MySQL数据库汉字转拼音全拼(大写、小写、拼音首字母)函数和ELT(INTERVAL(CONV(HEX(LEFT(CONVERT方式实现转拼音

省流

这个就行

SELECT

CASE WHEN ELT(INTERVAL(CONV(HEX(LEFT(CONVERT(`title` 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') REGEXP '[a-z]' 
 THEN ELT(INTERVAL(CONV(HEX(LEFT(CONVERT(`title` 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')
 WHEN UPPER(SUBSTRING(`title`,1,1)) REGEXP '[a-z]' THEN UPPER(SUBSTRING(`title`,1,1))
 WHEN UPPER(SUBSTRING(`title`,1,1)) REGEXP '[0-9.]' THEN '0-9'
 ELSE '其他'
 END AS nameFirst
FROM journal

一、使用函数etl语法

语法

SELECT
ELT(INTERVAL(CONV(HEX(LEFT(CONVERT('汉语' 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')

在这里插入图片描述
解析：ELT(INTERVAL(CONV(HEX(LEFT(CONVERT(‘汉语’ USING gbk),1)),16,10),

 # 对汉字进行编码
 CONVERT('汉语',USING gbk)  
 # 取汉字(字符串)的第一个字
 LEFT(CONVERT('汉语'USING gbk),1)
 # 转换成十六进制编码
 HEX(LEFT(CONVERT('汉语' USING gbk),1))
 # 十六进制转成十进制
 CONV(HEX(LEFT(CONVERT('汉语' USING gbk),1)),16,10)
 # INTERVAL(N,N1,N2,N3,…) N1,N2,N3,…为递增的有序整数。函数返回N在有序整数中的位置。
 INTERVAL(CONV(HEX(LEFT(CONVERT('汉语' USING gbk),1)),16,10)
 # ELT(N,str1,str2,str3,…) 若N = 1，则返回值为 str1 ，若N = 2，则返回值为 str2 ，以此类推

使用的函数中的单个作用

ELT(N,str1,str2,str3,…) 若N = 1，则返回值为 str1 ，若N = 2，则返回值为 str2 ，以此类推。
INTERVAL(N,N1,N2,N3,…) N1,N2,N3,…为递增的有序整数。函数返回N在有序整数中的位置。
CONV(N,from_base,to_base) 不同数基间转换数字。返回值为数字的N字符串表示，由from_base基转化为 to_base 基。本例中为将十六进制转换为十进制。
CONVERT(FieldName USING gbk) 将数据转换为gbk字符集。
HEX(CHAR) 返回字符的十六进制数。
LEFT(STR,N) 取STR字符串左边开始的N个字符。

二、通过汉字拼音对照表自定义函数

1.创建汉字拼音对照临时表

-- 汉字拼音对照临时表
CREATE TABLE IF NOT EXISTS `t_base_pinyin` (
  `pin_yin_` varchar(255) CHARACTER SET gbk NOT NULL,
  `code_` int(11) NOT NULL,
  PRIMARY KEY (`code_`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

