How to get the first letter of Chinese characters _mysql in MySQL

DROP FUNCTION IF EXISTS ' getpy '; 
DELIMITER;; CREATE FUNCTION ' getpy ' (in_string VARCHAR (65534)) RETURNS mediumtext CHARSET UTF8 BEGIN DECLARE tmp_str VARCHAR (65534) c Harset GBK DEFAULT '; #截取字符串, each time the intercepted string is stored in the variable, initially the function parameter in_string value DECLARE tmp_len SMALLINT default 0; #tmp_str的长度 DECLARE tmp_char VARCHAR (2) C Harset gbk default '; #截取字符, each left (tmp_str,1) return value is stored in the variable DECLARE tmp_rs VARCHAR (65534) charset gbk default '; #结果字符串 DE  CLARE tmp_cc VARCHAR (2) CharSet GBK DEFAULT '; #拼音字符, storing the phonetic first character SET tmp_str = in_string of a single Chinese character, assigning in_string to Tmp_str set Tmp_len = LENGTH (TMP_STR); #初始化长度 while Tmp_len > 0 does #如果被计算的tmp_str长度大于0则进入该while SET Tmp_char = left (tmp_str,1); #获 
Take the first character in the leftmost tmp_str, note that this is the first character, which may or may not be the character. 
SET TMP_CC = Tmp_char #左端首个字符赋值给拼音字符 if LENGTH (Tmp_char) >1 then# determines whether the first character on the left is a multi-byte or single-byte character, and if multibyte is considered to be a Chinese character and given the following pinyin, it is not treated as a single byte. SELECT ELT (INTERVAL (CONV (HEX (Tmp_char), 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 ', into tmp_cc; 
#获得汉字拼音首字符 End IF; 
Set tmp_rs = CONCAT (TMP_RS,TMP_CC); #将当前tmp_str左端首个字符拼音首字符与返回字符串拼接 Set tmp_str = SUBSTRING (tmp_str,2); #将tmp_str左端首字符去除 
SET Tmp_len = LENGTH (TMP_STR); #计算当前字符串长度 end While; 
Return to Tmp_rs #返回结果字符串 end;; DELIMITER;