CREATE DEFINER=`root`@`localhost` FUNCTION `replaceYunmu`(pinyin_ varchar(100) charset 'utf32') RETURNS varchar(100) CHARSET utf32
    DETERMINISTIC
    COMMENT '替换韵母'
BEGIN
-- # 使用方法
-- # SELECT replaceYunmu('zhāngsān'); ---> zhangsan
-- # 多音字用逗号分割
SET @result="";
-- # 去掉空格
SELECT REPLACE(pinyin_,' ','') into @pinyin_ ;
SELECT
	REGEXP_REPLACE (
	    REGEXP_REPLACE (
		    REGEXP_REPLACE (
                REGEXP_REPLACE (
                    REGEXP_REPLACE (
                        REGEXP_REPLACE ( @pinyin_, 
                            "[āáǎà]", 'a' ),
                                "[ōóǒò]", 'o' ),
                                    "[ēéěè]", 'e' ),
                                        '[īíǐì]', 'i' ),
                                            '[ūúǔù]','u'),
                                                '[ǖǘǚǜü]','v')
	into @result;
RETURN @result;

END;