2.插入对照表数据

-- 插入对照表数据
INSERT INTO t_base_pinyin (pin_yin_,code_)  VALUES ("a", 20319),("ai", 20317),("an", 20304),("ang", 20295),("ao", 20292),("ba", 20283),("bai", 20265),("ban", 20257),("bang", 20242),("bao", 20230),("bei", 20051),("ben", 20036),("beng", 20032),("bi", 20026),("bian", 20002),("biao", 19990),("bie", 19986),("bin", 19982),("bing", 19976),("bo", 19805),("bu", 19784),("ca", 19775),("cai", 19774),("can", 19763),("cang", 19756),("cao", 19751),("ce", 19746),("ceng", 19741),("cha", 19739),("chai", 19728),("chan", 19725),("chang", 19715),("chao", 19540),("che", 19531),("chen", 19525),("cheng", 19515),("chi", 19500),("chong", 19484),("chou", 19479),("chu", 19467),("chuai", 19289),("chuan", 19288),("chuang", 19281),("chui", 19275),("chun", 19270),("chuo", 19263),("ci", 19261),("cong", 19249),("cou", 19243),("cu", 19242),("cuan", 19238),("cui", 19235),("cun", 19227),("cuo", 19224),("da", 19218),("dai", 19212),("dan", 19038),("dang", 19023),("dao", 19018),("de", 19006),("deng", 19003),("di", 18996),("dian", 18977),("diao", 18961),("die", 18952),("ding", 18783),("diu", 18774),("dong", 18773),("dou", 18763),("du", 18756),("duan", 18741),("dui", 18735),("dun", 18731),("duo", 18722),("e", 18710),("en", 18697),("er", 18696),("fa", 18526),("fan", 18518),("fang", 18501),("fei", 18490),("fen", 18478),("feng", 18463),("fo", 18448),("fou", 18447),("fu", 18446),("ga", 18239),("gai", 18237),("gan", 18231),("gang", 18220),("gao", 18211),("ge", 18201),("gei", 18184),("gen", 18183),("geng", 18181),("gong", 18012),("gou", 17997),("gu", 17988),("gua", 17970),("guai", 17964),("guan", 17961),("guang", 17950),("gui", 17947),("gun", 17931),("guo", 17928),("ha", 17922),("hai", 17759),("han", 17752),("hang", 17733),("hao", 17730),("he", 17721),("hei", 17703),("hen", 17701),("heng", 17697),("hong", 17692),("hou", 17683),("hu", 17676),("hua", 17496),("huai", 17487),("huan", 17482),("huang", 17468),("hui", 17454),("hun", 17433),("huo", 17427),("ji", 17417),("jia", 17202),("jian", 17185),("jiang", 16983),("jiao", 16970),("jie", 16942),("jin", 16915),("jing", 16733),("jiong", 16708),("jiu", 16706),("ju", 16689),("juan", 16664),("jue", 16657),("jun", 16647),("ka", 16474),("kai", 16470),("kan", 16465),("kang", 16459),("kao", 16452),("ke", 16448),("ken", 16433),("keng", 16429),("kong", 16427),("kou", 16423),("ku", 16419),("kua", 16412),("kuai", 16407),("kuan", 16403),("kuang", 16401),("kui", 16393),("kun", 16220),("kuo", 16216),("la", 16212),("lai", 16205),("lan", 16202),("lang", 16187),("lao", 16180),("le", 16171),("lei", 16169),("leng", 16158),("li", 16155),("lia", 15959),("lian", 15958),("liang", 15944),("liao", 15933),("lie", 15920),("lin", 15915),("ling", 15903),("liu", 15889),("long", 15878),("lou", 15707),("lu", 15701),("lv", 15681),("luan", 15667),("lue", 15661),("lun", 15659),("luo", 15652),("ma", 15640),("mai", 15631),("man", 15625),("mang", 15454),("mao", 15448),("me", 15436),("mei", 15435),("men", 15419),("meng", 15416),("mi", 15408),("mian", 15394),("miao", 15385),("mie", 15377),("min", 15375),("ming", 15369),("miu", 15363),("mo", 15362),("mou", 15183),("mu", 15180),("na", 15165),("nai", 15158),("nan", 15153),("nang", 15150),("nao", 15149),("ne", 15144),("nei", 15143),("nen", 15141),("neng", 15140),("ni", 15139),("nian", 15128),("niang", 15121),("niao", 15119),("nie", 15117),("nin", 15110),("ning", 15109),("niu", 14941),("nong", 14937),("nu", 14933),("nv", 