Understanding Joins and Window Functions in SQL

Introduction In this article, we will explore two of the most powerful and widely used features in SQL: JOINs and Window Functions. We will begin by understanding what they are and how they work, and then walk through practical examples to see when, where, and why they are used in real-world scenarios. Let's start with joins: What are Joins? In Structured Query Language (SQL), a join is a clause used to combine rows from two or more tables based on a related column between them. The purpose of a joins is to retrieve data that is spread across multiple tables into a single table, providing a unified view. Example: In database with an orders and customers table, a join can be used to answer questions such as which customer placed an order. Type of Joins 1. INNER JOIN It combines two or more tables based on a specified common column with matching values and only returns the set of records that have a match in all the involved tables. The rows that don't have a match in the other table(s)