修改执行语句 MySQL root 密码：

ALTER USER 'root'@'localhost' IDENTIFIED BY 'xxxxxx'; 

报错：

ERROR 1396 (HY000): Operation ALTER USER failed for 'root'@'localhost' 

执行语句：

use mysql; select user,host from user where user='root'; 

发现 host 列的值是 因此，将修改后的密码语句改为：

ALTER USER 'root'@'%' IDENTIFIED WITH mysql_native_password BY 'xxxxxx'; flush privileges; 

问题解决。