mysql 默认有个root用户，但是这个用户权限太大，一般只在管理数据库时候才用。如果在项目中要连接 MySQL 数据库，则建议新建一个权限较小的用户来连接。
在 MySQL 命令行模式下输入如下命令可以为 MySQL 创建一个新用户：
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CREATE USER username IDENTIFIED BY ‘password‘; |
新用户创建完成，但是此刻如果以此用户登陆的话，会报错，因为我们还没有为这个用户分配相应权限，分配权限的命令如下：
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GRANT ALL PRIVILEGES ON *.* TO ‘username‘@‘localhost‘ IDENTIFIED BY ‘password‘; |
授予username用户在所有数据库上的所有权限。
如果此时发现刚刚给的权限太大了，如果我们只是想授予它在某个数据库上的权限，那么需要切换到root 用户撤销刚才的权限，重新授权：
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EVOKE ALL PRIVILEGES ON *.* FROM ‘username‘@‘localhost‘;GRANT ALL PRIVILEGES ON wordpress.* TO ‘username‘@‘localhost‘ IDENTIFIED BY ‘password‘; |
甚至还可以指定该用户只能执行 select 和 update 命令：
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GRANT SELECT, UPDATE ON wordpress.* TO ‘username‘@‘localhost‘ IDENTIFIED BY ‘password‘; |
这样一来，再次以username登陆 MySQL，只有wordpress数据库是对其可见的，并且如果你只授权它select权限，那么它就不能执行delete 语句。
另外每当调整权限后，通常需要执行以下语句刷新权限：
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FLUSH PRIVILEGES; |
删除刚才创建的用户：
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仔细上面几个命令，可以发现不管是授权，还是撤销授权，都要指定响应的host（即 @ 符号后面的内容），因为以上及格命令实际上都是在操作mysql 数据库中的user表，可以用如下命令查看相应用户及对应的host:
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SELECT User, Host FROM user; |
MySQL Study之--MySQL用户及权限管理
MySQL服务器通过MySQL权限表来控制用户对数据库的访问，MySQL权限表存放在mysql数据库里，由mysql_install_db脚本初始化。这些MySQL权限表分别user，db，table_priv，columns_priv和host。下面分别介绍一下这些表的结构和内容：
user权限表：记录允许连接到服务器的用户帐号信息，里面的权限是全局级的。
db权限表：记录各个帐号在各个数据库上的操作权限。
table_priv权限表：记录数据表级的操作权限。
columns_priv权限表：记录数据列级的操作权限。
host权限表：配合db权限表对给定主机上数据库级操作权限作更细致的控制。这个权限表不受GRANT和REVOKE语句的影响。
案例分析：
一、创建用户并授权（root用户)
[[email protected] ~]# mysql -u root -poracle
mysql> select version()g
+-------------------------------------------+
| version() |
+-------------------------------------------+
| 5.6.25-enterprise-commercial-advanced-log |
+-------------------------------------------+
1 row in set (0.00 sec)
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| prod |
| test |
+--------------------+
5 rows in set (0.01 sec)
1、建立tom用户并授权（特权管理用户）
mysql> grant all on prod.* to ‘tom‘@‘%‘ identified by ‘tom‘ with grant option;
Query OK, 0 rows affected (0.00 sec)
查看用户创建是否成功：
mysql> select user,host from user ;
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+-------+-----------+| user | host |+-------+-----------+| tom | % || root | 127.0.0.1 || root | ::1 || | localhost || root | localhost || scott | localhost || | mysrv || root | mysrv |+-------+-----------+8 rows in set (0.00 sec) |
查看tom用户的授权：
mysql> show grants for tom;
+----------------------------------------------------------------------------------------------------+
| Grants for [email protected]% |
+----------------------------------------------------------------------------------------------------+
| GRANT USAGE ON *.* TO ‘tom‘@‘%‘ IDENTIFIED BY PASSWORD ‘*71FF744436C7EA1B954F6276121DB5D2BF68FC07‘ |
| GRANT ALL PRIVILEGES ON `prod`.* TO ‘tom‘@‘%‘ WITH GRANT OPTION |
+----------------------------------------------------------------------------------------------------+
GRANT 语法:
GRANT privileges (columns)
ON what
TO user IDENTIFIED BY "password"
WITH GRANT OPTION
权限列表:
ALTER: 修改表和索引。
CREATE: 创建数据库和表。
DELETE: 删除表中已有的记录。
DROP: 抛弃(删除)数据库和表。
INDEX: 创建或抛弃索引。
INSERT: 向表中插入新行。
REFERENCE: 未用。
SELECT: 检索表中的记录。
UPDATE: 修改现存表记录。
FILE: 读或写服务器上的文件。
PROCESS: 查看服务器中执行的线程信息或杀死线程。
RELOAD: 重载授权表或清空日志、主机缓存或表缓存。
SHUTDOWN: 关闭服务器。
