- From: Richard Newman <r.newman@reading.ac.uk>
- Date: Sat, 11 Nov 2006 13:09:15 -0800
- To: "Adrian Walker" <adriandwalker@gmail.com>
- Cc: Richard Cyganiak <richard@cyganiak.de>, SW-forum list <semantic-web@w3.org>
- Message-Id: <0ABF0936-EB17-49B3-B59F-511415737391@reading.ac.uk>
(Assuming you mean this Richard, rather than Richard Cyganiak.) A first stab: Q1: Select names of authors who have not authored ex:thePublicationWeAreConsidering: PREFIX ex: <http://example.com/> SELECT DISTINCT ?name WHERE { ?author ex:hasName ?name . OPTIONAL { ?pub ex:hasAuthor ?author . } FILTER (!bound(?pub) || (?pub != ex:thePublicationWeAreConsidering)) } Q2 I would perform by two queries: SELECT DISTINCT ?pub { ?pub ex:associatedWith ex:fu-berlin . } SELECT DISTINCT ?name { ?author ex:authored <...> . # for each publication ?author ex:hasName ?name . } but there may be a way to do it through multiple nested optionals. SPARQL is not the best tool for every job. -R On 11 Nov 2006, at 12:26 PM, Adrian Walker wrote: > Hi Richard -- > > Actually, the question is a more general one about closed world > negation, universal quantifiers, and sparql. > > So, how would you express in sparql Q1 and Q2 generalized by > dropping the author affiliation "fu-berlin" part? > > Thanks, -- Adrian > > Internet Business Logic (R) > Executable open vocabulary English > Online at www.reengineeringllc.com > Shared use is free > > Adrian Walker > Reengineering > Phone: USA 860 830 2085 > > > > On 11/11/06, Richard Cyganiak <richard@cyganiak.de> wrote: > > On 11 Nov 2006, at 20:00, Richard Newman wrote: > >> So I'm wondering please whether it is possible to write in sparql > >> queries equivalent to > >> > >> Q1 show me the name of a person who is missing from the list > >> of authors of a publication from fu-berlin > >> > >> Q2 show me the names of people who are on the list of > >> authors of every publication from fu-berlin > >> > >> Thanks for your thoughts about this, in particular, actual sparql > >> queries. > >> > >> -- > >> Adrian > >> > > > > I'll allow Chris to provide some real queries, as I'm unfamiliar > > with the details of the ontology. > > Unfortunately the original DBLP dataset does not contain author > affiliations. Therefore we can't answer this kind of query. > > Richard > > > > > > > -R > > > > > >
Received on Saturday, 11 November 2006 21:09:34 UTC