MySQL Study之--MySQL用户及权限管理

MySQL Study之--MySQL用户及权限管理

    MySQLserver通过MySQL权限表来控制用户对数据库的訪问。MySQL权限表存放在mysql数据库里。由mysql_install_db脚本初始化。

这些MySQL权限表分别user，db，table_priv。columns_priv和host。以下分别介绍一下这些表的结构和内容：

user权限表：记录同意连接到server的用户帐号信息，里面的权限是全局级的。
db权限表：记录各个帐号在各个数据库上的操作权限。
table_priv权限表：记录数据表级的操作权限。
columns_priv权限表：记录数据列级的操作权限。
host权限表：配合db权限表对给定主机上数据库级操作权限作更仔细的控制。

这个权限表不受GRANT和REVOKE语句的影响。

案例分析：

一、创建用户并授权（root用户)
[root@mysrv ~]# mysql -u root -poracle

mysql> select version()g
+-------------------------------------------+
| version()                                 |
+-------------------------------------------+
| 5.6.25-enterprise-commercial-advanced-log |
+-------------------------------------------+
1 row in set (0.00 sec)
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| prod               |
| test               |
+--------------------+
5 rows in set (0.01 sec)


1、建立tom用户并授权（特权管理用户）

mysql> grant all on prod.* to 'tom'@'%' identified by 'tom' with grant option;
Query OK, 0 rows affected (0.00 sec)

查看用户创建是否成功：
mysql> select user,host from user ;

+-------+-----------+
| user  | host      |
+-------+-----------+
| tom   | %         |
| root  | 127.0.0.1 |
| root  | ::1       |
|       | localhost |
| root  | localhost |
| scott | localhost |
|       | mysrv     |
| root  | mysrv     |
+-------+-----------+
8 rows in set (0.00 sec)

查看tom用户的授权：
mysql> show grants for tom;
+----------------------------------------------------------------------------------------------------+
| Grants for tom@%                                                                                   |
+----------------------------------------------------------------------------------------------------+
| GRANT USAGE ON *.* TO 'tom'@'%' IDENTIFIED BY PASSWORD '*71FF744436C7EA1B954F6276121DB5D2BF68FC07' |
| GRANT ALL PRIVILEGES ON `prod`.* TO 'tom'@'%' WITH GRANT OPTION                                    |
+----------------------------------------------------------------------------------------------------+

GRANT 语法: 
GRANT privileges (columns)
    ON what
    TO user IDENTIFIED BY "password"
    WITH GRANT OPTION


权限列表:
ALTER: 改动表和索引。
CREATE: 创建数据库和表。
DELETE: 删除表中已有的记录。
DROP: 抛弃(删除)数据库和表。
INDEX: 创建或抛弃索引。
INSERT: 向表中插入新行。

REFERENCE: 未用。

SELECT: 检索表中的记录。
UPDATE: 改动现存表记录。
FILE: 读或写server上的文件。

PROCESS: 查看server中运行的线程信息或杀死线程。
RELOAD: 重载授权表或清空日志、主机缓存或表缓存。
SHUTDOWN: 关闭server。
ALL: 全部权限。ALL PRIVILEGES同义词。

USAGE: 特殊的 "无权限" 权限。
用 户账户包含 "username" 和 "host" 两部分，后者表示该用户被同意从何地接入。

tom@'%' 表示不论什么地址，默认能够省略。还能够是 "tom@192.168.1.%"、"tom@%.abc.com" 等。数据库格式为 db@table，能够是 "test.*" 或 "*.*"，前者表示 test 数据库的全部表，后者表示全部数据库的全部表。 
子句 "WITH GRANT OPTION" 表示该用户能够为其它用户分配权限。 


2、我们用 root 再创建几个用户。然后由 test 数据库的管理员tom为他们分配权限。

mysql> create user 'tom1' identified by 'tom1' ,'tom2' identified by 'tom2';
Query OK, 0 rows affected (0.00 sec)

mysql> select user,host from user ;

