mysql数据库用户授权 mysql 数据库授权

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mob64ca14079fb3 2023-10-30 17:26:12

文章标签 mysql数据库用户授权 mysql 授权 mysql ide 字段 文章分类 MySQL 数据库

grant 授权

什么是用户授权：在数据库服务器上添加新的连接用户，并设置权限和密码。

为什么要用授权：如果没有授权用户，那么只能有root用户在本机登陆数据库，其它用户无法登陆。

没有授权时，其它主机也无法访问数据库。

指令格式:

mysql> grant 权限列表 on 库名 to 用户名@"客户端地址" identified by "密码" ;

权限列表:

all 所有权限

usage 只能连接上数据库，没有任何权限

select,update,inseret ... 个别权限，这个权限对所有字段有效

select,update(字段1,字段2...) 只能对指定的字段有相应的权

库名:

*.* 所有库所有表

库名.* 一个库

库名.表名一张表

用户名:

授权时可以自定义,要有标识性,容易记,可以名中看出用途存储在mysql库的user表里

客户端地址:

% 表示互联网上的所有主机0

192.168.4.% 网段内的所有主机

192.168.4.1 1台主机

localhost 数据库服务器本机

授权举例1:

添加admin用户,允许从192.168.4.0/24网段连接,对db3库的user表有查询权限,密码为123456

mysql> grant select on db3.user to admin@"192.168.4.%" identified by "123456";

授权举例2:

添加admin2,允许从本机连接,允许以db3库的所有表有查询,更新,插入删除记录权限,密码为123456

mysql> grant select ,insert,update,delete on db3.* toadmin2@"localhost" identifiedby "123456";

授权库

grant授权的信息是保存在授权库中的，mysql库记录了授权信息，主要的表如下：

user 记录已有的授权用户及权限

db 记录已有授权用户对数据库的访问权限

tables_priv 记录已有授权用户对表的访问权限

columns_priv 记录已有授权用户对字段的访问权限

一查看当前columns_priv，tables_priv,db,user表中的授权用户

mysql> select user,host,db,table_name,column_name frommysql.columns_priv;

Emptyset (0.00sec) #columns_priv表当前为空，说明当前数据库没有真对某些字段的授权mysql> select user,host,db,table_name frommysql.tables_priv;

