问题：mysql -uroot -p
输入设置的密码
竟然报错了！
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YSE)
修改步骤：
# /etc/init.d/service 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/service mysql start
# mysql -u root -p
Enter password:
mysql>
OK！root用户可以成功访问数据库了