One of the most mindboggling values in the Oracle database is the NULL value. In the one before it, it was possible to convert 2 to a varchar2 value.
This chapter explores the first two types and shows you how they can be nested inside one another. LAB OBJECTIVES After completing this lab, you will be able to An IF statement has two forms: IF-THEN and IF-THEN-ELSE.
An IF-THEN statement allows you to specify only one group of actions to take.
Syntax: If expr1 contains a NULL value, then return expr3.
If the value of expr1 contains a non-NULL value, then return expr2.
The difference between reserved words and keywords is that you cannot use reserved words as identifiers.