MySQL Study之--MySQL用户及权限管理

今天药忘吃喽~ 2022-08-02 14:36 327阅读 0赞

**MySQL Study之--MySQL用户及权限管理**

MySQL服务器通过MySQL权限表来控制用户对数据库的访问，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。下面分别介绍一下这些表的结构和内容：

**user权限表**：记录允许连接到服务器的用户帐号信息，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细致的控制。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 ;**

**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: 修改表和索引。  
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: 修改现存表记录。  
FILE: 读或写服务器上的文件。  
PROCESS: 查看服务器中执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: 关闭服务器。  
ALL: 所有权限，ALL PRIVILEGES同义词。  
USAGE: 特殊的 "无权限" 权限。  
用 户账户包括 "username" 和 "host" 两部分，后者表示该用户被允许从何地接入。tom@'%' 表示任何地址，默认可以省略。还可以是 "tom@192.168.1.%"、"tom@%.abc.com" 等。数据库格式为 db@table，可以是 "test.\*" 或 "\*.\*"，前者表示 test 数据库的所有表，后者表示所有数据库的所有表。   
**子句 "WITH GRANT OPTION" 表示该用户可以为其他用户分配权限。 **  
  
  
**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，并授权用户访问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 t2\\G;**  
\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* 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:\\Users\\Administrator>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再重新登陆：**  
**C:\\Users\\Administrator>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、修改用户口令：**  
  
**1、root用户修改普通用户口令**  
**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重新登陆：**  
**C:\\Users\\Administrator>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:\\Users\\Administrator>mysql -h 192.168.8.240 -utom1 -poracle**  
**mysql>**  
  
**2、普通用户修改自己密码：**  
**C:\\Users\\Administrator>mysql -h 192.168.8.240 -utom1 -poracle**  
**mysql> set password=password('tom1');**  
Query OK, 0 rows affected (0.00 sec)  
  
**重新登陆：  
C:\\Users\\Administrator>mysql -h 192.168.8.240 -utom1 -ptom1**  
**mysql>**  
\---新密码登陆成功 ！

**三、删除用户：**

**1、回收用户所有权限**  
 **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;**

**------- 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;  
**修改密码:**  
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可以在几个层次上控制访问权限**  
1，整个服务器，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**  
%              匹配所有主机  
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，并且只能在本机访问；  
::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 数据库中所有表数据的权利。**  
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 数据库开发人员，创建表、索引、视图、存储过程、函数。。。等权限。**  
grant 创建、修改、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 临时表权限。**  
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、查看视图源代码 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’  
其中，关键字 “privileges” 可以省略。  
**grant 高级 DBA 管理 MySQL 中所有数据库的权限。**  
grant all on \*.\* to dba@’localhost’

**MySQL grant 权限，分别可以作用在多个层次上。**  
**1. grant 作用在整个 MySQL 服务器上：**  
grant select on \*.\* to dba@localhost; -- dba 可以查询 MySQL 中所有数据库中的表。  
grant all on \*.\* to dba@localhost; -- dba 可以管理 MySQL 中的所有数据库  
**2. grant 作用在单个数据库上：**  
grant select on testdb.\* to dba@localhost; -- dba 可以查询 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：修改完权限以后 一定要刷新服务，或者重启服务，刷新服务用：FLUSH PRIVILEGES。**