Mysql用户管理相关知识介绍

朱雀 2020-05-13 15:56 910阅读 0赞

当前使用的user及host:

```shell
mysql> select USER();
+----------------+
| USER()         |
+----------------+
| root@localhost |
+----------------+
1 row in set (0.00 sec)
```

添加用户

mysql5以前版本直接使用 INSERT 向 mysql 表中插入mysql用户了,mysql5之后不可以这样操作

```shell
mysql> insert into mysql.user(Host,User,Password) values('localhost','test_user',password('123123'));
ERROR 1062 (23000): Duplicate entry 'localhost-test_user' for key 'PRIMARY'
```

增加用户 {授予用户指定数据表权限 [使用 GRANT 命令 对用户进行相应授权]}

```shell
mysql> GRANT all privileges ON table1.* TO 
'test_user'@'localhost' IDENTIFIED BY '123123' WITH GRANT OPTION;
Query OK, 0 rows affected (0.02 sec)
```

IDENTIFIED BY 指定用户的登录密码

ALL PRIVILEGES 是表示所有权限，也可以使用 select、update 等权限

*.\ 中前面的*号用来指定数据库名，后面的*号用来指定表名

TO 表示将权限赋予某个用户

ON 用来指定权限针对哪些库和表

'test_user'@'localhost' 表示test_user用户，@后面接限制的主机，可以是IP、IP段、域名以及%，%表示任何地方

WITH GRANT OPTION 这个选项表示该用户可以将自己拥有的权限授权给别人

需要刷新系统权限表[flush privilege] 该用户才能生效登录

```shell
mysql> flush privileges;
```

删除用户

```shell
mysql> drop user 'test_user'@'localhost';
```

查看当前用户的权限

```shell
mysql> SHOW GRANTS;
+----------------------------------------------------------------------------------------------------------------------------------------+
| Grants for root@localhost                                                                                                              |
+----------------------------------------------------------------------------------------------------------------------------------------+
| GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost' IDENTIFIED BY PASSWORD '\*E56A114692FE0DE073F9A1DD68A00EEB9703F3F1' WITH GRANT OPTION |
| GRANT PROXY ON ''@'' TO 'root'@'localhost' WITH GRANT OPTION                                                                           |
+----------------------------------------------------------------------------------------------------------------------------------------+
```

查看某个用户的权限

```shell
mysql> show grants for 'test_user'@'localhost'
+------------------------------------------------------------------------------------------------------------+
| Grants for test_user@localhost                                                                                   |
+------------------------------------------------------------------------------------------------------------+
| GRANT USAGE ON *.* TO 'test_user'@'localhost' IDENTIFIED BY PASSWORD '\*E56A114692FE0DE073F9A1DD68A00EEB9703F3F1' |
| GRANT ALL PRIVILEGES ON table1.* TO 'test_user'@'localhost' WITH GRANT OPTION                                 |
+------------------------------------------------------------------------------------------------------------+
```

对账户重命名

```shell
mysql> rename user 'test_user'@'localhost' to 'bb'@'localhost';
```

修改密码

1.用set password命令

```java
mysql> SET PASSWORD FOR 'test_user'@'localhost' = PASSWORD('123456');
```

2.用 mysqladmin [进入bin目录]

备注:{格式: mysqladmin -u用户名 -p旧密码 password 新密码]

```mysql
/usr/bin$ mysqladmin -utest_user -p123456 password 123123
mysqladmin: Can't turn off logging; error: 'Access denied; you need (at least one of) the SUPER privilege(s) for this operation'
```

3.用 update 直接编辑 user 表

```shell
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
mysql> update user set PASSWORD = PASSWORD('123123') where user = 'test_user';
Query OK, 1 row affected (0.04 sec)
Rows matched: 1  Changed: 1  Warnings: 0
```