Change password of MySQL version 5.7 and 8.0

5.7 edition （centos7 Li test ）

1、 Forget the password , Skip detection

The first one is , use docker Installed , Into the container /etc/mysql And externally mounted direct modification files

[[email protected] mysqlconfig]# docker exec -it 97ca731b5ff4 /bin/bash

[email protected]:/# mysql -uroot -p
Enter password:
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)

[email protected]:/# cd /etc/mysql/conf.d

[email protected]:/# vi docker.cnf
[mysqld]
skip-host-cache
skip-name-resolve
skip-grant-tables # Add this line 

If there is no... In the container vi Instructions , Also unwilling to install , You can also modify it from the attached path , I use it here. docker-compose Installed

[[email protected] ~]# cat docker-compose.yml
version: "2.1"
services:
  mysql:
    image: mysql:5.7.20
    restart: unless-stopped
    ports:
     - "3306:3306"
    environment:
     MYSQL_ROOT_PASSWORD: 123456
    volumes:
     - /data/docker/mysql/mysql:/var/lib/mysql
     - /data/docker/mysql/mysqlconfig:/etc/mysql

[[email protected] ~]#
[[email protected] conf.d]# pwd
/data/docker/mysql/mysqlconfig/conf.d

[[email protected] conf.d]# vi docker.cnf
[mysqld]
skip-host-cache
skip-name-resolve
skip-grant-tables # Add this line 

If there's nothing here , Just use it again docker run Run a test mysql, And then use docker cp To copy the inside of the container /etc/mysql Catalog , Be careful not to mount the directory , Or you'll play for nothing
Example ：
Pay attention to the whole catalogue here , During my experiment , In case of incomplete documents , Containers don't work

[[email protected] tmp]# docker cp 97ca731b5ff4:/etc/mysql .

Here is the official operating environment mysql Container mount Directory , It's mentioned above

[[email protected] tmp]# cp mysql/* /data/docker/mysql/mysqlconfig/

The second kind , Direct will mysql Installed on the host , I didn't do a test , Online modification /etc/mysql/my.cnf file , It also increases skip-grant-tables

2、 Empty password

#  Write the new password directly , Neither old nor new passwords can log in 
[email protected]:/# mysql -uroot -p
Enter password:
#  The display content is omitted 

mysql> use mysql
mysql> update user set authentication_string='' where  user = 'root';

3、 Write new password

mysql> use mysql
mysql> update user set authentication_string=password('123456')  where user='root';

#  It's also OK to write in the following way , It's convenient 
mysql> update mysql.user set authentication_string=password('123456')  where user='root';

4、 Refresh the permissions

mysql> flush privileges;

5、 give root All permissions of all databases of the user

mysql> grant all privileges on *.* to [email protected]'%' identified by '123456';
mysql> flush privileges;

---

8.0 edition （Ubuntu 20.04.3 Made in , Someone else's machine , It's not easy to do too many experiments ）

1、 By default, the account secret is automatically generated

During installation , Directly installed in the host , The automatically generated account and password used , So I don't know root password
Automatically generated account and password
account number ：debian-sys-maint
password ：BcJnVUVx3JlY0Vq5
Because of the password , So it is reset after logging in directly root password , There is no such step as setting password free login

2、 Empty password （ And 5.7 There's a difference ）

[email protected]:~$ mysql -udebian-sys-maint -pBcJnVUVx3JlY0Vq5

#  At this moment , Confused to change the password encryption method , It doesn't matter if there's no impact 
mysql> update mysql.user set authentication_string=PASSWORD('newPwd'), plugin='mysql_native_password' where user='root';
mysql> select user ,plugin from mysql.user;
+------------------+-----------------------+
| user             | plugin                |
+------------------+-----------------------+
| root             | mysql_native_password |
| debian-sys-maint | caching_sha2_password |
| mysql.infoschema | caching_sha2_password |
| mysql.session    | caching_sha2_password |
| mysql.sys        | caching_sha2_password |
| root             | mysql_native_password |
| zsw              | caching_sha2_password |
+------------------+-----------------------+
7 rows in set (0.00 sec)

mysql> use mysql
mysql> update user set authentication_string=''  where  user='root';

#  I saw it on the Internet ,authentication_string=''  There is none here password Field , Because the contents in the table below are mysql 8.0 Li changed 
mysql> show fields from user; # Or use describe user;
#  The content here is omitted 
| plugin                   | char(64)                          | NO   |     | caching_sha2_password |       |
| authentication_string    | text                              | YES  |     | NULL                  |       |
#  The content here is omitted 

3、 Write new password

mysql> use mysql
mysql> update user set authentication_string='123456#Abc'  where  user='root';

4、 Refresh the permissions

mysql> flush privileges;

5、 give root All permissions of all databases of the user

mysql> grant all privileges on *.* to [email protected]'%' identified by '123456#Abc';
mysql> flush privileges;

---

Add ：
// Delete user .

mysql>use mysql;
mysql>delete from user where User="test" and Host="localhost";
mysql>flush privileges;

// Delete user's database

mysql>drop database test;