Re: [Dbpedia-dutch] Still a problem with list queries, alas

[Dimitris K. <ji...@gm...>]

Hi Gerard,

(I added the mailing list in cc)

this is normal SPARQL behavior.
Since more than one of your predicates (in fact all of them: object, adres,
objnr) have more than one values, SPARQL returns a combination for all of
them.

here's a simple explanation [1]
and a few similar cases, but not exactly the same [2], [3], [4]

Maybe you should use the list items inside the resource to get them (e.g.
[5]) in a query like this:
SELECT *  WHERE

{
   ?s dbpedia-owl:listItemOf
dbpedia-nl:Lijst_van_gemeentelijke_monumenten_in_Haaksbergen .
   ?s dbpedia-owl:address ?address .
   ?s dbpedia-owl:municipalityCode  ?mCode .
}

[1]
http://www.franz.com/agraph/support/documentation/4.7/sparql-tutorial.html#header3-35
[2]
http://stackoverflow.com/questions/5135577/dbpedia-query-returns-some-musicals-more-than-once-despite-filters
[3]
http://answers.semanticweb.com/questions/3488/duplicate-columns-in-sparql-result
[4]
http://answers.semanticweb.com/questions/20090/how-to-filter-out-duplicate-results-in-sparql-select-due-to-multiple-rdftypes
[5]
http://nl.dbpedia.org/page/Lijst_van_gemeentelijke_monumenten_in_Haaksbergen__Boerderij__1


On Sat, Feb 23, 2013 at 10:46 AM, Gerard Kuys <Ger...@bi...>wrote:

>  Hi Dimitris,
>
> Although undeniably we are making progress with the querying of lists, we
> come across new problems to solve every time. After my initial enthousiasm
> about the fact that we finally could query objects coming from a Wikipedia,
> I had a closer look at the results.
>
> Take 'Lijst van gemeentelijke monumenten in Haaksbergen' for example.
>
> When I entert the following query:
>
> PREFIX prop-nl: <http://nl.dbpedia.org/property/>
>
> SELECT ?monument ?itemAdres ?itemObjnr  WHERE
>
> {
>
>    <
> http://nl.dbpedia.org/resource/Lijst_van_gemeentelijke_monumenten_in_Haaksbergen>
> prop-nl:object ?monument .
>    <
> http://nl.dbpedia.org/resource/Lijst_van_gemeentelijke_monumenten_in_Haaksbergen>
> prop-nl:adres ?itemAdres .
>    <
> http://nl.dbpedia.org/resource/Lijst_van_gemeentelijke_monumenten_in_Haaksbergen>
> prop-nl:objnr ?itemObjnr .
>
> }
>
> the results I get do not represent the single objects in the list. In
> fact, what is happing is a multiplication of each element with each other
> element. There are not so many "Grenspaal" objects in the list, nor do
> "Grenspalen" have that many addresses nor that many object IDs. I don't
> know whether it is easy or difficult to fix this one (of course I hope it
> will be easy), but this is a rather important issue. Do you agree?
>
> Kind regards,
>
> Gerard
>



-- 
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