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Jena TDB for storing and querying using API

I am new to Jena-TDB and SPARQL, so this might be a dumb question. I am using tdb-0.9.0 on Windows XP.

I am creating a TDB model for my file trail_1.rdf. My understanding here (correct me if I am wrong) is that the following code will read the given rdf file in the TDB model, and also save / load (not sure which is the best word) model in this directory D:\Project\Store_DB\data1\tdb:

// open TDB dataset
String directory = "D:\\Project\\Store_DB\\data1\\tdb";
Dataset dataset = TDBFactory.createDataset(directory);

Model tdb = dataset.getDefaultModel();

// read the input file
String source = "D:\\Project\\Store_DB\\tmp\\trail_1.rdf";
FileManager.get().readModel( tdb, source);

tdb.close();
dataset.close();

Is this understanding correct?

In accordance with my understanding, since the model has been stored in the directory D:\Project\Store_DB\data1\tdb, I should be able to run a request on it at some later point in time.

So, to request TDB storage in D:\Project\Store_DB\data1\tdb, I tried the following, but it doesn't print anything:

String directory = "D:\\Project\\Store_DB\\data1\\tdb" ;
Dataset dataset = TDBFactory.createDataset(directory) ;

Iterator<String> graphNames = dataset.listNames();
while (graphNames.hasNext()) {
    String graphName = graphNames.next();
    System.out.println(graphName);
}

I also tried this, which also did not print anything:

    String directory = "D:\\Project\\Store_DB\\data1\\tdb" ;
    Dataset dataset = TDBFactory.createDataset(directory) ;

    String sparqlQueryString = "SELECT (count(*) AS ?count) { ?s ?p ?o }" ;

    Query query = QueryFactory.create(sparqlQueryString) ;
    QueryExecution qexec = QueryExecutionFactory.create(query, dataset) ;
    ResultSet results = qexec.execSelect() ;
    ResultSetFormatter.out(results) ;

? - , ?

+5
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(ii) , listNames , , . ,

Model tdb = dataset.getDefaultModel();

, , .. . listNames -, :

Model tdb = dataset.getNamedGraph( "graph42" );

- . , .

- , , bin/tdbdump (Linux) bat\tdbdump.bat (Windows).

(iii) , TDB, , . : TDB- ( tdbdump), , , .

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1 :

   String directory = "D:\\Project\\Store_DB\\data1\\tdb";
   Dataset dataset = TDBFactory.createDataset(directory);

   Model tdb = dataset.getDefaultModel();

   // read the input file
   String source = "D:\\Project\\Store_DB\\tmp\\trail_1.rdf";
   FileManager.get().readModel( tdb, source);

   dataset.commit();//INCLUDE THIS STAMEMENT

   tdb.close();
   dataset.close();

3 :)....

+2

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