> -----Original Message-----
> From:
public-rdf-dawg-comments-request@... [mailto:public-rdf-dawg-
>
comments-request@...] On Behalf Of Arjohn Kampman
> Sent: 30 October 2009 14:17
> To:
public-rdf-dawg-comments@...
> 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
