How do you actually create new databases with apache jena tdb?

Question

I an complete beginner regarding RDF Stores / Semantic Web so this is rather a basic question. In RDBMS or Neo4j you can create new database with "CREATE DATABASE"-Command. But how does it work with apache jena tdb?

I couldn't find anything specific or maybe the answer is too obvious: I don't know if this is the correct approach, but it seems like it can be done with TDB Datasets ? Though I am not sure if this is the same as creating a database like in a RDBMS.

Answer 1

In Apache Jena, a dataset can be seen as the equivalent of a RDBMS or Neo4j database.

You can create a TDB dataset and add RDF triples in it like this:

String directory = "/Users/orto/tmp/tdbTest";
Dataset dataset = TDBFactory.createDataset(directory);
dataset.begin(ReadWrite.WRITE);
try {
  Model model = dataset.getDefaultModel();
  String personURI = "https://example.com/JohnDo";
  model.createResource(personURI)
          .addProperty(VCARD.FN, "John Do")
          .addProperty(VCARD.N,
                  model.createResource()
                          .addProperty(VCARD.Given, "John")
                          .addProperty(VCARD.Family, "Do"));
  dataset.commit();
} finally {
  dataset.end();
  dataset.close();
}

To query the dataset with a SPARQL query, you can do like this:

String directory = "/Users/orto/tmp/tdbTest";
String queryString = "SELECT ?x WHERE {?x <http://www.w3.org/2001/vcard-rdf/3.0#FN> \"John Do\"}";
Dataset dataset = TDBFactory.createDataset(directory);
Query query = QueryFactory.create(queryString);
dataset.begin(ReadWrite.READ) ;
try (QueryExecution qexec = QueryExecutionFactory.create(query, dataset)) {
  ResultSet results = qexec.execSelect();
  ResultSetFormatter.out(System.out, results, query);
} finally {
  dataset.end();
  dataset.close();

}

For more information, read the documentation.