DROP PROCEDURE IF EXISTS add_migration;
delimiter ??
CREATE PROCEDURE `add_migration`()
BEGIN
DECLARE v INT DEFAULT 1;
SET v = (SELECT COUNT(*) FROM `migrations` WHERE `id`='20171111071007');
IF v=0 THEN
INSERT INTO `migrations` VALUES ('20171111071007');
-- Add your query below.

-- Required event for Ahn'Qiraj entry (negative -> event must not be active)
UPDATE `areatrigger_teleport` SET `required_event` = -83 WHERE `id` IN (4008, 4010);

-- End of migration.
END IF;
END??
delimiter ; 
CALL add_migration();
DROP PROCEDURE IF EXISTS add_migration;