+-------+-----------+
| user  | host      |
+-------+-----------+
| tom   | %         |
| tom1  | %         |
| tom2  | %         |
| root  | 127.0.0.1 |
| root  | ::1       |
|       | localhost |
| root  | localhost |
| scott | localhost |
|       | mysrv     |
| root  | mysrv     |
+-------+-----------+
10 rows in set (0.00 sec)

root用户退出，tom登陆，并授权用户訪问prod库

[root@mysrv ~]# mysql -u tom -ptom    
ERROR 1045 (28000): Access denied for user 'tom'@'localhost' (using password: YES)

tom用户竟不能登陆！

！！

再对tom用户授权：
mysql> grant all on prod.* to 'tom'@'localhost' identified by 'tom' with grant option;;
Query OK, 0 rows affected (0.00 sec)

mysql> show grants for tom;
+----------------------------------------------------------------------------------------------------+
| Grants for tom@%                                                                                   |
+----------------------------------------------------------------------------------------------------+
| GRANT USAGE ON *.* TO 'tom'@'%' IDENTIFIED BY PASSWORD '*71FF744436C7EA1B954F6276121DB5D2BF68FC07' |
| GRANT ALL PRIVILEGES ON `prod`.* TO 'tom'@'%' WITH GRANT OPTION                                    |
+----------------------------------------------------------------------------------------------------+
2 rows in set (0.00 sec)

mysql> use mysql;
Database changed
mysql> select user,host from user ;

+-------+-----------+
| user  | host      |
+-------+-----------+
| tom   | %         |
| tom1  | %         |
| tom2  | %         |
| root  | 127.0.0.1 |
| root  | ::1       |
|       | localhost |
| root  | localhost |
| scott | localhost |
| tom   | localhost |
|       | mysrv     |
| root  | mysrv     |
+-------+-----------+
11 rows in set (0.00 sec)

tom登陆：
[root@mysrv ~]# mysql -u tom -ptom prod

mysql> select database();
+------------+
| database() |
+------------+
| prod       |
+------------+
1 row in set (0.01 sec)

mysql> select current_user();
+----------------+
| current_user() |
+----------------+
| tom@localhost  |
+----------------+
1 row in set (0.00 sec)

创建表：

mysql> show tables;
+----------------+
| Tables_in_prod |
+----------------+
| t1             |
+----------------+
1 row in set (0.00 sec)

mysql> create table t2 as select * from t1;
Query OK, 3 rows affected (0.15 sec)
Records: 3  Duplicates: 0  Warnings: 0

查看表信息：

mysql> desc t2;
+-------+-------------+------+-----+---------+-------+
| Field | Type        | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| id    | int(11)     | YES  |     | NULL    |       |
| name  | varchar(10) | YES  |     | NULL    |       |
+-------+-------------+------+-----+---------+-------+
2 rows in set (0.01 sec)

mysql> show create table t2;
+-------+---------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table                                                                                                              |
+-------+---------------------------------------------------------------------------------------------------------------------------+
| t2    | CREATE TABLE `t2` (
  `id` int(11) DEFAULT NULL,
  `name` varchar(10) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1 |
+-------+---------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.01 sec)

mysql> show create table t2G;
*************************** 1. row ***************************
       Table: t2
Create Table: CREATE TABLE `t2` (
  `id` int(11) DEFAULT NULL,
  `name` varchar(10) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1
1 row in set (0.00 sec)

mysql> select * from t2;
+------+-------+
| id   | name  |
+------+-------+
|   10 | tom   |
|   20 | jerry |
|   30 | rose  |
+------+-------+
3 rows in set (0.00 sec)

3、tom用户为tom1，tom2授权
mysql> grant select on prod.* to tom1;
Query OK, 0 rows affected (0.00 sec)

mysql> grant select on prod.* to tom2;
Query OK, 0 rows affected (0.02 sec)

mysql> grant insert,update on prod.* to tom2;
Query OK, 0 rows affected (0.00 sec)

tom2登陆（从远程登陆）：

C:UsersAdministrator>mysql -h 192.168.8.240 -utom2 -ptom2

mysql> select database();
+------------+
| database() |
+------------+
| NULL       |
+------------+
1 row in set (0.00 sec)

mysql> use prod;
Database changed
mysql> select database();
+------------+
| database() |
+------------+
| prod       |
+------------+
1 row in set (0.00 sec)

mysql> select current_user();
+----------------+
| current_user() |
+----------------+
| tom2@%         |
+----------------+
1 row in set (0.00 sec)

