mysql語句查詢使用者許可權過程詳解
阿新 • • 發佈：2020-01-09
在MySQL中，如何檢視一個使用者被授予了那些許可權呢？ 授予使用者的許可權可能分全域性層級許可權、資料庫層級許可權、表層級別許可權、列層級別許可權、子程式層級許可權。具體分類如下：
全域性層級
全域性許可權適用於一個給定伺服器中的所有資料庫。這些許可權儲存在mysql.user表中。GRANT ALL ON *.*和REVOKE ALL ON *.*只授予和撤銷全域性許可權。
資料庫層級
資料庫許可權適用於一個給定資料庫中的所有目標。這些許可權儲存在mysql.db和mysql.host表中。GRANT ALL ON db_name.*和REVOKE ALL ON db_name.*只授予和撤銷資料庫許可權。
表層級
表許可權適用於一個給定表中的所有列。這些許可權儲存在mysql.tables_priv表中。GRANT ALL ON db_name.tbl_name和REVOKE ALL ON db_name.tbl_name只授予和撤銷表許可權。
列層級
列許可權適用於一個給定表中的單一列。這些許可權儲存在mysql.columns_priv表中。當使用REVOKE時，您必須指定與被授權列相同的列。
子程式層級
CREATE ROUTINE,ALTER ROUTINE,EXECUTE和GRANT許可權適用於已儲存的子程式。這些許可權可以被授予為全域性層級和資料庫層級。而且，除了CREATE ROUTINE外，這些許可權可以被授予為子程式層級，並存儲在mysql.procs_priv表中。
1：那麼我們來建立一個測試賬號test，授予全域性層級的許可權。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>
那麼可以用下面兩種方式查詢授予test的許可權。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：那麼我們來建立一個測試賬號test，授予資料庫層級的許可權。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; --可以看到無任何授權。 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：那麼我們來建立一個測試賬號test，授予表層級的許可權。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：那麼我們來建立一個測試賬號test，授予列層級的許可權。如下所示：
mysql> drop user test; 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 (0.00 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：那麼我們來建立一個測試賬號test，授子程式層級的許可權。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 (0.00 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，如果需要檢視使用者被授予的許可權，就需要從這五個層級來檢視被授予的許可權。從上到下或從小到上，逐一檢查各個層級被授予的許可權。
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