Hi,
Consider the following example.
I have a querystring = "select ?customerName where {?customerName
ns:purchased "AndroidPhone"^^xsd:String}"
Query = QueryFactory.create(queryString);
qexec = QueryExecutionFactory.create(queryString, model)
// assume model is defined previously
*resultSet = qexec.execSelect();*
As a result of execution, answer will be stored in resultSet. Question that
I am trying to answer is, after calling execSelect() function (which means
the given query graph or query algebra would be generated and is going to
be executed against dataset to fetch answer). Is it possible to change the
query. i.e say "customerName" is to "customer" (before generation of query
algebra or query graph) and then allow engine to generate query algebra for
the same and let it get executed.
- Ankur Padia.
On Tue, Feb 18, 2014 at 4:24 PM, Andy Seaborne <[email protected]> wrote:
> On 18/02/14 10:02, Ankur Padia wrote:
>
>> Hello everyone,
>>
>>
> What are you trying to do? A concrete example would help.
>
> I am new to ARQ (SPARQL Engine) of Jena. I wanted to know is it
>> possible to manipulate the subject or object part of the triple after
>> calling execute function (e.g. execSelect) and before getting result.
>>
>
> If you just want to modify the results, then write a ResultSet
> implementation that takes the underlying one and rewrites the part of
> result row each time.
>
> You could intercept the execution of the query either at the algebra or
> evaluation changes
>
> http://jena.apache.org/documentation/query/algebra.html
> http://jena.apache.org/documentation/query/arq-query-eval.html
>
> Depending on what you are trying to do, that may be a somewhat complicated
> way to go about it.
>
> Andy
>
> Moreover, is there any documentation that describes query life cycle i.e
>> form the query string how each part of the query is handled.
>>
>> Thanking you, in advance.
>>
>> - Ankur Padia.
>>
>>
>
