Re: SPARQL Grammar updated

On 26/04/2010 10:45 AM, Steve Harris wrote:
> On 2010-04-25, at 18:11, Andy Seaborne wrote:
>> * GROUP_CONCAT(?x,?y ; SEPARATOR=";")
>> At F2F3, we converged on this named parameters form of GROUP_CONCAT.  I suggested a uniform treatment with params available in custom aggregates. However, having tried this, I found it leads to complexity without obvious benefit.
>> Question:
>> Is this legal:
>>   GROUP_CONCAT(?x,?y ; SEPARATOR=?sep)
>> where ?sep is some in-scope variable?  For now, I've made the separator a fixed string depending clarification.
> I think constants only is a good idea. As I mentioned at the F2F, it otherwise raises a host of issues around grouped v's non-grouped values.

I'm happy to leave it as a fixed string.

> As everything after the ; is passed directly to the set function, that expression must either be GROUP BY ?sep, or it would have to be SAMPLE(?sep), or similar, and I don't really want to go there.

It could be made to work by requiring ?sep to be a variable in the group 
key (related to what is legal to project).


Received on Thursday, 29 April 2010 19:09:21 UTC