查看初始随机密码

grep -o 'password .*' /var/log/mysqld.log |awk '{print $6}'

mysql -uroot -p

初次修改root密码

USE mysql;
ALTER USER 'root'@'localhost' IDENTIFIED BY 'MyNewPass4!';

允许外网访问

UPDATE user SET host='%' WHERE user='root';

mysql5.7及以下 授权

GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY 'MyNewPass4!' WITH GRANT OPTION;

FLUSH PRIVILEGES;
exit

mysql8.0及以上 授权

SET GLOBAL VALIDATE_PASSWORD.POLICY=0;

CREATE USER 'root'@'%' IDENTIFIED BY 'MyNewPass4!';
GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' WITH GRANT OPTION;

FLUSH PRIVILEGES;
exit

mysql5.7及以下 非初次修改账户密码

UPDATE mysql.user SET authentication_string=password('mypassword') WHERE user='root';

FLUSH PRIVILEGES;

mysql8.0及以上 非初次修改账户密码

ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'mypassword';

FLUSH PRIVILEGES;