| 1 | How does the GROUP BY clause work together with aggregate functions? SQL Server › Aggregate Functions & GROUP BY | SQL Server | Aggregate Functions & GROUP BY | Beginner |
| 2 | How do the ROLLUP and CUBE extensions to GROUP BY help you generate subtotal and grand total rows in a single query? SQL Server › Aggregate Functions & GROUP BY | SQL Server | Aggregate Functions & GROUP BY | Advanced |
| 3 | How would you calculate a running total or a percentage of total using aggregate functions combined with window functions? SQL Server › Aggregate Functions & GROUP BY | SQL Server | Aggregate Functions & GROUP BY | Advanced |
| 4 | What are aggregate functions in SQL Server, and what are the most common ones? SQL Server › Aggregate Functions & GROUP BY | SQL Server | Aggregate Functions & GROUP BY | Beginner |
| 5 | How do you filter the results of a grouped query based on an aggregated value, such as only showing customers who spent more than a certain amount? SQL Server › Aggregate Functions & GROUP BY | SQL Server | Aggregate Functions & GROUP BY | Intermediate |
| 6 | How do you correctly combine WHERE and HAVING in the same query to filter both individual rows and grouped results? SQL Server › Aggregate Functions & GROUP BY | SQL Server | Aggregate Functions & GROUP BY | Intermediate |
| 7 | What is the difference between COUNT(*), COUNT(1), and COUNT(column_name) in SQL Server? SQL Server › Aggregate Functions & GROUP BY | SQL Server | Aggregate Functions & GROUP BY | Intermediate |
| 8 | What is a window function in SQL Server, and how is it different from a regular aggregate function used with GROUP BY? SQL Server › Window Functions | SQL Server | Window Functions | Beginner |
| 9 | How does the PARTITION BY clause within a window function differ from GROUP BY, and why is this distinction useful? SQL Server › Window Functions | SQL Server | Window Functions | Intermediate |
| 10 | How do LAG and LEAD window functions let you access values from a previous or following row without needing a self join? SQL Server › Window Functions | SQL Server | Window Functions | Intermediate |