PL/SQL If
PL/SQL If
PL/SQL supports the programming language features like conditional statements and iterative statements. Its programming constructs are similar to how you use in programming languages like Java and C++.
Syntax for IF Statement:
There are different syntaxes for the IF-THEN-ELSE statement.
Syntax: (IF-THEN statement):
- IF condition
- THEN
- Statement: {It is executed when condition is true}
- END IF;
This syntax is used when you want to execute statements only when condition is TRUE.
Syntax: (IF-THEN-ELSE statement):
- IF condition
- THEN
- {...statements to execute when condition is TRUE...}
- ELSE
- {...statements to execute when condition is FALSE...}
- END IF;
This syntax is used when you want to execute one set of statements when condition is TRUE or a different set of statements when condition is FALSE.
Syntax: (IF-THEN-ELSIF statement):
- IF condition1
- THEN
- {...statements to execute when condition1 is TRUE...}
- ELSIF condition2
- THEN
- {...statements to execute when condition2 is TRUE...}
- END IF;
This syntax is used when you want to execute one set of statements when condition1 is TRUE or a different set of statements when condition2 is TRUE.
Syntax: (IF-THEN-ELSIF-ELSE statement):
- IF condition1
- THEN
- {...statements to execute when condition1 is TRUE...}
- ELSIF condition2
- THEN
- {...statements to execute when condition2 is TRUE...}
- ELSE
- {...statements to execute when both condition1 and condition2 are FALSE...}
- END IF;
It is the most advance syntax and used if you want to execute one set of statements when condition1 is TRUE, a different set of statement when condition2 is TRUE or a different set of statements when both the condition1 and condition2 are FALSE.
When a condition is found to be TRUE, the IF-THEN-ELSE statement will execute the corresponding code and not check the conditions any further.
If there no condition is met, the ELSE portion of the IF-THEN-ELSE statement will be executed.
ELSIF and ELSE portions are optional.
Example of PL/SQL If Statement
Let's take an example to see the whole concept:
DECLARE
a number(3) := 500;
BEGIN
-- check the boolean condition using if statement
IF( a < 20 ) THEN
-- if condition is true then print the following
dbms_output.put_line('a is less than 20 ' );
ELSE
dbms_output.put_line('a is not less than 20 ' );
END IF;
dbms_output.put_line('value of a is : ' || a);
END;
After the execution of the above code in SQL prompt, you will get the following result:
a is not less than 20 value of a is : 500 PL/SQL procedure successfully completed.
