1、查看当前系统数据库
# mysql -uroot -p
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| erp |
+--------------------+
3 rows in set (0.00 sec)2、切换数据库
mysql> use erp;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed2. 权限回收准备工作
1、统计当前环境所有的用户（%表示所有机器可访问；127.0.0.1、localhost表示本机可访问）
mysql> SELECT DISTINCT CONCAT(‘User: ‘‘‘,user,‘‘‘@‘‘‘,host,‘‘‘;‘) AS query FROM mysql.user;
+-----------------------------------------+
| query |
+-----------------------------------------+
| User: ‘root‘@‘%‘; |
| User: ‘root‘@‘127.0.0.1‘; |
| User: ‘root‘@‘::1‘; |
| User: ‘‘@‘localhost‘; |
| User: ‘root‘@‘localhost‘; |
| User: ‘erp‘@‘%‘; |
+-----------------------------------------+
5 rows in set (0.00 sec)2、统计业务用户具有哪些权限以用户名erp举例如下
mysql> show grants for ‘erp‘@‘%‘;
+------------------------------------------------------------------------------------+
| Grants for erp@% |
+------------------------------------------------------------------------------------+
| GRANT USAGE ON *.* TO ‘erp‘@‘%‘ IDENTIFIED BY PASSWORD ‘*******‘ |
| GRANT ALL PRIVILEGES ON `ump`.* TO ‘ump‘@‘%‘ |
+------------------------------------------------------------------------------------+
2 rows in set (0.00 sec)3. 操作回收高危权限
1、回收所有权限或回收某一权限，比如drop权限
mysql> revoke all privileges on erp.* from ‘erp‘@‘%‘;
mysql> revoke drop on erp.* from ‘erp‘@‘%‘;
mysql> flush privileges;备注：
（1）列举部分特殊的服务器权限及其功能说明：
super：拥有此权限允许用户终止任何查询；修改全局变量的SET语句；使用CHANGE MASTER，PURGE MASTER LOGS
shutdown：关闭数据库
show databases：查看数据库
replication client：查询master server、slave server状态
replication slave：查看从服务器
reload：拥有此权限才可执行flush [tables | logs | privileges]
process：拥有此权限才可以执行SHOW PROCESSLIST和KILL命令
file：拥有file权限才可以执行 select ..into outfile和load data infile…操作（2）普通用户权限及其功能说明：
all：允许任何操作(usage权限不能被回收)
usage：只允许登录
alter：修改数据库的表
alter routine：修改/删除存储过程
create：创建表
create routine：创建存储过程
create temporary tables：创建临时表
create：创建新的数据库或表
create view：创建视图
delete：删除表数据
drop：删除数据库/表
event：创建/更改/删除/查看事件
execute：执行权限
grant option：将自身所拥有的权限授予其他用户
index：创建/删除索引
insert：添加表数据
lock tables：锁表
references：将其它表的一个字段作为某一个表的外键约束
select：查询表数据
show view：查看视图
trigger：创建触发器
update：更新表数据2、重新授权必要权限
mysql> grant select,insert,alter,update,delete,create,execute on erp.* to ‘erp‘@‘%‘ ;
mysql> flush privileges;3、确认权限
mysql> show grants for ‘erp‘@‘%‘;4. 注意事项
1）、file, process, super为危险权限，切勿权限授予管理员以外的账号；
mysql> revoke file,process,super on erp.* from ‘erp‘@‘%‘;2）、查看某个或所有用户的服务器权限，确认普通账号没有授权上述三种危险权限
mysql> select * from mysql.user where user=‘erp‘\G;
*************************** 1. row ***************************
Host: %
User: erp
Password: *33F471D4D8A84CD6C0
Select_priv: N
Insert_priv: N
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 (0.00 sec)
mysql> select * from mysql.user \G;3）、授予某张表权限，权限信息保存在mysql.tables_priv表中
mysql> grant select on dbname.tablename to ‘username‘@‘%‘ with grant option;
mysql> select * from mysql.tables_priv;
select * from mysql.tables_priv;
+-----------+-----+-------+------------+----------------+---------------------+-------+
| Host | Db | User | Table_name | Grantor | Timestamp | Table_priv | Column_priv |
+-----------+-----+-------+------------+----------------+---------------------+-------+
| % | dbname | username | tablename | root@localhost | 0000-00-00 00:00:00 | Select,Grant | |
+-----------+-----+-------+------------+----------------+---------------------+-------+4）、授予某个字段权限，权限信息保存在mysql.columns_priv表中
mysql> grant select(Column_name) on dbname.tablename to ‘username‘@‘%‘ with grant option;
mysql> select * from mysql.columns_priv;
select * from mysql.columns_priv;
+-----------+-----+-------+------------+-------------+---------------------+----------+
| Host | Db | User | Table_name | Column_name | Timestamp | Column_priv |
+-----------+-----+-------+------------+-------------+---------------------+----------+
| % | dbname | username | tablename | Column_name | 0000-00-00 00:00:00 | Select|
+-----------+-----+-------+------------+-------------+---------------------+----------+5）、当使用如下命令回收权限时，它回收的只是全局的权限，username用户其他的权限，比如对dbname数据库的权限，对tablename表的权限，对某个Column_name字段的权限仍然持有。
mysql> revoke all privileges on *.* from ‘username‘@‘localhost‘;所以为了回收用户的所有权限，要使用如下命令
mysql> revoke all privileges,grant option from ‘username‘@‘%‘;