John Sterrett walks through one of the most important set operators:
Selecting the two tables is easy if we know what change occurred and there aren’t many changes. This can get complicated quickly. Therefore, if we just want to quickly know if we have differences lets take a look at my goto method using EXCEPT. To make this example easier to read instead of using “SELECT *” I will just focus on columns that are changing. In a real example, I would want to know if any columns changed.
One of the nicest things about set comparison operators is that they innately understand the concept of NULL.