mysql 5.7 学习

mysql -uroot -proot

MySQL5.7 mysql.user表没有password字段改 authentication_string；

一. 创建用户:

命令:CREATE USER 'username'@'host' IDENTIFIED BY 'password';

例子: CREATE USER 'dog'@'localhost' IDENTIFIED BY '123456';

CREATE USER 'dog2'@'localhost' IDENTIFIED BY '';

PS：username - 你将创建的用户名,

host - 指定该用户在哪个主机上可以登陆，此处的"localhost"，是指该用户只能在本地登录，不能在另外一台机器上远程登录，如果想远程登录的话，将"localhost"改为"%"，表示在任何一台电脑上都可以登录;也可以指定某台机器可以远程登录;

password - 该用户的登陆密码,密码可以为空,如果为空则该用户可以不需要密码登陆服务器。

二.授权:

命令:GRANT privileges ON databasename.tablename TO 'username'@'host'

PS: privileges - 用户的操作权限,如SELECT , INSERT , UPDATE 等(详细列表见该文最后面).如果要授予所的权限则使用ALL.;databasename - 数据库名,tablename-表名,如果要授予该用户对所有数据库和表的相应操作权限则可用*表示, 如*.*.

例子: GRANT SELECT, INSERT ON mq.* TO 'dog'@'localhost ';

三.创建用户同时授权

mysql> grant all privileges on mq.* to test@localhost identified by '1234';
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)

PS:必须执行flush privileges;

否则登录时提示：ERROR 1045 (28000): Access denied for user 'user'@'localhost' (using password: YES )

四.设置与更改用户密码

命令:SET PASSWORD FOR 'username'@'host' = PASSWORD('newpassword');

例子: SET PASSWORD FOR 'dog2'@'localhost' = PASSWORD("dog");

五.撤销用户权限

命令: REVOKE privilege ON databasename.tablename FROM 'username'@'host';

说明: privilege, databasename, tablename - 同授权部分.

例子: REVOKE SELECT ON mq.* FROM 'dog2'@'localhost';

PS: 假如你在给用户'dog'@'localhost ''授权的时候是这样的(或类似的):GRANT SELECT ON test.user TO 'dog'@'localhost ', 则在使用REVOKE SELECT ON *.* FROM 'dog'@'localhost ';命令并不能撤销该用户对test数据库中user表的SELECT 操作.相反,如果授权使用的是GRANT SELECT ON *.* TO 'dog'@'localhost ';则REVOKE SELECT ON test.user FROM 'dog'@'localhost ';命令也不能撤销该用户对test数据库中user表的Select 权限.

具体信息可以用命令SHOW GRANTS FOR 'dog'@'localhost '; 查看.

六.删除用户

命令: DROP USER 'username'@'host';

七.查看用户的授权

mysql> show grants for dog@localhost;
+---------------------------------------------+
| Grants for dog@localhost |
+---------------------------------------------+
| GRANT USAGE ON *.* TO 'dog'@'localhost' |
| GRANT INSERT ON `mq`.* TO 'dog'@'localhost' |
+---------------------------------------------+
2 rows in set (0.00 sec)

PS:GRANT USAGE:mysql usage权限就是空权限，默认create user的权限，只能连库，啥也不能干

ps 之前收集了很多mysql 的命令，结果今天在mysql 5.7中失效了，因此在整理一下

mysql> CREATE USER 'root'@'192.168.1.17' IDENTIFIED BY 'root';
Query OK, 0 rows affected (0.00 sec)

创建用户

mysql> CREATE USER 'root'@'%' IDENTIFIED BY 'root';
Query OK, 0 rows affected (0.00 sec)

root 用户可以在任何机器上登录，且拥有任何表的任何权限

mysql> grant all privileges on *.* to root@'%' identified by 'root';
Query OK, 0 rows affected, 1 warning (0.00 sec)

-----------------------------------------======================================================================

mysql> set global validate_password_policy=0;
Query OK, 0 rows affected (0.05 sec)
mysql>
mysql>
mysql> set global validate_password_mixed_case_count=0;
Query OK, 0 rows affected (0.00 sec)
mysql> set global validate_password_number_count=3;
Query OK, 0 rows affected (0.00 sec)
mysql> set global validate_password_special_char_count=0;
Query OK, 0 rows affected (0.00 sec)
mysql> set global validate_password_length=3;
Query OK, 0 rows affected (0.00 sec)
mysql> SHOW VARIABLES LIKE 'validate_password%';
+--------------------------------------+-------+
| Variable_name | Value |
+--------------------------------------+-------+
| validate_password_dictionary_file | |
| validate_password_length | 3 |
| validate_password_mixed_case_count | 0 |
| validate_password_number_count | 3 |
| validate_password_policy | LOW |
| validate_password_special_char_count | 0 |
+--------------------------------------+-------+
6 rows in set (0.00 sec)

FLUSH PRIVILEGES;

4）修改简单密码：

[sql] view plain copy

mysql> SET PASSWORD FOR 'root'@'localhost' = PASSWORD('123');
Query OK, 0 rows affected, 1 warning (0.00 sec)