Hi Max,
What do you mean by namespace declarations? Do you mean query prefixes?
I don't understand why this query may need a prefix. It is a very simple
query without URIs:
SELECT * { ?s ?p ?o }
Best,
Daniel
Maximilian Behnert-Brodhun <[email protected]> writes:
> Dear Pan,
>
> did you try add namespace declarations into your query?
>
> Best regards
>
> Max
>
> Am Mo., 11. März 2024 um 14:45 Uhr schrieb Anna P <
> [email protected]>:
>
>> Dear Jena support team,
>>
>> Currently I just started to work on a SPARQL project using Jena and I could
>> not get a solution when I query a model.
>> I imported a turtle file and ran a simple query, and the snippet code is
>> shown below. However, I got the error.
>>
>> public class App {
>> public static void main(String[] args) {
>> try {
>> Model model = RDFDataMgr.loadModel('data.ttl', Lang.TURTLE);
>> RDFDataMgr.write(System.out, model, Lang.TURTLE);
>> String queryString = "SELECT * { ?s ?p ?o }";
>> Query query = QueryFactory.create(queryString);
>> QueryExecution qe = QueryExecutionFactory.create(query, model);
>> ResultSet results = qe.execSelect();
>> ResultSetFormatter.out(System.out, results, query);
>> qe.close();
>> } catch (Exception e) {
>> e.printStackTrace();
>> }
>> }
>> }
>>
>> Here is the error message:
>>
>> org.apache.jena.riot.RiotException: Not registered as a SPARQL result set
>> output syntax: Lang:SPARQL-Results-JSON
>> at
>>
>> org.apache.jena.sparql.resultset.ResultsWriter.write(ResultsWriter.java:179)
>> at
>>
>> org.apache.jena.sparql.resultset.ResultsWriter.write(ResultsWriter.java:156)
>> at
>>
>> org.apache.jena.sparql.resultset.ResultsWriter.write(ResultsWriter.java:149)
>> at
>>
>> org.apache.jena.sparql.resultset.ResultsWriter$Builder.write(ResultsWriter.java:96)
>> at
>>
>> org.apache.jena.query.ResultSetFormatter.output(ResultSetFormatter.java:308)
>> at
>>
>> org.apache.jena.query.ResultSetFormatter.outputAsJSON(ResultSetFormatter.java:516)
>> at de.unistuttgart.ki.esparql.App.main(App.java:46)
>>
>>
>> Thank you for your time and help!
>>
>> Best regards,
>>
>> Pan
>>
