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Posted to users@jena.apache.org by mehmet mehmet <me...@gmail.com> on 2016/04/27 17:12:58 UTC
Query display nothing
String queryString ="PREFIX dbr: <http://dbpedia.org/resource/> " + "PREFIX
dbprop:<http://dbpedia.org/property/>" +
"SELECT * " + "WHERE {" + " dbr:Germany dbprop:capital ?x"+ "}" ;
at the end I display it
System.out.println(soln.getResource("x".toString()));
*But it displays nothing (no error message but no output)*
*What is the problem in the code.*
Re: Query display nothing
Posted by Andy Seaborne <an...@apache.org>.
On 28/04/16 12:55, mehmet mehmet wrote:
> Yes I used Dbpedia endpoint and if I do not give call to toString(), it
> gives me error.
The something else is wrong. In java, String.toString() is defined to be
"return this;"
Please provide a minimal, complete example of your code.
minimal -> just enough to illustrate the question
complete -> something someone can run without change.
Andy
>
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>
> On Thu, Apr 28, 2016 at 11:42 AM, Lorenz B. <
> buehmann@informatik.uni-leipzig.de> wrote:
>
>> Debugging a query is more efficient if you print the query to the command
>> line first, and put it in the Virtuoso web interface - I suppose that you
>> use the offical DBpedia endpoint.
>> By the way, it's not clear why you call toString() on "x" .
>>
>> I think you need to provide more information, before anyone can answer
>>> your questions.
>>>
>>> What is the actual endpoint or dataset you are executing on? What is
>>> the code executing the query?
>>>
>>> On Wed, Apr 27, 2016 at 5:12 PM, mehmet mehmet <me...@gmail.com>
>>> wrote:
>>>
>>>> String queryString ="PREFIX dbr: <http://dbpedia.org/resource/> " +
>>>> "PREFIX
>>>> dbprop:<http://dbpedia.org/property/>" +
>>>>
>>>> "SELECT * " + "WHERE {" + " dbr:Germany dbprop:capital ?x"+ "}" ;
>>>>
>>>> at the end I display it
>>>>
>>>> System.out.println(soln.getResource("x".toString()));
>>>>
>>>>
>>>> *But it displays nothing (no error message but no output)*
>>>>
>>>> *What is the problem in the code.*
>>>>
>>>
>> --
>> Lorenz Bühmann
>> AKSW group, University of Leipzig
>> Group: http://aksw.org - semantic web research center
>>
>>
>
Re: Query display nothing
Posted by mehmet mehmet <me...@gmail.com>.
Yes I used Dbpedia endpoint and if I do not give call to toString(), it
gives me error.
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www.avast.com
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On Thu, Apr 28, 2016 at 11:42 AM, Lorenz B. <
buehmann@informatik.uni-leipzig.de> wrote:
> Debugging a query is more efficient if you print the query to the command
> line first, and put it in the Virtuoso web interface - I suppose that you
> use the offical DBpedia endpoint.
> By the way, it's not clear why you call toString() on "x" .
>
> I think you need to provide more information, before anyone can answer
>> your questions.
>>
>> What is the actual endpoint or dataset you are executing on? What is
>> the code executing the query?
>>
>> On Wed, Apr 27, 2016 at 5:12 PM, mehmet mehmet <me...@gmail.com>
>> wrote:
>>
>>> String queryString ="PREFIX dbr: <http://dbpedia.org/resource/> " +
>>> "PREFIX
>>> dbprop:<http://dbpedia.org/property/>" +
>>>
>>> "SELECT * " + "WHERE {" + " dbr:Germany dbprop:capital ?x"+ "}" ;
>>>
>>> at the end I display it
>>>
>>> System.out.println(soln.getResource("x".toString()));
>>>
>>>
>>> *But it displays nothing (no error message but no output)*
>>>
>>> *What is the problem in the code.*
>>>
>>
> --
> Lorenz Bühmann
> AKSW group, University of Leipzig
> Group: http://aksw.org - semantic web research center
>
>
Re: Query display nothing
Posted by "Lorenz B." <bu...@informatik.uni-leipzig.de>.
Debugging a query is more efficient if you print the query to the
command line first, and put it in the Virtuoso web interface - I suppose
that you use the offical DBpedia endpoint.
By the way, it's not clear why you call toString() on "x" .
> I think you need to provide more information, before anyone can answer
> your questions.
>
> What is the actual endpoint or dataset you are executing on? What is
> the code executing the query?
>
> On Wed, Apr 27, 2016 at 5:12 PM, mehmet mehmet <me...@gmail.com> wrote:
>> String queryString ="PREFIX dbr: <http://dbpedia.org/resource/> " + "PREFIX
>> dbprop:<http://dbpedia.org/property/>" +
>>
>> "SELECT * " + "WHERE {" + " dbr:Germany dbprop:capital ?x"+ "}" ;
>>
>> at the end I display it
>>
>> System.out.println(soln.getResource("x".toString()));
>>
>>
>> *But it displays nothing (no error message but no output)*
>>
>> *What is the problem in the code.*
--
Lorenz Bühmann
AKSW group, University of Leipzig
Group: http://aksw.org - semantic web research center
Re: Query display nothing
Posted by Martynas Jusevičius <ma...@graphity.org>.
I think you need to provide more information, before anyone can answer
your questions.
What is the actual endpoint or dataset you are executing on? What is
the code executing the query?
On Wed, Apr 27, 2016 at 5:12 PM, mehmet mehmet <me...@gmail.com> wrote:
> String queryString ="PREFIX dbr: <http://dbpedia.org/resource/> " + "PREFIX
> dbprop:<http://dbpedia.org/property/>" +
>
> "SELECT * " + "WHERE {" + " dbr:Germany dbprop:capital ?x"+ "}" ;
>
> at the end I display it
>
> System.out.println(soln.getResource("x".toString()));
>
>
> *But it displays nothing (no error message but no output)*
>
> *What is the problem in the code.*