原文地址
http://www.centospub.com/make/mysql.html安装MySQL。[root@sample ~]# yum -y install mysql-server ← 安装MySQL
[root@sample ~]# yum -y install php-mysql ← 安装php-mysql
配置MySQL[root@sample ~]#gedit /etc/my.cnf ← 编辑MySQL的配置文件[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
# Default to using old password format for compatibility with mysql 3.x
# clients (those using the mysqlclient10 compatibility package).
old_passwords=1 ← 找到这一行，在这一行的下面添加新的规则，让MySQL的默认编码为UTF-8
default-character-set = utf8 ← 添加这一行
然后在配置文件的文尾填加如下语句：
[mysql]
default-character-set = utf8
启动MySQL服务[root@sample ~]# chkconfig mysqld on ← 设置MySQL服务随系统启动自启动
[root@sample ~]# chkconfig --list mysqld ← 确认MySQL自启动
mysqld 0:off 1:off 2:on 3:on 4:on 5:on 6:off ← 如果2--5为on的状态就OK
[root@sample ~]#/etc/rc.d/init.d/mysqld start ← 启动MySQL服务Initializing MySQL database: [ OK ]
Starting MySQL: [ OK ]
MySQL初始环境设定
[1]为MySQL的root用户设置密码
MySQL在刚刚被安装的时候，它的root用户是没有被设置密码的。首先来设置MySQL的root密码。
[root@sample ~]# mysql -u root ← 用root用户登录MySQL服务器Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 2 to server version: 4.1.20
Type 'help;' or '\h' for help. Type '\c' to clear the buffer.
mysql> select user,host,password from mysql.user; ← 查看用户信息
+------+------------------------------+---------------+
| user | host | password |
+------+------------------------------+---------------+
| root | localhost | | ← root密码为空
| root | sample.centospub.com | | ← root密码为空
| | sample.centospub.com | |
| | localhost | |
|root | % |XXX |
| | | |
+------+------------------------------+---------------+
4 rows in set (0.00 sec)
mysql> set password for root@localhost=password('在这里填入root密码'); ← 设置root密码
Query OK, 0 rows affected (0.01 sec)
mysql> set password for root@'sample.centospub.com'=password('在这里填入root密码'); ← 设置root密码
Query OK, 0 rows affected (0.01 sec)
只有设置了这个才可以，才可以通过数据库来安装网址
mysql> set password for root@'xxx'=password('xxx'); ← 设置root密码
Query OK, 0 rows affected (0.01 sec)
mysql> select user,host,password from mysql.user; ← 查看用户信息
+------+--------------------------------+--------------------------+
| user | host | password |
+------+--------------------------------+--------------------------+
| root | localhost | 19b68057189b027f | ← root密码被设置
| root | sample.centospub.com | 19b68057189b027f | ← root密码被设置
| | sample.centospub.com | |
| | localhost | |
+------+--------------------------------+--------------------------+
4 rows in set (0.01 sec)
mysql> exit ← 退出MySQL服务器
Bye
然后，测试一下root密码有没有生效。
[root@sample ~]# mysql -u root ← 通过空密码用root登录ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO) ← 出现此错误信息说明密码设置成功
[root@localhost ~]# mysql -u root -h sample.centospub.com ← 通过空密码用root登录
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO) ← 出现此错误信息说明密码设置成功
[root@sample ~]#mysql -u root -p ← 通过密码用root登录
Enter password: ← 在这里输入密码Welcome to the MySQL monitor. Commands end with ; or \g. ← 确认用密码能够成功登录
Your MySQL connection id is 5 to server version: 4.1.20
Type 'help;' or '\h' for help. Type '\c' to clear the buffer.
mysql> exit
Bye
[root@sample ~]# mysql -u root -h sample.centospub.com -p ← 通过密码用root登录
Enter password: ← 在这里输入密码
Welcome to the MySQL monitor. Commands end with ; or \g. ← 确认用密码能够成功登录
Your MySQL connection id is 6 to server version: 4.1.20
Type 'help;' or '\h' for help. Type '\c' to clear the buffer.
