mysql权限管理(一)
当我们安装完mysql后,可以发现登陆mysql后会创建一个mysql的数据库
打开mysql数据库后可以发现有许多表
user表
mysql> desc user;
+------------------------+-----------------------------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+------------------------+-----------------------------------+------+-----+---------+-------+
| Host | char(60) | NO | PRI | | |
| User | char(16) | NO | PRI | | |
| Password | char(41) | NO | | | |
| 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 | |
| Reload_priv | enum('N','Y') | NO | | N | |
| Shutdown_priv | enum('N','Y') | NO | | N | |
| Process_priv | enum('N','Y') | NO | | N | |
| File_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 | |
| Show_db_priv | enum('N','Y') | NO | | N | |
| Super_priv | enum('N','Y') | NO | | N | |
| Create_tmp_table_priv | enum('N','Y') | NO | | N | |
| Lock_tables_priv | enum('N','Y') | NO | | N | |
| Execute_priv | enum('N','Y') | NO | | N | |
| Repl_slave_priv | enum('N','Y') | NO | | N | |
| Repl_client_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 | |
| Create_user_priv | enum('N','Y') | NO | | N | |
| Event_priv | enum('N','Y') | NO | | N | |
| Trigger_priv | enum('N','Y') | NO | | N | |
| Create_tablespace_priv | enum('N','Y') | NO | | N | |
| ssl_type | enum('','ANY','X509','SPECIFIED') | NO | | | |
| ssl_cipher | blob | NO | | NULL | |
| x509_issuer | blob | NO | | NULL | |
| x509_subject | blob | NO | | NULL | |
| max_questions | int(11) unsigned | NO | | 0 | |
| max_updates | int(11) unsigned | NO | | 0 | |
| max_connections | int(11) unsigned | NO | | 0 | |
| max_user_connections | int(11) unsigned | NO | | 0 | |
| plugin | char(64) | YES | | | |
| authentication_string | text | YES | | NULL | |
+------------------------+-----------------------------------+------+-----+---------+-------+
可以发现,我们登陆的信息其实都保存在这里面,同时还有数据库表等访问权限.权限列是以priv结尾的字段.这些权限包括了查询,修改,关闭服务,超级权限,加载用户等高级权限,高级权限就是用于数据库的管理权限 如果要修改权限可以使用grant命令来修改权限,同时也可以使用update表来修改. grant_priv表示是否有grant执行权限.shutdown_priv是否有关闭mysql服务权限.super_priv表示是否有超级权限,execute_priv表示是否有执行存储过程和韩束等功能 ssl_type,ssl_cipher,x509_issuer,x509_subject,其中ssl表示用来加密,x509标准用来标识用户,通常数据库不支持ssl,可以使用show variables like 'have_openssl' 来查看是否有ssl功能,如果值为Disabled,表示不支持ssl功能 max_questions,max_updates,max_connections和ma_user_connections.前面两个是允许每小时查询和更新的次数,max_connections表示每小时可以建立多少个连接,max_user_connections表示单个用户可以同时具有的连接数,默认为0,表示无限制
2. db表和host表
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 | |
+-----------------------+---------------+------+-----+---------+-------+
mysql> desc host;
+-----------------------+---------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-----------------------+---------------+------+-----+---------+-------+
| Host | char(60) | NO | PRI | | |
| Db | char(64) | 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 | |
| Trigger_priv | enum('N','Y') | NO | | N | |
+-----------------------+---------------+------+-----+---------+-------+
db表对应了用户和每个数据库中的具体权限
Host,Db,User分别代表主机名,数据库名称,用户名
host表是db表的扩展,如果db表中找不到host字段的值,那么就会到host表中去查,但是host表很少用到,通常db表的设置已经满足要求了
可以发现db表和host表的权限几乎一模一样.create_routine_priv,alter_routine_priv表示用户是否具有创建和修改存储过程的权限而user表是针对所有数据库设置的,如果user表的select_priv为Y,那么该用户可以查看所有mysql中数据库表,如果只设置用户只有数据库test表的查询权限,那么select_priv设置为N,而这个select_priv权限则记录在db表中.db表中的select_priv的值为Y,由此可知,数据库权限先由表user来查找,然后再db表
3.tables_priv表和columns_priv
tables_priv可以对单个表进行权限设置.columns_priv可以对单个数据列权限设置
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)
mysql> desc columns_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 | | |
| Column_name | char(64) | NO | PRI | | |
| Timestamp | timestamp | NO | | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP |
| Column_priv | set('Select','Insert','Update','References') | NO | | | |
+-------------+----------------------------------------------+------+-----+-------------------+-----------------------------+
7 rows in set (0.00 sec)
tables_priv表中Table_priv可以发现只能选择set集合里面的权限,Timestamp表示权限需改的时间,Grantor表示的是权限是谁设置的.Column_priv表示可以对所有列的操作
columns_priv表中Column_name表示要设置的列,Column_priv其实跟上述描述的一样
4.procs_priv表
procs_priv表可以对存储过程和存储函数进行权限设置
mysql> desc procs_priv
-> ;
+--------------+----------------------------------------+------+-----+-------------------+-----------------------------+
| Field | Type | Null | Key | Default | Extra |
+--------------+----------------------------------------+------+-----+-------------------+-----------------------------+
| Host | char(60) | NO | PRI | | |
| Db | char(64) | NO | PRI | | |
| User | char(16) | NO | PRI | | |
| Routine_name | char(64) | NO | PRI | | |
| Routine_type | enum('FUNCTION','PROCEDURE') | NO | PRI | NULL | |
| Grantor | char(77) | NO | MUL | | |
| Proc_priv | set('Execute','Alter Routine','Grant') | NO | | | |
| Timestamp | timestamp | NO | | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP |
+--------------+----------------------------------------+------+-----+-------------------+-----------------------------+
routine_name表示存储过程或函数的名字,其他的都在set或者enum里面设置了不用我解释了.