Hi Marco, We have been able to recreate this "tag not defined" error you report running that DBpedia query against the Jena provider and development are working on fixing it. I shall let you know when a fix is available ...
Best Regards Hugh Williams Professional Services OpenLink Software Web: http://www.openlinksw.com Support: http://support.openlinksw.com Forums: http://boards.openlinksw.com/support Twitter: http://twitter.com/OpenLink On 25 May 2010, at 10:18, Marco FOSSATI wrote: > Hello Hugh and everyone, > > You can find the answers to your questions below. > I've already tried to use the HTTP Client Java API from Apache to communicate > with Virtuoso (with a POST method): all the queries seem here to work > perfectly, including the "cursed" one. > When I got on the Virtuoso Jena Provider, I've realized that the same job > could be done with 3 lines of code. > The choice actually depends on the reliability of the API. > > Best regards, > > Marco FOSSATI > Research and Development Engineer > Arisem a Thales company > 1-5, Avenue Carnot > 91883 Massy Cedex > Tél. : +33 01 69 75 30 24 > Fax : +33 01 69 75 31 56 > www.arisem.com > > > Hugh Williams wrote: >> >> Hi Marco, >> >> I have tested the query you report against a local DBpedia 3.5.1 Instance we >> have in-house via the Virtuoso Jena Provider and it runs fine for me. It is >> specifically the addition of the order by in the query that results in the >> problem on your machine ? > Yes, I've tried to run the query without the ORDER BY clause and it works > fine. > I' ve also found that the problem deals with the foaf:name property and NOT > with the rdfs:label one. > For example, this query WORKS: > SELECT ?test WHERE { <http://dbpedia.org/resource/Unreal_II:_The_Awakening> > <http://www.w3.org/2000/01/rdf-schema#label> ?test } ORDER BY ?test > > This query DOESN'T: > SELECT ?test WHERE { <http://dbpedia.org/resource/Unreal_II:_The_Awakening> > <http://xmlns.com/foaf/0.1/name> ?test } ORDER BY ?test > > N.B.: All the queries WORK if launched from the SPARQL endpoint, but not via > Java. >> >> What Virtuoso release are you running as I have seen the "Tag 20 not >> defined" error with earlier v5 builds from about a year ago but that issue >> has long since been resolved and does not occur with the components shipped >> with the latest v6 product or those from the VOSDownload page link you refer >> to below. If you have been using multiple Virtuoso versions please ensure >> their is only the one virt_jena and virtjdbc3 jar files on the system and >> that you are not picking up an old version. > I'm running the Virtuoso Open Source Edition (multi threaded), Version > 6.1.1.3127, Build Apr 4 2010, Compiled for Linux (x86_64-pc-linux-gnu), on a > Debian Lenny distro. > I firstly downloaded the sources tarball from the web, but I encountered > problems when trying to compile them; I found then a Debian package in the > Sid repository and easily installed it. >> >> The Virtuoso open source and commercial products use the same Virtuoso Jena >> Provider, thus the link you used below does give you the official commercial >> provider. Their are no Maven repositories for it, the source are available >> in the open source archive (~/binsrc/jena) , should you want to access them >> ... >> >> Best Regards >> Hugh Williams >> Professional Services >> OpenLink Software >> Web: http://www.openlinksw.com >> Support: http://support.openlinksw.com >> Forums: http://boards.openlinksw.com/support >> Twitter: http://twitter.com/OpenLink >> >> On 24 May 2010, at 10:24, Marco FOSSATI wrote: >> >>> Hello, >>> >>> I'm working with the Virtuoso Jena Driver API to query a local DBpedia >>> ontology and process information with Jena API. >>> When launching a query with an ORDER BY clause, the following exception is >>> thrown: >>> >>> Exception in thread "main" com.hp.hpl.jena.shared.JenaException: Can not >>> create ResultSet.:virtuoso.jdbc3.VirtuosoException: Tag 20 not defined. >>> >>> Here an example of SPARQL query that won't work: >>> >>> SELECT ?title >>> WHERE { { <http://dbpedia.org/resource/Unreal_II:_The_Awakening> >>> <http://xmlns.com/foaf/0.1/name> ?title } UNION { >>> <http://dbpedia.org/resource/Unreal_II:_The_Awakening> >>> <http://www.w3.org/2000/01/rdf-schema#label> ?title } } >>> ORDER BY ?title >>> >>> I found the virt_jena and virtjdbc3 jars in the OpenSource Virtuoso Wiki >>> (here). >>> As I'd like to use them in my application, I'm wondering if there is an >>> official release of this API, if it is maintained and if there is any Maven >>> 2 artifact set. >>> >>> Best regards, >>> >>> Marco FOSSATI >>> Research and Development Engineer >>> Arisem a Thales company >>> 1-5, Avenue Carnot >>> 91883 Massy Cedex >>> Tél. : +33 01 69 75 30 24 >>> Fax : +33 01 69 75 31 56 >>> www.arisem.com >>> ------------------------------------------------------------------------------ >>> >>> _______________________________________________ >>> Virtuoso-devel mailing list >>> [email protected] >>> https://lists.sourceforge.net/lists/listinfo/virtuoso-devel >> > ------------------------------------------------------------------------------ > > _______________________________________________ > Virtuoso-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/virtuoso-devel
