SQL Joins and Window Functions

1. JOINS Sometimes it is very difficult to look through data to get specific things. For example, you want the name of customers who made purchases as well as the name of the products they bought. You have a sales table which only has customer_id and product_id, the product names are in a different table say the products table and the names of the customers are found in the customers table. As a normal person you would open the sales table and note down the Product IDs and the Customer IDs then move to the customers table and get the names of the customers represented by the specific customer ID then finally move to the products table and do the same. That's so hectic! Makes you wonder....what if there was a way to link all these tables and see whatever I want without having to open each table alone? Well my friend, you are lucky! I introduce to you the concept of JOINS. Joins provide a way that enables us connect multiple tables so that you can SELECT the columns you want to see from