mysql ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)

mysql 安装后，登录报错，虽然安装时设置了密码。

ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)

解决方法：

# mysql -u root mysql
mysql> UPDATE user SET Password=PASSWORD('newpassword') where USER='root';
mysql> FLUSH PRIVILEGES;
mysql> quit
# /etc/init.d/mysqld restart

在命令行再次修改后，重启mysql服务即可。