When attempting to connect to MySQL or MariaDB, error 1045 (28000): Access denied for user 'username'@'localhost' (using password: YES) appears. 

1. In Tereminal, type mysql -u root;
2. Update the password using one of the following commands
   • UPDATE mysql.user SET Password=PASSWORD('password') WHERE User='root';
   • UPDATE mysql.user SET authentication_string=PASSWORD('password')  WHERE  User='root';
3. FLUSH PRIVILEGES;

Follow these steps if you are unable to connect to MariaDB with commands such as mysql, mysql -u root, and mysql -u root -p.

1. In Terminal, type /sbin/service mariadb stop
2. Type mysqld_safe --skip-grant-tables &
3. There will be a flashing cursor. Type mysql -u root
4. Type use mysql;
5. Type update user set password=PASSWORD("new-password") where User='root';
6. Type exit
7. Now try to log into MariaDB with the command mysql -u root -p;