Hi Hugh and everyone,

I was wondering if you have any news about that "Tag not defined" error.
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 <http://www.arisem.com/>


Hugh Williams wrote:
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 <http://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 <http://www.openlinksw.com/>
Support: http://support.openlinksw.com <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 <http://virtuoso.openlinksw.com/dataspace/dav/wiki/Main/VOSDownload#Jena>). 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 <http://www.arisem.com/>
------------------------------------------------------------------------------

_______________________________________________
Virtuoso-devel mailing list
[email protected] <mailto:[email protected]>
https://lists.sourceforge.net/lists/listinfo/virtuoso-devel

------------------------------------------------------------------------------

_______________________________________________
Virtuoso-devel mailing list
[email protected] <mailto:[email protected]>
https://lists.sourceforge.net/lists/listinfo/virtuoso-devel

Reply via email to