On Mon, Mar 28, 2016 at 6:02 PM Christopher Johnson < [email protected]> wrote:
> Hi, > > I have encountered a problem with federating Wikidata entities with LOD > based on the abundant external resource "literal identifiers" that are > represented in Wikidata. An external resource identifier should include > the entire IRI to the resource, not just the "id", otherwise the external > resource cannot be federated in a SPARQL query without concatenating the > IRI to the literal identifier and binding to a new variable. > > I think that Wikidata properties that expect explicit Identifiers in the > range should thus be defined as "object properties" rather than "datatype > properties". The javascript id linking gadget in the UI also typically > borks the link when a IRI is inputted as an identifier making it less > likely for people to do it properly. I assume that this is a "policy" that > was established for bot id imports, that unfortunately has produced a lot > of "not so useful" data. > > The triple pattern fragment implementation that I am working with does not > allow bind grouping in the sparql query, so this unfortunately makes > federation of Wikidata entities by Identifiers nearly impossible. Hence, > the only federation that I have been able to do effectively is "to" > Wikidata not "from" it.... > > If anyone is interested, I have setup Wikidata as a TPF datasource here: > http://orbeon-bb.wmflabs.org/wdqs-sparql The API works by passing an > encoded subject, predicate or object parameter like: > http://orbeon-bb.wmflabs.org/wdqs-sparql?object=%22Berlin%22%40de > That's being worked on with https://phabricator.wikimedia.org/T121274 and https://phabricator.wikimedia.org/T73992 and was one of the main reasons we introduced a new datatype for identifiers recently. Cheers Lydia -- Lydia Pintscher - http://about.me/lydia.pintscher Product Manager for Wikidata Wikimedia Deutschland e.V. Tempelhofer Ufer 23-24 10963 Berlin www.wikimedia.de Wikimedia Deutschland - Gesellschaft zur Förderung Freien Wissens e. V. Eingetragen im Vereinsregister des Amtsgerichts Berlin-Charlottenburg unter der Nummer 23855 Nz. Als gemeinnützig anerkannt durch das Finanzamt für Körperschaften I Berlin, Steuernummer 27/029/42207.
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