In the general case you cannot do this unless as part of your insert you include some form of time stamp/provenance information that you can test for
TDB does not keep any record of when a specific piece of data was inserted so if you want this functionality you need to implement it as part of your data model and application logic Rob On 06/01/2015 10:51, "[email protected]" <[email protected]> wrote: >Thanks for your answer, but how to query when I don't know the object >value.I want to query the latest insert object value, without deleting >the data inserted before . > > > >[email protected] > >From: Andy Seaborne >Date: 2015-01-06 17:39 >To: users >Subject: Re: How to query the latest insert data from TDB dataset >On 06/01/15 01:21, [email protected] wrote: >> I have insert three statments : subject="ind1" predicate="intID" >>object=0,1,2 into my TDB dataset,and I want to select the latest insert >>data "2",but the dataset reply all the data. >> Here is the query part: >> dataset.begin(ReadWrite.READ); >> >>model=dataset.getNamedModel("http://www.semanticweb.org/HRAtest01.owl#";); >> String qs1 = "SELECT ?x WHERE { >><http://www.semanticweb.org/HRAtest01.owl#"+sub+";> >><http://www.semanticweb.org/HRAtest01.owl#"+pre+";> ?x }"; > >SELECT ?x { <...> <...> ?x . FILTER (?x = 2 ) } > >though if you know the answer is 2 > >ASK{ { <...> <...> 2 } > >return true/false depending on presence of that triple. > >Andy > >> QueryExecution qExec=QueryExecutionFactory.create(qs1, model); >> try { >> ResultSet rs = qExec.execSelect() ; >> ResultSetFormatter.out(rs) ; >> } >> finally >> { >> qExec.close() ; >> } >> the answer: >> ----- >> | x | >> ===== >> | 0 | >> | 1 | >> | 2 | >> ----- >> >
