原文地址
http://www.centospub.com/make/mysql.html安裝MySQL。[root@sample ~]# yum -y install mysql-server ← 安裝MySQL
[root@sample ~]# yum -y install php-mysql ← 安裝php-mysql
配置MySQL[root@sample ~]#gedit /etc/my.cnf ← 編輯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 ← 找到這一行，在這一行的下面添加新的規則，讓MySQL的默認編碼為UTF-8
default-character-set = utf8 ← 添加這一行
然后在配置文件的文尾填加如下語句：
[mysql]
default-character-set = utf8
啟動MySQL服務[root@sample ~]# chkconfig mysqld on ← 設置MySQL服務隨系統啟動自啟動
[root@sample ~]# chkconfig --list mysqld ← 確認MySQL自啟動
mysqld 0:off 1:off 2:on 3:on 4:on 5:on 6:off ← 如果2--5為on的狀態就OK
[root@sample ~]#/etc/rc.d/init.d/mysqld start ← 啟動MySQL服務Initializing MySQL database: [ OK ]
Starting MySQL: [ OK ]
MySQL初始環境設定
[1]為MySQL的root用戶設置密碼
MySQL在剛剛被安裝的時候，它的root用戶是沒有被設置密碼的。首先來設置MySQL的root密碼。
[root@sample ~]# mysql -u root ← 用root用戶登錄MySQL服務器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; ← 查看用戶信息
+------+------------------------------+---------------+
| user | host | password |
+------+------------------------------+---------------+
| root | localhost | | ← root密碼為空
| root | sample.centospub.com | | ← root密碼為空
| | sample.centospub.com | |
| | localhost | |
|root | % |XXX |
| | | |
+------+------------------------------+---------------+
4 rows in set (0.00 sec)
mysql> set password for root@localhost=password('在這里填入root密碼'); ← 設置root密碼
Query OK, 0 rows affected (0.01 sec)
mysql> set password for root@'sample.centospub.com'=password('在這里填入root密碼'); ← 設置root密碼
Query OK, 0 rows affected (0.01 sec)
只有設置了這個才可以，才可以通過數據庫來安裝網址
mysql> set password for root@'xxx'=password('xxx'); ← 設置root密碼
Query OK, 0 rows affected (0.01 sec)
mysql> select user,host,password from mysql.user; ← 查看用戶信息
+------+--------------------------------+--------------------------+
| user | host | password |
+------+--------------------------------+--------------------------+
| root | localhost | 19b68057189b027f | ← root密碼被設置
| root | sample.centospub.com | 19b68057189b027f | ← root密碼被設置
| | sample.centospub.com | |
| | localhost | |
+------+--------------------------------+--------------------------+
4 rows in set (0.01 sec)
mysql> exit ← 退出MySQL服務器
Bye
然后，測試一下root密碼有沒有生效。
[root@sample ~]# mysql -u root ← 通過空密碼用root登錄ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO) ← 出現此錯誤信息說明密碼設置成功
[root@localhost ~]# mysql -u root -h sample.centospub.com ← 通過空密碼用root登錄
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO) ← 出現此錯誤信息說明密碼設置成功
[root@sample ~]#mysql -u root -p ← 通過密碼用root登錄
Enter password: ← 在這里輸入密碼Welcome to the MySQL monitor. Commands end with ; or \g. ← 確認用密碼能夠成功登錄
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 ← 通過密碼用root登錄
Enter password: ← 在這里輸入密碼
Welcome to the MySQL monitor. Commands end with ; or \g. ← 確認用密碼能夠成功登錄
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服務器
Bye
[2] 刪除匿名用戶
在MySQL剛剛被安裝后，存在用戶名、密碼為空的用戶。這使得數據庫服務器有無需密碼被登錄的可能性。為消除隱患，將匿名用戶刪除。
[root@sample ~]# mysql -u root -p ← 通過密碼用root登錄
Enter password: ← 在這里輸入密碼
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; ← 查看用戶信息
+------+----------------------------+
| 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=''; ← 刪除匿名用戶
Query OK, 2 rows affected (0.17 sec)
mysql> select user,host from mysql.user; ← 查看用戶信息
+------+----------------------------+
| user | host |
+------+----------------------------+
| root | localhost |
| root | sample.centospub.com |
+------+----------------------------+
2 rows in set (0.00 sec)
mysql> exit ← 退出MySQL服務器
Bye
好了，下面都不是必須的了！
測試MySQL
[root@sample ~]# mysql -u root -p ← 通過密碼用root登錄
Enter password: ← 在這里輸入密碼
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 '在這里定義密碼'; ← 建立對test數據庫有完全操作權限的名為centospub的用戶
