How to grant all privileges to root user in MySQL 8.0

Starting with MySQL 8 you no longer can (implicitly) create a user using the GRANT command. Use CREATE USER instead, followed by the GRANT statement:

mysql> CREATE USER 'root'@'%' IDENTIFIED BY 'PASSWORD';
mysql> GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' WITH GRANT OPTION;
mysql> FLUSH PRIVILEGES;

Caution about the security risks about WITH GRANT OPTION, see:

• Grant all privileges on database