Ubuntu 20.04 installing mysql8.0 and modifying the MySQL password

Preface

The blogs found on the Internet about this kind of blog are either mysql The version is out of date or completely useless , Wasted a lot of my time , So I shared my successful experience with you , I hope we can reduce the time for detours .

Mysql Installation

It's simple , In a word

sudo apt install mysql-server

Msql Password modification

To change the password, we have to go first mysql, With administrator privileges, no matter what password you enter, you can succeed .

sudo mysql -u root -p

The result is as shown in the figure , Indicates installation is complete

Next, log out

quit;

And then to mysql Initialization of password settings

sudo mysql_secure_installation

The following configuration is shown in the figure

#1
VALIDATE PASSWORD PLUGIN can be used to test passwords...
Press y|Y for Yes, any other key for No: N ( choice N , No strong password verification )

#2
Please set the password for root here...
New password: ( Input password )
Re-enter new password: ( Repeat input )
( Here he will ask you if you want to change your password , First choice y)
#3
By default, a MySQL installation has an anonymous user,
allowing anyone to log into MySQL without having to have
a user account created for them...
Remove anonymous users? (Press y|Y for Yes, any other key for No) : N ( choice N, Don't delete anonymous users )

#4
Normally, root should only be allowed to connect from
'localhost'. This ensures that someone cannot guess at
the root password from the network...
Disallow root login remotely? (Press y|Y for Yes, any other key for No) : N ( choice N, allow root Remote connection )

#5
By default, MySQL comes with a database named 'test' that
anyone can access...
Remove test database and access to it? (Press y|Y for Yes, any other key for No) : N ( choice N, Don't delete test database )

#6
Reloading the privilege tables will ensure that all changes
made so far will take effect immediately.
Reload privilege tables now? (Press y|Y for Yes, any other key for No) : Y ( choice Y, The modification will take effect immediately )

Log in after finishing

sudo mysql -uroot -p

choice mysql database

use mysql;

Try setting the password for the first time , This time, an error may be reported Your password does not satisfy the current policy requirements, This is because the length of your password does not meet the length requirements , If no error is reported, the following steps are not required .

ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY ' password ';

If an error is reported, perform the following steps

SHOW VARIABLES LIKE 'validate_password%';

mysql The following parameters will be output

+--------------------------------------+--------+
		| Variable_name                        | Value  |
		+--------------------------------------+--------+
		| validate_password.check_user_name    | ON     |
		| validate_password.dictionary_file    |        |
		| validate_password.length             | 8      |// This is the password length you want to set 
		| validate_password.mixed_case_count   | 1      |
		| validate_password.number_count       | 1      |
		| validate_password.policy             | MEDIUM |
		| validate_password.special_char_count | 1      |
		+--------------------------------------+--------+
		7 rows in set (0.01 sec)

Then we will compare the parameters of your computer with those here , Generally speaking, except that the password length is different, it is the same , If it does not always exist, modify it as follows .

1 mysql> set global validate_password.policy=0;
	Query OK, 0 rows affected (0.00 sec)

2 mysql> set global validate_password.special_char_count=0;
	Query OK, 0 rows affected (0.00 sec)

3 mysql> set global validate_password.length=6;
	Query OK, 0 rows affected (0.00 sec)

4 mysql> set global validate_password.mixed_case_count=0;
	Query OK, 0 rows affected (0.00 sec)

After that, let's see if the parameter modification is successful

mysql> SHOW VARIABLES LIKE 'validate_password%';
	+--------------------------------------+-------+
	| Variable_name                        | Value |
	+--------------------------------------+-------+
	| validate_password.check_user_name    | ON    |
	| validate_password.dictionary_file    |       |
	| validate_password.length             | 6     |
	| validate_password.mixed_case_count   | 0     |
	| validate_password.number_count       | 1     |
	| validate_password.policy             | LOW   |
	| validate_password.special_char_count | 0     |
	+--------------------------------------+-------+
	7 rows in set (0.01 sec)

Finally, re-enter the previous command to change the password .（ Note that the password should be the same length as the one you modified above ）

ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY ' password ';

Save the settings and exit

flush privileges;

quit;

Finally, let's test whether the modification is successful

mysql -u root -p // Don't add... Here sudo

Input password , Can enter into mysql If no error is reported, the password is successfully modified .