-- 授权一个用户（zhangsan）密码123，可以对所有的库，所有的表做所有操作。
mysql> grant all on *.* to [email protected]‘%‘ identified by ‘123‘;
Query OK, 0 rows affected (0.17 sec)
--刷新生效，否则就要重启MySQL服务才可以。
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
--浏览当前MySQL用户信息
mysql> select user,host,password from mysql.user;
+----------+-----------------+-------------------------------------------+
| user | host | password |
+----------+-----------------+-------------------------------------------+
| root | localhost | *23AE809DDACAF96AF0FD78ED04B6A265E05AA257 |
| root | 127.0.0.1 | |
| | localhost | |
| zhangsan | % | *23AE809DDACAF96AF0FD78ED04B6A265E05AA257 |
| admin | 192.168.112.132 | *23AE809DDACAF96AF0FD78ED04B6A265E05AA257 |
+----------+-----------------+-------------------------------------------+
5 rows in set (0.00 sec)
-- 移除一些权限
-- revoke:只删除了用户权限，但没有删除这个用户
mysql> revoke insert,delete on *.* from [email protected] identified by‘123‘;
-- 查看指定用户的权限信息
mysql> show grants for [email protected];
+------------------------------------------------------------------------------------------------------------+
| Grants for [email protected] |
+------------------------------------------------------------------------------------------------------------+
| GRANT USAGE ON *.* TO ‘xbb‘@‘localhost‘ IDENTIFIED BY PASSWORD ‘*23AE809DDACAF96AF0FD78ED04B6A265E05AA257‘ |
+------------------------------------------------------------------------------------------------------------+
--drop user:删除了整个用户及其权限（包括数据字典中的数据）
mysql> drop user ‘xbb‘@‘localhost‘;
Query OK, 0 rows affected (0.00 sec)
mysql> select user,host from mysql.user;
+------------------+-----------+
| user | host |
+------------------+-----------+
| root | 127.0.0.1 |
| debian-sys-maint | localhost |
| root | localhost |
| root | wangxg |
+------------------+-----------+
4 rows in set (0.00 sec)
原文地址：https://www.cnblogs.com/zhouzhishuai/p/9550259.html