Quote Originally Posted by JeenLeen View Post
The half of my output that was deleted were statistics not related to Grade, so the Grade column was null. And null is less than 0 according to the programming language's logic.
Weird logic in whatever language you're using, that--in SQL server, at any rate, NULL is explicitly not equivalent to *any* value; this is why you can't find all the NULL values in a list using something like SELECT * FROM list WHERE column = NULL, because the "column = NULL" will never be true even if the value in the column is actually NULL. (You would have to use IS NULL instead of the direct equals statement).