ALL: 所有权限，ALL PRIVILEGES同义词。
USAGE: 特殊的 "无权限" 权限。
用 户账户包括 "username" 和 "host" 两部分，后者表示该用户被允许从何地接入。[email protected]‘%‘ 表示任何地址，默认可以省略。还可以是 "[email protected]%"、"[email protected]%.abc.com" 等。数据库格式为 [email protected]，可以是 "test.*" 或 "*.*"，前者表示 test 数据库的所有表，后者表示所有数据库的所有表。
子句 "WITH GRANT OPTION" 表示该用户可以为其他用户分配权限。
2、我们用 root 再创建几个用户，然后由 test 数据库的管理员tom为他们分配权限。
mysql> create user ‘tom1‘ identified by ‘tom1‘ ,‘tom2‘ identified by ‘tom2‘;
Query OK, 0 rows affected (0.00 sec)
mysql> select user,host from user ;
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+-------+-----------+| user | host |+-------+-----------+| tom | % || tom1 | % || tom2 | % || root | 127.0.0.1 || root | ::1 || | localhost || root | localhost || scott | localhost || | mysrv || root | mysrv |+-------+-----------+10 rows in set (0.00 sec) |
root用户退出，tom登陆，并授权用户访问prod库
[[email protected] ~]# mysql -u tom -ptom
ERROR 1045 (28000): Access denied for user ‘tom‘@‘localhost‘ (using password: YES)
tom用户竟不能登陆！！！
再对tom用户授权：
mysql> grant all on prod.* to ‘tom‘@‘localhost‘ identified by ‘tom‘ with grant option;;
Query OK, 0 rows affected (0.00 sec)
mysql> show grants for tom;
+----------------------------------------------------------------------------------------------------+
| Grants for [email protected]% |
+----------------------------------------------------------------------------------------------------+
| GRANT USAGE ON *.* TO ‘tom‘@‘%‘ IDENTIFIED BY PASSWORD ‘*71FF744436C7EA1B954F6276121DB5D2BF68FC07‘ |
| GRANT ALL PRIVILEGES ON `prod`.* TO ‘tom‘@‘%‘ WITH GRANT OPTION |
+----------------------------------------------------------------------------------------------------+
2 rows in set (0.00 sec)
mysql> use mysql;
Database changed
mysql> select user,host from user ;
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+-------+-----------+| user | host |+-------+-----------+| tom | % || tom1 | % || tom2 | % || root | 127.0.0.1 || root | ::1 || | localhost || root | localhost || scott | localhost || tom | localhost || | mysrv || root | mysrv |+-------+-----------+11 rows in set (0.00 sec) |
tom登陆：
[[email protected] ~]# mysql -u tom -ptom prod
mysql> select database();
+------------+
| database() |
+------------+
| prod |
+------------+
1 row in set (0.01 sec)
mysql> select current_user();
+----------------+
| current_user() |
+----------------+
| [email protected] |
+----------------+
1 row in set (0.00 sec)
创建表：
mysql> show tables;
+----------------+
| Tables_in_prod |
+----------------+
| t1 |
+----------------+
1 row in set (0.00 sec)
mysql> create table t2 as select * from t1;
Query OK, 3 rows affected (0.15 sec)
Records: 3 Duplicates: 0 Warnings: 0
查看表信息：
mysql> desc t2;
+-------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| id | int(11) | YES | | NULL | |
| name | varchar(10) | YES | | NULL | |
+-------+-------------+------+-----+---------+-------+
2 rows in set (0.01 sec)
mysql> show create table t2;
+-------+---------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table |
+-------+---------------------------------------------------------------------------------------------------------------------------+
| t2 | CREATE TABLE `t2` (
`id` int(11) DEFAULT NULL,
`name` varchar(10) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1 |
+-------+---------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.01 sec)
mysql> show create table t2G;
*************************** 1. row ***************************
Table: t2
Create Table: CREATE TABLE `t2` (
