Solves problem of: access denied for user root using password YES Stop mySQL:
sudo systemctl stop mysql
Restart mySQL, skipping grant tables:
sudo mysqld_safe --skip-grant-tables
Login:
mysql -u root
In SQL shell, look if users exist:
select User, password,plugin FROM mysql.user ;
Update the users (plugin null enables for all plugins):
update mysql.user set password=PASSWORD('mypassword'), plugin = NULL WHERE User = 'root';
exit;
In Unix shell stop mySQL without grant tables, then restart with grant tables:
sudo service mysql stop
sudo service mysql start