Query OK, 0 rows affected (0.03 sec)
mysql> select user from mysql.user where user='centospub'; ← 確認centospub用戶的存在與否
+---------+
| user |
+---------+
| centospub | ← 確認centospub已經被建立
+---------+
1 row in set (0.01 sec)
mysql> exit ← 退出MySQL服務器
Bye
[root@sample ~]# mysql -u centospub -p ← 用新建立的centospub用戶登錄MySQL服務器
Enter password: ← 在這里輸入密碼
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; ← 建立名為test的數據庫
Query OK, 1 row affected (0.00 sec)
mysql> show databases; ← 查看系統已存在的數據庫
+-------------+
| Database |
+-------------+
| test |
+-------------+
1 row in set (0.00 sec)
mysql> use test ← 連接到數據庫
Database changed
mysql> create table test(num int, name varchar(50)); ← 在數據庫中建立表
Query OK, 0 rows affected (0.03 sec)
mysql> show tables; ← 查看數據庫中已存在的表
+-------------------+
| Tables_in_test |
+-------------------+
| test |
+-------------------+
1 row in set (0.01 sec)
mysql> insert into test values(1,'Hello World!'); ← 插入一個值到表中
Query OK, 1 row affected (0.02 sec)
mysql> select * from test; ← 查看數據庫中的表的信息
+------+-------------------+
| 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，賦予新的值
Query OK, 1 row affected (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> select * from test; ← 查看數據庫中的表的信息
+------+----------------------+
| num | name |
+------+----------------------+
| 1 | Hello Everyone! | ← 確認被更新到新的值
+------+----------------------+
1 row in set (0.01 sec)
mysql> delete from test where num=1; ← 刪除表內的值
Query OK, 1 row affected (0.00 sec)
mysql> select * from test; ← 確認刪除結果
Empty set (0.01 sec)
mysql> drop table test; ← 刪除表
Query OK, 0 rows affected (0.01 sec)
mysql> show tables; ← 查看表信息
Empty set (0.00 sec) ← 確認表已被刪除
mysql> drop database test; ← 刪除名為test的數據庫
Query OK, 0 rows affected (0.01 sec)
mysql> show databases; ← 查看已存在的數據庫
Empty set (0.01 sec) ← 確認test數據庫已被刪除（這里非root用戶的關系，看不到名為mysql的數據庫）
mysql> exit ← 退出MySQL服務器
Bye
然后，刪除測試用過的遺留用戶。
[root@sample ~]# mysql -u root -p ← 通過密碼用root登錄
Enter password: ← 在這里輸入密碼
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用戶對數據庫的操作權限
Query OK, 0 rows affected (0.00 sec)
mysql> delete from mysql.user where user='centospub' and host='localhost'; ← 刪除centospub用戶
Query OK, 1 row affected (0.01 sec)
mysql> select user from mysql.user where user='centospub'; ← 查找用戶centospub，確認已刪除與否
Empty set (0.01 sec) ← 確認centospub用戶已不存在
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 ← 重新啟動HTTP服務
Stopping httpd: [ OK ]
Starting httpd: [ OK ]
用sudo時提示"xxx is not in the sudoers file. This incident will be reported.其中XXX是你的用戶名，也就是你的用戶名沒有權限使用sudo,我們只要修改一下/etc/sudoers文件就行了。下面是修改方法：
1）進入超級用戶模式。也就是輸入"su -",系統會讓你輸入超級用戶密碼，輸入密碼后就進入了超級用戶模式。（當然，你也可以直接用root用）
2）添加文件的寫權限。也就是輸入命令"chmod u+w /etc/sudoers"。
3）編輯/etc/sudoers文件。也就是輸入命令"vim /etc/sudoers",輸入"i"進入編輯模式，找到這一 行："root ALL=(ALL) ALL"在起下面添加"xxx ALL=(ALL) ALL"(這里的xxx是你的用戶名)，然后保存（就是先按一 下Esc鍵，然后輸入":wq"）退出。
4）撤銷文件的寫權限。也就是輸入命令"chmod u-w /etc/sudoers"。
1、添加用戶，首先用adduser命令添加一個普通用戶，命令如下：
#adduser junguoguo//添加一個名為junguoguo的用戶
#passwd junguoguo //修改密碼
Changing password for user junguoguo.
New UNIX password: //在這里輸入新密碼
Retype new UNIX password: //再次輸入新密碼
passwd: all authentication tokens updated successfully.
2、賦予root權限
方法一： 修改 /etc/sudoers 文件，找到下面一行，把前面的注釋（#）去掉
## Allows people in group wheel to run all commands
%wheel ALL=(ALL) ALL
然后修改用戶，使其屬于root組（wheel），命令如下：
#usermod -g root junguoguo
修改完畢，現在可以用junguoguo帳號登錄，然后用命令 su – ，即可獲得root權限進行操作。
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
修改完畢，現在可以用junguoguo帳號登錄，然后用命令 su – ，即可獲得root權限進行操作。
方法三： 修改 /etc/passwd 文件，找到如下行，把用戶ID修改為 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賬戶登錄后，直接獲取的就是root帳號的權限。