我正在使用 Jena 启动 SPARQL 查询。该查询适用于 DBpedia SPARQL 端点！我在查询验证器上验证了查询并得到了同样的错误

Question

我需要找到与 e.g.lagaan 电影相似的电影，基于常见的 properties.I 尝试了下面的代码，但是当我使用 jena 时我得到了下面的异常，虽然查询工作正常在 sparql 端点中。

sparql 端点中的输出：

similar movies                                  similarity score 
http://dbpedia.org/resource/Lagaan                 177
http://dbpedia.org/resource/Jodhaa_Akbar            44
http://dbpedia.org/resource/Jaane_Tu..._Ya_Jaane_Na 42
http://dbpedia.org/resource/Swades                  42
http://dbpedia.org/resource/Rangeela_(film)         40
http://dbpedia.org/resource/Dil_Ne_Jise_Apna_Kahaa  38
http://dbpedia.org/resource/Love_You_Hamesha        37
http://dbpedia.org/resource/Sholay                  37
http://dbpedia.org/resource/Kannathil_Muthamittal   36
http://dbpedia.org/resource/Andaaz                  36
http://dbpedia.org/resource/Jaan-E-Mann             36
http://dbpedia.org/resource/Sarfarosh               36
http://dbpedia.org/resource/Saathiya_(film)         36
http://dbpedia.org/resource/Sillunu_Oru_Kaadhal     36
http://dbpedia.org/resource/Doli_Saja_Ke_Rakhna     36
http://dbpedia.org/resource/Dil_Se..                36
http://dbpedia.org/resource/Rang_De_Basanti         36
http://dbpedia.org/resource/Lage_Raho_Munna_Bhai    36
http://dbpedia.org/resource/Ishq_Vishk              36

对于我尝试过的任何其他查询，我得到了相同的异常错误，尽管该查询在 sparql 端点和查询验证器中工作正常。我尝试了下面 link SPARQL parse error with Jena, but DBpedia accepts the query 中给出的解决方案，但对我不起作用。

import com.hp.hpl.jena.query.QueryExecution;
import com.hp.hpl.jena.query.QueryExecutionFactory;
import com.hp.hpl.jena.query.QuerySolution;
import com.hp.hpl.jena.query.ResultSet;

public class Dbpedia {

    public static void main(String[] args) {
        // TODO Auto-generated method stub

        String service="http://dbpedia.org/sparql";
        String query= " PREFIX dbpedia: <http://dbpedia.org/resource/> "
                + "PREFIX dbpedia-owl: <http://dbpedia.org/ontology/> "
                + "select ?similar (count(?p) as ?similarity) "
                + "where { values ?movie { dbpedia:Lagaan }"
                + " ?similar ?p ?o ; a dbpedia-owl:Film . "
                + "?movie   ?p ?o .} group by "
                + "?similar ?movie having count(?p) > 35 order by desc(?similarity)";
        QueryExecution e=QueryExecutionFactory.sparqlService(service, query);
        ResultSet rs=e.execSelect();
        while (rs.hasNext()) {
            QuerySolution qs=rs.nextSolution();
            System.out.println(qs);
        }
    }

}

错误：

Exception in thread "main" com.hp.hpl.jena.query.QueryParseException: Encountered " ">" "> "" at line 1, column 350.
Was expecting one of:
    <EOF> 
    <IRIref> ...
    <PNAME_NS> ...
    <PNAME_LN> ...
    "limit" ...
    "offset" ...
    "order" ...
    "values" ...
    "exists" ...
    "not" ...
    "count" ...
    "min" ...
    "max" ...
    "sum" ...
    "avg" ...
    "sample" ...
    "group_concat" ...
    "bound" ...
    "coalesce" ...
    "if" ...
    "bnode" ...
    "iri" ...
    "uri" ...
    "str" ...
    "strlang" ...
    "strdt" ...
    "datatype" ...
    "lang" ...
    "langmatches" ...
    "isURI" ...
    "isIRI" ...
    "isBlank" ...
    "isLiteral" ...
    "isNumeric" ...
    "regex" ...
    "sameTerm" ...
    "RAND" ...
    "ABS" ...
    "CEIL" ...
    "FLOOR" ...
    "ROUND" ...
    "CONCAT" ...
    "SUBSTR" ...
    "STRLEN" ...
    "REPLACE" ...
    "UCASE" ...
    "LCASE" ...
    "ENCODE_FOR_URI" ...
    "CONTAINS" ...
    "STRSTARTS" ...
    "STRENDS" ...
    "STRBEFORE" ...
    "STRAFTER" ...
    "YEAR" ...
    "MONTH" ...
    "DAY" ...
    "HOURS" ...
    "MINUTES" ...
    "SECONDS" ...
    "TIMEZONE" ...
    "TZ" ...
    "NOW" ...
    "UUID" ...
    "STRUUID" ...
    "MD5" ...
    "SHA1" ...
    "SHA256" ...
    "SHA384" ...
    "SHA512" ...
    "(" ...

