MySQL Database Basics Explained for Linux and Cloud Engineers

Introduction

MySQL is one of the most popular open-source relational database management systems (RDBMS).
It is widely used in web applications, cloud platforms, and enterprise environments.
As a Linux or Cloud Engineer, understanding MySQL basics helps you in installation, configuration, troubleshooting, and supporting application teams.

What is a Database?

A database is an organized collection of data. Instead of keeping data in text files or spreadsheets, databases store data in a structured way so that applications can quickly read and write it.

For example: A shopping website stores users, products, and orders in different database tables.

Relational Database Basics

• Tables: Similar to Excel sheets with rows and columns.
• Rows: Each record (example: one user information).
• Columns: Fields (example: user_id, name, email).
• Primary Key: A unique identifier for each row (example: user_id).
• Foreign Key: A reference to connect one table with another (example: orders linked to user_id).

Why MySQL?

• Free and open-source.
• Very fast and reliable.
• Easy to integrate with PHP, Python, Java, WordPress, etc.
• Supported on Linux, Windows, and Cloud platforms.

MySQL Installation (Linux)

On Rocky Linux / CentOS:

sudo dnf install mysql-server -y
sudo systemctl start mysqld
sudo systemctl enable mysqld

On Ubuntu/Debian:

sudo apt update
sudo apt install mysql-server -y
sudo systemctl start mysql
sudo systemctl enable mysql

Basic MySQL Commands

• Login to MySQL:
  mysql -u root -p
• Show databases:
  SHOW DATABASES;
• Create a database:
  CREATE DATABASE mydb;
• Create a user:
  CREATE USER 'myuser'@'localhost' IDENTIFIED BY 'password';
• Grant privileges:
  GRANT ALL PRIVILEGES ON mydb.* TO 'myuser'@'localhost';
• Use a database:
  USE mydb;
• Create a table:
  CREATE TABLE users (id INT AUTO_INCREMENT PRIMARY KEY, name VARCHAR(50), email VARCHAR(100));
• Insert data:
  INSERT INTO users (name, email) VALUES ('Shahzad', 'shahzad@example.com');
• Select data:
  SELECT * FROM users;

MySQL Important Files in Linux

• /etc/my.cnf → Main configuration file.
• /var/lib/mysql/ → Default data directory.
• /var/log/mysqld.log → Log file for errors.

MySQL for Cloud Engineers

In cloud platforms (AWS RDS, GCP Cloud SQL, Azure Database for MySQL), MySQL is offered as a managed service.
This means engineers don’t have to manage installation and patching, only focus on performance, backups, and connectivity.

Use Cases of MySQL

• Websites and CMS (WordPress, Joomla, Drupal).
• E-commerce platforms (Magento, WooCommerce).
• Cloud-native applications.
• Enterprise data storage and analytics.

Conclusion

MySQL is simple to learn but very powerful for real-world applications.
By understanding databases, tables, basic SQL commands, and MySQL configuration files,
Linux and Cloud Engineers can support developers and manage production systems efficiently.