What is the default root pasword for MySQL 5.7

Question

Cannot login to MySQL database after fresh install with root ID and empty/no password like other older MySQL versions do

Answer 1

As of Ubuntu 20.04 with MySql 8.0 : you can set the password that way:

1. login to mysql with sudo mysql -u root

2. change the password:

USE mysql;
UPDATE user set authentication_string=NULL where User='root';
FLUSH privileges;
ALTER USER 'root'@'localhost' IDENTIFIED WITH caching_sha2_password BY 'My-N7w_And.5ecure-P@s5w0rd';
FLUSH privileges;
QUIT

now you should be able to login with mysql -u root -p (or to phpMyAdmin with username root) and your chosen password.

P,S:

You can also login with user debian-sys-maint, the password is written in the file /etc/mysql/debian.cnf