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mysql语句查询用户权限过程详解

在MySQL中,如何查看一个用户被授予了那些权限呢? 授予用户的权限可能分全局层级权限、数据库层级权限、表层级别权限、列层级别权限、子程序层级权限。具体分类如下:


全局层级

全局权限适用于一个给定服务器中的所有数据库。这些权限存储在mysql.user表中。GRANT ALL ON *.*和REVOKE ALL ON *.*只授予和撤销全局权限。


数据库层级

数据库权限适用于一个给定数据库中的所有目标。这些权限存储在mysql.db和mysql.host表中。GRANT ALL ON db_name.*和REVOKE ALL ON db_name.*只授予和撤销数据库权限。


表层级

表权限适用于一个给定表中的所有列。这些权限存储在mysql.tables_priv表中。GRANT ALL ON db_name.tbl_name和REVOKE ALL ON db_name.tbl_name只授予和撤销表权限。


列层级

列权限适用于一个给定表中的单一列。这些权限存储在mysql.columns_priv表中。当使用REVOKE时,您必须指定与被授权列相同的列。


子程序层级

CREATE ROUTINE, ALTER ROUTINE, EXECUTE和GRANT权限适用于已存储的子程序。这些权限可以被授予为全局层级和数据库层级。而且,除了CREATE ROUTINE外,这些权限可以被授予为子程序层级,并存储在mysql.procs_priv表中。


1:那么我们来创建一个测试账号test,授予全局层级的权限。如下所示:

mysql> grant select,insert on *.* to test@’%’ identified by ‘test’;

Query OK, 0 rows affected (0.01 sec)

mysql> flush privileges;

Query OK, 0 rows affected (0.00 sec)

mysql> 那么可以用下面两种方式查询授予test的权限。如下所示:

mysql> show grants for test;

+————————————————————————————————————–+

| Grants for test@% |

+————————————————————————————————————–+

| GRANT SELECT, INSERT ON *.* TO ‘test’@’%’ IDENTIFIED BY PASSWORD ‘*94BDCEBE19083CE2A1F959FD02F964C7AF4CFC29’ |

+————————————————————————————————————–+

1 row in set (0.00 sec)

mysql> select * from mysql.user where user=’test’\G;

*************************** 1. row ***************************

Host: %

User: test

Password: *94BDCEBE19083CE2A1F959FD02F964C7AF4CFC29

Select_priv: Y

Insert_priv: Y

Update_priv: N

Delete_priv: N

Create_priv: N

Drop_priv: N

Reload_priv: N

Shutdown_priv: N

Process_priv: N

File_priv: N

Grant_priv: N

References_priv: N

Index_priv: N

Alter_priv: N

Show_db_priv: N

Super_priv: N

Create_tmp_table_priv: N

Lock_tables_priv: N

Execute_priv: N

Repl_slave_priv: N

Repl_client_priv: N

Create_view_priv: N

Show_view_priv: N

Create_routine_priv: N

Alter_routine_priv: N

Create_user_priv: N

Event_priv: N

Trigger_priv: N

Create_tablespace_priv: N

ssl_type:

ssl_cipher:

x509_issuer:

x509_subject:

max_questions: 0

max_updates: 0

max_connections: 0

max_user_connections: 0

plugin: mysql_native_password

authentication_string:

password_expired: N

1 row in set (0.04 sec)

ERROR:

No query specified

mysql>

2:那么我们来创建一个测试账号test,授予数据库层级的权限。如下所示:

mysql> drop user test;

Query OK, 0 rows affected (0.00 sec)

mysql> grant select,insert,update,delete on MyDB.* to test@’%’ identified by ‘test’;

Query OK, 0 rows affected (0.01 sec)

mysql>

mysql> select * from mysql.user where user=’test’\G; –可以看到无任何授权。

mysql> select * from mysql.db where user=’test’\G;

*************************** 1. row ***************************

Host: %

Db: MyDB

User: test

Select_priv: Y

Insert_priv: Y

Update_priv: Y

Delete_priv: Y

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

1 row in set (0.04 sec)

ERROR:

No query specified

mysql>

mysql> show grants for test;

+—————————————————————————————————–+

| Grants for test@% |

+—————————————————————————————————–+

| GRANT USAGE ON *.* TO ‘test’@’%’ IDENTIFIED BY PASSWORD ‘*94BDCEBE19083CE2A1F959FD02F964C7AF4CFC29’ |

| GRANT SELECT, INSERT, UPDATE, DELETE ON `MyDB`.* TO ‘test’@’%’ |

+—————————————————————————————————–+

2 rows in set (0.00 sec)

mysql>
3:那么我们来创建一个测试账号test,授予表层级的权限。如下所示:

mysql> drop user test;