    at com.hp.hpl.jena.sparql.lang.ParserSPARQL11.perform(ParserSPARQL11.java:102)
    at com.hp.hpl.jena.sparql.lang.ParserSPARQL11.parse$(ParserSPARQL11.java:53)
    at com.hp.hpl.jena.sparql.lang.SPARQLParser.parse(SPARQLParser.java:37)
    at com.hp.hpl.jena.query.QueryFactory.parse(QueryFactory.java:148)
    at com.hp.hpl.jena.query.QueryFactory.create(QueryFactory.java:80)
    at com.hp.hpl.jena.query.QueryFactory.create(QueryFactory.java:53)
    at com.hp.hpl.jena.query.QueryFactory.create(QueryFactory.java:41)
    at com.hp.hpl.jena.query.QueryExecutionFactory.sparqlService(QueryExecutionFactory.java:311)
    at com.hp.hpl.jena.query.QueryExecutionFactory.sparqlService(QueryExecutionFactory.java:298)
    at com.wiki.Dbpedia.main(Dbpedia.java:22)

我尝试删除 group by 子句，该子句由查询验证器验证并在 sparql 端点提供一些输出但是当我运行它在 eclipse

中时再次出现相同的异常

" PREFIX  dbpedia-owl: <http://dbpedia.org/ontology/> " +
          " PREFIX  dbpedia: <http://dbpedia.org/resource/> " +
              " SELECT  ?similar " +
              " WHERE " +
              " { VALUES ?movie { dbpedia:Lagaan } " + 
              " ?similar ?p ?o ."+
              " ?similar <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> dbpedia-owl:Film ." +
              " ?movie ?p ?o " +
              " } ";

变化：` 查询验证器 returns 当我将 () 添加到 having 时，如下查询输出如@AndyS

所说

1 PREFIX  dbpedia-owl: <http://dbpedia.org/ontology/>
  2 PREFIX  rdf:  <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
  3 
  4 SELECT  ?similar (count(?p) AS ?similarity)
  5 WHERE
  6   { VALUES ?movie { <http://dbpedia.org/resource/Lagaan> }
  7     ?similar ?p ?o .
  8     ?similar rdf:type dbpedia-owl:Film .
  9     ?movie ?p ?o
 10   }
 11 GROUP BY ?similar ?movie
 12 HAVING ( count(?p) > 35 )
 13 ORDER BY DESC(?similarity)

我在 eclipse 中将查询更改为以下，但同样的错误。

String query= "PREFIX  dbpedia-owl: <http://dbpedia.org/ontology/>"+
              "PREFIX  rdf:  <http://www.w3.org/1999/02/22-rdf-syntax-ns#>"+
              "SELECT  ?similar (count(?p) AS ?similarity)" +
                      "WHERE" +
                      "{ VALUES ?movie { <http://dbpedia.org/resource/Lagaan> }"+
                      "?similar ?p ?o ."+
                      "?similar rdf:type dbpedia-owl:Film ."+
                      "?movie ?p ?o"+
                      "}"+
                      "GROUP BY ?similar ?movie"+
                      "HAVING ( count(?p) > 35 )"+
                      "ORDER BY DESC(?similarity)";

更正查询：

String query="PREFIX dbpprop: <http://dbpedia.org/property/> "
            + " PREFIX dbpedia: <http://dbpedia.org/resource/> "
            + "PREFIX dbpedia-owl: <http://dbpedia.org/ontology/> "
            + "select ?similar (count(?p) as ?similarity) "
            + "where { values ?movie { <http://dbpedia.org/resource/Lagaan> }"
            + " ?similar ?p ?o ; a dbpedia-owl:Film . "
            + "?movie   ?p ?o .} group by "
            + "?similar ?movie having(count(?p) > 35) order by desc(?similarity)";

查找电影 link 的新查询，电影名称为：

prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#>
prefix dbpedia-owl: <http://dbpedia.org/ontology/>
 SELECT  *WHERE
    {   
    { 
  select distinct ?film where  {
  ?film a dbpedia-owl:Film .
  ?film rdfs:label ?label .
  filter regex( str(?label), "Lagaan", "i")
  }
  limit 10
   }

现在如何将此查询的输出传递给相似性查询？

根据@Joshau Taylor 的建议，修改后的查询使用 wikiredirects 来处理拼写错误的电影名称：

PREFIX  rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX  dbo:  <http://dbpedia.org/ontology/>
PREFIX  owl:  <http://www.w3.org/2002/07/owl#>
SELECT  ?s ?other (count(*) AS ?similarity)
WHERE
{ 
{ 
SELECT  ?s WHERE { 
  { ?s rdfs:label "Veer zara"@en .
  ?s <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> owl:Thing
}
UNION
   { ?altName rdfs:label "Veer zara"@en .
    ?altName dbo:wikiPageRedirects ?s
    }
 }
 }
     ?s ?p ?o .
     ?other <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> dbo:Film .
     ?other ?p ?o
   }
GROUP BY ?s ?other
HAVING ( count(?p) > 25 )
ORDER BY DESC(?similarity)

Answer 1

看来这个问题在评论中得到了解决。这是为访问者着想的社区维基答案（以防评论被删除）：

Put some newlines in the query and see exactly where parser referes to. It will be the place the parse error starts. HAVING clause needs () for legal SPARQL 1.1 having (count(?p) > 35). – AndyS

{ dbpedia:Lagaan } isn't right either – AndyS yesterday

i got it.It needed a space after the angular bracket in the prefix. – Kulsum Fatima

我正在使用 Jena 启动 SPARQL 查询。该查询适用于 DBpedia SPARQL 端点！我在查询验证器上验证了查询并得到了同样的错误

I'm using Jena to launch a SPARQL query. The query works in DBpedia SPARQL endpoint! I verified the query at query validator and got the same error

java

eclipse

sparql

jena

dbpedia