Presumably you realise i mean 0, but have a reason for thinking null is more appropriate? More precisely in my mind it ought to be 0 in the type of the expression being summed.
It makes sense from a 'business' perspective. The combined weight of 0 items would be 0. It would be consistent with the arithmetic in expressions, where adding null results in a null. Consider you have two tables of similar things, apples and oranges, but wanted to know the combined weight. At one moment there are no oranges. sum(apples) = x sum(oranges) = null/0 sum(apples) + sum(oranges) = null/x blah blah ... something induction and base cases ... blah On Tue, Feb 3, 2009 at 11:12 PM, Thomas Kellerer < [email protected]> wrote: > > On 2 Feb., 19:36, Mike Goodwin <[email protected]> wrote: > > It surprised me that the sum over 0 rows comes to null and not zero. > > So what is the sum of "nothing"? > > DROP TABLE IF EXISTS x; > CREATE TABLE x (val INTEGER); > INSERT INTO x values (null); > SELECT sum(val) FROM x; > > also returns null. > > > > > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "H2 Database" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/h2-database?hl=en -~----------~----~----~----~------~----~------~--~---
