- From: Seaborne, Andy <andy.seaborne@hp.com>
- Date: Fri, 30 Oct 2009 15:33:48 +0000
- To: Arjohn Kampman <arjohn.kampman@aduna-software.com>, "public-rdf-dawg-comments@w3.org" <public-rdf-dawg-comments@w3.org>
> -----Original Message----- > From: public-rdf-dawg-comments-request@w3.org [mailto:public-rdf-dawg- > comments-request@w3.org] On Behalf Of Arjohn Kampman > Sent: 30 October 2009 14:17 > To: public-rdf-dawg-comments@w3.org > Subject: SPARQL 1.1: project expressions and type errors > > Dear WG, > > I was wondering how a SPARQL query engine should handle project > expressions that apply an operator to an incompatible argument. For > example with the following query with ?p bound to a URI: > > select ?s, datatype(?p) as ?q > where { ?s ?p ?o } > > I can think of two ways to handle this: > 1) Produce a solution with ?q unbound > 2) Do not produce solutions for these cases > > What would be the best way to handle this? Yes - this is one of issue that needs to be nailed down. We need to go for a consistent error handling approach with, say, aggregates. Another choice - fail the whole query - would seem out of keeping. For me, your choice (2) accords closely with errors in FILTERs. Andy > > Regards, > > -- > Arjohn Kampman, Senior Software Engineer > Aduna - Semantic Power > www.aduna-software.com
Received on Friday, 30 October 2009 15:35:20 UTC