#intermediate

SQL Joins

In the SQL Basics tutorial, we worked with a single table at a time. But real databases almost always have multiple related tables — customers and orders, students and courses, products and categories. Joins are how you combine rows from two or more tables based on a related column. Understanding joins is one of the most important SQL skills you can have. They come up constantly in application development, data analysis, and technical interviews. Read more →

April 3, 2026

EC2 Basics

Amazon EC2 (Elastic Compute Cloud) is AWS’s core compute service. It lets you run virtual servers — called instances — in the cloud. Instead of buying and maintaining physical hardware, you can launch a server in minutes, use it for as long as you need, and shut it down when you’re done. If you’ve been through the AWS Getting Started guide, you already have an AWS account. In this tutorial, we’ll launch an EC2 instance, connect to it via SSH, run a simple web server, and then clean everything up so you don’t get charged. Read more →

April 3, 2026