List Top Customers and Monthly Order Counts in SQL

Q: How do I practice SQL interview questions?

PracHub provides an interactive SQL console where you can write and test queries against real database schemas. Get instant feedback and compare your solution with the expected output.

Q: What difficulty level is this coding question?

This is a medium difficulty Data Manipulation (SQL/Python) question, commonly asked during Technical Screen rounds at Amazon.

Q: What role is this question designed for?

This question is commonly asked for Data Scientist candidates at Amazon during technical interviews.

Question

Orders

| order_id | customer_id | order_date | amount |
|----------|-------------|------------|--------|
| 1        | 101         | 2023-01-05 | 120.50 |
| 2        | 102         | 2023-01-10 | 75.00  |
| 3        | 101         | 2023-01-12 | 40.25  |
| 4        | 103         | 2023-01-15 | 220.90 |
| 5        | 104         | 2023-01-20 | 15.00  |

##### Scenario

Analyst must query customer orders stored in a relational database.

##### Question

Write SQL to list the top three customers by total spend. Write SQL to return monthly order counts for 2023, ordered chronologically.

##### Hints

Group-by, aggregates, date functions, ordering.

PracHub · Accepted Answer

This question evaluates a candidate's ability to perform SQL aggregation, grouping, top‑N selection, and date-based summarization to compute customer spend and chronological monthly order counts.

Quick Overview

List Top Customers and Monthly Order Counts in SQL