解决mysql“Access denied for user 'root'@'localhost'”

大致意思就是给mysql中的root用户添加密码 （密码我就用******表示）

[ooo@localhost ~]$ mysqladmin -u root -p ******
Enter password:
mysqladmin: connect to server at 'localhost' failed
error: 'Access denied for user 'root'@'localhost' (using password: YES)'

[ooo@localhost ~]$ sudo /etc/init.d/mysqld stop
停止 MySQL： [确定]


[ooo@localhost ~]$ sudo mysqld_safe --user=mysql --skip-grant-tables --skip-networking &
[1] 17641

[ooo@localhost ~]$ nohup: ignoring input and redirecting stderr to stdout
Starting mysqld daemon with databases from /var/lib/mysql
mysql -u root mysql （注意这里要自己输入 没提示的）
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.0.67 Source distribution

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql> UPDATE user SET Password=PASSWORD('******') where USER='root';
Query OK, 3 rows affected (0.02 sec)
Rows matched: 3 Changed: 3 Warnings: 0

mysql> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.01 sec)

mysql> quit
Bye


[ooo@localhost ~]$ sudo /etc/init.d/mysqld restart
STOPPING server from pid file /var/run/mysqld/mysqld.pid
081205 12:11:33 mysqld ended

停止 MySQL： [确定]
启动 MySQL： [确定]
[1]+ Done sudo mysqld_safe --user=mysql --skip-grant-tables --skip-networking
[ooo@localhost ~]$ mysql -u root -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.0.67 Source distribution

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| test |
+--------------------+
3 rows in set (0.00 sec)

mysql> quit
Bye
[ooo@localhost ~]$

################################################

我的系统是6.06，最近新装好的mysql在进入mysql工具时，总是有错误提示:
# mysql -uroot -p
Enter password:
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

使用网上介绍的方法修改root用户的密码：
# mysqladmin -uroot -p password 'newpassword'
Enter password:
mysqladmin: connect to server at 'localhost' failed
error: 'Access denied for user 'root'@'localhost' (using password: YES)'

现在终于被我找到了解决方法，如下（请先测试方法三，谢谢！）：

方法一：
# /etc/init.d/mysql stop
# mysqld_safe --user=mysql --skip-grant-tables --skip-networking &
# mysql -u root mysql
mysql> UPDATE user SET Password=PASSWORD('newpassword') where USER='root';
mysql> FLUSH PRIVILEGES;
mysql> quit

# /etc/init.d/mysql restart
# mysql -uroot -p
Enter password: <输入新设的密码newpassword>

mysql>

方法二：
直接使用/etc/mysql/debian.cnf文件中[client]节提供的用户名和密码:
# mysql -udebian-sys-maint -p
Enter password: <输入[client]节的密码>
mysql> UPDATE user SET Password=PASSWORD('newpassword') where USER='root';
mysql> FLUSH PRIVILEGES;
mysql> quit

# mysql -uroot -p
Enter password: <输入新设的密码newpassword>

mysql>

方法三：
这种方法我没有进行过测试，因为我的root用户默认密码已经被我修改过了，那位有空测试一下，把结果告诉我，谢谢！
# mysql -uroot -p
Enter password: <输入/etc/mysql/debian.cnf文件中[client]节提供的密码>

至此，困惑多时的问题解决了！