Mastering SQL Joins and Window Functions

Introduction SQL (Structured Query Language) is a powerful tool used to search, manage, and analyze large amounts of data. It is widely used by data enthusiasts, software developers and even marketing professionals. In real-world databases, data is not stored in one large table. It is divided into multiple related tables. This makes storage efficient and avoids duplication. To work effectively with such data, you must understand SQL joins and window functions. These two features allow you to combine data correctly and perform advanced analysis without losing important details. SQL Joins A JOIN in SQL is used to combine rows from two or more tables based on a related column. This relationship is usually created using: A primary key (unique identifier in one table) A foreign key (reference to that key in another table) Joins are essential when working with relational databases because data is often split across multiple tables. Importance of Joins Combining related data from multiple tab