mysql中用戶管理和權限控制的示例分析

這篇文章主要介紹mysql中用戶管理和權限控制的示例分析，文中介紹的非常詳細，具有一定的參考價值，感興趣的小伙伴們一定要看完！

一：用戶的創建（兩種方法）：

方法一：CREATE USER 'username'@'%' IDENTIFIED BY 'password';

方法二：GRANT select ON databasename.tablename TO 'username'@'%' ;

二：mysql root用戶密碼設置以及修改。

方法1： 用SET PASSWORD命令

　　mysql -u root

　　mysql> SET PASSWORD FOR 'root'@'localhost' = PASSWORD('newpass');

方法2：用mysqladmin

　　mysqladmin -u root password "newpass"

　　如果root已經設置過密碼，采用如下方法

　　mysqladmin -u root password oldpass "newpass"

方法3： 用UPDATE直接編輯user表

　　mysql -u root

　　mysql> use mysql;

　　mysql> UPDATE user SET Password = PASSWORD('newpass') WHERE user = 'root';

　　mysql> FLUSH PRIVILEGES;

在丟失root密碼的時候，可以這樣

　　mysqld_safe --skip-grant-tables&

　　mysql -u root mysql

　　mysql> UPDATE user SET password=PASSWORD("new password") WHERE user='root';

　　mysql> FLUSH PRIVILEGES;

三：重點講解創建mysql用戶時，@后面的ip的意義：就是為了限制登陸mysql的ip，具體有如下：

1)只允許在本地登錄；

mysql>  CREATE USER 'liuwenhe'@'localhost' IDENTIFIED BY 'liuwenhelocal';

Query OK, 0 rows affected (0.00 sec)

2）允許在192.168.0網段登陸mysql；

mysql> CREATE USER 'liuwenhe'@'192.168.0.%' IDENTIFIED BY 'liuwenhe0';

Query OK, 0 rows affected (0.00 sec)

3）允許在192.168.8網段登陸mysql；

mysql> CREATE USER 'liuwenhe'@'192.168.8.%' IDENTIFIED BY 'liuwenhe8';

Query OK, 0 rows affected (0.00 sec)

4）沒有限制，也就是可以在任何網絡段登陸（前提是網絡得通）；

mysql> CREATE USER 'liuwenhe'@'%' IDENTIFIED BY 'liuwenheall';

Query OK, 0 rows affected (0.00 sec)

針對上面這幾個liuwenhe用戶做了一些測試，結果如下：

1） 'liuwenhe'@'192.168.0.%'這類的用戶是不能在本地登錄的，要想在本地登錄，需要有localhost或者127.0.0.1的登陸權限；

需要注意的是，如果你只創建了用戶 'liuwenhe'@'localhost' ，

1.mysql>  CREATE USER 'liuwenhe'@'localhost' IDENTIFIED BY 'liuwenhelocal';

Query OK, 0 rows affected (0.00 sec)

mysql> select host,user from mysql.user;

+--------------+----------+

| host         | user     |

+--------------+----------+

| %            | ogg      |

| %            | root     |

| 127.0.0.1    | root     |

| 192.168.0.%  | ncms     |

| 192.168.0.13 | rep      |

| localhost    | liuwenhe |

| localhost    | ncms     |

| localhost    | ogg      |

| localhost    | root     |

| server01     | root     |

+--------------+----------+

10 rows in set (0.00 sec)

如下兩種登陸方式都能成功：

[root@server02 ~]# mysql -uliuwenhe -pliuwenhelocal  -hlocalhost

[root@server02 ~]# mysql -uliuwenhe -pliuwenhelocal  -h227.0.0.1

2.如果你只創建了liuwenhe'@'l127.0.0.1'，

mysql> select host,user from mysql.user;

+--------------+----------+

| host         | user     |

+--------------+----------+

| %            | ogg      |

| %            | root     |

| 127.0.0.1    | liuwenhe |

| 127.0.0.1    | root     |

| 192.168.0.%  | ncms     |

| 192.168.0.13 | rep      |

| localhost    | ncms     |

| localhost    | ogg      |

| localhost    | root     |

| server01     | root     |

+--------------+----------+

10 rows in set (0.00 sec)

只能通過mysql -uliuwenhe -pliuwenhelocal  -h227.0.0.1登陸，不能通過 mysql -uliuwenhe -pliuwenhelocal  -hlocalhost登陸；

[root@server02 ~]# mysql -uliuwenhe -pliuwenhelocal  -h227.0.0.1

Warning: Using a password on the command line interface can be insecure.

