Georgi Kobilarov wrote: > Hey Rob, > > >> I've noticed a couple of examples where there seem to be entries at >> http://dbpedia.org/page/ but when performing a SPARQL query against > the >> dataset I get no results returned e.g. >> >> http://dbpedia.org/page/iPhone >> >> returns a page with data but running : >> >> SELECT ?predicate ?object WHERE { <http://dbpedia.org/resource/iPhone> >> ?predicate ?object . } >> >> at the SPARQL interface returns no results. > > Interesting one... > >> Could someone explain why ? > > Yes, I can. > There simply are no triples matching the pattern > {dbpedia:iPhone ?p ?o . } > > The output pages (dbpedia.org/page/ and dbpedia.org/data/) are generated > on-the-fly via a "DESCRIBE <x>" query, which is equivalent (in > Virtuoso's implementation, no necessarily by spec) to > SELECT * where { <x> ?p ?o . } UNION SELECT * where { ?s ?p <x> . } > > In your example, there are only > S P dbpedia:iPhone > triples available. > > If you look at dbpedia.org/page/iPhone you will see, that the properties > are named "is blabla of", which indicates that those triples match to { > ?s ?p dbpedia:iPhone .}
Thanks, that makes sense now :) > > Apple's mobile phone you are looking for has the URI > http://dbpedia.org/resource/IPhone (with an upper case "I"). That's > really an interesting example, because the URI does not match the > article's title in Wikipedia (which has a lower case "i"). > > This raises another question then - why do the redirects all point to the 'iPhone' resource and not the 'IPhone' resource ? e.g. SELECT ?predicate ?object WHERE { <http://dbpedia.org/resource/Iphone> ?predicate ?object . } returns : http://dbpedia.org/property/redirect -> http://dbpedia.org/resource/iPhone Is this pointing to the wrong resource ? > Best, > > Georgi > > > -- > Georgi Kobilarov > Freie Universität Berlin > www.georgikobilarov.com > -- Robert Lee, Director Rattle Research Ltd. rattleresearch.com tel: 0114 2706977 ---- This e-mail (and any attachments) is confidential and may contain personal views which are not the views of Rattle Research unless specifically stated. If you have received this email in error, please delete it from your system: do not use, copy or distribute the information in any way nor act in reliance on it and notify the sender immediately. ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone _______________________________________________ Dbpedia-discussion mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/dbpedia-discussion
