本文主要给大家简单讲讲MySQL.db数据库层权限该如何设置，相关专业术语大家可以上网查查或者找一些相关书籍补充一下，这里就不涉猎了，我们就直奔主题吧，希望mysql.db数据库层权限该如何设置这篇文章可以给大家带来一些实际帮助。
创新互联坚持“要么做到，要么别承诺”的工作理念，服务领域包括：成都网站设计、成都网站建设、企业官网、英文网站、手机端网站、网站推广等服务，满足客户于互联网时代的芮城网站设计、移动媒体设计的需求，帮助企业找到有效的互联网解决方案。努力成为您成熟可靠的网络建设合作伙伴！
1# 数据库层权限记录位置
表级别的权限记录在mysql.tables_priv表中。
(root@localhost)[mysql]> (root@localhost)[mysql]> desc tables_priv;
+-------------+-----------------------------------------------------------------------------------------------------------------------------------+------+-----+-------------------+-----------------------------+
| Field | Type | Null | Key | Default | Extra |
+-------------+-----------------------------------------------------------------------------------------------------------------------------------+------+-----+-------------------+-----------------------------+
| Host | char(60) | NO | PRI | | |
| Db | char(64) | NO | PRI | | |
| User | char(16) | NO | PRI | | |
| Table_name | char(64) | NO | PRI | | |
| Grantor | char(77) | NO | MUL | | |
| Timestamp | timestamp | NO | | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP |
| Table_priv | set('Select','Insert','Update','Delete','Create','Drop','Grant','References','Index','Alter','Create View','Show view','Trigger') | NO | | | |
| Column_priv | set('Select','Insert','Update','References') | NO | | | |
+-------------+-----------------------------------------------------------------------------------------------------------------------------------+------+-----+-------------------+-----------------------------+
8 rows in set (0.00 sec)然而关于数据库层面的权限记录在mysql.db表中
(root@localhost)[mysql]> desc db;
+-----------------------+---------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-----------------------+---------------+------+-----+---------+-------+
| Host | char(60) | NO | PRI | | |
| Db | char(64) | NO | PRI | | |
| User | char(16) | NO | PRI | | |
| Select_priv | enum('N','Y') | NO | | N | |
| Insert_priv | enum('N','Y') | NO | | N | |
| Update_priv | enum('N','Y') | NO | | N | |
| Delete_priv | enum('N','Y') | NO | | N | |
| Create_priv | enum('N','Y') | NO | | N | |
| Drop_priv | enum('N','Y') | NO | | N | |
| Grant_priv | enum('N','Y') | NO | | N | |
| References_priv | enum('N','Y') | NO | | N | |
| Index_priv | enum('N','Y') | NO | | N | |
| Alter_priv | enum('N','Y') | NO | | N | |
| Create_tmp_table_priv | enum('N','Y') | NO | | N | |
| Lock_tables_priv | enum('N','Y') | NO | | N | |
| Create_view_priv | enum('N','Y') | NO | | N | |
| Show_view_priv | enum('N','Y') | NO | | N | |
| Create_routine_priv | enum('N','Y') | NO | | N | |
| Alter_routine_priv | enum('N','Y') | NO | | N | |
| Execute_priv | enum('N','Y') | NO | | N | |
| Event_priv | enum('N','Y') | NO | | N | |
| Trigger_priv | enum('N','Y') | NO | | N | |
+-----------------------+---------------+------+-----+---------+-------+
22 rows in set (0.00 sec)
(root@localhost)[mysql]> select * from db\G
*************************** 1. row ***************************
Host: %
Db: sample
User: test1
Select_priv: Y
Insert_priv: N
Update_priv: N
Delete_priv: N
Create_priv: Y
Drop_priv: N
Grant_priv: N
References_priv: N
Index_priv: N
Alter_priv: N
Create_tmp_table_priv: N
Lock_tables_priv: N
Create_view_priv: N
Show_view_priv: N
Create_routine_priv: N
Alter_routine_priv: N
Execute_priv: N
Event_priv: N
Trigger_priv: N
1 row in set (0.00 sec)这条对应的grant语句是：
