用户管理
我们知道在Mysql中root用户是最高权限的用户，其他用户的创建和权限授予都是通过root用户来操作的
查看用户
在root用户界面下
select user,host,password from mysql.user;
+------+-----------+-------------------------------------------+
| user | host | password |
+------+-----------+-------------------------------------------+
| root | localhost | *23AE809DDACAF96AF0FD78ED04B6A265E05AA257 |
| root | 127.0.0.1 | |
| root | ::1 | |
| | localhost | |
+------+-----------+-------------------------------------------+创建用户
指定ip和用户名登录
指定ip为192.168.1.17的mm用户登录
create user 'mm'@'192.168.1.17' identified by '123';
identified by 'password'表示为创建的用户设置密码，可以省略
+------+--------------+-------------------------------------------+
| user | host | password |
+------+--------------+-------------------------------------------+
| root | localhost | *23AE809DDACAF96AF0FD78ED04B6A265E05AA257 |
| root | 127.0.0.1 | |
| root | ::1 | |
| | localhost | |
| mm | 192.168.1.17 | *23AE809DDACAF96AF0FD78ED04B6A265E05AA257 |
+------+--------------+-------------------------------------------+指定ip地址段和用户名登录
指定ip地址段的mm用户登录
create user 'mm'@'192.168.1.%' identified by '123';
+------+--------------+-------------------------------------------+
| user | host | password |
+------+--------------+-------------------------------------------+
| root | localhost | *23AE809DDACAF96AF0FD78ED04B6A265E05AA257 |
| root | 127.0.0.1 | |
| root | ::1 | |
| | localhost | |
| mm | 192.168.1.17 | *23AE809DDACAF96AF0FD78ED04B6A265E05AA257 |
| mm | 192.168.1.% | *23AE809DDACAF96AF0FD78ED04B6A265E05AA257 |
+------+--------------+-------------------------------------------+
如果不指定ip，则默认是所有的ip都可以登录
create user 'hh' identified by '123';
+------+--------------+-------------------------------------------+
| user | host | password |
+------+--------------+-------------------------------------------+
| root | localhost | *23AE809DDACAF96AF0FD78ED04B6A265E05AA257 |
| root | 127.0.0.1 | |
| root | ::1 | |
| | localhost | |
| mm | 192.168.1.17 | *23AE809DDACAF96AF0FD78ED04B6A265E05AA257 |
| mm | 192.168.1.% | *23AE809DDACAF96AF0FD78ED04B6A265E05AA257 |
| hh | % | *23AE809DDACAF96AF0FD78ED04B6A265E05AA257 |
+------+--------------+-------------------------------------------+
注意：mysql识别用户是通过用户名和ip联合识别的，其中localhost和127.0.0.1被认为是两个不同的ip，也就是说，mm@'localhost'和mm@'127.0.0.1'是两个不同的用户！
删除用户
删除用户不能直接对mysql.user表进行操作，而是使用drop语句
drop user 'mm'@'192.168.1.17';
drop user 'hh'; # host为%时，可以省略不写修改用户（用户名和ip)
语法为
rename user '用户名'@'IP地址' to '新用户名'@'IP地址';
修改mm用户的登录ip为192.168.1.111
rename user 'mm'@'192.168.1.%' to 'gf'@'192.168.1.111';
+------+---------------+-------------------------------------------+
| user | host | password |
+------+---------------+-------------------------------------------+
| root | localhost | *23AE809DDACAF96AF0FD78ED04B6A265E05AA257 |
| root | 127.0.0.1 | |
| root | ::1 | |
| | localhost | |
| gf | 192.168.1.111 | *23AE809DDACAF96AF0FD78ED04B6A265E05AA257 |
| sh | % | *23AE809DDACAF96AF0FD78ED04B6A265E05AA257 |
| ss | % | |
+------+---------------+-------------------------------------------+
修改密码
语法
SET PASSWORD FOR '用户名'@'IP地址' = PASSWORD('新密码');
修改gf用户的密码为456
set password for 'gf'@'192.168.1.111'=password('456');+------+---------------+-------------------------------------------+
| user | host | password |
+------+---------------+-------------------------------------------+
| root | localhost | *23AE809DDACAF96AF0FD78ED04B6A265E05AA257 |
| root | 127.0.0.1 | |
| root | ::1 | |
| | localhost | |
| gf | 192.168.1.111 | *531E182E2F72080AB0740FE2F2D689DBE0146E04 |
| sh | % | *23AE809DDACAF96AF0FD78ED04B6A265E05AA257 |
| ss | % | |
+------+---------------+-------------------------------------------+查看权限
语法
show grants for '用户'@'IP地址'
查看root用户的权限
show grants for 'root'@'localhost';
+----------------------------------------------------------------------------------------------------------------------------------------+
| Grants for root@localhost
|
+----------------------------------------------------------------------------------------------------------------------------------------+
| GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost' IDENTIFIED BY PASSWORD '*23AE809DDACAF96AF0FD78ED04B6A265E05AA257' WITH GRANT OPTION |
| GRANT PROXY ON ''@'' TO 'root'@'localhost' WITH GRANT OPTION
|
+----------------------------------------------------------------------------------------------------------------------------------------+
可以看到root用户拥有所有(最高)权限
查看gf用户权限
show grants for 'gf'@'192.168.1.111';
+---------------------------------------------------------------------------------------------------------------+
| Grants for [email protected]
|
+---------------------------------------------------------------------------------------------------------------+
| GRANT USAGE ON *.* TO 'gf'@'192.168.1.111' IDENTIFIED BY PASSWORD '*531E182E2F72080AB0740FE2F2D689DBE0146E04' |
+---------------------------------------------------------------------------------------------------------------+
授权
语法
grant 权限1,权限2,权限3 on 数据库名.表名 to "用户"@'IP地址';
授予gf用户查询，插入，更新权限
grant select ,insert,update on *.*to "gf"@'192.168.1.111';
授予用户所有权限
grant all privileges on 数据库名.表名 to "用户"@'IP地址';
给sh用户授予mysql库的所有权限
grant all privileges on mysql.* to 'sh';
注意：
1）授权后需要重新登录才生效
2）不能对同一个用户，多次授权不同的权限。否则会有多条授权规则，最终以最严格的权限为准。
取消权限
语法
revoke 权限1 on 数据库名.表名 from "用户"@'IP地址';
取消gf用户对mysql库的多有表的更新权限
revoke update on *.* from 'gf'@'192.168.1.111';
取消所有权限
revoke all privileges on *.* from 'gf'@'192.168.1.111';
注意：取消的权限必须与授予的权限完全一致，不能取消部分权限
备份
备份数据和表结构
在命令行下
mysqldump -u root -p db1 > db1.sql仅备份表结构
mysqldump -u root -p -d db1 > db2.sql
恢复
登录mysql，创建数据库
create database db10;
退出mysql，在命令行下将备份导入db10数据库里
mysqldump -u root -p -d db10 < db1.sql
提示Dump completed表示导入成功