W3C home > Mailing lists > Public > public-lod@w3.org > March 2011

Re: Quick reality check please

From: Hugh Glaser <hg@ecs.soton.ac.uk>
Date: Mon, 21 Mar 2011 11:08:12 +0000
To: "<nathan@webr3.org>" <nathan@webr3.org>
CC: Linked Data community <public-lod@w3.org>
Message-ID: <EMEW3|775ed14c862915e66b898fe72deceac2n2KB8g02hg|ecs.soton.ac.uk|70153CC4-2CD1-4CD9-B1EE-F87A21FBDCC6@ecs.soton.ac.uk>
Thanks guys.
Sigh - not that one again.
The problem was I hadn't noticed I was getting back the yago URI, not the dbpedia resource.
It's just so hard :-)

Right - now I am officially pissed off.
The number of times I have wasted time trying to SPARQL for exact strings, only to find I have missed the @en or the ^^<http://www.w3.org/2001/XMLSchema#string>)
And then had to start messing about scrubbing around in xml or rdf to find out what I had missed.
All because the html version of SPARQL results decides I don't need to be bothered with trivia like that.

Just who was it that decided that this information was surplus to requirements when returning html from a SPARQL query?
It isn't. The primary reason anyone would be looking at the results of a SPARQL query is to work out exactly what is in the store.
So they can start querying.
And essentially the html is lying to me.
(Not just the dbpedia endpoint, but it seems pretty universal.)

This just isn't joined up:
When I do
select * where {<http://dbpedia.org/resource/World_Wide_Web_Consortium> ?p ?o}
I get back stuff that includes lines such as:
http://www.w3.org/2000/01/rdf-schema#label	World Wide Web Consortium
But if I now put back in essentially what I got out:
select * where {?s <http://www.w3.org/2000/01/rdf-schema#label> "World Wide Web Consortium"}
I get back

The HTML, spreadsheet, Javascript and CSV give no hint of the lang.
So it is not just about a person having a problem - if I wrote an agent to process output and chose CSV I would have the same problem.

Time to improve the html output at the least?


PS While we are in SPARQL for dummies mode ( :-) ) what is the best way of doing a query for an exact string where I don't care about the language or the datatype?
I'm sure this is easy in SPARQL 1.1, as there have been so many users who would have needed it. I am hoping that the answer is not regex for such a common thing.

On 21 Mar 2011, at 01:05, Nathan wrote:

> select distinct ?s where {?s ?p "Arts and Humanities Research Council"@en}
> :)
> Hugh Glaser wrote:
>> dbpedia sparql endpoint is not doing what I expect.
>> select distinct ?s where {?s ?p "World Wide Web Consortium"}
>> gives an answer
>> select distinct ?s where {?s ?p "Arts and Humanities Research Council"}
>> doesn't.
>> But both
>> http://dbpedia.org/resource/World_Wide_Web_Consortium
>> and
>> http://dbpedia.org/resource/Arts_and_Humanities_Research_Council
>> are there with dbpprop:name and rdfs:label and the string.
>> What am I doing wrong?
>> The two queries as the actual URLs:
>> http://dbpedia.org/sparql?default-graph-uri=http%3A%2F%2Fdbpedia.org&query=select+distinct+%3Fs+where+%7B%3Fs+%3Fp+%22World+Wide+Web+Consortium%22%7D&debug=on&timeout=&format=text%2Fhtml&save=display&fname=
>> http://dbpedia.org/sparql?default-graph-uri=http%3A%2F%2Fdbpedia.org&query=select+distinct+%3Fs+where+%7B%3Fs+%3Fp+%22Arts+and+Humanities+Research+Council%22%7D&debug=on&timeout=&format=text%2Fhtml&save=display&fname=
>> Hope this is not a senior moment, but suspect it is :-)

Hugh Glaser,  
              Intelligence, Agents, Multimedia
              School of Electronics and Computer Science,
              University of Southampton,
              Southampton SO17 1BJ
Work: +44 23 8059 3670, Fax: +44 23 8059 3045
Mobile: +44 78 9422 3822, Home: +44 23 8061 5652
Received on Monday, 21 March 2011 11:09:16 UTC

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