On Sat, Nov 21, 2009 at 4:35 PM, Hendrik <[email protected]> wrote: > Hi All, > > I'm new using SPARQL and try to query some information using dbpedia. I got > problem when i try to query a property value which started with is ... of. > For Example when i access this page : dbpedia.org/resource/Coffee, it > display is dbprop:exportGoods of ..... > However, when i try to access the value of this property using sparql it > does not give any result. I try the other property without is..of and the > query can give the results. > > What's wrong with my query?
The "is ... of" idiom is a way of talking about inverse direction of properties. So if "danbri has 'age' property '37'", then also we get " '37' is age of danbri. " This can get confusing when the property names already have 'is...of' in the name: "Cat subClassOf Mammal." & "Mammal is subClassOf of Cat" is a bit confusing. I wish in the original RDF WG we'd used 'superProperty' and 'superClass' instead as the names for those relationships, then we could say 'Cat superClass Mammal. Mammal is superClass of Cat.', which would have worked fine. But back re your query: try reversing the variable names; when it tells you something 'is dbprop:exportGoods of', it means that there is some other object with an exportGoods property whose value is the current thing. Hope this helps, Dan ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ Dbpedia-discussion mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/dbpedia-discussion
