MySQL 數據庫賦權

1、進入數據庫，查看數據庫賬戶

# 進入數據庫
mysql –u root –p
---> 輸入密碼...

# 使用 mysql 庫
use mysql; 

# 展示 mysql 庫中所有表
show tables; 

# 查看數據庫中 用戶地址 和 用戶
select host,user from user;

2、新增用戶

insert into user (Host,User,Password)values('localhost','zhengying',password('123456'));

# 查詢驗證用戶新增成功
select host,user from user;

3、查看用戶權限

# 查看 MySQL 數據庫中所有用戶
mysql> select distinct concat('User: ''',user,'''@''',host,''';') as query from mysql.user;

+---------------------------------------+
| query                                 |
+---------------------------------------+
| User: 'root'@'127.0.0.1';             |
| User: ''@'localhost';                 |
| User: 'evan'@'localhost';             |
| User: 'root'@'localhost';             |
| User: 'zhengying'@'localhost';        |
| User: ''@'localhost.localdomain';     |
| User: 'root'@'localhost.localdomain'; |
+---------------------------------------+

# 查看 MySQL 數據庫中 zhengying 用戶的權限
mysql> show grants for 'zhengying'@'localhost';
# error 報錯提示 zhengying 用戶沒有權限
ERROR 1141 (42000): There is no such grant defined for user 'zhengying' on host 'localhost'

4、對用戶賦權

• 當 權限1，權限2，權限3，權限n 被 all privileges 或者 all 代替，表示賦予用戶全部權限
• 當 數據庫名稱.表名稱 被 *.* 代替，表示賦予用戶操作服務器上所有數據庫所有表的權限
• 用戶地址可以是 localhost，也可以是 IP 地址，機器名字，域名，還可以用 "%" 表示從任何地址連接
• 連接口令 不能為空，否則創建失敗

mysql> grant 權限1,權限2,…權限n on 數據庫名稱.表名稱 to "用戶名"@"用戶地址" identified by "連接口令";

# 給用戶賦所有權限
mysql> grant all privileges on *.* to "zhengying"@"%" identified by "123456";

# 刷新權限
mysql> flush privileges;  

mysql> grant select,insert,update,delete,create,drop on user.t_user to "zhengying"@"localhost" identified by "123456";
# 給本機用戶 zhengying 分配可對數據庫 user 的 t_user 表進行select,insert,update,delete,create,drop 等操作的權限，並設定口令為 123456

# 刷新權限
mysql> flush privileges;

mysql> grant all privileges on user.* to "zhengying"@"localhost" identified by "123456";
# 給本機用戶 zhengying 分配可對數據庫 user 所有表進行所有操作的權限，並設定口令為 123456

# 刷新權限
mysql> flush privileges;

# 查看用戶權限
mysql> show grants for 'zhengying'@'localhost';

+-------------------------------------------------------------------------------------------------------------------+
| Grants for zhengying@localhost                                                                                    |
+-------------------------------------------------------------------------------------------------------------------+
| GRANT ALL PRIVILEGES ON `user`.* TO 'zhengying'@'localhost'                                                       |
+-------------------------------------------------------------------------------------------------------------------+

5、取消用戶權限

• revoke select on *.* from 'evan'@'localhost';　　取消用戶 evan 的 select 權限
• revoke all on *.* from 'evan'@'localhost';　　取消用戶 evan 的所有權限

mysql> show grants for 'evan'@'localhost';
+--------------------------------------------------------------------------------------------------------------+
| Grants for evan@localhost                                                                                    |
+--------------------------------------------------------------------------------------------------------------+
| GRANT SELECT ON *.* TO 'evan'@'localhost' IDENTIFIED BY PASSWORD '*6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9' |
+--------------------------------------------------------------------------------------------------------------+

# 取消用戶 evan 的 select 權限
mysql> revoke select on *.* from 'evan'@'localhost';

mysql> flush privileges;

mysql> show grants for 'evan'@'localhost';
+-------------------------------------------------------------------------------------------------------------+
| Grants for evan@localhost                                                                                   |
+-------------------------------------------------------------------------------------------------------------+
| GRANT USAGE ON *.* TO 'evan'@'localhost' IDENTIFIED BY PASSWORD '*6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9' |
+-------------------------------------------------------------------------------------------------------------+