1.用户
1.1 用户信息
mysql> use mysql;
Database changed
mysql> select host,user,authentication_string from user;
+-----------+---------------+-------------------------------------------+
| host | user | authentication_string |
+-----------+---------------+-------------------------------------------+
| localhost | root | * 81 F5E21E35407D884A6CD4A731AEBFB6AF209E1B |
| localhost | mysq l .session | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE |
| localhost | mysql .sys | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE |
+-----------+---------------+-------------------------------------------+
-- 可以通过 desc user 初步查看一下表结构
字段解释：
host ： 表示这个用户可以从哪个主机登陆，如果是 localhost ，表示只能从本机登陆
user ： 用户名
authentication_string ： 用户密码通过 password 函数加密后的
*_priv ： 用户拥有的权限
1.2 创建用户
语法：
create user ' 用户名 ' @ ' 登陆主机 /ip' identified by ' 密码 ' ;
案例：
mysql> create user 'wmh' @ 'localhost' identified by '12345678' ;
Query OK, 0 rows affected ( 0.06 sec)
mysql> select user,host,authentication_string from user;
+---------------+-----------+-------------------------------------------+
| user | host | authentication_string |
+---------------+-----------+-------------------------------------------+
| root | % | *A2F7C9D334175DE9AF4DB4F5473E0BD0F5FA9E75 |
| mysql .session | localhost | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE |
| mysql .sys | localhost | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE |
| wmh | localhost | * 84 AAC12F54AB666ECFC2A83C676908C8BBC381B1 | -- 新增用户
+---------------+-----------+-------------------------------------------+
4 rows in set ( 0.00 sec)
1.3 删除用户
语法：
drop user ' 用户名 ' @ ' 主机名'
示例：
mysql> select user,host,authentication_string from user;
+---------------+-----------+-------------------------------------------+
| user | host | authentication_string |
+---------------+-----------+-------------------------------------------+
| root | % | *A2F7C9D334175DE9AF4DB4F5473E0BD0F5FA9E75 |
| mysql .session | localhost | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE |
| mysql .sys | localhost | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE |
| wmh | localhost | * 84 AAC12F54AB666ECFC2A83C676908C8BBC381B1 |
+---------------+-----------+-------------------------------------------+
4 rows in set ( 0.00 sec)
mysql> drop user wmh; -- 尝试删除
ERROR 1396 (HY000): Operation DROP USER failed for 'wmh' @ '%' -- <= 直接给个用户名，不能删除，它默认是% ，表示所有地方可以登陆的用户mysql> drop user 'wmh' @ 'localhost' ; -- 删除用户
Query OK, 0 rows affected ( 0.00 sec)
mysql> select user,host,authentication_string from user;
+---------------+-----------+-------------------------------------------+
| user | host | authentication_string |
+---------------+-----------+-------------------------------------------+
| root | % | *A2F7C9D334175DE9AF4DB4F5473E0BD0F5FA9E75 |
| mysql .session | localhost | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE |
| mysql .sys | localhost | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE |
+---------------+-----------+-------------------------------------------+
3 rows in set ( 0.00 sec)
1.4 修改用户密码
语法：
自己改自己密码
set password=password( ' 新的密码 ' );
root用户修改指定用户的密码
set password for '用户名'@'主机名'=password('新的密码')；
mysql> select host,user, authentication_string from user;
+-----------+---------------+-------------------------------------------+
| host | user | authentication_string |
+-----------+---------------+-------------------------------------------+
| % | root | *A2F7C9D334175DE9AF4DB4F5473E0BD0F5FA9E75 |
| localhost | mysql .session | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE |
| localhost | mysql .sys | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE |
| localhost | wmh | * 84 AAC12F54AB666ECFC2A83C676908C8BBC381B1 |
