MYSQL 传汉字获取拼音首字母

CREATE DEFINER=`by`@`%` FUNCTION `fun_pinyin`(`P_NAME` VARCHAR(255)) RETURNS varchar(255) CHARSET utf8
    NO SQL
BEGIN
    DECLARE V_COMPARE VARCHAR(255);
    DECLARE V_RETURN VARCHAR(255);
    DECLARE I INT;
    SET I = 1;
    SET V_RETURN = '';
    while I <= char_length(P_NAME) do
        SET V_COMPARE = SUBSTR(P_NAME, I, 1);
        IF (V_COMPARE != '') THEN
            SET V_RETURN = CONCAT(V_RETURN, fun_first_pinyin(V_COMPARE));
        END IF;
        SET I = I + 1;
    end while;
    IF (ISNULL(V_RETURN) or V_RETURN = '') THEN
        SET V_RETURN = P_NAME;
    END IF;
    RETURN V_RETURN;
END

CREATE DEFINER=`by`@`%` FUNCTION `fun_first_pinyin`(`P_NAME` VARCHAR(5)) RETURNS varchar(5) CHARSET utf8
    NO SQL
BEGIN
    DECLARE V_RETURN VARCHAR(5);
    SET V_RETURN = ELT(INTERVAL(CONV(HEX(left(CONVERT(P_NAME USING gbk),1)),16,10),
        0xB0A1,0xB0C5,0xB2C1,0xB4EE,0xB6EA,0xB7A2,0xB8C1,0xB9FE,0xBBF7,
        0xBFA6,0xC0AC,0xC2E8,0xC4C3,0xC5B6,0xC5BE,0xC6DA,0xC8BB,
        0xC8F6,0xCBFA,0xCDDA,0xCEF4,0xD1B9,0xD4D1),
    'A','B','C','D','E','F','G','H','J','K','L','M','N','O','P','Q','R','S','T','W','X','Y','Z');
        IF ISNULL(V_RETURN) or V_RETURN = '' THEN
            RETURN '';
        ELSE
            RETURN V_RETURN;
        END IF;
END