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Re: graph keyword and exists and scope

From: james anderson <james@dydra.com>
Date: Fri, 17 Jun 2016 19:36:30 +0000
Message-ID: <010201555fdd5d2d-fe3fe69b-44ea-425b-95c8-f4183682d0af-000000@eu-west-1.amazonses.com>
To: public-sparql-dev@w3.org

> On 2016-06-17, at 21:10, Jeremy J Carroll <jjc@syapse.com> wrote:
> 
> Given the interesting conversation about EXISTS, I have a slightly related question
> 
> 
>  select *
> { graph <eg:graph> {
>       ?s <eg:b> ?o
>       FILTER EXISTS {
>           ?s <eg:c> ?o
>      }
>  }
> }
> 
> 
> is the <eg:c> matched against the default graph or <eg:graph>?

given the definitions in the recommendation, {?s <eg:c> ?o } should apply to the given graph.

while the definition does not take the trouble to describe the meaning specific to forms, i have understood only 
- {graph <x>  {graph <y> … } } to limit the scope
- {graph ?x … } to have scope limited by projection which did not include ?x
- {graph ?? { service … } } to limit scope

where, for the service case, i am ambivalent.

> 
> I sometimes get results for this sort of query that surprise me, and so I tend to explicitly repeat the graph scope.

best regards, from berlin,
---
james anderson | james@dydra.com | http://dydra.com
Received on Friday, 17 June 2016 19:37:01 UTC

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