PL/SQL Flow Control

Flow control allows the sequence of execution to be altered by some condition, usually an IF statement, and all programming languages implement flow control.  In this chapter we discuss PL/SQL’s implementation of flow control, focusing on the various IF/THEN  conditional statements, followed by the various loop implementations. 

In a nutshell, flow control allows the programmer to check a condition, and decide which path the program will take through the code.  The condition checked is a Boolean (returning either “true” or “false”).  Any PL/SQL evaluation, function, or compound statement can be used in the check condition as long as the result is a Boolean true/false result.  In PL/SQL the condition evaluation can be enclosed in parentheses for clarity but that is not a requirement.  Let’s take a closer look.