## With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

No credit card required

## Lab Objectives

After this Lab, you will be able to:

The NULLIF and COALESCE functions are defined by the ANSI 1999 standard to be “CASE abbreviations.” Both functions can be used as a variety of the CASE expression.

#### NULLIF Function

The NULLIF function compares two expressions. If they are equal, then the function returns NULL; otherwise, it returns the value of the first expression. The NULLIF has the following structure:

`NULLIF (expression1, expression2) `

If expression1 is equal to expression2, then NULLIF returns NULL. If expression1 does not equal expression2, NULLIF returns expression1. Note that the NULLIF function does the opposite of the NVL ...

## With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

No credit card required