求助!如何启用预装的MYSQL……

求助!如何启用预装的MYSQL……

小弟使用的是fedora 9 ,我记得在安装时安装了数据库软件MYSQL,但是不知道如何启用该软件,我使用的桌面环境是GNOME,请各位高手帮忙!!!      
想起用,提示如下错误:
[mt@localhost ~]$ mysql
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)
[mt@localhost ~]$ mysql
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)      
去mysql官网下载一个mysql装上再试试,可能装的时候少了啥东西。      
apple@apple:~$ mysql -h 127.0.0.1 -u root -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 29
Server version: 5.0.67-0ubuntu6 (Ubuntu)

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

mysql>      
[mtd@localhost ~]$ mysql -h 127.0.0.1 -u root -p
Enter password:
ERROR 2003 (HY000): Can't connect to MySQL server on '127.0.0.1' (111)

这是怎么回事?      
mysql
启动了吗?      
我执行了  “系统”---“管理”---“服务”---     开启了"mysqld" ,并将其状态设置为“start”,
再在终端中执行:“ mysql -h 127.0.0.1 -u root -p”
提示:
[mtd@localhost ~]$ mysql -h 127.0.0.1 -u root -p
Enter password:
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)      
我执行了yum install mysql*
安装了许多插件,之后运行   mysql
[root@localhost mtd]# mysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.0.51a Source distribution

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.
大家看看是否成功了!谢谢!      
我再执行          依然提示!!!这是怎么回事???
[root@localhost mtd]# mysql -h 127.0.0.1 -u root -p      
Enter password:
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)      
你的安装过程有问题