mysql创建、查询function

show function status;
show create function  get_spell;

mysql> show variables like '%func%'; 
+---------------------------------+-------+
| Variable_name                   | Value |
+---------------------------------+-------+
| log_bin_trust_function_creators | OFF   |
+---------------------------------+-------+

 set global log_bin_trust_function_creators=1; 

delimiter $$
CREATE DEFINER=`root`@`%` FUNCTION `get_spell`(NAME VARCHAR(255) CHARSET gbk) RETURNS varchar(255) CHARSET gbk
BEGIN
    DECLARE mycode INT;
    DECLARE tmp_lcode VARCHAR(2) CHARSET gbk;
    DECLARE lcode INT;
     DECLARE tmp_rcode VARCHAR(2) CHARSET gbk;
    DECLARE rcode INT;
     DECLARE mypy VARCHAR(255) CHARSET gbk DEFAULT '';
    DECLARE lp INT;
     SET mycode = 0;
    SET lp = 1;
     SET NAME = HEX(NAME);
     WHILE lp < LENGTH(NAME) DO
         SET tmp_lcode = SUBSTRING(NAME, lp, 2);
        SET lcode = CAST(ASCII(UNHEX(tmp_lcode)) AS UNSIGNED);
        SET tmp_rcode = SUBSTRING(NAME, lp + 2, 2);
        SET rcode = CAST(ASCII(UNHEX(tmp_rcode)) AS UNSIGNED);
        IF lcode > 128 THEN
            SET mycode =65536 - lcode * 256 - rcode ;
            SELECT CONCAT(mypy,spell) INTO mypy FROM base_spell_code WHERE CODE >= ABS(mycode) ORDER BY CODE ASC LIMIT 1;
            SET lp = lp + 4;
        ELSE
            SET mypy = CONCAT(mypy,CHAR(CAST(ASCII(UNHEX(SUBSTRING(NAME, lp, 2))) AS UNSIGNED)));
            SET lp = lp + 2;
        END IF;
    END WHILE;
    RETURN LOWER(mypy);
END $$
delimiter ;

参考：

http://my.oschina.net/u/1273696/blog/181995
http://blog.csdn.net/god123209/article/details/7577138