centOS Linux下用yum 安装mysql

注意：centOS Linux系统下用yum 安装mysql，必须在网络环境下进行安装；关于Linux系统下如何连接网络，前一篇文章有介绍，请参考！

                                      第一篇：安装和配置MySQL

  第一步：安装MySQL

[root@192 local]# yum -y install mysql-server ← 安装MySQL

[root@192 local]# yum -y install php-mysql ← 安装php-mysql

 

  第二步：配置MySQL

[root@192 local] #vim /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

 

       第二篇：启动MySQL和初始环境设定

 

  第一步:启动MySQL服务

[root@192 local]#chkconfig mysqld on ← 设置MySQL服务随系统启动自启动

[root@192 local]#chkconfig --list mysqld ← 确认MySQL自启动
mysqld          0:关闭  1:关闭  2:启用  3:启用  4:启用  5:启用  6:关闭

                                              ← 如果2--5为启用(或on)的状态就OK

[root@192 local]#/etc/rc.d/init.d/mysqld start ← 启动MySQL服务

初始化 MySQL 数据库： Installing MySQL system tables...
OK
Filling help tables...
OK

To start mysqld at boot time you have to copy
support-files/mysql.server to the right place for your system

PLEASE REMEMBER TO SET A PASSWORD FOR THE MySQL root USER !
To do so, start the server, then issue the following commands:
/usr/bin/mysqladmin -u root password 'new-password'
/usr/bin/mysqladmin -u root -h 192.168.0.1 password 'new-password'

Alternatively you can run:
/usr/bin/mysql_secure_installation

which will also give you the option of removing the test
databases and anonymous user created by default.  This is
strongly recommended for production servers.

See the manual for more instructions.

You can test the MySQL daemon with mysql-test-run.pl
cd mysql-test ; perl mysql-test-run.pl

Please report any problems with the /usr/bin/mysqlbug script!

The latest information about MySQL is available on the web at
http://www.mysql.com
Support MySQL by buying support/licenses at http://shop.mysql.com
                                                           [确定]
启动 mysqld：                                              [确定]

 

  第二步：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@192 local]#mysql -u root  ← 在没设置密码之时，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
Server version: 5.0.95 Source distribution

Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

 

mysql> select user,host,password from mysql.user; ← 查看用户信息
mysql> select user,host,password from mysql.user;
+------+-------------+----------+
| user | host        | password |
+------+-------------+----------+
| root | localhost   |          |
| root | 192.168.0.1 |          |
| root | 127.0.0.1   |          |
|      | localhost   |          |
|      | 192.168.0.1 |          |
+------+-------------+----------+
5 rows in set (0.03 sec)

mysql> set password for root@localhost=password ('在这里填入root密码'); ← 设置root密码

譬如，在我的系统中，我是如下设置：

mysql> set password for root@localhost=password ('wangyun');

Query OK, 0 rows affected (0.01 sec)

mysql> set password for root@192.168.0.1=password ('wangyun');
Query OK, 0 rows affected (0.01 sec)

mysql> set password for root@127.0.0.1=password ('wangyun');
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   | 5f2dfe4b07af795b |
| root | 192.168.0.1 | 5f2dfe4b07af795b |
| root | 127.0.0.1   | 5f2dfe4b07af795b |
|      | localhost   |                  |
|      | 192.168.0.1 |                  |
+------+-------------+------------------+
5 rows in set (0.01 sec)

mysql> exit ← 退出MySQL服务器
Bye

 

 [2]测试设置的root密码是否生效

 

[root@192 local]# 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@192 local]# 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
Server version: 5.0.95 Source distribution

...  ...

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

[root@192 local]# mysql -u root -h 127.0.0.1 -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 13
Server version: 5.0.95 Source distribution

......

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> exit ← 退出MySQL服务器
Bye

 

 [3] 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@192 local]# mysql -u root -p  ← 通过密码用root登录
Enter password:    ← 在这里输入密码

 

mysql> select user,host from mysql.user;
+------+-------------+
| user | host        |
+------+-------------+
| root | 127.0.0.1   |
|      | 192.168.0.1 |
| root | 192.168.0.1 |
|      | localhost   |
| root | localhost   |
+------+-------------+
5 rows in set (0.03 sec)

 

mysql> delete from mysql.user where user=''; ← 删除匿名用户

Query OK, 2 rows affected (0.04 sec)

 

mysql> select user,host from mysql.user;  ← 查看用户信息

+------+-------------+
| user | host        |
+------+-------------+
| root | 127.0.0.1   |
| root | 192.168.0.1 |
| root | localhost   |
+------+-------------+
3 rows in set (0.00 sec)

 

mysql> exit;   ←退出MySQL服务器
Bye

 

第三篇：测试

经过第一篇和第二篇这二部分的设置，MySQL就可以正常试用。

好了，第三篇的内容都不是必须的了！
我们来测试MySQL，前学习或复习常用的SQL语句。

[root@192 local]#mysql -u centospub-p;  ← 通过密码用root登录
Enter password: ← 在这里输入密码

mysql> grant all privileges on test.* tocentospub@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

譬如，在我的系统中，设置如下：

mysql> grant all privileges ontest.* tocentospub@localhost identified by'wangyun';

                                  
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 |
+-----------+
1 row in set (0.02 sec)

mysql> exit;
Bye
[root@192 local]# 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

 

mysql>create database test; ← 建立名为test的数据库
mysql> show databases;       ← 查看系统已存在的数据库

+--------------------+
| Database           |
+--------------------+
| information_schema |
| test               |
+--------------------+
2 rows in set (0.01 sec)

mysql> use test ← 连接到数据库
Database changed

mysql> create table test     
    -> (
    -> num int ,      ← 在数据库中建立表
    -> name varchar(50)
    -> );
Query OK, 0 rows affected (0.14 sec)

mysql> show tables; ← 查看数据库中已存在的表
+----------------+
| Tables_in_test |
+----------------+
| test           |
+----------------+
1 row in set (0.02 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 (0.14 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            |
+------+-----------------+    ← 确认被更新到新的值
|    1 | Hello Everyone! |  
+------+-----------------+
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 (0.01 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@192 local]# mysql -u root -p;
Enter password:
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 (0.01 sec)

mysql> delete from mysql.user where user='centospub'and host='localhost';

                                                  ← 删除centospub用户
Query OK, 1 row affected (0.14 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 (0.00 sec)

mysql> exit;
Bye

[root@192 local]# /etc/rc.d/init.d/httpd restart ← 重新启动HTTP服务
                                                 ← 注意：语句后面无需;分号
停止 httpd：                                               [确定]
启动 httpd：                                               [确定]