IF-THEN-ELSE Statement

This MariaDB tutorial explains how to use the IF-THEN-ELSE statement in MariaDB with syntax and examples.

Description

In MariaDB, the IF-THEN-ELSE statement is used to execute code when a condition is TRUE, or execute different code if the condition evaluates to FALSE.

Syntax

The syntax for the IF-THEN-ELSE statement in MariaDB is:

IF condition1 THEN

   {...statements to execute when condition1 is TRUE...}

 

[ ELSEIF condition2 THEN

   {...statements to execute when condition2 is TRUE...} ]

 

[ ELSE

   {...statements to execute when both condition1 and condition2 are FALSE...} ]

 

END IF;

ELSEIF

Optional. You would use the ELSEIF condition when you want to execute a set of statements when a second condition (ie: condition2) is TRUE.

ELSE

Optional. You would use the ELSE condition when you want to execute a set of statements when none of the IF or ELSEIF conditions evaluated to TRUE.

Note

• Once a condition is found to be TRUE, the IF-THEN-ELSE statement will execute the corresponding code and not evaluate the conditions any further.
• If no condition is met, the ELSE portion of the IF-THEN-ELSE statement will be executed.
• It is important to note that the ELSEIF and ELSE portions are optional.

Example

The following is example using the IF-THEN-ELSE statement in a MariaDB function:

DELIMITER //

 

CREATE FUNCTION PageCount ( value INT )

RETURNS varchar(10) DETERMINISTIC

 

BEGIN

 

   DECLARE level varchar(20);

 

   IF value < 500 THEN

      SET level = 'Low';

 

   ELSEIF value >= 500 AND value <= 4000 THEN

      SET level = 'Medium';

 

   ELSE

      SET level = 'High';

 

   END IF;

 

   RETURN level;

 

END; //

 

DELIMITER ;

In this IF-THEN-ELSE statement example, we've created a function called PageCount. It has one parameter called value and it returns a varchar(10). The function will return the level based on the value.