Hi!
Thanks for your answer both! Yep, the problem was in the parenthesis. Sorry
if the message arrive twice to the mailing list, I had some problems with
the email!
Cheers
On 11 May 2014 18:27, Andy Seaborne <a...@apache.org> wrote:
> On 9 May 2014 11:38, Alejandro Rodríguez González
> <alejan...@alejandrorg.com> wrote:
> > Hi all,
> >
> > Maybe this question has been already answered or is in the documentation,
> > but I can't find an answer.
> >
> > I have a code to perform a set of SPARQL queries against a concrete
> > dataset. My problem is that, the SPARQL query is making use of datatype()
> > function, and it seems that Jena is not recognizing this function (and
> > therefore return me an error).
> >
> > The query that I want to perform is the following:
> >
> > *SELECT distinct datatype(?o) as ?datatype*
>
> The syntax is:
>
> SELECT distinct (datatype(?o) as ?datatype)
>
> The () are not to do with DISTINCT, they come from the AS part:
>
> (expression AS ?variable)
>
> > *FROM <@NAMED_GRAPH>*
> > *WHERE {*
> > * ?s a <@SUBJECT_TYPE> .*
> > *?s <@PREDICATE_TYPE> ?o . *
> > * FILTER isLiteral(?o)*
> > *}*
> > *group by ?o*
> >
> >
> > Originally it was "SELECT distinct(datatype(?o)) as ?datatype" but I saw
> > that distinct should be used without parenthesis. (I also try with
> "SELECT
> > distinct datatype ?o as..." with no positive result).
> >
> > An example of the query:
> >
> > SELECT distinct datatype(?o) as ?datatype
> > FROM <http://bio2rdf.org/bio2rdf.dataset:bio2rdf-affymetrix-20131220>
> > WHERE {
> > ?s a <http://bio2rdf.org/affymetrix_vocabulary:Genechip-Array> .
> > ?s <http://bio2rdf.org/affymetrix_vocabulary:x-unigene> ?o .
> > FILTER isLiteral(?o)
> > }
> > group by ?o
> >
> > If I perform the query against the endpoint (
> > http://s4.semanticscience.org:14001/sparql), it runs fine (in this case
> is
> > not returning any result, but no errors are thrown):
> >
> >
> http://s4.semanticscience.org:14001/sparql?default-graph-uri=&query=SELECT+distinct+datatype%28%3Fo%29+as+%3Fdatatype%0D%0AFROM+%3Chttp%3A%2F%2Fbio2rdf.org%2Fbio2rdf.dataset%3Abio2rdf-affymetrix-20131220%3E%0D%0AWHERE+%7B%0D%0A+%3Fs+a+%3Chttp%3A%2F%2Fbio2rdf.org%2Faffymetrix_vocabulary%3AGenechip-Array%3E+.%0D%0A%3Fs+%3Chttp%3A%2F%2Fbio2rdf.org%2Faffymetrix_vocabulary%3Ax-unigene%3E+%3Fo+.+++%0D%0A+FILTER+isLiteral%28%3Fo%29%0D%0A%7D%0D%0Agroup+by+%3Fo&format=text%2Fhtml&timeout=0&debug=on
> >
> > However, when I use my code (which generates the query ok, I check it
> > printing the query), it returns the following exception:
> > http://pastebin.com/qhzyxJKn
> >
> > The code which performs the query is here (the method which throws the
> > exception is the QueryFactory.create(..): http://pastebin.com/2VVgKyZT
> >
> > I guess that it is a problem "calling" datatype function, but not sure
> how
> > to solve it.
> >
> > Thanks!
> >
> > --
> > Dr. Alejandro Rodríguez González - PhD
> >
> > Bioinformatics at Centre for Plant Biotechnology and Genomics UPM-INIA
> > Polytechnic University of Madrid
> > http://www.alejandrorg.com
> > Phone: +34 914524900 . Ext: 25550
> >
> >
> > *Once the game is over, the king and the pawn go back in the same box. -
> > Italian proverb*
>
On 11 May 2014 18:20, james anderson <ja...@dydra.com> wrote:
> good evening dr rodriguez;
>
> On 11 May 2014, at 01:12, Alejandro Rodríguez González <
> alejandro.rod....@gmail.com> wrote:
>
> SELECT distinct datatype(?o) as ?datatype
> FROM <http://bio2rdf.org/bio2rdf.dataset:bio2rdf-affymetrix-20131220>
> WHERE {
> ?s a <http://bio2rdf.org/affymetrix_vocabulary:Genechip-Array> .
> ?s <http://bio2rdf.org/affymetrix_vocabulary:x-unigene> ?o .
> FILTER isLiteral(?o)
> }
> group by ?o
>
>
>
> note that, where you have indicated the “group by ?o”, you have specified
> an aggregation.
> of this aggregation, strictly speaking, the ?o in the projection clause
> should be used with the“sample” operator before it can be supplied to
> ‘datatype’.
> although, perhaps jena makes an exception here...
>
> best regards, from berlin,
>
>
>
> ---
> james anderson | ja...@dydra.com | http://dydra.com
>
--
Dr. Alejandro Rodríguez González - PhD
Bioinformatics at Centre for Plant Biotechnology and Genomics UPM-INIA
Polytechnic University of Madrid
http://www.alejandrorg.com
Phone: +34 914524900 . Ext: 25550
*Once the game is over, the king and the pawn go back in the same box. -
Italian proverb*