+-----------+-----------+-----+------------+ #tables_priv表中只有系统默认的授权用户msyql.sys
| user | host | db | table_name |
+-----------+-----------+-----+------------+
| mysql.sys | localhost | sys | sys_config |
+-----------+-----------+-----+------------+mysql> select user,host,db frommysql.db;+-----------+-----------+-----+ #db表中也是系统默认授权用户mysql.sys
| user | host | db |
+-----------+-----------+-----+
| mysql.sys | localhost | sys |
+-----------+-----------+-----+mysql> select user,host from mysql.user;+-----------+-----------+ #user表中有系统默认用户mysql.sys和root
| user | host |
+-----------+-----------+
| mysql.sys | localhost |
| root | localhost |
+-----------+-----------+二 添加真对school.student表中“学号”，“姓名”，“性别”这三个字段的授权用户col_user
mysql> grant select,update(学号,姓名,性别),insert on school.student to col_user@'%' identified by "123456";mysql> select user,host,db,table_name,column_name frommysql.columns_priv;
#在columns_priv表中查看授权用户,每条记录是一个授权字段+----------+------+--------+------------+-------------+
| user | host | db | table_name | column_name |
+----------+------+--------+------------+-------------+
| col_user | % | school | student | 姓名 |
| col_user | % | school | student | 学号 |
| col_user | % | school | student | 性别 |
+----------+------+--------+------------+-------------+mysql> select user,host,db,table_name frommysql.tables_priv;+-----------+-----------+--------+------------+ #在tables_priv表中也可以看到该用户对school.student表有访问权限
| user | host | db | table_name | #具体权限需要用show grants查看
+-----------+-----------+--------+------------+
| col_user | % | school | student |
| mysql.sys | localhost | sys | sys_config |
+-----------+-----------+--------+------------+
mysql> show grants for col_user@'%';                 #通过show grants查看col_user对school.student的具体权限
+-----------------------------------------------------------------------------------------------+
| Grants for col_user@%                                                                         |
+-----------------------------------------------------------------------------------------------+
| GRANT USAGE ON *.* TO 'col_user'@'%'                                                          |
| GRANT SELECT, INSERT, UPDATE (性别, 学号, 姓名) ON `school`.`student` TO 'col_user'@'%'         |
+-----------------------------------------------------------------------------------------------+
mysql> select user,host,db frommysql.db;+-----------+-----------+-----+ #db表中看不到该用户
| user | host | db |
+-----------+-----------+-----+
| mysql.sys | localhost | sys |
+-----------+-----------+-----+mysql> select user,host from mysql.user;+-----------+-----------+ #在user表中可以看到该用户
| user | host |
+-----------+-----------+
| col_user | % |
| mysql.sys | localhost |
| root | localhost |
+-----------+-----------+mysql>三 添加授权用户tab_user1,tab_user2对表school.teacher，school.student的访问权限
mysql> grant all on school.teacher to tab_user1@'%' identified by "123456";mysql> grant select on school.student to tab_user2@'%' identified by "123456";mysql> select user,host,db,table_name,column_name frommysql.columns_priv;
#colunm_priv表中授权记录的用户没有变化+----------+------+--------+------------+-------------+
| user | host | db | table_name | column_name |
+----------+------+--------+------------+-------------+
| col_user | % | school | student | 姓名 |
| col_user | % | school | student | 学号 |
| col_user | % | school | student | 性别 |
+----------+------+--------+------------+-------------+#tables_priv表中可以看到tab_user1,tab_user2用户
mysql> select user,host,db,table_name frommysql.tables_priv;+-----------+-----------+--------+------------+
| user | host | db | table_name |
+-----------+-----------+--------+------------+
| col_user | % | school | student |
| tab_user1 | % | school | teacher |
| tab_user2 | % | school | student |
| mysql.sys | localhost | sys | sys_config |
+-----------+-----------+--------+------------+mysql> show grants for tab_user1@'%'; #通过show grants可以看出tab_user1,tab_user2的具体授权权限+---------------------------------------------------------------+
| Grants for tab_user1@% |
+---------------------------------------------------------------+
| GRANT USAGE ON *.* TO 'tab_user1'@'%' |
| GRANT ALL PRIVILEGES ON `school`.`teacher` TO 'tab_user1'@'%' |
+---------------------------------------------------------------+mysql> show grants for tab_user2@'%';+-------------------------------------------------------+
| Grants for tab_user2@% |
+-------------------------------------------------------+
| GRANT USAGE ON *.* TO 'tab_user2'@'%' |
| GRANT SELECT ON `school`.`student` TO 'tab_user2'@'%' |
+-------------------------------------------------------+mysql> select user,host,db frommysql.db; #db表中没有变化+-----------+-----------+-----+
| user | host | db |
+-----------+-----------+-----+
| mysql.sys | localhost | sys |
+-----------+-----------+-----+mysql> select user,host from mysql.user; #user表中可以看到tab_user1,tab_user2+-----------+-----------+
| user | host |
+-----------+-----------+
| col_user | % |
| tab_user1 | % |
| tab_user2 | % |
| mysql.sys | localhost |
| root | localhost |

| Grants for tab_user1@% |
+---------------------------------------------------------------+
| GRANT USAGE ON *.* TO 'tab_user1'@'%' |
| GRANT ALL PRIVILEGES ON `school`.`teacher` TO 'tab_user1'@'%' |
+---------------------------------------------------------------+mysql> show grants for tab_user2@'%';+-------------------------------------------------------+
| Grants for tab_user2@% |
+-------------------------------------------------------+
| GRANT USAGE ON *.* TO 'tab_user2'@'%' |
| GRANT SELECT ON `school`.`student` TO 'tab_user2'@'%' |
+-------------------------------------------------------+mysql> select user,host,db frommysql.db; #db表中没有变化+-----------+-----------+-----+
| user | host | db |
+-----------+-----------+-----+
| mysql.sys | localhost | sys |
+-----------+-----------+-----+mysql> select user,host from mysql.user; #user表中可以看到tab_user1,tab_user2+-----------+-----------+
| user | host |
+-----------+-----------+
| col_user | % |
| tab_user1 | % |
| tab_user2 | % |
| mysql.sys | localhost |
| root | localhost |