mysql> exit ← 退出MySQL服务器
Bye
[2] 删除匿名用户
在MySQL刚刚被安装后，存在用户名、密码为空的用户。这使得数据库服务器有无需密码被登录的可能性。为消除隐患，将匿名用户删除。
[root@sample ~]# mysql -u root -p ← 通过密码用root登录
Enter password: ← 在这里输入密码
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 7 to server version: 4.1.20
Type 'help;' or '\h' for help. Type '\c' to clear the buffer.
mysql> select user,host from mysql.user; ← 查看用户信息
+------+----------------------------+
| user | host |
+------+----------------------------+
| | localhost |
| root | localhost |
| | sample.centospub.com |
| root | sample.centospub.com |
+------+----------------------------+
4 rows in set (0.02 sec)
mysql> delete from mysql.user where user=''; ← 删除匿名用户
Query OK, 2 rows affected (0.17 sec)
mysql> select user,host from mysql.user; ← 查看用户信息
+------+----------------------------+
| user | host |
+------+----------------------------+
| root | localhost |
| root | sample.centospub.com |
+------+----------------------------+
2 rows in set (0.00 sec)
mysql> exit ← 退出MySQL服务器
Bye
好了，下面都不是必须的了！
测试MySQL
[root@sample ~]# mysql -u root -p ← 通过密码用root登录
Enter password: ← 在这里输入密码
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 9 to server version: 4.1.20
Type 'help;' or '\h' for help. Type '\c' to clear the buffer.
mysql> grant all privileges on test.* to centospub@localhost identified by '在这里定义密码'; ← 建立对test数据库有完全操作权限的名为centospub的用户
Query OK, 0 rows affected (0.03 sec)
mysql> select user from mysql.user where user='centospub'; ← 确认centospub用户的存在与否
+---------+
| user |
+---------+
| centospub | ← 确认centospub已经被建立
+---------+
1 row in set (0.01 sec)
mysql> exit ← 退出MySQL服务器
Bye
[root@sample ~]# mysql -u centospub -p ← 用新建立的centospub用户登录MySQL服务器
Enter password: ← 在这里输入密码
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 10 to server version: 4.1.20
Type 'help;' or '\h' for help. Type '\c' to clear the buffer.
mysql> create database test; ← 建立名为test的数据库
Query OK, 1 row affected (0.00 sec)
mysql> show databases; ← 查看系统已存在的数据库
+-------------+
| Database |
+-------------+
| test |
+-------------+
1 row in set (0.00 sec)
mysql> use test ← 连接到数据库
Database changed
mysql> create table test(num int, name varchar(50)); ← 在数据库中建立表
Query OK, 0 rows affected (0.03 sec)
mysql> show tables; ← 查看数据库中已存在的表
+-------------------+
| Tables_in_test |
+-------------------+
| test |
+-------------------+
1 row in set (0.01 sec)
mysql> insert into test values(1,'Hello World!'); ← 插入一个值到表中
Query OK, 1 row affected (0.02 sec)
mysql> select * from test; ← 查看数据库中的表的信息
+------+-------------------+
| num | name |
+------+-------------------+
| 1 | Hello World! |
+------+-------------------+
1 row in set (0.00 sec)
mysql> update test set name='Hello Everyone!'; ← 更新表的信息，赋予新的值
Query OK, 1 row affected (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> select * from test; ← 查看数据库中的表的信息
+------+----------------------+
| num | name |
+------+----------------------+
| 1 | Hello Everyone! | ← 确认被更新到新的值
+------+----------------------+
1 row in set (0.01 sec)
mysql> delete from test where num=1; ← 删除表内的值
Query OK, 1 row affected (0.00 sec)
mysql> select * from test; ← 确认删除结果
Empty set (0.01 sec)
mysql> drop table test; ← 删除表
Query OK, 0 rows affected (0.01 sec)
mysql> show tables; ← 查看表信息
Empty set (0.00 sec) ← 确认表已被删除
mysql> drop database test; ← 删除名为test的数据库
Query OK, 0 rows affected (0.01 sec)
mysql> show databases; ← 查看已存在的数据库
Empty set (0.01 sec) ← 确认test数据库已被删除（这里非root用户的关系，看不到名为mysql的数据库）
mysql> exit ← 退出MySQL服务器
Bye
然后，删除测试用过的遗留用户。
[root@sample ~]# mysql -u root -p ← 通过密码用root登录
Enter password: ← 在这里输入密码
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 12 to server version: 4.1.20
Type 'help;' or '\h' for help. Type '\c' to clear the buffer.
