- From: Steve Harris <steve.harris@garlik.com>
- Date: Wed, 18 Nov 2009 11:27:07 +0000
- To: Andy Seaborne <andy.seaborne@talis.com>
- Cc: SPARQL Working Group <public-rdf-dawg@w3.org>
On 17 Nov 2009, at 14:32, Andy Seaborne wrote: > We're mixing several things here: > > 1/ What happens with AS in SELECT when the expression evaluates to > an error. > 2/ What happens for aggregates of empty groups. > 3/ What happens with errors in the expression being aggregated. True. > Another design to consider, is (case 1) that > > error AS ?x > > leaves ?x unbound and (2) aggregates of empty sets are errors. > > We then have what aggregates do about errors in their aggregate > expression (case 3). Skip or error. I prefer skip because I want > SUM(xsd:integer(?x)) to return something. That more-or-less matches what MySQL does in this case, though it issues warnings when you have dodgy casts. SPARQL (and SQL as far as I know) has no concept of warnings though. Agreed that it would good for SUM(xsd:integer(?x)) to return something. - Steve -- Steve Harris, CTO, Garlik Limited 2 Sheen Road, Richmond, TW9 1AE, UK +44(0)20 8973 2465 http://www.garlik.com/ Registered in England and Wales 535 7233 VAT # 849 0517 11 Registered office: Thames House, Portsmouth Road, Esher, Surrey, KT10 9AD
Received on Wednesday, 18 November 2009 11:27:36 UTC