Hi Jason, In you sources: > Query sparql = QueryFactory.create(qStr); > VirtuosoQueryExecution vqd = VirtuosoQueryExecutionFactory.create(sparql, graph);
Based on this, SPARQL query will be parsed by Jena ARQ and after this, it will
be converted back to String before send to Virtuoso.
Therefore Jena ARQ could change your original query a little.
You could check it with something:
String qStr = "PREFIX base: <http://base.org#> PREFIX xsd:
<http://www.w3.org/2001/XMLSchema#> SELECT ?s {?s base:name \"test_sensor\"^^xsd:string}";
Query sparql = QueryFactory.create(qStr);
System.out.println(sparql.toString());
The output log will be:
-----------------------------------------
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
PREFIX base: <http://base.org#>
SELECT ?s
WHERE
{ ?s base:name "test_sensor" }
-----------------------------------------
You could see, that Jena ARQ changed your query text a little, so it doesn't
work as expected.
I offer change you code like:
- Query sparql = QueryFactory.create(qStr);
- VirtuosoQueryExecution vqd =
VirtuosoQueryExecutionFactory.create(sparql, graph);
+
+ VirtuosoQueryExecution vqd =
VirtuosoQueryExecutionFactory.create(qStr, graph);
so your query will not be changed by Jena ARQ.
On 01/25/2018 07:42 AM, Jason Koh wrote:
Dear Hugh and the community, I have created a regenerator repository: https://github.com/jbkoh/virtjena_regenerator If available, please review the problem. I think it's the problem of Virt Jena, your feedback would be much useful for me to write the right code. Thanks! With regards, Jason Koh cseweb.ucsd.edu/~jbkoh <http://cseweb.ucsd.edu/~jbkoh> On Tue, Jan 23, 2018 at 12:50 PM, Jason Koh <jb...@eng.ucsd.edu <mailto:jb...@eng.ucsd.edu>> wrote: Forgot to clarify the configuration: Ubuntu 16.04 (64bit) Virtuoso 7.2.4.2 Virtuoso Jean: virt_jena3 Virtuodo JDBC: virtjdbc4 Java: openjdk version "1.8.0_151" Thank you. With regards, Jason Koh cseweb.ucsd.edu/~jbkoh <http://cseweb.ucsd.edu/~jbkoh> On Tue, Jan 23, 2018 at 12:46 PM, Jason Koh <jb...@eng.ucsd.edu <mailto:jb...@eng.ucsd.edu>> wrote: Here's the Java code snippet not working: ```java String nameStr = "test_sensor1"; String BASE = "http://base.org#";; String uuid = "xxxxx"; Node name = NodeFactory.createLiteralByValue(nameStr, XSDstring); Node point = NodeFactory.createURI(BASE + uuid); Node hasName = NodeFactory.createURI(BASE + "name"); graph.add(new Triple(point, hasName, name)); String qStr = "PREFIX base: <http://base.org#>\n" + "SELECT ?s WHERE {\n" + "?s base:name \"test_sensor1\" . \n" + "}"; Query sparql = QueryFactory.create(qStr); VirtuosoQueryExecution vqd = VirtuosoQueryExecutionFactory.create(sparql, graph); ResultSet results = vqd.execSelect(); while (results.hasNext()) { QuerySolution result = results.nextSolution(); System.out.println(result.get("s").toString()); } System.out.println("Done"); } ``` The value ``results`` is empty and this code does not print anything. I can make a regenerator. Let me know if that helps. With regards, Jason Koh cseweb.ucsd.edu/~jbkoh <http://cseweb.ucsd.edu/~jbkoh> On Tue, Jan 23, 2018 at 12:16 PM, Jason Koh <jb...@eng.ucsd.edu <mailto:jb...@eng.ucsd.edu>> wrote: Hi Hugh, I inserted the tripled through /Virtuoso Jena/ and I can see triples like ``ex:xxxx base:name test_sensor0`` when I query just with ?s ?p ?o. However, I don't get any result with ``?s base:name "test_sensor0"``. As you showed, it works with command line insertions. Let me verify the source of the problem once again and come back. Thank you! With regards, Jason Koh cseweb.ucsd.edu/~jbkoh <http://cseweb.ucsd.edu/~jbkoh> On Tue, Jan 23, 2018 at 3:17 AM, Hugh Williams <hwilli...@openlinksw.com <mailto:hwilli...@openlinksw.com>> wrote: Hi Jason, What exactly is not working for you ? As the following works for me: SQL> SPARQL PREFIX base: <base> INSERT DATA { GRAPH <koh> { <1> base:name "sensor1" . } }; Done. -- 1 msec. SQL> SPARQL SELECT * FROM <koh> WHERE {?s ?p ?o};s p o LONG VARCHAR LONG VARCHAR LONG VARCHAR_______________________________________________________________________________1 basename sensor11 Rows. -- 2 msec. SQL> SPARQL PREFIX base: <base> SELECT ?s {?s base:name "sensor1"}; s LONG VARCHAR _______________________________________________________________________________ 1 1 Rows. -- 1 msec. SQL> SPARQL PREFIX base: <base> SELECT ?g ?s {GRAPH ?g {?s base:name "sensor1"}}; g s LONG VARCHAR LONG VARCHAR _______________________________________________________________________________ koh 1 1 Rows. -- 1 msec. SQL> Best Regards Hugh Williams Professional Services OpenLink Software, Inc. // http://www.openlinksw.com/ Weblog -- http://www.openlinksw.com/blogs/ <http://www.openlinksw.com/blogs/> LinkedIn -- http://www.linkedin.com/company/openlink-software/ <http://www.linkedin.com/company/openlink-software/> Twitter -- http://twitter.com/OpenLink Google+ -- http://plus.google.com/100570109519069333827/ <http://plus.google.com/100570109519069333827/> Facebook -- http://www.facebook.com/OpenLinkSoftware <http://www.facebook.com/OpenLinkSoftware> Universal Data Access, Integration, and Management Technology Providers > On 23 Jan 2018, at 09:58, Jason Koh <jb...