I am giving the code after query, may be the problem exist in these lines.
Query query = QueryFactory.create(str);
QueryExecution qexec = QueryExecutionFactory.create(query, model) ;
ResultSet results = qexec.execSelect() ;
while (results.hasNext())
{
QuerySolution binding = results.nextSolution();
Resource subj = (Resource) binding.get("s");
ss= subj.getLocalName().toString();
System.out.println(ss);
On Mon, Jul 3, 2017 at 2:12 PM, Sidra shah <[email protected]> wrote:
> Hello Lorenz, BookCategory is a data property whose value is string (Java
> or Semantic Web).
>
> The print out of the query is given:
>
> PREFIX rdf:<http://www.w3.org/1999/02/22-rdf-syntax-ns#>
> PREFIX mo:<http://www.semanticweb.org/ontologies/2017/5/
> untitled-ontology-758#>
> SELECT * WHERE { ?s rdf:type mo:Book.?s mo:BookCategory ?book.
> FILTER ( ?book ='Semantic Web' ). }
>
> The prefixes are Ok because for simple queries (without Filter), it works.
>
> On Mon, Jul 3, 2017 at 11:12 AM, Lorenz Buehmann <[email protected]
> leipzig.de> wrote:
>
>> Is it Java code?
>>
>> Print the query string that is created.
>>
>> Check the prefixes.
>>
>> Make sure that you properly distinguish between literals and URIs -> is
>> a book category a literal or a resource? Is the value of str a URI or a
>> literal?
>>
>>
>> On 03.07.2017 07:12, Sidra shah wrote:
>> > Hello
>> >
>> > I have a Book class having Java and Semantic Web sub classes.
>> > Java class have some instances: JSP, Java by Dietel, JDBC
>> > Semantic Web has also some instances: SPARQL, Semantic Programming, etc.
>> >
>> > I have a data property BookCategory for each instance which will be
>> either
>> > Java or Semantic Web
>> >
>> > I have a combo box where users if select Java, all java books will be
>> > displayed and similarly for semantic web.
>> >
>> > The following query does not work. (Display nothing)
>> >
>> > String str=jComboBox1.getSelectedItem().toString();
>> >
>> > SELECT * WHERE { ?s rdf:type mo:Book.?s mo:BookCategory ?book FILTER (
>> > ?book ='str' ). }
>> >
>>
>>
>