+-----------+---------------+-------------------------------------------+
4 rows in set ( 0.00 sec)
mysql> set password for 'wmh' @ 'localhost' =password( '87654321' );
Query OK, 0 rows affected, 1 warning ( 0.00 sec)
mysql> select host,user, authentication_string from user;
+-----------+---------------+-------------------------------------------+
| host | user | authentication_string |
+-----------+---------------+-------------------------------------------+
| % | root | *A2F7C9D334175DE9AF4DB4F5473E0BD0F5FA9E75 |
| localhost | mysql .session | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE |
| localhost | mysql .sys | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE |
| localhost | wmh | * 5 D24C4D94238E65A6407DFAB95AA4EA97CA2B199 |
+-----------+---------------+-------------------------------------------+
4 rows in set ( 0.00 sec)
2.数据库的权限
MySQL数据库提供的权限列表：
2.1 给用户授权
刚创建的用户没有任何权限。需要给用户授权。
语法 :
grant 权限列表 on 库 . 对象名 to ' 用户名 ' @ ' 登陆位置 ' [identified by ' 密码 ' ]
说明：
权限列表，多个权限用逗号分开
*.* : 代表本系统中的所有数据库的所有对象（表，视图，存储过程等）
库 .* : 表示某个数据库中的所有数据对象 ( 表，视图，存储过程等 )
identified by 可选。 如果用户存在，赋予权限的同时修改密码 , 如果该用户不存在，就是创建用户
案例：
-- 使用 root 账号
-- 终端 A
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| 57 test |
| bit_index |
| ccdata_pro |
| innodb_test |
| musicserver |
| myisam_test |
| mysql |
| order_sys |
| performance_schema |
| scott |
| sys |
| test |
| vod_system |
+--------------------+
14 rows in set ( 0.00 sec)
mysql> use test;
Database changed
mysql> show tables;
+----------------+
| Tables_in_test |
+----------------+
| account |
| student |
| user |
+----------------+
3 rows in set ( 0.01 sec)
-- 给用户 wmh 赋予 test 数据库下所有文件的 select 权限
mysql> grant select on test.* to 'wmh' @ 'localhost' ;
Query OK, 0 rows affected ( 0.01 sec)
-- 使用 wmh 账号
-- 终端 B
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
+--------------------+
1 row in set ( 0.00 sec)
-- 暂停等 root 用户给 wmh 赋完权之后，在查看
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| test | -- 赋完权之后，就能看到新的表
+--------------------+
2 rows in set ( 0.01 sec)
mysql> use test;
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
mysql> show tables;
+----------------+
| Tables_in_test |
+----------------+
| account |
| student |
| user |
+----------------+
3 rows in set ( 0.00 sec)
mysql> select * from account;
+----+--------+---------+
| id | name | blance |
+----+--------+---------+
| 2 | 李四 | 321.00 |
| 3 | 王五 | 5432.00 |
| 4 | 赵六 | 543.90 |
| 5 | 赵六 | 543.90 |
+----+--------+---------+
4 rows in set ( 0.00 sec)
-- 没有删除权限
mysql> delete from account;
ERROR 1142 ( 42000 ): DELETE command denied to user 'wmh' @ 'localhost' for table
'account'
备注：特定用户现有查看权限
mysql> show grants for 'wmh' @ '%' ;
+-----------------------------------------------+
| Grants for wmh@% |
+-----------------------------------------------+
| GRANT USAGE ON *.* TO 'wmh' @ '%' |
| GRANT ALL PRIVILEGES ON `test`.* TO 'wmh' @ '%' |
+-----------------------------------------------+
2 rows in set ( 0.00 sec)
mysql> show grants for 'root' @ '%' ;
+-------------------------------------------------------------+
| Grants for root@% |
+-------------------------------------------------------------+
| GRANT ALL PRIVILEGES ON *.* TO 'root' @ '%' WITH GRANT OPTION |
+-------------------------------------------------------------+
1 row in set ( 0.00 sec)
注意：如果发现赋权限后，没有生效，执行如下指令：
flush privileges;
2.2 回收权限
语法 ：
revoke 权限列表 on 库 . 对象名 from ' 用户名 ' @ ' 登陆位置 ' ；
示例：
-- 回收 wmh 对 test 数据库的所有权限
--root 身份，终端 A
mysql> revoke all on test.* from 'wmh' @ 'localhost' ;
Query OK, 0 rows affected ( 0.00 sec)
--wmh 身份，终端 B
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| test |
+--------------------+
2 rows in set ( 0.00 sec)
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
+--------------------+
1 row in set ( 0.00 sec)