1# 创建用户的一些限制和注意点
用户名长度必须不超过16个字符
用户名是大小写敏感的
2# 创建用户
语法：
(root@localhost)[(none)]> help create user
Name: 'CREATE USER'
Description:
Syntax:
CREATE USER user_specification [, user_specification] ...
user_specification:
user [ identified_option ]
auth_option: {
IDENTIFIED BY 'auth_string'
| IDENTIFIED BY PASSWORD 'hash_string'
| IDENTIFIED WITH auth_plugin
| IDENTIFIED WITH auth_plugin AS 'hash_string'
}
The CREATE USER statement creates new MySQL accounts. An error occurs
if you try to create an account that already exists.按照语法，最简答的创建用户的方法：
c(root@localhost)[mysql]> create user test1;
Query OK, 0 rows affected (0.00 sec)
(root@localhost)[mysql]> select user,host,password from user;
+-------+-----------+-------------------------------------------+
| user | host | password |
+-------+-----------+-------------------------------------------+
| root | localhost | *A0F874BC7F54EE086FCE60A37CE7887D8B31086B |
| test1 | % | |
+-------+-----------+-------------------------------------------+
2 rows in set (0.00 sec)
2 rows in set (0.00 sec)reate user test1;这个时候其实密码是空的，可以空密码登录的。
[mysql@mysql01 ~]$ mysql -S /data/mysqldata/3306/mysql.sock -utest1
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.6.31-log Source distribution
Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
(test1@localhost)[(none)]> 但是没有任何权限：（USAGE这个权限，是代表废物的意思！嗯，就是这样）
(test1@localhost)[(none)]> show grants;
+-----------------------------------+
| Grants for test1@% |
+-----------------------------------+
| GRANT USAGE ON *.* TO 'test1'@'%' |
+-----------------------------------+
1 row in set (0.00 sec)3# 给用户设置密码：
命令
(root@localhost)[mysql]> help set password
Name: 'SET PASSWORD'
Description:
Syntax:
SET PASSWORD [FOR user] = password_option
password_option: {
PASSWORD('auth_string')
| OLD_PASSWORD('auth_string')
| 'hash_string'
}给test1设置一个密码：
(root@localhost)[mysql]> set password for test1=password('passwordtest');
Query OK, 0 rows affected (0.00 sec)
(root@localhost)[mysql]> select user,host,password from user where user='test1';
+-------+------+-------------------------------------------+
| user | host | password |
+-------+------+-------------------------------------------+
| test1 | % | *A76A397AE758994B641D5C456139B88F40610926 |
+-------+------+-------------------------------------------+
1 row in set (0.00 sec)
至于OLD_PASSWORD()函数，是为了兼容老版本的密码而存在，古老的mysql4。
然而，set password for
(root@localhost)[mysql]> alter user test1 identified by 'password4test1';
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'identified by 'password4test1'' at line 1
(root@localhost)[mysql]> 以上可见报错了。原因是5.6还不支持这种密码修改方式：
(root@localhost)[mysql]> help alter user;
Name: 'ALTER USER'
Description:
Syntax:
ALTER USER user_specification [, user_specification] ...