+-----------+-----------+mysql>四 添加授权用户db_user1,db_user2用户对库school,school2的访问权限
mysql> grant all on school.* to db_user1@'%' identified by "123456";mysql> grant select on school2.* to db_user2@'%' identified by "123456";mysql> select user,host,db,table_name,column_name frommysql.columns_priv;
#只要没有对任意表中字段的授权，column_priv表不会有变化+----------+------+--------+------------+-------------+
| user | host | db | table_name | column_name |
+----------+------+--------+------------+-------------+
| col_user | % | school | student | 姓名 |
| col_user | % | school | student | 学号 |
| col_user | % | school | student | 性别 |
+----------+------+--------+------------+-------------+mysql> select user,host,db,table_name frommysql.tables_priv;
#添加了真对库的授权用户，没有对表的授权用户所以db表中也不会变化+-----------+-----------+--------+------------+
| user | host | db | table_name |
+-----------+-----------+--------+------------+
| col_user | % | school | student |
| tab_user1 | % | school | teacher |
| tab_user2 | % | school | student |
| mysql.sys | localhost | sys | sys_config |
+-----------+-----------+--------+------------+mysql> select user,host,db frommysql.db; #db表中可以看到添加的授权用户+-----------+-----------+---------+
| user | host | db |
+-----------+-----------+---------+
| db_user1 | % | school |
| db_user2 | % | school2 |
| mysql.sys | localhost | sys |
+-----------+-----------+---------+mysql> select user,host from mysql.user; #只要添加了授权用户user表中都会有记录+-----------+-----------+
| user | host |
+-----------+-----------+
| col_user | % |
| db_user1 | % |
| db_user2 | % |
| tab_user1 | % |
| tab_user2 | % |
| mysql.sys | localhost |
| root | localhost |
+-----------+-----------+mysql>五 添加授权用户user对所有库和表有访问权限
mysql> grant all on *.* to user@'%' identified by "123456";mysql> select user,host,db,table_name,column_name frommysql.columns_priv;+----------+------+--------+------------+-------------+
| user | host | db | table_name | column_name |
+----------+------+--------+------------+-------------+
| col_user | % | school | student | 姓名 |
| col_user | % | school | student | 学号 |
| col_user | % | school | student | 性别 |
+----------+------+--------+------------+-------------+
3 rows in set (0.00sec)
mysql> select user,host,db,table_name frommysql.tables_priv;+-----------+-----------+--------+------------+
| user | host | db | table_name |
+-----------+-----------+--------+------------+
| col_user | % | school | student |
| tab_user1 | % | school | teacher |
| tab_user2 | % | school | student |
| mysql.sys | localhost | sys | sys_config |
+-----------+-----------+--------+------------+
4 rows in set (0.01sec)
mysql> select user,host,db frommysql.db;+-----------+-----------+---------+
| user | host | db |
+-----------+-----------+---------+
| db_user1 | % | school |
| db_user2 | % | school2 |
| mysql.sys | localhost | sys |
+-----------+-----------+---------+
3 rows in set (0.00sec)
mysql> select user,host from mysql.user; #只有在user表中可以看到use_user+-----------+-----------+
| user | host |
+-----------+-----------+
| col_user | % |
| db_user1 | % |
| db_user2 | % |
| tab_user1 | % |
| tab_user2 | % |
| use_user | % |
| mysql.sys | localhost |
| root | localhost |
+-----------+-----------+mysql>

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