Blazegraph全文搜索和总计数

Question

在SPARQL中，我可以执行以下查询，以便在一个查询结果中检索字段和总计数：

SELECT  ?total ?s
WHERE
  { 
    { SELECT  (COUNT(?s) AS ?total)
      WHERE
        { ?s  <https://some/predicate/for/var1>  ?var1 ;
              <https://some/predicate/for/var1>  ?var2
          FILTER ( ( ?var1 = "something" ) && ( ?var2 = "something2" ) )
        }
    }
    { SELECT  ?s
      WHERE
        { ?s  <https://some/predicate/for/var1>  ?var1 ;
           <https://some/predicate/for/var1>  ?var2
       FILTER ( ( ?var1 = "something" ) && ( ?var2 = "something2" ) )
        }
   LIMIT   3
  }
 }

它返回如下内容(字段与我在查询中提供的特定谓词和过滤器相匹配)：

+-------+----------------------------------------+
| total |                   s                    |
+-------+----------------------------------------+
|   150 | http://the/path/to/the/subject         |
|   150 | http://the/path/to/another/subject     |
|   150 | http://the/path/to/yet/another/subject |
+-------+----------------------------------------+

我想对full text search queries做同样的事情，它可以像下面这样使用?s bds:search “something” .但是，使用与前一个相同的结构组成一个查询是不起作用的：

PREFIX  bds:  <http://www.bigdata.com/rdf/search#>
SELECT  ?total ?s ?org
WHERE
{
{ SELECT  (COUNT(?s) AS ?total)
    WHERE{
          ?matchedValue
                    bds:search        "something" ;
                    bds:relevance     ?score ;
                    bds:rank          ?rank .
          ?s        ?matchedProperty  ?matchedValue
          FILTER ( ! isBlank(?s) )
    }
}
{ SELECT  ?s ?matchedProperty ?score ?rank
    WHERE{
          ?matchedValue
                    bds:search        "something" ;
                    bds:relevance     ?score ;
                    bds:rank          ?rank .
          ?s        ?matchedProperty  ?matchedValue
          FILTER ( ! isBlank(?s) )
    }
    LIMIT 10 
 }
}

尽管如此，这些子查询仍然分别返回正确的结果。

Answer 1

正如@stanislav-kralin正确提到的，并且来自issue in Jira，您必须显式地使用SERVICE子句：

PREFIX  bds:  <http://www.bigdata.com/rdf/search#>
SELECT  ?total ?s ?org
WHERE
{
  { SELECT  (COUNT(?s) AS ?total)
      WHERE {
         SERVICE <http://www.bigdata.com/rdf/search#search> {
              ?matchedValue
                        bds:search        "something" ;
                        bds:relevance     ?score ;
                        bds:rank          ?rank .
          }
          ?s        ?matchedProperty  ?matchedValue
          FILTER ( ! isBlank(?s) )
        }
}
  { SELECT  ?s ?matchedProperty ?score ?rank
      WHERE {
         SERVICE <http://www.bigdata.com/rdf/search#search> {
            ?matchedValue
                  bds:search        "something" ;
                  bds:relevance     ?score ;
                  bds:rank          ?rank .
          }
          ?s        ?matchedProperty  ?matchedValue
          FILTER ( ! isBlank(?s) )
        }
      LIMIT 10 
 }
}