mysql某列递增的存储过程

DELIMITER $$

USE `test`$$

DROP PROCEDURE IF EXISTS `ins`$$

CREATE DEFINER=`root`@`localhost` PROCEDURE `ins`()
BEGIN
    DECLARE i INT;
    SET @i=1;
    UPDATE student SET id=CONCAT("S20130521",CONCAT(@i:=@i+1,"")) WHERE id="";
    END$$

DELIMITER ;