本文讨论两个报错：Operation ALTER USER failed for 'root'@'%'与Plugin 'mysql_native_password' is not loaded
报错Operation ALTER USER failed for ‘root‘@’%’
安装mysql后，更改初始密码时，按照教程输入ALTER USER 'root'@'%' IDENTIFIED BY '123';，报错Operation ALTER USER failed for 'root'@'%'。（或者输入ALTER USER 'root'@'localhost' IDENTIFIED BY '123';，报错Operation ALTER USER failed for 'root'@'localhost'）
解决：在已登录mysql后输入
use mysql
select user,host from user;
如上图，显示user中root的host为localhost，则应输入ALTER USER 'root'@'localhost' IDENTIFIED BY '123';
反之，若显示user中root的host为%，则应输入ALTER USER 'root'@'%' IDENTIFIED BY '123';
报错Plugin ‘mysql_native_password’ is not loaded
上文中的代码已经避开了接下来讨论的这一个ERROR。实际上，在网上教程中，我查到的代码是ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY '123';，然后遇到报错Plugin 'mysql_native_password' is not loaded，如下图所示。
我在网上查到的资料中没有线索。这时，我发现有人提到
MySQL5.8从开始将caching_sha2_password替代mysql_native_password作为默认的身份验证插件
于是我将代码中的mysql_native_password改为caching_sha2_password，即输入：
ALTER USER 'root'@'localhost' IDENTIFIED WITH caching_sha2_password BY '123';
成功。
后来我查阅资料，又发现直接省略这部分就行：
ALTER USER 'root'@'localhost' IDENTIFIED BY '123456';
