Just because the query is legal SPARQL doesn't mean that it it matches
any of your data? I can send this query to DBpedia, and I get no
results, not because there's no such person, but because DBpedia
doesn't include any data about this person:
select ?person where {
?person a dbpedia-owl:Person ;
foaf:name "Rafiq"@en ;
}
What's your data? Why do you expect your query to work?
On Tue, Jan 7, 2014 at 1:00 PM, Rafiq <[email protected]> wrote:
> Hi,
>
> Here is my query
>
> SELECT ?x ?y WHERE {
> ?x <http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
> <http://www.lehigh.edu/~zhp2/2004/0401/univ-bench.owl#Student> .
> ?y <http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
> <http://www.lehigh.edu/~zhp2/2004/0401/univ-bench.owl#Course> .
> <http://www.Department0.University0.edu/AssociateProfessor0>
> <http://www.lehigh.edu/~zhp2/2004/0401/univ-bench.owl#teacherOf> ?y .
> ?x <http://www.lehigh.edu/~zhp2/2004/0401/univ-bench.owl#takesCourse> ?y
> }
>
> When I execute it I get the answer below:
>
> {
> "head": {
> "vars": [ "x" , "y" ]
> } ,
> "results": {
> "bindings": [
>
> ]
> }
> }
>
> I could not find any valid reason why it returns this answer. I validated
> the query using online validator, its absolutely fine.
> Then I modify the query.. the query turns into the following:
>
> 'SELECT ?x ?y WHERE {?x a ?Student . ?y a ?Course . ?AssociateProfessor0
> ?teacherOf ?y . ?x ?takesCourse ?y}'
>
> I left it two days, it did not return anything because the query could not
> be parsed. Where did I do mistake if I did any?
>
>
> I have a few modified queries with single variable worked fine however, this
> one did not. I want to believe
> the number of variable when is two (X, Y) creating a problem?
>
>
> For your information, I am using Fuseqi server with TDB store.
>
> Regards,
> Rafiq
--
Joshua Taylor, http://www.cs.rpi.edu/~tayloj/
