Hello Alex,
On Fri, 2012-06-29 at 13:52 +0300, Alex wrote:
>
> select ?o from
> <http://www.heppnetz.de/ontologies/goodrelations/v1.owl> where{filter
> not exists{?o comment1212 ?x}}
>
>
> And I get a syntax error: Virtuoso 37000 Error SP030: SPARQL compiler,
> line 2: syntax error at 'comment1212' before '?x'. Not an internal
> error.
Indeed it's a syntax error to use "comment1212", i.e. neither
angle-bracketed URI like "<comment1212>" nor QName like
"prefix:comment1212" or ":comment1212" with proper prefix declaration.
Even if it's fixed, the query will return nothing because filtering can
only shorten the set of bindings and the set is initially empty because
there's no triple pattern that could produce a binding. Probably you
need something like
select distinct ?o ... where { ?s ?p ?o . filter not exists { ?o ... } }
Best Regards,
Ivan Mikhailov
OpenLink Software
http://virtuoso.openlinksw.com
