Window functions allow you to apply calculations against "sets" or groups of data. These sets are known as windows. Many books classify window functions as an advanced topic in T-SQL. But,in fact, once you see some practical examples, window function are fairly easy to understand. In this video I will demonstrate how to

Rank rows (both dense ranks and "normal" ranks.
Add row numbers.
Create running / Cumulative totals
Extract the first and last records from a set (window) of records.

Sample files to create the database and the T-SQL are available on my website http://www.analyticsinaction.com/wind....

I also have a comprehensive 60 minute T-SQL course available at Udemy : https://www.udemy.com/t-sql-for-data-...