所以我正在使用的查询是：

I am using sparql to find a location of entity. I have urls from dbpedia-spootlight and want to find location for them. So the query I am using is:

PREFIX geo: <http://www.w3.org/2003/01/geo/wgs84_pos#> 
PREFIX dbo: <http://dbpedia.org/ontology/> 
SELECT DISTINCT * 
WHERE { ?uri rdfs:label ?label . 
OPTIONAL { ?uri geo:lat ?lat . ?uri geo:long ?long } . 
OPTIONAL { ?uri dbpedia-owl:country ?dbpediaContry . ?dbpediaContry dbpprop:cctld ?ccTLD } . 
FILTER (?uri = <URL>  && lang(?label) = "en" ) } 

，直到我获得以下网址，这都很好： http://dbpedia.org / resource / Valencia，_Spain 。
它具有指向 http://dbpedia.org/resource/Valencia 的WikiPageRedirects，并且没有其他数据。
我迷路了，我该如何构建查询来检查带有重定向的案例。

and it was fine until I have got this url: http://dbpedia.org/resource/Valencia,_Spain . It has wikiPageRedirects to http://dbpedia.org/resource/Valencia and no other data. I have got lost how could i build query to check cases with redirects.

有人可以帮助我吗？

推荐答案

尝试更改查询的第一部分以使用 UNION 例如

Try changing the first part of your query to use a UNION e.g.

PREFIX geo: <http://www.w3.org/2003/01/geo/wgs84_pos#> 
PREFIX dbo: <http://dbpedia.org/ontology/> 
PREFIX dbp: <http://dbpedia.org/property/>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>

SELECT DISTINCT * 
WHERE
{ 
  { 
    ?uri rdfs:label ?label . 
  } 
  UNION 
  { 
    [] dbo:wikiPageRedirects ?uri .
    ?uri rdfs:label ?label .
  }
  OPTIONAL 
  { 
    ?uri geo:lat ?lat ;
         geo:long ?long 
  }
  OPTIONAL 
  {
    ?uri dbo:country ?dbpediaContry . 
    ?dbpediaContry dbp:cctld ?ccTLD 
  }
  FILTER (SAMETERM(?uri, <URL>)  && lang(?label) = "en" ) 
} 

UNION 可让您查找事物包含URI的对象和通过重定向包含URI的对象，然后再应用其余查询。注意，我还更改了您的 FILTER 以使用 SAMETERM（），这将使查询更快。

The UNION allow you to find things that have a URI and those that have a URI via a redirect before then applying the rest of your query. Note I also changed your FILTER to use SAMETERM() which should make the query faster.

通常，如果您在进行此类 FILTER 设置常量的查询时，强烈建议您替换将？uri 变量与< URL> 一起使用，应该会看到更好的性能

In general if you have this kind of query where you are doing that sort of a FILTER to set a constant I would strongly suggest just replacing all uses of the ?uri variable with <URL> instead which should see much better performance

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