Thanks!
Peter ----- Original Message ---- > From: Ivan Mikhailov <imikhai...@openlinksw.com> > To: Peter Ansell <p_ans...@yahoo.com> > Cc: Virtuoso Users List <virtuoso-users@lists.sourceforge.net> > Sent: Tuesday, 25 November, 2008 2:36:55 AM > Subject: Re: [Virtuoso-users] query about sparql optional semantics > > Hello Peter, > > Yes this is a bug and I hope to fix it soon. > > Best Regards, > > Ivan Mikhailov > OpenLink Software > http://virtuoso.openlinksw.com > > On Sun, 2008-11-23 at 21:06 -0800, Peter Ansell wrote: > > Hi all, > > > > I am not an expert of the semantics of how OPTIONAL works in SPARQL but I > > am a > little surprised at some results I am getting. I am executing the following > queries on a copy of the database which is normally at > http://go.bio2rdf.org/sparql although it is down at the moment. > > > > No results query: > > > > SELECT * WHERE { GRAPH { OPTIONAL { > > ?label . } OPTIONAL { > ?title . } OPTIONAL { > ?goName } > } } > > > > Results query: > > > > SELECT * WHERE { GRAPH { OPTIONAL { > ?goName } > } } > > > > The only difference between the queries is that I take out two of the > > optional > statements and it returns the result which should have matched in the first > one... Or am I doing something wrong? > > > > For reference, I am trying to efficiently seek a label for a given item > without knowing beforehand which predicate will be there, as the subject URI > is > generated from a query on the bio2rdf software which in turn generates the > SPARQL query (I am actually using a CONSTRUCT internally but the behaviour is > the same as the SELECT) > > > > Cheers, > > > > Peter > > > > > > > > Start your day with Yahoo!7 and win a Sony Bravia TV. Enter now > http://au.docs.yahoo.com/homepageset/?p1=other&p2=au&p3=tagline > > > > ------------------------------------------------------------------------- > > This SF.Net email is sponsored by the Moblin Your Move Developer's challenge > > Build the coolest Linux based applications with Moblin SDK & win great > > prizes > > Grand prize is a trip for two to an Open Source event anywhere in the world > > http://moblin-contest.org/redirect.php?banner_id=100&url=/ > > _______________________________________________ > > Virtuoso-users mailing list > > Virtuoso-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/virtuoso-users Start your day with Yahoo!7 and win a Sony Bravia TV. Enter now http://au.docs.yahoo.com/homepageset/?p1=other&p2=au&p3=tagline