`id` int(11) DEFAULT NULL,
`name` varchar(10) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1
1 row in set (0.00 sec)
mysql> select * from t2;
+------+-------+
| id | name |
+------+-------+
| 10 | tom |
| 20 | jerry |
| 30 | rose |
+------+-------+
3 rows in set (0.00 sec)
3、tom用户为tom1，tom2授权
mysql> grant select on prod.* to tom1;
Query OK, 0 rows affected (0.00 sec)
mysql> grant select on prod.* to tom2;
Query OK, 0 rows affected (0.02 sec)
mysql> grant insert,update on prod.* to tom2;
Query OK, 0 rows affected (0.00 sec)
tom2登陆（从远程登陆）：
C:UsersAdministrator>mysql -h 192.168.8.240 -utom2 -ptom2
mysql> select database();
+------------+
| database() |
+------------+
| NULL |
+------------+
1 row in set (0.00 sec)
mysql> use prod;
Database changed
mysql> select database();
+------------+
| database() |
+------------+
| prod |
+------------+
1 row in set (0.00 sec)
mysql> select current_user();
+----------------+
| current_user() |
+----------------+
| [email protected]% |
+----------------+
1 row in set (0.00 sec)
mysql> show grants for tom2;
+------------------------------------------------------------------+
| Grants for [email protected]% |
+------------------------------------------------------------------+
| GRANT USAGE ON *.* TO ‘tom2‘@‘%‘ IDENTIFIED BY PASSWORD |
| GRANT SELECT, INSERT, UPDATE ON `prod`.* TO ‘tom2‘@‘%‘ |
+------------------------------------------------------------------+
2 rows in set (0.00 sec)
mysql> show tables;
+----------------+
| Tables_in_prod |
+----------------+
| t1 |
| t2 |
+----------------+
2 rows in set (0.00 sec)
mysql> select * from t1;
+------+-------+
| id | name |
+------+-------+
| 10 | tom |
| 20 | jerry |
| 30 | rose |
+------+-------+
3 rows in set (0.00 sec)
mysql> select * from t2;
+------+-------+
| id | name |
+------+-------+
| 10 | tom |
| 20 | jerry |
| 30 | rose |
+------+-------+
3 rows in set (0.00 sec)
mysql> insert into t1 values (40,‘john‘);
Query OK, 1 row affected (0.00 sec)
mysql> commit;
Query OK, 0 rows affected (0.09 sec)
mysql> select * from t1;
+------+-------+
| id | name |
+------+-------+
| 10 | tom |
| 20 | jerry |
| 30 | rose |
| 40 | john |
+------+-------+
4 rows in set (0.00 sec)
mysql> update t1 set name=‘ellen‘ where id=40;
Query OK, 1 row affected (0.01 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> select * from t1;
+------+-------+
| id | name |
+------+-------+
| 10 | tom |
| 20 | jerry |
| 30 | rose |
| 40 | ellen |
+------+-------+
4 rows in set (0.00 sec)
mysql> delete from t1;
ERROR 1142 (42000): DELETE command denied to user ‘tom2‘@‘192.168.8.254‘ for tab
le ‘t1‘
mysql> commit;
Query OK, 0 rows affected (0.05 sec)
mysql> select * from t1;
+------+-------+
| id | name |
+------+-------+
| 10 | tom |
| 20 | jerry |
| 30 | rose |
| 40 | ellen |
+------+-------+
4 rows in set (0.00 sec)
4、回收tom2的update权限：
mysql> revoke update on prod.* from tom2;
Query OK, 0 rows affected (0.00 sec)
tom2再重新登陆：
C:UsersAdministrator>mysql -h 192.168.8.240 -utom2 -ptom2
mysql> use prod;
Database changed
mysql> update t1 set name=‘lily‘ where id=10;
ERROR 1142 (42000): UPDATE command denied to user ‘tom2‘@‘192.168.8.254‘ for tab
le ‘t1‘
---update失败！
二、修改用户口令：
1、root用户修改普通用户口令
mysql> set password for tom1=password(‘oracle‘);
Query OK, 0 rows affected (0.01 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
tom1重新登陆：
C:UsersAdministrator>mysql -h 192.168.8.240 -utom1 -ptom1
Warning: Using a password on the command line interface can be insecure.
