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From Reto Bachmann-Gmür <r...@apache.org>
Subject Re: extend ResultSet with ResultSetMetaData
Date Fri, 29 Mar 2013 19:37:33 GMT
Sounds convincing. But maybe wait a few weeks till we have the
fastlane and sparql 1.1 stuff in place as.

Cheers,
Reto

On Tue, Mar 19, 2013 at 4:29 PM, Minto van der Sluis <minto@xup.nl> wrote:
> Hi Reto,
>
> Let me put it differently. If Clerezza is complient with [1] or [2] what
> would the response look like if the query has no results? In particular
> the head [3] section.  IMO this section can not be constructed without
> meta data as there are no results to derive the information from.
> Looking at the code for ResultSetMessageBodyWriter I think it will even
> NPE in the method createVariable if a no entries ResultSet is supplied.
>
> On the other hand Apache Jena has a ResultSet with metadata. This class
> contains the following method.
>
>     public List<String> getResultVars() ;
>
> Regards,
>
> Minto
>
> [1] http://www.w3.org/TR/rdf-sparql-XMLres/
> [2] http://www.w3.org/TR/rdf-sparql-json-res/
> [3] http://www.w3.org/TR/rdf-sparql-XMLres/#head
>
> Op 19-3-2013 15:33, Reto Bachmann-Gmür schreef:
>> Hi Minto
>>
>> If I'm not mistaken the situation for SQL is a bit different as the
>> metadata of the result cannot be infered from the query. With Sparql I
>> don't see how this metadata would be dependent on the actual result.
>>
>> Maybe Hasan can tell more about this.
>>
>> Cheers,
>> Reto
>>
>> On Mon, Mar 18, 2013 at 10:19 PM, Minto van der Sluis <minto@xup.nl> wrote:
>>
>>> Hi folks,
>>>
>>> Is it feasible to extend the current sparqle ResultSet with an interface
>>> to extract metadata without consuming the resultset. I was thinking of
>>> something like java.sql.ResultSetMetaData.
>>>
>>> Why?
>>> I've created sort of a decorator to show some metadata of a ResultSet
>>> and I had to consume the resultset to find out which columns were there.
>>> However the current situation allows to consume the ResultSet only once.
>>>
>>> It probably is feasible. The question is more like, if I create a patch
>>> will it be accepted?
>>>
>>> Regards,
>>>
>>> Minto
>>>
>>> --
>>> ir. ing. Minto van der Sluis
>>> Software innovator / renovator
>>> Xup BV
>>>
>>>
>
>
> --
> ir. ing. Minto van der Sluis
> Software innovator / renovator
> Xup BV
>
> Mobiel: +31 (0) 626 014541
>

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