Use if statement with LOOP statement
Conditional if statements in SQL are used to perform different actions based on different conditions.
Understand with Example
The Tutorial illustrate a example from if statement with LOOP statement. In this example we create a procedure display that accept no as input parameter and data type is int. The Begin Statement include a declare keyword that define the variable and its data type. The if and else is used to execute the code if the condition is true or the condition is false.
Create Procedure
DELIMITER $$ DROP PROCEDURE IF EXISTS display$$ CREATE PROCEDURE display(no int) BEGIN DECLARE count INT DEFAULT 0; display: LOOP SET count=count+1; select count; IF count=no THEN LEAVE display; END IF; END LOOP display; END$$ DELIMITER ; |
Call Procedure
call display(5); |
Result
+-------+ | count | +-------+ | 1 | +-------+ 1 row in set (0.00 sec) +-------+ | count | +-------+ | 2 | +-------+ 1 row in set (0.01 sec) +-------+ | count | +-------+ | 3 | +-------+ 1 row in set (0.05 sec) +-------+ | count | +-------+ | 4 | +-------+ 1 row in set (0.05 sec) +-------+ | count | +-------+ | 5 | +-------+ 1 row in set (0.05 sec) |