Hello,
Sorry for not being more specific.
I am trying to get all the ?s and ?p that has for instance "Emri" as object.
Then I want to use the above value of ?s, change the value of the predicate to
<http://www.w3.org/TR/html4/Class1> and get all the objects with that match.
The problem is that when I query just
?s ?p ?attr .
FILTER regex(?attr , "Emri").
-----I get the three results, one of them is:
_:b0
<http://www.w3.org/TR/html4/Name>
"Emri"
----------------
When I query just for:
_:b0 <http://www.w3.org/TR/html4/Class1> ?class .
----I get many objects as result.
But, then I try this:
?s ?p ?attr .
FILTER regex(?attr , "Emri") .
?s <http://www.w3.org/TR/html4/Class1> ?class .
then I get no matches? Is there maybe because there are three subjects returned
from the first query(?s ?p ?attr .), or can I not change the value of the
predicate on the second query after it has been initialized from the first one.
Thanks a lot for your help.
On 2021/04/01 05:57:41, Lorenz Buehmann <buehm...@informatik.uni-leipzig.de>
wrote:
> without showing the data impossible to help, sorry. I mean, in the end
> the query has to match the data, but we only know the query know - so
> how can we help here?
>
> One possible error is the triple pattern
>
> ?s <http://www.w3.org/TR/html4/Class1> ?class .
>
>
> what is the idea behind this? Is there really a property <Class1> in the
> data? If not and if you want to get an instance of the Class <Class1>
> you have to use
>
> ?s a <http://www.w3.org/TR/html4/Class1> .
>
> On 31.03.21 16:12, emri mbiemri wrote:
> > Dear all,
> >
> > I am trying to query something from an RDF/XML file with SPARQL but when I
> > try queries like this:
> >
> > SELECT DISTINCT ?class
> > WHERE {
> >
> > ?s ?p ?attr .
> > FILTER regex(?attr , "Emri") .
> > ?s <http://www.w3.org/TR/html4/Class1> ?class .
> >
> > it should after the FILTER command initialize ?s = _:b0 , but it doesn't?
> >
> > Hope for any support.
>
