Oracle and PL/SQL Recipes: A Problem-Solution Approach

3-2. Choosing Between Two Mutually Exclusive Conditions

Problem

You have two conditions that are mutually exclusive. You want to execute one set of statements if the first condition evaluates to TRUE. Otherwise, if the first condition is FALSE or NULL, then execute a different set of statements.

Solution

Use an IF-ELSE statement to evaluate the condition and execute the statements that correspond to it if the condition evaluates to TRUE. In the following example, a given employee ID is used to query the EMPLOYEES table. If that employee exists, then the employee record will be retrieved. If not found, then a message will be displayed stating that no match was found.

DECLARE   employee                employees%ROWTYPE;   emp_count               ...