> So, in some cases (explicite addition), NULL + 0 = NULL. (we all know > that NULL != NULL). However, the "sum" function skips NULLs. This > seems inconsistant.
NULL + 0 is not valid since you can't do a binary operation on only one number (zero is a number, NULL is not). So it returns an appropriate result when you ask it to do something it can't do. I understand the rational for "NULL + anything" returning NULL (makes > sense mathematically). I understand the utility of having "sum" skip > NULLs. However, we can now construct a math in the sql engine where > a+b+c != a+b+c. Yucky. > Only where one of the variables is different than the other side of the equation. --- The Castles of Dereth Calendar: a tour of the art and architecture of Asheron's Call http://www.lulu.com/content/77264