14930),("nuan", 14929),("nue", 14928),("nuo", 14926),("o", 14922),("ou", 14921),("pa", 14914),("pai", 14908),("pan", 14902),("pang", 14894),("pao", 14889),("pei", 14882),("pen", 14873),("peng", 14871),("pi", 14857),("pian", 14678),("piao", 14674),("pie", 14670),("pin", 14668),("ping", 14663),("po", 14654),("pu", 14645),("qi", 14630),("qia", 14594),("qian", 14429),("qiang", 14407),("qiao", 14399),("qie", 14384),("qin", 14379),("qing", 14368),("qiong", 14355),("qiu", 14353),("qu", 14345),("quan", 14170),("que", 14159),("qun", 14151),("ran", 14149),("rang", 14145),("rao", 14140),("re", 14137),("ren", 14135),("reng", 14125),("ri", 14123),("rong", 14122),("rou", 14112),("ru", 14109),("ruan", 14099),("rui", 14097),("run", 14094),("ruo", 14092),("sa", 14090),("sai", 14087),("san", 14083),("sang", 13917),("sao", 13914),("se", 13910),("sen", 13907),("seng", 13906),("sha", 13905),("shai", 13896),("shan", 13894),("shang", 13878),("shao", 13870),("she", 13859),("shen", 13847),("sheng", 13831),("shi", 13658),("shou", 13611),("shu", 13601),("shua", 13406),("shuai", 13404),("shuan", 13400),("shuang", 13398),("shui", 13395),("shun", 13391),("shuo", 13387),("si", 13383),("song", 13367),("sou", 13359),("su", 13356),("suan", 13343),("sui", 13340),("sun", 13329),("suo", 13326),("ta", 13318),("tai", 13147),("tan", 13138),("tang", 13120),("tao", 13107),("te", 13096),("teng", 13095),("ti", 13091),("tian", 13076),("tiao", 13068),("tie", 13063),("ting", 13060),("tong", 12888),("tou", 12875),("tu", 12871),("tuan", 12860) ,("tui", 12858),("tun", 12852),("tuo", 12849),("wa", 12838),("wai", 12831),("wan", 12829),("wang", 12812),("wei", 12802),("wen", 12607),("weng", 12597),("wo", 12594),("wu", 12585),("xi", 12556),("xia", 12359),("xian", 12346),("xiang", 12320),("xiao", 12300),("xie", 12120),("xin", 12099),("xing", 12089),("xiong", 12074),("xiu", 12067),("xu", 12058),("xuan", 12039),("xue", 11867),("xun", 11861),("ya", 11847),("yan", 11831),("yang", 11798),("yao", 11781),("ye", 11604),("yi", 11589),("yin", 11536),("ying", 11358),("yo", 11340),("yong", 11339),("you", 11324),("yu", 11303),("yuan", 11097),("yue", 11077),("yun", 11067),("za", 11055),("zai", 11052),("zan", 11045),("zang", 11041),("zao", 11038),("ze", 11024),("zei", 11020),("zen", 11019),("zeng", 11018),("zha", 11014),("zhai", 10838),("zhan", 10832),("zhang", 10815),("zhao", 10800),("zhe", 10790),("zhen", 10780),("zheng", 10764),("zhi", 10587),("zhong", 10544),("zhou", 10533),("zhu", 10519),("zhua", 10331),("zhuai", 10329),("zhuan", 10328),("zhuang", 10322),("zhui", 10315),("zhun", 10309),("zhuo", 10307),("zi", 10296),("zong", 10281),("zou", 10274),("zu", 10270),("zuan", 10262),("zui", 10260),("zun", 10256),("zuo", 10254);

3.创建汉字转换拼音函数

-- 建立汉字转换拼音函数
DROP FUNCTION IF EXISTS to_pinyin;
DELIMITER $
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;
    # 返回小写中文拼音全拼 RETURN LOWER(mypy);
	# 返回大写中文拼音全拼RETURN UPPER(mypy);
	# 返回中文拼音首字母大写
    RETURN SUBSTRING(UPPER(mypy),1,1);
END;
$
DELIMITER ;

注意：如果数据库开启了binlog日志在创建函数时可能会报错

This function has none of DETERMINISTIC, NO SQL, or READS SQL DATA in its declaration and binary logging is enabled (you *might* want to use the less safe log_bin_trust_function_creators variable)

可暂时先执行

set global log_bin_trust_function_creators=1;

或者在mysql配置文件中（windows为my.ini,linux为my.cnf）增加一行配置,然后要重启mysql实例！

# 1代表on，0代表off
log_bin_trust_function_creators=1

4.结果测试

汉字返回首字母
在这里插入图片描述
英文返回大写首字母