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.

By understanding the difference between IN, EXISTS, NOT IN, and NOT EXISTS, you can avoid a very common problem when NULLs appear in the data of a subquery. Scott Stephens helps you understand ...

For example, NOT NULL assigned to the field CUSTOMER in the table SASDEMO.CUSTOMER does not allow a row to be added unless there is a value for CUSTOMER. Columns can also be defined as NOT NULL WITH ...

For example, Ben Nadel, co-founder and lead engineer at InVision App, who is an expert in Adobe's ColdFusion web app server platform, states that null values should absolutely not be used in ...