mysql> revoke all privileges on *.* from centospub@localhost; ← 取消centospub用户对数据库的操作权限
Query OK, 0 rows affected (0.00 sec)
mysql> delete from mysql.user where user='centospub' and host='localhost'; ← 删除centospub用户
Query OK, 1 row affected (0.01 sec)
mysql> select user from mysql.user where user='centospub'; ← 查找用户centospub，确认已删除与否
Empty set (0.01 sec) ← 确认centospub用户已不存在
mysql> flush privileges; ← 刷新，使以上操作生效
Query OK, 0 rows affected (0.01 sec)
mysql> exit
Bye
[root@sample ~]# /etc/rc.d/init.d/httpd restart ← 重新启动HTTP服务
Stopping httpd: [ OK ]
Starting httpd: [ OK ]
用sudo时提示"xxx is not in the sudoers file. This incident will be reported.其中XXX是你的用户名，也就是你的用户名没有权限使用sudo,我们只要修改一下/etc/sudoers文件就行了。下面是修改方法：
1）进入超级用户模式。也就是输入"su -",系统会让你输入超级用户密码，输入密码后就进入了超级用户模式。（当然，你也可以直接用root用）
2）添加文件的写权限。也就是输入命令"chmod u+w /etc/sudoers"。
3）编辑/etc/sudoers文件。也就是输入命令"vim /etc/sudoers",输入"i"进入编辑模式，找到这一 行："root ALL=(ALL) ALL"在起下面添加"xxx ALL=(ALL) ALL"(这里的xxx是你的用户名)，然后保存（就是先按一 下Esc键，然后输入":wq"）退出。
4）撤销文件的写权限。也就是输入命令"chmod u-w /etc/sudoers"。
1、添加用户，首先用adduser命令添加一个普通用户，命令如下：
#adduser junguoguo//添加一个名为junguoguo的用户
#passwd junguoguo //修改密码
Changing password for user junguoguo.
New UNIX password: //在这里输入新密码
Retype new UNIX password: //再次输入新密码
passwd: all authentication tokens updated successfully.
2、赋予root权限
方法一： 修改 /etc/sudoers 文件，找到下面一行，把前面的注释（#）去掉
## Allows people in group wheel to run all commands
%wheel ALL=(ALL) ALL
然后修改用户，使其属于root组（wheel），命令如下：
#usermod -g root junguoguo
修改完毕，现在可以用junguoguo帐号登录，然后用命令 su – ，即可获得root权限进行操作。
方法二： 修改 /etc/sudoers 文件，找到下面一行，在root下面添加一行，如下所示：
## Allow root to run any commands anywhere
root ALL=(ALL) ALL
junguoguo ALL=(ALL) ALL
修改完毕，现在可以用junguoguo帐号登录，然后用命令 su – ，即可获得root权限进行操作。
方法三： 修改 /etc/passwd 文件，找到如下行，把用户ID修改为 0 ，如下所示：
junguoguo:x:500:500:junguoguo:/home/junguoguo:/bin/bash
修改后如下
junguoguo:x:0:500:junguoguo:/home/junguoguo:/bin/bash
保存，用junguoguo账户登录后，直接获取的就是root帐号的权限。