Solve the MySQL connection problem in Ubuntu (error 1045 (28000): Access denied for user 'root' @ 'localhost &

My system is ubuntu8.04. The newly installed MySQL always has an error prompt when it enters the MySQL tool:

# Mysql-uroot-P
Enter password:
Error 1045 (28000): Access denied for user 'root' @ 'localhost'
(Using password: No)

Use the methods described on the Internet to change the password of the root user:
# Mysqladmin-uroot-P password 'newpassword'
Enter password:
Mysqladmin: connect to server at 'localhost' failed
Error: 'Access denied for user' root' @ 'localhost' (using password:
Yes )'

Now I finally found the solution:

Switch to the root user and enter the MySQL bin directory,
Root @ CPS-desktop:/usr/local/MySQL/bin #/etc/init. d/MySQL stop

Root @ CPS-desktop:/usr/local/MySQL/bin #./mysqld_safe -- user = MySQL -- skip-grant-tables -- skip-networking
&

Root @ CPS-desktop:/usr/local/MySQL/bin #./MySQL-u root MySQL

Mysql> Update user SET Password = PASSWORD ('newpassword') Where
User = 'root ';
Mysql> flush privileges;
Mysql> quit;

Finally, restart the database:
Root @ CPS-desktop:/usr/local/MySQL/bin #/etc/init. d/MySQL restart

Root @ CPS-desktop:/usr/local/MySQL/bin # mysql-u root-P

Enter Password: <enter the new password newpassword>

Mysql>