How to install MYSQL server correctly.

• sudo apt update
• sudo apt install mysql-server
• sudo mysql_secure_installation

log into mysql server

• sudo mysql
• SELECT user,authentication_string,plugin,host FROM mysql.user;

then you can find root has no password. Add password for user you want by alter your user. eg : I replace my password to root by password ad password.

• ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'password';
• FLUSH PRIVILEGES;

then check password.

• SELECT user,authentication_string,plugin,host FROM mysql.user;
• exit