mysql> show grants for tom2;
+------------------------------------------------------------------+
| Grants for tom2@%                                                |
+------------------------------------------------------------------+
| GRANT USAGE ON *.* TO 'tom2'@'%' IDENTIFIED BY PASSWORD <secret> |
| GRANT SELECT, INSERT, UPDATE ON `prod`.* TO 'tom2'@'%'           |
+------------------------------------------------------------------+
2 rows in set (0.00 sec)

mysql> show tables;
+----------------+
| Tables_in_prod |
+----------------+
| t1             |
| t2             |
+----------------+
2 rows in set (0.00 sec)

mysql> select * from t1;
+------+-------+
| id   | name  |
+------+-------+
|   10 | tom   |
|   20 | jerry |
|   30 | rose  |
+------+-------+
3 rows in set (0.00 sec)

mysql> select * from t2;
+------+-------+
| id   | name  |
+------+-------+
|   10 | tom   |
|   20 | jerry |
|   30 | rose  |
+------+-------+
3 rows in set (0.00 sec)

mysql> insert into t1 values (40,'john');
Query OK, 1 row affected (0.00 sec)
mysql> commit;
Query OK, 0 rows affected (0.09 sec)

mysql> select * from t1;
+------+-------+
| id   | name  |
+------+-------+
|   10 | tom   |
|   20 | jerry |
|   30 | rose  |
|   40 | john  |
+------+-------+
4 rows in set (0.00 sec)

mysql> update t1 set name='ellen' where id=40;
Query OK, 1 row affected (0.01 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> select * from t1;
+------+-------+
| id   | name  |
+------+-------+
|   10 | tom   |
|   20 | jerry |
|   30 | rose  |
|   40 | ellen |
+------+-------+
4 rows in set (0.00 sec)

mysql> delete from t1;
ERROR 1142 (42000): DELETE command denied to user 'tom2'@'192.168.8.254' for tab
le 't1'
mysql> commit;
Query OK, 0 rows affected (0.05 sec)

mysql> select * from t1;
+------+-------+
| id   | name  |
+------+-------+
|   10 | tom   |
|   20 | jerry |
|   30 | rose  |
|   40 | ellen |
+------+-------+
4 rows in set (0.00 sec)


4、回收tom2的update权限：
mysql> revoke update on prod.* from tom2;
Query OK, 0 rows affected (0.00 sec)

tom2再又一次登陆：
C:UsersAdministrator>mysql -h 192.168.8.240 -utom2 -ptom2

mysql> use prod;
Database changed
mysql> update t1 set name='lily' where id=10;
ERROR 1142 (42000): UPDATE command denied to user 'tom2'@'192.168.8.254' for tab
le 't1'
---update失败！

二、改动用户口令：

1、root用户改动普通用户口令
mysql> set password for tom1=password('oracle');
Query OK, 0 rows affected (0.01 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

tom1又一次登陆：
C:UsersAdministrator>mysql -h 192.168.8.240 -utom1 -ptom1
Warning: Using a password on the command line interface can be insecure.
ERROR 1045 (28000): Access denied for user 'tom1'@'192.168.8.254' (using passwor
d: YES)
---旧口令登陆失败！

C:UsersAdministrator>mysql -h 192.168.8.240 -utom1 -poracle
mysql>

2、普通用户改动自己password：
C:UsersAdministrator>mysql -h 192.168.8.240 -utom1 -poracle
mysql> set password=password('tom1');
Query OK, 0 rows affected (0.00 sec)

又一次登陆：
C:UsersAdministrator>mysql -h 192.168.8.240 -utom1 -ptom1
mysql>
---新password登陆成功 ！

三、删除用户：

1、回收用户全部权限
mysql> revoke all on prod.* from tom2;
Query OK, 0 rows affected (0.01 sec)

2、删除用户
mysql> drop user tom2;
Query OK, 0 rows affected (0.00 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

mysql> select user,host from user;

+-------+-----------+
| user  | host      |
+-------+-----------+
| jerry | %         |
| rose  | %         |
| tom   | %         |
| tom1  | %         |
| root  | 127.0.0.1 |
| root  | ::1       |
|       | localhost |
| jerry | localhost |
| root  | localhost |
| rose  | localhost |
| scott | localhost |
| tom   | localhost |
|       | mysrv     |
| root  | mysrv     |
+-------+-----------+
14 rows in set (0.00 sec)

