If you're working with analytical queries in SQL Server, this guide to window functions is worth your attention: https://www.c-sharpcorner.com/article/sql-window-functions-explained-examples-best-practices2/

SQL window functions allow you to perform advanced calculations across related rows without collapsing your result set—an essential feature for reporting, forecasting, and trend analysis.

This article will walk you through the practical examples of window functions using dbForge Studio for SQL Server, one of the most powerful SQL development tools for writing and optimizing code. With its help, you will learn the following:

🔹 How the OVER() clause works
🔹 The difference between PARTITION BY and ORDER BY
🔹 ROWS vs RANGE behavior
🔹 Ranking functions: ROW_NUMBER(), RANK(), DENSE_RANK(), NTILE()
🔹 Aggregate window functions: SUM() OVER(), AVG() OVER(), COUNT() OVER()
🔹 Value-based functions: LAG(), LEAD(), FIRST_VALUE(), LAST_VALUE()

You'll see clear examples of the following operations:
✔ Running totals
✔ Sales forecasting
✔ Salary ranking
✔ Comparative analysis between previous and next rows

For developers, analysts, and DBAs, mastering window functions is not optional — it’s a competitive advantage. The right tools will help you write, test, and optimize complex analytical queries faster and more efficiently.

Window functions are not just a feature. They're the foundation for advanced SQL-powered analytics.

Have you used LAG() or NTILE() in production scenarios? What was your use case?