On Thu, 8 Sep 2005, Marcus Welz wrote: > Yes, the NULL as it is returned by SUM means "No data to answer your > question". > > If that query returned 0 (as SQLite currently does), rather than NULL (as > the standard specifies), it would not allow me to figure out whether I sold > $0 worth of items or if I didn't sell anything at all.
Exactly! I was reading through the thread wondering when this point would be made (and getting ready to make it myself.) The SUM() of non-NULL values can be 0! If SQL(ite) would return 0 for all NULL input there would be no way do make the distiction between a SUM() that's 0 and 'no data to be summed'. Which can be an important distinction. Please! Make SQLite return NULL for all NULL input. I totally agree that null handeling seems/is inconsistent as hell at times... It seems hackish here and there. Which, IMHO, is the ALL THE REASON jou need to to just follow the standard! Rgds, Mark. > -----Original Message----- > From: Puneet Kishor [mailto:[EMAIL PROTECTED] > Sent: Thursday, September 08, 2005 6:50 PM > To: sqlite-users@sqlite.org > Subject: Re: [sqlite] SUM and NULL values > > > On Sep 8, 2005, at 5:45 PM, Marcus Welz wrote: > > > If "SELECT SUM(amt)" means "How much did I sell?" > > > > Then the "NULL" should mean, "You didn't sell anything.", no? > > > > no... NULL means, "I don't have any data to answer that question" which > is very different from "I sold $0 worth of things" or "I didn't sell > anything." > > -- > Puneet Kishor > > Regards, Mark
