Re: [dotNetRDF-Develop] FROM and FROM NAMED

[Rob V. <rv...@do...>]

Wadea

It is helpful if you provide a complete example of what you have tried -
query, data and code - as otherwise we can only guess at what may/may not be
wrong.

FROM and FROM NAMED by themselves only set the graphs that different parts
of the query will operate over.  You still need to have the rest of the
query be valid with respect to those graphs, in particular as Tom already
noted you may need to be using GRAPH clauses for some/all of your query

Finally it is also important to understand that FROM and FROM NAMED refer to
the dataset you are querying, they do not automatically pull in external
graphs (from files or the web) so any graphs you mention with a FROM/FROM
NAMED must actually be in the dataset you are querying.

>From your question you sound like you are hoping dotNetRDF will do this for
you which is not the default behaviour, however you can use the
DiskDemandTripleStore/WebDemandTripleStore if you wish to create a dataset
that will automatically resolve graphs that aren't already in-memory.

Rob

From:  Tomasz Pluskiewicz <tom...@gm...>
Reply-To:  dotNetRDF Developer Discussion and Feature Request
<dot...@li...>
Date:  Thursday, 4 December 2014 10:26
To:  dotNetRDF Developer Discussion and Feature Request
<dot...@li...>
Subject:  Re: [dotNetRDF-Develop] FROM and FROM NAMED

> Hi Wadea
> 
> I understand that you should use GRAPH patterns to determine what graphs to
> query.
> 
> For example
> 
> SELECT *
> WHERE
> {
>    GRAPH ?g
>    {
>       // patterns
>    }
> }
> 
> This way you can then narrow down the ?g by using it in further filters or
> graph patterns. Does this help?
> 
> Regards,
> Tom
> 
> December 4 2014 10:39 AM, "Wadea Hijjawi" <csw...@gm...
> <mailto:%22Wadea%20Hijjawi%22%20%3Cc...@gm...%3E> > wrote:
>>  
>> 
>> Dear Sir/Madam
>> I have developed a SPARQL endpoint using dotnetrdf library ,  it works
>> perfect when choosing an external file (Turtle file)
>> but when try to execute query that have already "FROM" or "FROM NAMED" clause
>> it is return an empty result
>>  
>> is there an example (sample code) to use this library when we want to depend
>> on query itself to determine default and named graph?
>>  
>> thank you a lot 
>>  
>> -- 
>>  
>> 
>> Wadea Asad Hijjawi
>> 
>> ASP.NET <http://asp.net/>  & Oracle DB Developer
>> 
>> Civil Service  Bureau
>> 
>>  
>> 
>> 06-5604181  Ext:289
>> 
>>  
>> 
>>  
>> 
>>  
>> 
>>  
>> 
>>  
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