Because if you access a graph prior to starting a transaction you get a non-transactional graph and the database is accessed in non-transactional mode
When you then start a transaction the database switches to transactional mode access and uncommitted non-transactional changes are lost as a result Either always use transactions or never use transactions, we strongly recommend always using transactions as otherwise your data is subject to corruption and loss should your program exit unexpectedly or not clean up the resources properly If you really want to mix and match (which you really really shouldn't do) then you need to make sure that you call TDB.sync(graph) prior to starting your transaction to ensure the non-transactional changes are persisted Rob On 06/08/2015 15:32, "Евгений =)" <[email protected]> wrote: >Thanks! So I change code: >public class TestTdbTransactions { > public static void main(String[] args) { > Dataset dataset = TDBFactory.createDataset(); > dataset.begin(ReadWrite.WRITE); > DatasetGraph datasetGraph = dataset.asDatasetGraph(); > Graph graph = datasetGraph.getDefaultGraph(); > > // Fill graph. > graph.add( > new Triple( > NodeFactory.createURI("http://example/unit13";), > NodeFactory.createURI("http://example/name";), > NodeFactory.createLiteral("Unit 13", "en") > ) > ); > > graph.add( > new Triple( > NodeFactory.createURI("http://example/unit13";), > NodeFactory.createURI("http://example/type";), > NodeFactory.createURI("http://example/robot";) > ) > ); > > graph.add( > new Triple( > NodeFactory.createURI("http://example/unit13";), > NodeFactory.createURI("http://example/creationYear";), > NodeFactory.createURI("http://example/2015";) > ) > ); > > // Test. > UpdateRequest request = UpdateFactory.create( > "INSERT { ?s <http://example/value> '1' } WHERE { ?s < >http://example/creationYear> <http://example/2015> . }" > ); > UpdateAction.execute(request, dataset); > > dataset.commit(); > dataset.end(); > > RDFDataMgr.write(System.out, graph, RDFFormat.NTRIPLES); > } >} > >And it works! > >But if I move "dataset.begin(ReadWrite.WRITE);" after "Graph graph = >datasetGraph.getDefaultGraph();" this code doesn't work... why this >happens? > >2015-08-06 17:12 GMT+03:00 Rob Vesse <[email protected]>: > >> You are mixing non-transactional use with transactional use and this >> breaks things, your initial insert is in non-transactional mode but then >> you start a transaction so some of the changes get lost >> >> You should always stick to one usage model, we strongly recommend >> transactional use >> >> Simply moving your dataset.begin(ReadWrite.WRITE); call to before you >> start making changes to the graph should resolve your issue >> >> Rob >> >> On 06/08/2015 14:31, "Eugene Tenkaev (Hronom)" <[email protected]> wrote: >> >> >Hello everyone! >> >I use Apache Jena version 2.13.0. >> >I try to add in existing Graph new triple by using SPARQL, and triple >> >didn’t added, here is the code: >> >public class TestTransactions { >> > public static void main(String[] args) { >> > Dataset dataset = TDBFactory.createDataset(); >> > DatasetGraph datasetGraph = dataset.asDatasetGraph(); >> > Graph graph = datasetGraph.getDefaultGraph(); >> > >> > // Fill graph. >> > graph.add( >> > new Triple( >> > NodeFactory.createURI("http://example/unit13";), >> > NodeFactory.createURI("http://example/name";), >> > NodeFactory.createLiteral("Unit 13", "en") >> > ) >> > ); >> > >> > graph.add( >> > new Triple( >> > NodeFactory.createURI("http://example/unit13";), >> > NodeFactory.createURI("http://example/type";), >> > NodeFactory.createURI("http://example/robot";) >> > ) >> > ); >> > >> > graph.add( >> > new Triple( >> > NodeFactory.createURI("http://example/unit13";), >> > NodeFactory.createURI("http://example/creationYear";), >> > NodeFactory.createURI("http://example/2015";) >> > ) >> > ); >> > >> > // Test. >> > dataset.begin(ReadWrite.WRITE); >> > >> > UpdateRequest request = >> > UpdateFactory.create( >> > "INSERT { ?s <http://example/value> '1' } WHERE { ?s >> ><http://example/creationYear> <http://example/2015> . }" >> > ); >> > UpdateAction.execute(request, dataset); >> > >> > dataset.commit(); >> > dataset.end(); >> > >> > RDFDataMgr.write(System.out, graph, RDFFormat.NTRIPLES); >> > } >> >} >> > >> >If I remove “dataset.begin(ReadWrite.WRITE);”, “dataset.commit();” and >> >“dataset.end();” triple will be inserted… >> > >> >Test project on GitHub https://github.com/Hronom/test-jena >> >> >> >> >>
