在CentOS7下添加MySQL用户并设置相应权限

1.进入mysql命令行，输入root及密码

[root@localhost ~]# mysql -u root -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 19
Server version: 5.7.22 MySQL Community Server (GPL)
 
Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.
 
Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners.
 
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
 
mysql> 

2.用户管理及权限设置
// 管理用户

mysql> use mysql;
Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A
 
Database changed

 
//查询用户

mysql> select host,user from user;
+-----------+---------------+
| host      | user          |
+-----------+---------------+
| %         | root          |
| %         | test          |
| localhost | mysql.session |
| localhost | mysql.sys     |
| localhost | root          |
+-----------+---------------+
5 rows in set (0.00 sec)

 
//建立用户（用户：admin，密码:123456）

mysql> create user admin identified by '123456';
Query OK, 0 rows affected (0.00 sec)

 
// 删除用户admin

mysql> drop user admin;
Query OK, 0 rows affected (0.00 sec)

 
// 从新建立用户（用户：admins，密码:123456）

mysql> create user admins identified by '123456';
Query OK, 0 rows affected (0.00 sec)
 
mysql> select host, user from user;
+-----------+---------------+
| host      | user          |
+-----------+---------------+
| %         | admins        |
| %         | root          |
| %         | test          |
| localhost | mysql.session |
| localhost | mysql.sys     |
| localhost | root          |
+-----------+---------------+
6 rows in set (0.00 sec)
 
// 查看用户admins的权限
mysql> show grants for admins;
+------------------------------------+
| Grants for admins@%                |
+------------------------------------+
| GRANT USAGE ON *.* TO 'admins'@'%' |
+------------------------------------+
1 row in set (0.00 sec)
 
// 赋予权限（给用户admins，授予数据库test的查询权限）
mysql> grant select on test.* to admins;
Query OK, 0 rows affected (0.00 sec)
 
// 查看用户admins的权限
mysql> show grants for admins;
+------------------------------------------+
| Grants for admins@%                      |
+------------------------------------------+
| GRANT USAGE ON *.* TO 'admins'@'%'       |
| GRANT SELECT ON `test`.* TO 'admins'@'%' |
+------------------------------------------+
2 rows in set (0.00 sec)
 
// 收回权限（对用户admins，收回数据库test的查询权限）
mysql> revoke select on test.* from admins;
Query OK, 0 rows affected (0.01 sec)
 
// 查看用户admins的权限
mysql> show grants for admins;
+------------------------------------+
| Grants for admins@%                |
+------------------------------------+
| GRANT USAGE ON *.* TO 'admins'@'%' |
+------------------------------------+
1 row in set (0.00 sec)
 
// 赋予权限（给用户admins，授予数据库test的查询、更新、删除、插入等权限）
mysql> grant select, update, delete, insert on test.* to admins;
Query OK, 0 rows affected (0.00 sec)
 
// 查看用户admins的权限
mysql> show grants for admins;
+------------------------------------------------------------------+
| Grants for admins@%                                              |
+------------------------------------------------------------------+
| GRANT USAGE ON *.* TO 'admins'@'%'                               |
| GRANT SELECT, INSERT, UPDATE, DELETE ON `test`.* TO 'admins'@'%' |
+------------------------------------------------------------------+
2 rows in set (0.01 sec)
 
// 赋予权限（给用户admins，授予数据库test的新建表、删除表或删除数据库等权限）
mysql> grant create,drop on test.* to admins;
Query OK, 0 rows affected (0.00 sec)
 
// 查看用户admins的权限
mysql> show grants for admins;
+--------------------------------------------------------------------------------+
| Grants for admins@%                                                            |
+--------------------------------------------------------------------------------+
| GRANT USAGE ON *.* TO 'admins'@'%'                                             |
| GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, DROP ON `test`.* TO 'admins'@'%' |
+--------------------------------------------------------------------------------+
2 rows in set (0.00 sec)
 
// 刷新权限（使设置的权限生效）
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
 
 
 
 
// 查看root的权限
mysql> show grants for root;
+-------------------------------------------+
| Grants for root@%                         |
+-------------------------------------------+
| GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' |
+-------------------------------------------+
1 row in set (0.00 sec)

如下是用户能够享受的常见可能权限的简短列表。

ALL PRIVILEGES - 正如咱们前面所看到的，这将容许MySQL用户访问指定的数据库（或者若是系统中没有选择数据库）
CREATE-容许他们建立新的表或数据库
DROP-容许他们删除表或数据库
DELETE-容许他们从表中删除行
INSERT-容许它们向表中插入行
SELECT-容许他们使用Select命令来读取数据库
UPDATE-容许他们更新表行
GRANT OPTION - 容许他们授予或删除其余用户的权限
 

要向特定用户提供权限，能够使用此框架：

GRANT [type of permission] ON [database name].[table name] TO ‘[username]’@'localhost’;

若是要向其授予对任何数据库或任何表的访问权限，请确保在数据库名称或表名称的地方放置星号（*）。
每次更新或更改权限时，请务必使用Flush Privileges命令。

若是您须要撤消权限，则结构与授予的结构几乎相同：
REVOKE [type of permission] ON [database name].[table name] FROM ‘[username]’@‘localhost’;

正如您能够使用DROP删除数据库同样，您能够使用DROP彻底删除用户：
DROP USER ‘demo’@‘localhost’;

要测试您的新用户，请经过键入注销
quit

并使用此命令在终端中从新登陆： mysql -u [username]-p