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Re: [dotNetRDF-Develop] connecting to a BrighstarDB store from dotnetRDF
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From: Rob V. <rv...@do...> - 2014-12-02 11:25:26
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Ivan Kal appears to have confirmed what I said in my email, Brightstar is responding with unexpected data because you are using the incorrect endpoint URI Note that ListGraphs() is internally just a query to the remote database so as you suggested and Kal has confirmed the problem is in your connection settings. Correcting the endpoint URL should hopefully resolve your issue Rob From: Kal Ahmed <ka...@ne...> Reply-To: dotNetRDF Developer Discussion and Feature Request <dot...@li...> Date: Tuesday, 2 December 2014 08:18 To: dotNetRDF Developer Discussion and Feature Request <dot...@li...> Subject: Re: [dotNetRDF-Develop] connecting to a BrighstarDB store from dotnetRDF > Hi, > > I believe this is a problem with the URL you are using for the SPARQL > endpoint. The correct SPARQL endpoint for your store is > http://<IP>:8090/brightstar/<STORE>/sparql as described here: > http://brightstardb.readthedocs.org/en/latest/SPARQL_Endpoint/ > > Cheers > > Kal > > On Mon, Dec 1, 2014 at 4:28 PM, Iván Palomares <iva...@gm...> wrote: >> Hi, >> Thanks to all who are trying to help with this question. In order to try to >> find out the source of the problem, I replaced the code where the SparQL >> query is executed and shown, by something simple in which I attempt to obtain >> the graphs in the triplestore ans show its URIs. >> >> //Create a connection to BrightstarDB SPARQL Query endpoint >> SparqlConnector connect = new SparqlConnector(new >> Uri("http://<IP>:8090/brightstar/<STORE>")); >> PersistentTripleStore store = new PersistentTripleStore(connect); >> >> >> IEnumerable<Uri> graphs = connect.ListGraphs(); >> foreach (Uri uri in graphs) >> { >> Console.WriteLine(uri.ToString()); >> } >> >> Now I obtain a new exception in the ListGraphs() line, a RdfStorageException >> being unhandled: >> >> An unhandled exception of type 'VDS.RDF.Storage.RdfStorageException' occurred >> in dotNetRDF.dll >> >> Additional information: An unexpected error occurred while listing Graphs >> from the Store. See inner exception for further details >> >> This makes me thing that perhaps the source of the problem is not in the >> previous query itself, but rather somewhere before, in the connection >> settings? Maybe the classes SaprqlConnector and the PersistentTripleStore as >> a wrapper, are not the appropriate choice to connect to a BrightstarDB >> triplestore? >> >> Also, to give you more info, my triplestore has been directly imported into >> BrightstarDB from a .owl file that was previously generated from an ontology >> in Protegé. The importation process in BrightstarDB was done with a >> management tool called Polaris it seemingly was all done correctly, according >> to the output I received when I imported it. >> >> Kind regards, >> Iván >> >> 2014-12-01 12:02 GMT+00:00 Iván Palomares <iva...@gm...>: >>> Hi, >>> I'm currently trying to make a first connection from a .NET project with >>> dotnetRDF, to a BrightstarDB remote endpoint in which I have a triplestore. >>> The code I use is quite simple, just try to connect and execute a "trival" >>> SPARQL query, as follows (<IP>, <PORT> and <STORE_NAME> stand for the >>> existing address >>> and triplestore name I want to access): >>> >>> namespace ConsoleApplication3 >>> { >>> class ReadFromBrightstarDB >>> { >>> static void Main(string[] args) >>> { >>> //Create a connection to BrightstarDB SPARQL Query endpoint >>> SparqlConnector connect = new SparqlConnector(new >>> Uri("http://<IP>:<PORT>/brightstar/<STORE_NAME>")); >>> PersistentTripleStore store = new PersistentTripleStore(connect); >>> >>> Object results = store.ExecuteQuery("SELECT * WHERE {?s ?p ?o}"); >>> if(results is SparqlResultSet) >>> { >>> //Print out the results >>> SparqlResultSet rset = (SparqlResultSet)results; >>> foreach (SparqlResult result in rset) >>> { >>> Console.WriteLine(result.ToString()); >>> } >>> } >>> >>> } >>> } >>> } >>> When executing, I obtain an exception entitled "RDFParseException was >>> unhandled", with the following description: >>> >>> An unhandled exception of type 'VDS.RDF.Parsing.RdfParseException' occurred >>> in dotNetRDF.dll >>> Additional information: Unable to Parse a SPARQL Result Set from the >>> provided XML since the Document Element is not a <sparql> element! >>> >>> Any help would be appreciate, I'm quite new to .NET in general and >>> BrightStarDB as well as to SparQL, so maybe there is a very silly issue here >>> but I couldn't find it yet. >>> Thanks! >>> Iván >> >> >> ----------------------------------------------------------------------------->> - >> Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server >> from Actuate! Instantly Supercharge Your Business Reports and Dashboards >> with Interactivity, Sharing, Native Excel Exports, App Integration & more >> Get technology previously reserved for billion-dollar corporations, FREE >> http://pubads.g.doubleclick.net/gampad/clk?id=157005751&iu=/4140/ostg.clktrk >> _______________________________________________ >> dotNetRDF-develop mailing list >> dot...@li... >> https://lists.sourceforge.net/lists/listinfo/dotnetrdf-develop >> > > > > -- > Kal Ahmed > Director, Networked Planet Limited > e: kal...@ne... > w: www.networkedplanet.com <http://www.networkedplanet.com> > ------------------------------------------------------------------------------ > Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server from > Actuate! Instantly Supercharge Your Business Reports and Dashboards with > Interactivity, Sharing, Native Excel Exports, App Integration & more Get > technology previously reserved for billion-dollar corporations, FREE > http://pubads.g.doubleclick.net/gampad/clk?id=157005751&iu=/4140/ostg.clktrk__ > _____________________________________________ dotNetRDF-develop mailing list > dot...@li... > https://lists.sourceforge.net/lists/listinfo/dotnetrdf-develop |