user_specification:
user PASSWORD EXPIRE这里只有一个子句，就是设置密码过期
3# 账号的密码过期：
(root@localhost)[mysql]> alter user test1 password expire;
Query OK, 0 rows affected (0.00 sec)
(root@localhost)[mysql]> select user,host,password,password_expired from user;
+-------+-----------+-------------------------------------------+------------------+
| user | host | password | password_expired |
+-------+-----------+-------------------------------------------+------------------+
| root | localhost | *A0F874BC7F54EE086FCE60A37CE7887D8B31086B | N |
| test1 | % | *A76A397AE758994B641D5C456139B88F40610926 | Y |
+-------+-----------+-------------------------------------------+------------------+
2 rows in set (0.00 sec)可以看到账号密码已经过期。
但是过期以后还是可以登录，但是什么都干不了，会提示马上更改密码：
[mysql@mysql01 ~]$ mysql -S /data/mysqldata/3306/mysql.sock -utest1 -p'passwordtest'
Warning: Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.6.31-log
Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
(test1@localhost)[(none)]> select 1
-> ;
ERROR 1820 (HY000): You must SET PASSWORD before executing this statement
(test1@localhost)[(none)]>
#修改当前账户的密码：
(test1@localhost)[(none)]> set password = password('password4test1');
Query OK, 0 rows affected (0.00 sec)
(test1@localhost)[(none)]>
#再次尝试登录，并做查询测试
[mysql@mysql01 ~]$ mysql -S /data/mysqldata/3306/mysql.sock -utest1 -p'password4test1'
Warning: Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 5
Server version: 5.6.31-log Source distribution
Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
(test1@localhost)[(none)]> select 1;
+---+
| 1 |
+---+
| 1 |
+---+
1 row in set (0.00 sec)
#查询成功，说明密码更改成功。用管理账号查询use表查看账号状态：
(root@localhost)[mysql]> select user,host,password,password_expired from user;
+-------+-----------+-------------------------------------------+------------------+
| user | host | password | password_expired |
+-------+-----------+-------------------------------------------+------------------+
| root | localhost | *A0F874BC7F54EE086FCE60A37CE7887D8B31086B | N |
| test1 | % | *CFA887C680E792C2DCF622D56FB809E3F8BE63CC | N |
+-------+-----------+-------------------------------------------+------------------+
2 rows in set (0.00 sec)
4# 远程登录
在user表中，test1的host列值为%，代表可以从任意位置登录mysql
[mysql@mysql01 ~]$ mysql -utest1 -p'password4test1' -h 192.168.199.101 -P 3306
Warning: Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 11
Server version: 5.6.31-log Source distribution
Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
([email protected])[(none)]> 5# 比较完整方式创建用户
(root@localhost)[mysql]> create user test2@'%' identified by 'password4test2';
Query OK, 0 rows affected (0.00 sec)
(root@localhost)[mysql]> create user test2@'192.168.199.101' identified by 'test2local';
Query OK, 0 rows affected (0.00 sec)
(root@localhost)[mysql]> select user,host,password from user where user='test2';
+-------+-----------------+-------------------------------------------+
| user | host | password |
+-------+-----------------+-------------------------------------------+
| test2 | 192.168.199.101 | *74F386E8F5EEC7648BABDD0FCBA4524B97344856 |
| test2 | % | *5AB2E18AD9EE76F76E1C02E4DBF97BC7C3B4588B |
+-------+-----------------+-------------------------------------------+
2 rows in set (0.00 sec)
(root@localhost)[mysql]> 建立了两个test2，这两个test2是不同的，实际上应该说，用户test2@'192.168.199.101' 和用户test2@'%' 是两个不同的用户。
[mysql@mysql01 ~]$ mysql -utest2 -p'test2local' -h 192.168.199.101 -P 3306
Warning: Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 14
Server version: 5.6.31-log Source distribution
Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
([email protected])[(none)]>
[mysql@mysql01 ~]$ mysql -utest2 -S /data/mysqldata/3306/mysql.sock -p'password4test2'
Warning: Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 21
Server version: 5.6.31-log Source distribution
Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
(test2@localhost)[(none)]> 5# 修改密码：
1，set password 方式：
(root@localhost)[mysql]> set password for test1=password('password4test1');
Query OK, 0 rows affected (0.00 sec)2，直接update系统表user，这种方式需要刷新权限列表
(root@localhost)[mysql]> update user set password=password('password4test1') where user='test1';
Query OK, 0 rows affected (0.00 sec)
Rows matched: 1 Changed: 0 Warnings: 0
(root@localhost)[mysql]> flush privileges;
Query OK, 0 rows affected (0.00 sec)3，grant 方式
(root@localhost)[mysql]> grant usage on *.* to test1 identified by 'password4test1';
Query OK, 0 rows affected (0.01 sec)