mysql 8.0.11 以上版本修改root密码

8.0.11 以上版本移除了password方法

1.if you in skip-grant-tables mode
in mysqld_safe:

UPDATE mysql.user SET authentication_string=null WHERE User='root';
FLUSH PRIVILEGES;
exit;

and then, in terminal:

mysql -u root

in mysql:

ALTER USER 'root'@'localhost' IDENTIFIED WITH caching_sha2_password BY 'yourpasswd';

2.not in skip-grant-tables mode
just in mysql:

ALTER USER 'root'@'localhost' IDENTIFIED WITH caching_sha2_password BY 'yourpasswd';