mysql-community is what known as MySQL, version 8. The name mysql-community is just a distinct ebuild name to point a significant changes compared to version 5.x and that mysql-community is an open source version, not enterprise commercial software.
MySQL is the M in the lamp/lemp/llmp stack. It is a popular, & common database that accepts SQL statements. dev-db/mariadb & dev-db/percona-server are drop in replacements for MySQL.
root # emerge mysql-community
MySQL requires configuration upon instillation.
To deploy MySQL:
root # mysqld --initialize-insecure --default_authentication_plugin=mysql_native_password --datadir=/var/lib/mysql
This will create MySQL base directory, by default
/var/lib/mysql as well as an empty password for your initial database setup. This is preliminary step before setting up your password, see below
To start mysql:
root # rc-service mysql start
To start upon boot:
root # rc-update add mysql default
mysql_secure_installation. You will be promted for setting your password, as well as other required steps.
root # mysql_secure_installation
To use mysql you will need to run MySQL as the funtoo root user, logging in as the mysql database root user. The system root user is not the same as the database root user, and passwords for both should be different.
root # mysql -u root -p Enter password: mysql>
mysql is now blinking at you ready for SQL statements.
Root use is discouraged, for every database you require, create a user, and a database specific for the application, then allow the user access with as stripped down as possible permissions. We will use oleg examples of creating a oleg user & database.
root # mysql -u root -p Enter password: mysql> CREATE USER 'oleg'@'localhost' IDENTIFIED BY 'password'; mysql> GRANT ALL PRIVILEGES ON *.* TO 'oleg'@'localhost' ->WITH GRANT OPTION; mysql> \q
Let's login with "oleg" account we created above. And let's try creating a database.
root # mysql -u oleg -p mysql> CREATE DATABASE betelgeuse;
By default MySQL logs every action, including leaving plain text passwords in its history file.
To remove the history file:
root # rm /root/.mysql_history
To automatically remove future history:
root # ln -s /dev/null /root/.mysql_history
For further references, please, follow this great guide: https://downloads.mysql.com/docs/refman-8.0-en.pdf