ERROR 1045 (28000): Access denied for user ‘tom1‘@‘192.168.8.254‘ (using passwor
d: YES)
---旧口令登陆失败！
C:UsersAdministrator>mysql -h 192.168.8.240 -utom1 -poracle
mysql>
2、普通用户修改自己密码：
C:UsersAdministrator>mysql -h 192.168.8.240 -utom1 -poracle
mysql> set password=password(‘tom1‘);
Query OK, 0 rows affected (0.00 sec)
重新登陆：
C:UsersAdministrator>mysql -h 192.168.8.240 -utom1 -ptom1
mysql>
---新密码登陆成功 ！
三、删除用户：
1、回收用户所有权限
mysql> revoke all on prod.* from tom2;
Query OK, 0 rows affected (0.01 sec)
2、删除用户
mysql> drop user tom2;
Query OK, 0 rows affected (0.00 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
mysql> select user,host from user;
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+-------+-----------+| user | host |+-------+-----------+| jerry | % || rose | % || tom | % || tom1 | % || root | 127.0.0.1 || root | ::1 || | localhost || jerry | localhost || root | localhost || rose | localhost || scott | localhost || tom | localhost || | mysrv || root | mysrv |+-------+-----------+14 rows in set (0.00 sec) |
------- 摘要 --------------------------------------
创建用户:
GRANT insert, update ON testdb.* TO [email protected]‘%‘ IDENTIFIED BY ‘password‘ WITH GRANT OPTION;
CREATE USER user2 IDENTIFIED BY ‘password‘;
分配权限:
GRANT select ON testdb.* TO user2;
查看权限:
SHOW GRANTS FOR user1;
修改密码:
SET PASSWORD FOR user1 = PASSWORD(‘newpwd‘);
SET PASSWORD = PASSWORD(‘newpwd‘);
移除权限:
REVOKE all ON *.* FROM user1;
删除用户:
DROP USER user1;
数据库列表:
SHOW DATABASES;
数据表列表:
SHOW TABLES;
当前数据库:
SELECT DATABASE();
当前用户:
SELECT USER();
数据表结构:
DESCRIBE table1;
刷新权限:
FLUSH PRIVILEGES;
grant和revoke可以在几个层次上控制访问权限
1，整个服务器，使用 grant ALL 和revoke ALL
2，整个数据库，使用on database.*
3，特点表，使用on database.table
4，特定的列
5，特定的存储过程
user表中host列的值的意义
% 匹配所有主机
localhost localhost不会被解析成IP地址，直接通过UNIXsocket连接
127.0.0.1 会通过TCP/IP协议连接，并且只能在本机访问；
::1 ::1就是兼容支持ipv6的，表示同ipv4的127.0.0.1
grant 普通数据用户，查询、插入、更新、删除 数据库中所有表数据的权利。
grant select on testdb.* to [email protected]’%’
grant insert on testdb.* to [email protected]’%’
grant update on testdb.* to [email protected]’%’
grant delete on testdb.* to [email protected]’%’
或者，用一条 MySQL 命令来替代：
grant select, insert, update, delete on testdb.* to [email protected]’%’
grant 数据库开发人员，创建表、索引、视图、存储过程、函数。。。等权限。
grant 创建、修改、删除 MySQL 数据表结构权限。
grant create on testdb.* to [email protected]’192.168.0.%’;
grant alter on testdb.* to [email protected]’192.168.0.%’;
grant drop on testdb.* to [email protected]’192.168.0.%’;
grant 操作 MySQL 外键权限。
grant references on testdb.* to [email protected]’192.168.0.%’;
grant 操作 MySQL 临时表权限。
grant create temporary tables on testdb.* to [email protected]’192.168.0.%’;
grant 操作 MySQL 索引权限。
grant index on testdb.* to [email protected]’192.168.0.%’;
grant 操作 MySQL 视图、查看视图源代码 权限。
grant create view on testdb.* to [email protected]’192.168.0.%’;
grant show view on testdb.* to [email protected]’192.168.0.%’;
grant 操作 MySQL 存储过程、函数 权限。
grant create routine on testdb.* to [email protected]’192.168.0.%’; -- now, can show procedure status
grant alter routine on testdb.* to [email protected]’192.168.0.%’; -- now, you can drop a procedure
grant execute on testdb.* to [email protected]’192.168.0.%’;
grant 普通 DBA 管理某个 MySQL 数据库的权限。
grant all privileges on testdb to [email protected]’localhost’
其中，关键字 “privileges” 可以省略。
grant 高级 DBA 管理 MySQL 中所有数据库的权限。
grant all on *.* to [email protected]’localhost’
MySQL grant 权限，分别可以作用在多个层次上。
1. grant 作用在整个 MySQL 服务器上：
grant select on *.* to [email protected]; -- dba 可以查询 MySQL 中所有数据库中的表。
grant all on *.* to [email protected]; -- dba 可以管理 MySQL 中的所有数据库
2. grant 作用在单个数据库上：
grant select on testdb.* to [email protected]; -- dba 可以查询 testdb 中的表。
3. grant 作用在单个数据表上：
grant select, insert, update, delete on testdb.orders to [email protected];
4. grant 作用在表中的列上：
grant select(id, se, rank) on testdb.apache_log to [email protected];
5. grant 作用在存储过程、函数上：
grant execute on procedure testdb.pr_add to ’dba’@’localhost’
grant execute on function testdb.fn_add to ’dba’@’localhost’
注意：修改完权限以后 一定要刷新服务，或者重启服务，刷新服务用：FLUSH PRIVILEGES。