Query OK, 0 rows affected (0.00 sec)

mysql> flush privileges;

Query OK, 0 rows affected (0.00 sec)

mysql> grant all on MyDB.kkk to test@’%’ identified by ‘test’;

Query OK, 0 rows affected (0.01 sec)

mysql>

mysql> show grants for test;

+—————————————————————————————————–+

| Grants for test@% |

+—————————————————————————————————–+

| GRANT USAGE ON *.* TO ‘test’@’%’ IDENTIFIED BY PASSWORD ‘*94BDCEBE19083CE2A1F959FD02F964C7AF4CFC29’ |

| GRANT ALL PRIVILEGES ON `MyDB`.`kkk` TO ‘test’@’%’ |

+—————————————————————————————————–+

2 rows in set (0.00 sec)

mysql> select * from mysql.tables_priv\G;

*************************** 1. row ***************************

Host: %

Db: MyDB

User: test

Table_name: kkk

Grantor: root@localhost

Timestamp: 0000-00-00 00:00:00

Table_priv: Select,Insert,Update,Delete,Create,Drop,References,Index,Alter,Create View,Show view,Trigger

Column_priv:

1 row in set (0.01 sec)

ERROR:

No query specified

mysql>


4:那么我们来创建一个测试账号test,授予列层级的权限。如下所示:

mysql> drop user test;

Query OK, 0 rows affected (0.00 sec)

mysql> flush privileges;

Query OK, 0 rows affected (0.00 sec)

mysql> grant select (id, col1) on MyDB.TEST1 to test@’%’ identified by ‘test’;

Query OK, 0 rows affected (0.01 sec)

mysql> flush privileges;

Query OK, 0 rows affected (0.00 sec)

mysql>

mysql> select * from mysql.columns_priv;

+——+——+——+————+————-+———————+————-+

| Host | Db | User | Table_name | Column_name | Timestamp | Column_priv |

+——+——+——+————+————-+———————+————-+

| % | MyDB | test | TEST1 | id | 0000-00-00 00:00:00 | Select |

| % | MyDB | test | TEST1 | col1 | 0000-00-00 00:00:00 | Select |

+——+——+——+————+————-+———————+————-+

2 rows in set (0.00 sec)

mysql> show grants for test;

+—————————————————————————————————–+

| Grants for test@% |

+—————————————————————————————————–+

| GRANT USAGE ON *.* TO ‘test’@’%’ IDENTIFIED BY PASSWORD ‘*94BDCEBE19083CE2A1F959FD02F964C7AF4CFC29’ |

| GRANT SELECT (id, col1) ON `MyDB`.`TEST1` TO ‘test’@’%’ |

+—————————————————————————————————–+

2 rows in set (0.00 sec)

mysql>


5:那么我们来创建一个测试账号test,授子程序层级的权限。如下所示:

mysql> DROP PROCEDURE IF EXISTS PRC_TEST;

Query OK, 0 rows affected (0.00 sec)

mysql> DELIMITER //

mysql> CREATE PROCEDURE PRC_TEST()

-> BEGIN

-> SELECT * FROM kkk;

-> END //

Query OK, 0 rows affected (0.00 sec)

mysql> DELIMITER ;

mysql> grant execute on procedure MyDB.PRC_TEST to test@’%’ identified by ‘test’;

Query OK, 0 rows affected (0.01 sec)

mysql> flush privileges;

Query OK, 0 rows affected (0.00 sec)

mysql>

mysql> show grants for test;

+—————————————————————————————————–+

| Grants for test@% |

+—————————————————————————————————–+

| GRANT USAGE ON *.* TO ‘test’@’%’ IDENTIFIED BY PASSWORD ‘*94BDCEBE19083CE2A1F959FD02F964C7AF4CFC29’ |

| GRANT EXECUTE ON PROCEDURE `MyDB`.`prc_test` TO ‘test’@’%’ |

+—————————————————————————————————–+

2 rows in set (0.00 sec)

mysql> select * from mysql.procs_priv where User=’test’;

+——+——+——+————–+————–+—————-+———–+———————+

| Host | Db | User | Routine_name | Routine_type | Grantor | Proc_priv | Timestamp |

+——+——+——+————–+————–+—————-+———–+———————+

| % | MyDB | test | PRC_TEST | PROCEDURE | root@localhost | Execute | 0000-00-00 00:00:00 |

+——+——+——+————–+————–+—————-+———–+———————+

1 row in set (0.00 sec)

mysql>

所以,如果需要查看用户被授予的权限,就需要从这五个层级来查看被授予的权限。从上到下或从小到上,逐一检查各个层级被授予的权限。

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