(root@localhost)[mysql]> show grants for test1; +------------------------------------------------------------------------------------------------------+ | Grants for test1@% | +------------------------------------------------------------------------------------------------------+ | GRANT USAGE ON *.* TO 'test1'@'%' IDENTIFIED BY PASSWORD '*CFA887C680E792C2DCF622D56FB809E3F8BE63CC' | | GRANT SELECT, CREATE ON `sample`.* TO 'test1'@'%' | | GRANT ALL PRIVILEGES ON `sample`.`smp` TO 'test1'@'%' | | GRANT SELECT ON `mysql`.`user` TO 'test1'@'%' | +------------------------------------------------------------------------------------------------------+ 4 rows in set (0.00 sec)
第二条：
GRANT SELECT, CREATE ON sample.* TO 'test1'@'%'
尝试再增加权限：
(root@localhost)[mysql]> grant all privileges on sample.* to test1; Query OK, 0 rows affected (0.00 sec) (root@localhost)[mysql]> (root@localhost)[mysql]> (root@localhost)[mysql]> select * from db\G *************************** 1. row *************************** Host: % Db: sample User: test1 Select_priv: Y Insert_priv: Y Update_priv: Y Delete_priv: Y Create_priv: Y Drop_priv: Y Grant_priv: N References_priv: Y Index_priv: Y Alter_priv: Y Create_tmp_table_priv: Y Lock_tables_priv: Y Create_view_priv: Y Show_view_priv: Y Create_routine_priv: Y Alter_routine_priv: Y Execute_priv: Y Event_priv: Y Trigger_priv: Y 1 row in set (0.00 sec)
授予all privileges权限。注意点是grant option并不包含在all privileges里面。可以用with子句
(root@localhost)[mysql]> grant all privileges on sample.* to test1 with grant option; Query OK, 0 rows affected (0.00 sec) (root@localhost)[mysql]> select * from db\G *************************** 1. row *************************** Host: % Db: sample User: test1 Select_priv: Y Insert_priv: Y Update_priv: Y Delete_priv: Y Create_priv: Y Drop_priv: Y Grant_priv: Y References_priv: Y Index_priv: Y Alter_priv: Y Create_tmp_table_priv: Y Lock_tables_priv: Y Create_view_priv: Y Show_view_priv: Y Create_routine_priv: Y Alter_routine_priv: Y Execute_priv: Y Event_priv: Y Trigger_priv: Y 1 row in set (0.00 sec)
回收all privileges权限, 错误写法，revoke并不能带with grant option来回收grant option
(root@localhost)[mysql]> revoke all privileges on sample.* from test1 with grant option; ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'grant option' at line 1 (root@localhost)[mysql]>
这样写还是不对：
revoke all privileges, grant option on sample.* from test1; ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'on sample.* from test1' at line 1
分开写就可以了：
(root@localhost)[mysql]> revoke all privileges on sample.* from test1; Query OK, 0 rows affected (0.00 sec) (root@localhost)[mysql]> revoke grant option on sample.* from test1; Query OK, 0 rows affected (0.00 sec) (root@localhost)[mysql]>
grant option在授予的时候是用with子句，回收的时候需要单独回收。
2#一般用户可访问的数据库：
在test1用户下，查看可以访问的数据库：
(test1@localhost)[(none)]> show databases -> ; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | sample | +--------------------+ 3 rows in set (0.00 sec) (test1@localhost)[(none)]> (test1@localhost)[(none)]> (test1@localhost)[(none)]> (test1@localhost)[(none)]> use mysql; Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A Database changed (test1@localhost)[mysql]> show tables; +-----------------+ | Tables_in_mysql | +-----------------+ | user | #由于只有user表上被授予了select权限，所以show tables只能看到一个表 +-----------------+ 1 row in set (0.00 sec) (test1@localhost)[mysql]> show grants; +---------------------------------------------------------------------+ | Grants for test1@% | +---------------------------------------------------------------------+ | GRANT USAGE ON *.* TO 'test1'@'%' IDENTIFIED BY PASSWORD| | GRANT ALL PRIVILEGES ON `sample`.* TO 'test1'@'%' WITH GRANT OPTION | | GRANT ALL PRIVILEGES ON `sample`.`smp` TO 'test1'@'%' | | GRANT SELECT ON `mysql`.