------- 摘要 -------------------------------------- 

创建用户:
GRANT insert, update ON testdb.* TO user1@'%' IDENTIFIED BY 'password' WITH GRANT OPTION;
CREATE USER user2 IDENTIFIED BY 'password';
分配权限:
GRANT select ON testdb.* TO user2;
查看权限:
SHOW GRANTS FOR user1;
改动password:
SET PASSWORD FOR user1 = PASSWORD('newpwd');
SET PASSWORD = PASSWORD('newpwd');
移除权限:
REVOKE all ON *.* FROM user1; 
删除用户:
DROP USER user1;
数据库列表:
SHOW DATABASES;
数据表列表:
SHOW TABLES;
当前数据库:
SELECT DATABASE();
当前用户:
SELECT USER();
数据表结构:
DESCRIBE table1;
刷新权限:
FLUSH PRIVILEGES;

grant和revoke能够在几个层次上控制訪问权限
1，整个server，使用 grant ALL  和revoke  ALL
2，整个数据库。使用on  database.*
3。特点表，使用on  database.table
4，特定的列
5，特定的存储过程
 
user表中host列的值的意义
%              匹配全部主机
localhost    localhost不会被解析成IP地址，直接通过UNIXsocket连接
127.0.0.1      会通过TCP/IP协议连接，而且仅仅能在本机訪问；
::1                 ::1就是兼容支持ipv6的。表示同ipv4的127.0.0.1
 
grant 普通数据用户，查询、插入、更新、删除 数据库中全部表数据的权利。
grant select on testdb.* to common_user@’%’
grant insert on testdb.* to common_user@’%’
grant update on testdb.* to common_user@’%’
grant delete on testdb.* to common_user@’%’
或者，用一条 MySQL 命令来替代：
grant select, insert, update, delete on testdb.* to common_user@’%’
grant 数据库开发者，创建表、索引、视图、存储过程、函数。。。

等权限。
grant 创建、改动、删除 MySQL 数据表结构权限。
grant create on testdb.* to developer@’192.168.0.%’;
grant alter on testdb.* to developer@’192.168.0.%’;
grant drop on testdb.* to developer@’192.168.0.%’;
grant 操作 MySQL 外键权限。

grant references on testdb.* to developer@’192.168.0.%’;
grant 操作 MySQL 暂时表权限。

grant create temporary tables on testdb.* to developer@’192.168.0.%’;
grant 操作 MySQL 索引权限。

grant index on testdb.* to developer@’192.168.0.%’;
grant 操作 MySQL 视图、查看视图源码 权限。
grant create view on testdb.* to developer@’192.168.0.%’;
grant show view on testdb.* to developer@’192.168.0.%’;
grant 操作 MySQL 存储过程、函数 权限。

grant create routine on testdb.* to developer@’192.168.0.%’; -- now, can show procedure status
grant alter routine on testdb.* to developer@’192.168.0.%’; -- now, you can drop a procedure
grant execute on testdb.* to developer@’192.168.0.%’;
grant 普通 DBA 管理某个 MySQL 数据库的权限。
grant all privileges on testdb to dba@’localhost’
当中，keyword “privileges” 能够省略。
grant 高级 DBA 管理 MySQL 中全部数据库的权限。
grant all on *.* to dba@’localhost’

MySQL grant 权限，分别能够作用在多个层次上。
1. grant 作用在整个 MySQL server上：
grant select on *.* to dba@localhost; -- dba 能够查询 MySQL 中全部数据库中的表。

grant all on *.* to dba@localhost; -- dba 能够管理 MySQL 中的全部数据库
2. grant 作用在单个数据库上：
grant select on testdb.* to dba@localhost; -- dba 能够查询 testdb 中的表。
3. grant 作用在单个数据表上：
grant select, insert, update, delete on testdb.orders to dba@localhost;
4. grant 作用在表中的列上：
grant select(id, se, rank) on testdb.apache_log to dba@localhost;
5. grant 作用在存储过程、函数上：
grant execute on procedure testdb.pr_add to ’dba’@’localhost’
grant execute on function testdb.fn_add to ’dba’@’localhost’

注意：改动完权限以后 一定要刷新服务。或者重新启动服务。刷新服务用：FLUSH PRIVILEGES。