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is 3628

Server version: 5.6.26-enterprise-commercial-advanced-log MySQL Enterprise Server - Advanced Edition (Commercial)

Copyright (c) 2000, 2015, 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>

不能通過localhost登陸，如下報錯：

[root@server02 ~]# mysql -uliuwenhe -pliuwenhelocal  -hlocalhost

Warning: Using a password on the command line interface can be insecure.

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

2）如果你同時創建了'liuwenhe'@'192.168.0.%'和'liuwenhe'@'%'這兩個用戶，那么當你從192.168.0網段去登陸數據庫的時候，'liuwenhe'@'%'用戶是不能登陸數據庫的，只能通過'liuwenhe'@'192.168.0.%'登陸，但是當你刪除'liuwenhe'@'192.168.0.%'用戶的時候，'liuwenhe'@'%'用戶就可以登陸了，可以理解為mysql優先并且只會驗證匹配度高的用戶，

具體驗證過程如下：

mysql> select host,user from mysql.user;

+--------------+----------+

| host         | user     |

+--------------+----------+

| %            | liuwenhe |

| %            | ogg      |

| %            | root     |

| 127.0.0.1    | root     |

| 192.168.0.%  | liuwenhe |

| 192.168.0.%  | ncms     |

| 192.168.0.13 | rep      |

| localhost    | ncms     |

| localhost    | ogg      |

| localhost    | root     |

| server01     | root     |

+--------------+----------+

11 rows in set (0.00 sec)

在另一臺機器S244（192.168.0.244）嘗試登陸mysql：

使用'liuwenhe'@'%'用戶登錄失敗：如下

[root@S244 ~]# mysql -uliuwenhe -pliuwenheall  -h292.168.0.12

Warning: Using a password on the command line interface can be insecure.

ERROR 1045 (28000): Access denied for user 'liuwenhe'@'192.168.0.244' (using password: YES)

使用'liuwenhe'@'192.168.0.%'用戶登錄成功，如下：

[root@S244 ~]# mysql -uliuwenhe -pliuwenhe0  -h292.168.0.12

Warning: Using a password on the command line interface can be insecure.

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is 3679

Server version: 5.6.26-enterprise-commercial-advanced-log MySQL Enterprise Server - Advanced Edition (Commercial)

Copyright (c) 2000, 2014, 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>

當你刪除'liuwenhe'@'192.168.0.%'用戶的時候，'liuwenhe'@'%'用戶就可以登陸了，如下：

mysql> delete from mysql.user where user='liuwenhe' and host='192.168.0.%';

Query OK, 1 row affected (0.00 sec)

mysql> flush privileges;

Query OK, 0 rows affected (0.00 sec)

依舊在另一臺機器S244（192.168.0.244）嘗試使用'liuwenhe'@'%'用戶登陸mysql，成功了：

[root@S244 ~]# mysql -uliuwenhe -pliuwenheall  -h292.168.0.12

Warning: Using a password on the command line interface can be insecure.

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is 3681

Server version: 5.6.26-enterprise-commercial-advanced-log MySQL Enterprise Server - Advanced Edition (Commercial)

Copyright (c) 2000, 2014, 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>

3）我的這臺mysql所在的服務器上面有兩個ip,如下：

現在我創建了一個 'liuwenhe'@'192.168.8.%' ，

那么只能通過

mysql -uliuwenhe -pliuwenhe8 -h292.168.8.238登陸，不能通過mysql -uliuwenhe -pliuwenhe8 -h292.168.0.12登陸，同理創建了一個 'liuwenhe'@'192.168.0.%' ，只能通過

mysql -uliuwenhe -pliuwenhe0 -h292.168.0.12登陸，不能通過mysql -uliuwenhe -pliuwenhe0 -h292.168.8.238登陸

驗證如下：

mysql>  CREATE USER 'liuwenhe'@'192.168.0.%' IDENTIFIED BY 'liuwenhe0';

Query OK, 0 rows affected (0.00 sec)

mysql> flush privileges;

Query OK, 0 rows affected (0.00 sec)

mysql> exit

Bye

[root@server02 ~]# mysql -uliuwenhe -pliuwenhe0  -h292.168.0.12

Warning: Using a password on the command line interface can be insecure.

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is 3704

Server version: 5.6.26-enterprise-commercial-advanced-log MySQL Enterprise Server - Advanced Edition (Commercial)

Copyright (c) 2000, 2015, 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> exit

Bye

[root@server02 ~]# mysql -uliuwenhe -pliuwenhe0  -h292.168.8.238

Warning: Using a password on the command line interface can be insecure.

ERROR 1045 (28000): Access denied for user 'liuwenhe'@'192.168.8.238' (using password: YES)

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