DELIMITER $$
DROP PROCEDURE IF EXISTS `world`.`UNBOUND_DEMO` $$
CREATE DEFINER=`tusa`@`%` PROCEDURE `UNBOUND_DEMO`(districtName VARCHAR(35))
BEGIN
SELECT ID, Name, CountryCode,District,Population FROM City where District=districtName order by Name;
Select ID, Name, CountryCode,District,Population FROM City
WHERE District=districtName AND Population = (Select MAX(Population) from city where District=districtName );
END $$
DELIMITER ;
tusa@localhost:3306 [world]> CALL UNBOUND_DEMO('Lombardia');
+------+---------+-------------+-----------+------------+
| ID | Name | CountryCode | District | Population |
+------+---------+-------------+-----------+------------+
| 1497 | Bergamo | ITA | Lombardia | 117837 |
| 1480 | Brescia | ITA | Lombardia | 191317 |
| 1465 | Milano | ITA | Lombardia | 1300977 |
| 1496 | Monza | ITA | Lombardia | 119516 |
+------+---------+-------------+-----------+------------+
4 rows in set (0.00 sec)
+------+--------+-------------+-----------+------------+
| ID | Name | CountryCode | District | Population |
+------+--------+-------------+-----------+------------+
| 1465 | Milano | ITA | Lombardia | 1300977 |
+------+--------+-------------+-----------+------------+