I'm trying to put together a summary page for a db a customer has, and I'm trying to simply use SUM() to add up the fields as follows:SELECT SUM(CONVERT(numeric, ISNULL(Planned, 0))) AS Planned ...

Add SQL’s Not operator to find values that aren’t Null. Using Northwind, the sample database that comes with Access, I will create a few queries to illustrate using Is Null and Is Not Null.

When you use IN, you’re telling SQL to take a value and compare it against every value or set of values in a list using =. If any NULL values exist, a row will not be returned–even if both ...

Null means "undefined" in SQL, so numerous online services don't think Christopher Null exists. ... "Allowing NULL values makes you work extra hard to get the kind of data you are looking for.