- From: Andy Seaborne <andy.seaborne@talis.com>
- Date: Tue, 06 Apr 2010 09:07:39 +0100
- To: Steve Harris <steve.harris@garlik.com>
- CC: Lee Feigenbaum <lee@thefigtrees.net>, SPARQL Working Group <public-rdf-dawg@w3.org>
On 05/04/2010 10:16 PM, Steve Harris wrote: > On 2010-04-05, at 21:51, Lee Feigenbaum wrote: >>>> >>>> I wouldn't be in favor of this proposal - I'd find it very difficult to >>>> justify adding 2 forms of negation to SPARQL that seem virtually >>>> indistinguishable from one another in most scenarios. >>> >>> We are doing that under the F2F3 resolution (the second one) regardless >>> of my proposal and under the first proposal of the F2F, negation used >>> the syntax "NOT EXISTS". >> >> I believe that most of the user world would simply accept that the words used for negation as a graph pattern and negation in a filter are different. I don't think any such easy explanation can be given when both can be used as graph pattern keywords. > > Indeed, SQL has the MINUS table operation, and NOT EXISTS in the WHERE/FILTER operation as well. In SQL, MINUS goes outside SELECT, making it outside GROUP BY and separate from the join condition part of the SQL query. Andy
Received on Tuesday, 6 April 2010 08:08:11 UTC