- From: Paul Gearon <gearon@ieee.org>
- Date: Fri, 11 Sep 2009 23:27:51 -0400
- To: Lee Feigenbaum <lee@thefigtrees.net>
- Cc: Mirko <idonthaveenoughinformation@googlemail.com>, public-sparql-dev@w3.org
I'm late on this, I know, but all the same...
On Mon, Aug 31, 2009 at 6:06 AM, Lee Feigenbaum <lee@thefigtrees.net> wrote:
> SELECT DISTINCT should be unrelated to ORDER BY, which in turn should be
> unrelated to the graphs that comprise the default graph in your RDF dataset.
> If you are seeing a problem, perhaps you should contact the
> maintainers/supporters of your specific SPARQL implementation.
>
> Lee
SELECT DISTINCT will usually reorder data (depending on the
implementation), but ORDER BY will always override this. In this case,
it looks like the ordering on labelValue is being shuffled with SELECT
DISTINCT, which is perfectly fine, since there is no ordering on it
(only on dates).
I would recommend updating the query to order by labelValue after
date, thereby fixing the result:
SELECT ?labelValue FROM :graphA FROM :graphB
WHERE { ?post :contains :givenTag .
?post :contains ?tag .
?tag :label ?labelValue .
?post :created ?date
}
ORDER BY DESC (?date) ?labelValue
LIMIT 10
Regards,
Paul
> Mirko wrote:
>>
>> Hi,
>> I wonder how to solve this. I have the following query:
>>
>> SELECT ?labelValue FROM :graphA FROM :graphB
>> WHERE { ?post :contains :givenTag .
>> ?post :contains ?tag .
>> ?tag :label ?labelValue .
>> ?post :created ?date
>> }
>> ORDER BY DESC (?date)
>> LIMIT 10
>>
>> Now, I would like to have only distinct ?labelValues as results.
>> Unfortunately, in my case SELECT DISTINCT messes up the order when selecting
>> from several graphs.
>>
>> How could I make the results (?labelValue) of the above query distinct
>> while keeping the order?
>>
>> Thanks,
>> Mirko
>>
>>
>
>
Received on Saturday, 12 September 2009 03:28:31 UTC