Hi, It seems ResultSet is not usable after dataset has ended in this case. Invoking `ds.end()` after utilizing ResultSet solved this problem. Thanks for your time.
Best regards. ------------------ Wang Tonghe ------------------ Original ------------------ From: "Marc Agate";<[email protected]>; Date: Wed, Dec 27, 2017 11:34 AM To: "users"<[email protected]>; Subject: Re: RDF namespace is not compatible with OPTIONAL in ARQ Well, I use rdf namespace with Optional in almost all my queries and it wouldn't make any sense to not being able to use it with OPTIONAL. Print out your query and check the value of your k: prefix. Regarding the ResultSet, I am not sure it is still usable once the transaction has ended (ds.end()). You should use it in the method, eventually calling a utility class to process it and then return the processed data instead of the ResultSet itself. Marc Le mercredi 27 décembre 2017 à 11:22 +0800, hetong583 a écrit : > Hi, > 1) I am sure. Everything works fine if remove OPTIONAL clause. Any > change on rdf namespace also works, but you know, resultset is empty. > 2) Code failed while modelUri is not null. We always use a named > graph. > > > We use `TDBFactory.createDataset(tdbDir)` creating dataset. I think > it's a in memory dataset. No .lock file was found in our data > directory. > > > Thanks for your reply. > Best regards. > > > ------------------ > Wang Tonghe > > > > > > > > ------------------ Original ------------------ > From: "Marc Agate";<[email protected]>; > Date: Wed, Dec 27, 2017 11:01 AM > To: "users"<[email protected]>; > > Subject: Re: RDF namespace is not compatible with OPTIONAL in ARQ > > > > Hi, > > 1) Are you sure the placeholder substitution is coorect in : PREFIX > kg:<%s> ? (print out the query string after substitution) > 2) in which case is your code failing , modelUri null or modelUri not > null ? > > Are you switching between a named graph and the default model ? > > Is this a in memory dataset or not ? If not check for a .lock file in > your data directory. > > > > Marc > > > Le mercredi 27 décembre 2017 à 10:42 +0800, hetong583 a écrit : > > Yes, this is my execution function > > ``` > > public ResultSet execSelect(String queryStr) { > > ds.begin(ReadWrite.READ); > > try { > > Query query = QueryFactory.create(queryStr); > > QueryExecution qexec; > > if (modelUri != null) { > > qexec = QueryExecutionFactory.create(query, > > ds.getNamedModel(modelUri)); > > } else { > > qexec = QueryExecutionFactory.create(query, ds); > > } > > return qexec.execSelect(); > > } catch (Exception e) { > > logger.error(e.getMessage(), e); > > } finally { > > ds.end(); > > } > > return null; > > } > > > > > > > > ``` > > > > > > ------------------ > > Wang Tonghe > > > > > > > > > > > > > > > > ------------------ Original ------------------ > > From: "Marc Agate";<[email protected]>; > > Date: Wed, Dec 27, 2017 10:35 AM > > To: "users"<[email protected]>; > > > > Subject: Re: RDF namespace is not compatible with OPTIONAL in ARQ > > > > > > > > Hi! > > > > Did you first start the transaction with > > yourdataset.begin(ReadWrite.READ) ? > > > > Marc > > > > Le mercredi 27 décembre 2017 à 10:24 +0800, hetong583 a écrit : > > > Hello, > > > I tried to access TDB via SPARQL. However following query always > > > throws a TDBTransactionException: Not in a transaction. > > > ``` > > > PREFIX kg:<%s> > > > PREFIX rdf:<http://www.w3.org/1999/02/22-rdf-syntax-ns#> > > > SELECT ?entityUri ?name ?unit > > > WHERE > > > { ?entityUri rdf:type kg:AtomicMetric. > > > ?entityUri kg:Name ?name. > > > OPTIONAL { ?entityUri kg:Unit ?unit } } > > > > > > ``` > > > After several tries, I found that rdf namespace and `OPTIONAL` > > > cannot > > > appear simultaneously. And any modification on "http://www.w3.org > > > /1 > > > 99 > > > 9/02/22-rdf-syntax-ns#" will solve the problem. I use Jena 3.5 > > > and > > > I > > > found 3.6 also has this problom. > > > > > > > > > Following is the stacktrace. > > > ``` > > > org.apache.jena.tdb.transaction.TDBTransactionException: Not in a > > > transaction > > > > > > > > > at > > > org.apache.jena.tdb.transaction.DatasetGraphTransaction.get(Datas > > > et > > > Gr > > > aphTransaction.java:117) > > > at > > > org.apache.jena.tdb.transaction.DatasetGraphTransaction.getDatase > > > tG > > > ra > > > phToQuery(DatasetGraphTransaction.java:80) > > > at > > > org.apache.jena.tdb.store.GraphTxnTDB.getDatasetGraphTDB(GraphTxn > > > TD > > > B. > > > java:49) > > > at > > > org.apache.jena.tdb.store.GraphTDB.getNodeTupleTable(GraphTDB.jav > > > a: > > > 74 > > > ) > > > at > > > org.apache.jena.tdb.solver.SolverLib.execute(SolverLib.java:66) > > > at > > > org.apache.jena.tdb.solver.StageGeneratorDirectTDB.execute(StageG > > > en > > > er > > > atorDirectTDB.java:56) > > > at > > > org.apache.jena.tdb2.solver.StageGeneratorDirectTDB.execute(Stage > > > Ge > > > ne > > > ratorDirectTDB.java:53) > > > at > > > org.apache.jena.sparql.engine.main.OpExecutor.execute(OpExecutor. > > > ja > > > va > > > :128) > > > at > > > org.apache.jena.sparql.engine.main.ExecutionDispatch.visit(Execut > > > io > > > nD > > > ispatch.java:58) > > > at org.apache.jena.sparql.algebra.op.OpBGP.visit(OpBGP.java:49) > > > at > > > org.apache.jena.sparql.engine.main.ExecutionDispatch.exec(Executi > > > on > > > Di > > > spatch.java:46) > > > at > > > org.apache.jena.sparql.engine.main.OpExecutor.exec(OpExecutor.jav > > > a: > > > 11 > > > 7) > > > at > > > org.apache.jena.sparql.engine.main.OpExecutor.execute(OpExecutor. > > > ja > > > va > > > :88) > > > at org.apache.jena.sparql.engine.main.QC.execute(QC.java:52) > > > at > > > org.apache.jena.sparql.engine.main.iterator.QueryIterOptionalInde > > > x. > > > ne > > > xtStage(QueryIterOptionalIndex.java:51) > > > at > > > org.apache.jena.sparql.engine.iterator.QueryIterRepeatApply.makeN > > > ex > > > tS > > > tage(QueryIterRepeatApply.java:108) > > > at > > > org.apache.jena.sparql.engine.iterator.QueryIterRepeatApply.hasNe > > > xt > > > Bi > > > nding(QueryIterRepeatApply.java:65) > > > at > > > org.apache.jena.sparql.engine.iterator.QueryIteratorBase.hasNext( > > > Qu > > > er > > > yIteratorBase.java:114) > > > at > > > org.apache.jena.sparql.engine.iterator.QueryIterConvert.hasNextBi > > > nd > > > in > > > g(QueryIterConvert.java:58) > > > at > > > org.apache.jena.sparql.engine.iterator.QueryIteratorBase.hasNext( > > > Qu > > > er > > > yIteratorBase.java:114) > > > at > > > org.apache.jena.sparql.engine.iterator.QueryIteratorWrapper.hasNe > > > xt > > > Bi > > > nding(QueryIteratorWrapper.java:39) > > > at > > > org.apache.jena.sparql.engine.iterator.QueryIteratorBase.hasNext( > > > Qu > > > er > > > yIteratorBase.java:114) > > > at > > > org.apache.jena.sparql.engine.iterator.QueryIteratorWrapper.hasNe > > > xt > > > Bi > > > nding(QueryIteratorWrapper.java:39) > > > at > > > org.apache.jena.sparql.engine.iterator.QueryIteratorBase.hasNext( > > > Qu > > > er > > > yIteratorBase.java:114) > > > at > > > org.apache.jena.sparql.engine.ResultSetStream.hasNext(ResultSetSt > > > re > > > am > > > .java:74) > > > at > > > org.apache.jena.sparql.engine.ResultSetCheckCondition.hasNext(Res > > > ul > > > tS > > > etCheckCondition.java:55) > > > at > > > com.quantchi.intelquery.etl.LtpDict.getEntityFromTdb(LtpDict.java > > > :8 > > > 7) > > > > > > ``` > > > > > > > > > Thanks for your help. Let me know if you need any other > > > infomation. > > > Best regards. > > > > > > > > > > > > > > > ------------------ > > > Wang Tonghe
