使用存储过程，将汉字转换为拼音

代码如下：

CREATE FUNCTION `to_pinyin`(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, pin_yin_)
                INTO mypy
                FROM t_base_pinyin
                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