good afternoon;

> On 2015-07-26, at 18:46, Nauman Ramzan <[email protected]> wrote:
> 
> Dear James Anderson !
> Its a great favour from you. Thank you very much.
> 
> How can I get oid of that offer which have minimum price / at-least one
> offer id per product?
> 
> Thank you again.

in case one wonders, as i am mostly at a loss when it comes to divining the 
consequences of a query with no insight into the dataset, i invited nauman here:

   
http://dydra.com/nauman/question-prod-offers/@query#grouped-as-sub-select-of-sums
 
<http://dydra.com/nauman/question-prod-offers/@query#grouped-as-sub-select-of-sums>

and worked through several queries to illustrate to him, how a subselect and an 
aggregate work.


> 
> Regards
> Nauman
> 
> On Sun, Jul 26, 2015 at 3:35 PM, buehmann <
> [email protected]> wrote:
> 
>> You still don't get the usage of GROUP BY in SPARQL I guess.
>> You have to return the ?pid variable not only GROUP BY it. The reason is
>> that the ?pid has to be projected to the outer query.
>> 
>> And once you use GROUP BY, you can only return aggregates (min, max, etc)
>> or variables that you're grouping by. That means, you have also to group by
>> the ?condition variable.
>> 
>> Lorenz
>> 
>> 
>> […]

best regards, from berlin,




---
james anderson | [email protected] | http://dydra.com





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