Ubuntu mysql首次登录root密码

Sian

1、在Ubuntu上安装mysql

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parallels@ubuntu:~$ sudo apt install mysql

2、登录mysql时使用root用户，默认密码为空；

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parallels@ubuntu:~$ mysql -uroot -p
Enter password:
ERROR 1698 (28000): Access denied for user 'root'@'localhost'

3、无法登录，可能是密码不正确，也有可能密码为空，但mysql不允许直接使用空密码登录，也有可能root不能使用localhost主机名登录等等；
4、以上猜测适应所有mysql第一次root登录不成功的可能结论，但如果是Ubuntu中使用apt安装的mysql，有个文件需要关注一下；

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parallels@ubuntu:~$ sudo cat /etc/mysql/debian.cnf
# Automatically generated for Debian scripts. DO NOT TOUCH!
[client]
host     = localhost
user     = debian-sys-maint
password = pYL0Xezi0kD8cISU
socket   = /var/run/mysqld/mysqld.sock
[mysql_upgrade]
host     = localhost
user     = debian-sys-maint
password = pYL0Xezi0kD8cISU
socket   = /var/run/mysqld/mysqld.sock
parallels@ubuntu:~$

5、这里有mysql相关的用户名和密码，登录client中的user与password试了一下，还真登录上去了。

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parallels@ubuntu:~$ mysql -udebian-sys-maint -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.7.25-0ubuntu0.18.04.2 (Ubuntu)

Copyright (c) 2000, 2019, 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.

mysql>

6、查看当前用户，修改密码

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mysql> use mysql
Database changed
mysql> select User from user;
+------------------+
| User             |
+------------------+
| debian-sys-maint |
| mysql.session    |
| mysql.sys        |
| root             |
+------------------+
4 rows in set (0.00 sec)

mysql>

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mysql> update user SET authentication_string = PASSWORD('root') WHERE user = 'root';
Query OK, 1 row affected, 1 warning (0.01 sec)
Rows matched: 1  Changed: 1  Warnings: 1

mysql> update user set plugin = 'mysql_native_password' where User = 'root';
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> select User,authentication_string,plugin from user;
+------------------+-------------------------------------------+-----------------------+
| User             | authentication_string                     | plugin                |
+------------------+-------------------------------------------+-----------------------+
| root             | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B | mysql_native_password |
| mysql.session    | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE | mysql_native_password |
| mysql.sys        | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE | mysql_native_password |
| debian-sys-maint | *10C1A2E9D2EAE636C49E6D113EE86D10F8B2E108 | mysql_native_password |
+------------------+-------------------------------------------+-----------------------+
4 rows in set (0.00 sec)

mysql> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.00 sec)

mysql>

主要四条命令：

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mysql> use mysql
mysql> update user SET authentication_string = PASSWORD('root') WHERE user = 'root';
mysql> update user set plugin = 'mysql_native_password' where User = 'root';
mysql> FLUSH PRIVILEGES;

7、搞定

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parallels@ubuntu:~$ mysql -uroot -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 11
Server version: 5.7.25-0ubuntu0.18.04.2 (Ubuntu)

Copyright (c) 2000, 2019, 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.

mysql>