Egon -- On Jan 14, 2009, at 11:26 AM, Egon Willighagen wrote:
> On 1/14/09, Ted Thibodeau Jr <[email protected]> wrote: >> Without seeing your query, I can't be sure, > > PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> > PREFIX dbpedia-owl: <http://dbpedia.org/ontology/> > > select distinct ?c where {?c rdf:type dbpedia-owl:ChemicalCompound} I note that there was no ordering in that query -- which means that you may see *any* first and last value in your result set -- rows are returned in arbitrary order, and this may change between executions of the query. > Should not be overly many hits... That's easy to check with one of Virtuoso's aggregate extensions to SPARQL -- PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> PREFIX dbpedia-owl: <http://dbpedia.org/ontology/> SELECT COUNT (DISTINCT ?c) WHERE {?c rdf:type dbpedia-owl:ChemicalCompound} -- which gets -- callret-0 4379 > The SPARQL end point now returns > > http://dbpedia.org/resource/%28Benzylideneacetone%29iron_tricarbonyl > ... > http://dbpedia.org/resource/Congo_red When I add an ordering clause to the query -- PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> PREFIX dbpedia-owl: <http://dbpedia.org/ontology/> SELECT DISTINCT ?c WHERE {?c rdf:type dbpedia-owl:ChemicalCompound} ORDER BY ?c -- the range returned is -- <http://dbpedia.org/resource/%281S%29-1-Methyl-2%2C3%2C4%2C9-tetrahydro-1H-pyrido-3%2C4-b-indole > ... <http://dbpedia.org/resource/Calcium_oxide> I hope this clarifies things. Be seeing you, Ted -- A: Yes. http://www.guckes.net/faq/attribution.html | Q: Are you sure? | | A: Because it reverses the logical flow of conversation. | | | Q: Why is top posting frowned upon? Ted Thibodeau, Jr. // voice +1-781-273-0900 x32 Evangelism & Support // mailto:[email protected] OpenLink Software, Inc. // http://www.openlinksw.com/ http://www.openlinksw.com/weblogs/uda/ OpenLink Blogs http://www.openlinksw.com/weblogs/virtuoso/ http://www.openlinksw.com/blog/~kidehen/ Universal Data Access and Virtual Database Technology Providers ------------------------------------------------------------------------------ This SF.net email is sponsored by: SourcForge Community SourceForge wants to tell your story. http://p.sf.net/sfu/sf-spreadtheword _______________________________________________ Dbpedia-discussion mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/dbpedia-discussion
