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.