Below command will connect to MySQL using root user
manoj@manoj:~$ mysql -b -h localhost -u root -p
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 36
Server version: 5.5.24-0ubuntu0.12.04.1 (Ubuntu)
Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
Type ‘help;’ or ‘\h’ for help. Type ‘\c’ to clear the current input statement.
I have used Ubuntu 12.04 Desktop and MySQL version is 5.5.24
The same command will work in Windows – DOS.