@eng.ucsd.edu <mailto:jb...@eng.ucsd.edu>> wrote: > > Hi Kingsley, > > Thanks for the prompt response. I just tried it and it works well. I haven't compared the performance yet but wish the string match is faster. > > However, I am having trouble querying with the String Literal with SPARQL. The following query does not work for Virtuoso. > ```sparql > select ?s { > ?s base:name "sensor1". # also tried "sensor1"^^xsd:string but the same result. > } > ``` > This query returns empty result. > > If I query with no pattern (?s ?p ?o), I can see the following triple: > :xxxx base:name "sensor1", > > Can't sort out the problem. Do you have any ideas on this? > > Thank you! > > > > > > With regards, > Jason Koh > cseweb.ucsd.edu/~jbkoh <http://cseweb.ucsd.edu/~jbkoh> > > On Mon, Jan 22, 2018 at 2:52 PM, Kingsley Idehen <kide...@openlinksw.com <mailto:kide...@openlinksw.com>> wrote: > On 1/22/18 5:11 PM, Jason Koh wrote: >> Hi there, >> >> I am trying to use Virtuoso for metadata of city-scale sensor database. (metroinsight.io <http://metroinsight.io>). >> >> I wonder if there is a way to optimize certain SPARQL query pattern. I often query this: >> ```sparql >> select ?s where { >> ?s base:name ex:mySensor1 . >> } >> ``` >> >> I could optimize it by caching those with Redis or else, but I wonder if I can force indexing "name" properties in Virtuoso. >> >> Thank you! >> >> >> With regards, >> Jason Koh >> cseweb.ucsd.edu/~jbkoh <http://cseweb.ucsd.edu/~jbkoh> > > Have you looked at text indexing in Virtuoso with regards to SPARQL? > [1] http://docs.openlinksw.com/virtuoso/rdfsparqlrulefulltext/ <http://docs.openlinksw.com/virtuoso/rdfsparqlrulefulltext/> . > -- > Regards, > > Kingsley Idehen > Founder & CEO > OpenLink Software (Home Page: > http://www.openlinksw.com > ) > > Weblogs (Blogs): > Legacy Blog: > http://www.openlinksw.com/blog/~kidehen/ <http://www.openlinksw.com/blog/~kidehen/> > > Blogspot Blog: > http://kidehen.blogspot.com > > Medium Blog: > https://medium.com/@kidehen > > > Profile Pages: > Pinterest: > https://www.pinterest.com/kidehen/ <https://www.pinterest.com/kidehen/> > > Quora: > https://www.quora.com/profile/Kingsley-Uyi-Idehen <https://www.quora.com/profile/Kingsley-Uyi-Idehen> > > Twitter: > https://twitter.com/kidehen > > Google+: > https://plus.google.com/+KingsleyIdehen/about <https://plus.google.com/+KingsleyIdehen/about> > > LinkedIn: > http://www.linkedin.com/in/kidehen <http://www.linkedin.com/in/kidehen> > > > Web Identities (WebID): > Personal: > http://kingsley.idehen.net/public_home/kidehen/profile.ttl#i <http://kingsley.idehen.net/public_home/kidehen/profile.ttl#i> > > : > http://id.myopenlink.net/DAV/home/KingsleyUyiIdehen/Public/kingsley.ttl#this <http://id.myopenlink.net/DAV/home/KingsleyUyiIdehen/Public/kingsley.ttl#this> > > > > > ------------------------------------------------------------------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > Virtuoso-users mailing list > Virtuoso-users@lists.sourceforge.net <mailto:Virtuoso-users@lists.sourceforge.net> > https://lists.sourceforge.net/lists/listinfo/virtuoso-users <https://lists.sourceforge.net/lists/listinfo/virtuoso-users> > > > ------------------------------------------------------------------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot_______________________________________________ <http://sdm.link/slashdot_______________________________________________> > Virtuoso-users mailing list > Virtuoso-users@lists.sourceforge.net <mailto:Virtuoso-users@lists.sourceforge.net> > https://lists.sourceforge.net/lists/listinfo/virtuoso-users <https://lists.sourceforge.net/lists/listinfo/virtuoso-users> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Virtuoso-users mailing list Virtuoso-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/virtuoso-users
-- Best Regards, Sergey Malinin
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