汉字拼音首字母

CREATE DEFINER=`root`@`%` FUNCTION `getFirstPyCpp`(parss VARCHAR(255)) RETURNS varchar(1000) CHARSET utf8
BEGIN
    DECLARE vrerur VARCHAR(255);
    DECLARE vfirstcha VARCHAR(2); 
		SET vfirstcha = UPPER(LEFT(parss,1));
		SET vrerur = vfirstcha;
		IF LENGTH( vfirstcha) <> CHARACTER_LENGTH( vfirstcha ) THEN
		SET vrerur = ELT(INTERVAL(CONV(HEX(LEFT(CONVERT(parss 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');
		END IF;
RETURN vrerur; 
END

调用：SELECT getFirstPyCpp ( nickname ) AS szm FROM users