Install MySQL Database

MySQL is a popular database management system used within PHP environments. It store's most of your web-data.
An alternative Database is MariaDB and highly compatible with MySQL, because many of the developers of MySQL were involved in its development.
A list of some popular databases here.

Install MySQL:

$ sudo apt install mysql-server

 confirm installation by typing Y, and then ENTER.

When the installation is finished, it’s recommended to run a security script that comes pre-installed with MySQL. This script will remove some insecure default settings and lock down access to your database system. Start the interactive script by running:

$ sudo mysql_secure_installation

It present a question if you want to configure the VALIDATE PASSWORD PLUGIN.

Note: Enabling this feature is something of a judgment call. If enabled, passwords which don’t match the specified criteria will be rejected by MySQL with an error. It is safe to leave validation disabled, but you should always use strong, unique passwords for database credentials.

Answer Y for yes, or anything else to continue without enabling.

VALIDATE PASSWORD PLUGIN can be used to test passwords
and improve security. It checks the strength of password
and allows the users to set only those passwords which are
secure enough. Would you like to setup VALIDATE PASSWORD plugin?

Press y|Y for Yes, any other key for No:


If answer is Y, a new question follows

There are three levels of password validation policy:

LOW Length >= 8
MEDIUM Length >= 8, numeric, mixed case, and special characters
STRONG Length >= 8, numeric, mixed case, special characters and dictionary file

Please enter 0 = LOW, 1 = MEDIUM and 2 = STRONG: 1

Next question will ask to select and confirm a password for the MySQL root user. This is not to be confused with the system root. The database root user is an administrative user with full privileges over the database system.  Define a strong password here as an additional safety measure.

If password validation enabled, the password strength for the root password entered shown. If satisfactory, enter Y for “yes” at the prompt:

Estimated strength of the password: 100
Do you wish to continue with the password provided?(Press y|Y for Yes, any other key for No) : y


For remaining questions, press Y and hit the ENTER key at each prompt. This will remove some anonymous users and the test database, disable remote root logins, and load these new rules so that MySQL immediately activates the changes made.

When done, test if you’re able to log in to the MySQL console:
$ sudo mysql

A connection to the MySQL server is established as administrative database user root, which is inferred by the use of sudo when running this command. Output like this should be displayed:

Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 22
Server version: 8.0.19-0ubuntu5 (Ubuntu)

Copyright (c) 2000, 2020, 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>

Exit with command:

mysql> exit

MySQL installation successfully completed