MySQL basics after installation

Get root password after installation:

cat /var/log/mysqld.log | grep "temporary password"

Connect as root user:

mysql -u root -p{{ password_from_previous_step }}

Change root user password:

mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'MyNewPassword4!';

In case you do not want to run above query, run mysql_secure_installation script.

Create additional user:

mysql> CREATE USER 'john'@'localhost' IDENTIFIED BY 'MyNewPass4!';

To create a user for specified host use it's IP address instead of localhost: 192.168.1.10, or use '%' for all hostnames.

After user is added - you must set the permissions what he will have:

mysql> GRANT {{ PERMISSION }} ON {{ db_table }} to 'john'@'localhost';

There are the following permissions:
ALL PRIVILEGES, CREATE, DROP, DELETE, INSERT, SELECT, UPDATE
Example:

mysql> GRANT SELECT, UPDATE ON school.persons to 'john'@'%';
mysql> GRANT SELECT, UPDATE ON school.* to 'john'@'%';
mysql> GRANT ALL PRIVILEGES ON *.* to 'john'@'%';

Show permission grants for an user:

mysql> SHOW GRANTS for 'john'@'localhost';

Show all databases:

mysql> SHOW DATABASES;

Create new database:

mysql> CREATE DATABASE school;

Select or switch to new created database;

mysql> USE school;

Create a new table in selected database:

mysql> CREATE TABLE persons
(
  Name varchar(255),
  Age int,
  Location varchar(255)
);

Show all tables is selected database:

mysql> SHOW TABLES;

Add data to new created table:

mysql> INSERT INTO persons values("John Doe", 45, "New York");

View data from table in selected database:

mysql> SELECT * FROM persons;