`user` TO 'test1'@'%' | +---------------------------------------------------------------------+ 4 rows in set (0.00 sec)-----------------------------------------------------------------+ | Grants for test1@% | +-------------------------------------------------------------------+ | GRANT USAGE ON *.* TO 'test1'@'%' IDENTIFIED BY PASSWORD | | GRANT ALL PRIVILEGES ON `sample`.`smp` TO 'test1'@'%' | | GRANT SELECT ON `mysql`.`user` TO 'test1'@'%' | +-------------------------------------------------------------------+ 3 rows in set (0.00 sec) (test1@localhost)[mysql]>
sample数据库是被授予的all privileges,所以全库的表对象都是可用呗test1用户访问。至于mysql，只有user表上有一个select权限，所以也被归类在可用访问的数据库之列，但是实际上用show tables只能看到一个表。
3# 数据库层权限的从无到有，给一个用户授予权限后，db表的变化：
a# 建立一个新的数据库sample2
(root@localhost)[(none)]> create database sample2; Query OK, 1 row affected (0.00 sec)
这个时候查看用户test1所拥有的数据库权限，是只有sample数据库。MYSQL数据库并不显示。
(root@localhost)[mysql]> select * from db\G *************************** 1. row *************************** Host: % Db: sample User: test1 Select_priv: Y Insert_priv: Y Update_priv: Y Delete_priv: Y Create_priv: Y Drop_priv: Y Grant_priv: Y References_priv: Y Index_priv: Y Alter_priv: Y Create_tmp_table_priv: Y Lock_tables_priv: Y Create_view_priv: Y Show_view_priv: Y Create_routine_priv: Y Alter_routine_priv: Y Execute_priv: Y Event_priv: Y Trigger_priv: Y 1 row in set (0.00 sec) (root@localhost)[mysql]> #这个时候test1用户去尝试访问sample2数据库也是失败的： (test1@localhost)[sample]> use sample2 ERROR 1044 (42000): Access denied for user 'test1'@'%' to database 'sample2' (test1@localhost)[sample]>
运行授权语句，对test1受援sample2的select权限，这个时候mysql.db数据库中出现了2行数据，多了一行关于sample2的记录：
(root@localhost)[mysql]> select * from db\G *************************** 1. row *************************** Host: % Db: sample2 User: test1 Select_priv: Y Insert_priv: N Update_priv: N Delete_priv: N Create_priv: N Drop_priv: N Grant_priv: N References_priv: N Index_priv: N Alter_priv: N Create_tmp_table_priv: N Lock_tables_priv: N Create_view_priv: N Show_view_priv: N Create_routine_priv: N Alter_routine_priv: N Execute_priv: N Event_priv: N Trigger_priv: N *************************** 2. row *************************** Host: % Db: sample User: test1 Select_priv: Y Insert_priv: Y Update_priv: Y Delete_priv: Y Create_priv: Y Drop_priv: Y Grant_priv: Y References_priv: Y Index_priv: Y Alter_priv: Y Create_tmp_table_priv: Y Lock_tables_priv: Y Create_view_priv: Y Show_view_priv: Y Create_routine_priv: Y Alter_routine_priv: Y Execute_priv: Y Event_priv: Y Trigger_priv: Y 2 rows in set (0.00 sec)
从记录可用看到test1用户对sample2数据库拥有select权限。也就是访问权限，表示里面的对象都具有。但是里面是没有表的。
(test1@localhost)[(none)]> use sample2; Database changed (test1@localhost)[sample2]> show tables; Empty set (0.00 sec)
#并且test1用户可用select出smp表的数据。 (test1@localhost)[sample2]> select * from smp; +------+------+ | id | name | +------+------+ | 1 | aaa | +------+------+ 1 row in set (0.00 sec) # 然而test1用户并不显示的拥有任在sample2上的表权限。所谓的权限的继承。 (test1@localhost)[information_schema]> select * from TABLE_PRIVILEGES where TABLE_SCHEMA='sample2'; Empty set (0.00 sec)
#奇怪，并没有给表smp授权select，受援的是select on sample2.*。尝试单独对表收回select 权限：
(root@localhost)[sample2]> revoke select on sample2.smp from test1; ERROR 1147 (42000): There is no such grant defined for user 'test1' on host '%' on table 'smp' #以失败告终。显示的revoke并不能收回隐式继承来的权限。 (test1@localhost)[sample2]> show tables; +-------------------+ | Tables_in_sample2 | +-------------------+ | smp | +-------------------+ 1 row in set (0.00 sec)
mysql.db数据库层权限该如何设置就先给大家讲到这里，对于其它相关问题大家想要了解的可以持续关注我们的行业资讯。我们的板块内容每天都会捕捉一些行业新闻及专业知识分享给大家的。
