The WHILE statement is another mechanism to loop over a set of statements until a condition is true.
[begin_label:] WHILE search_condition DO
statement_list
END WHILE [end_label]
mysql>
mysql> DELIMITER //
mysql> CREATE FUNCTION myFunction (quantity INT(10)) RETURNS INT(10)
-> BEGIN
->
-> WHILE quantity MOD 12 > 0 DO
-> SET quantity = quantity + 1;
-> END WHILE;
->
-> RETURN quantity;
->
-> END
-> //
Query OK, 0 rows affected (0.00 sec)
mysql> DELIMITER ;
mysql>
mysql> select myFunction(10);
+----------------+
| myFunction(10) |
+----------------+
| 12 |
+----------------+
1 row in set (0.00 sec)
mysql>
mysql> select myFunction(24);
+----------------+
| myFunction(24) |
+----------------+
| 24 |
+----------------+
1 row in set (0.00 sec)
mysql>
mysql> drop function myFunction;
Query OK, 0 rows affected (0.00 sec)
mysql>