Count, Return, Find, and Select in SQL Queries
Company: OneMain Financial
Role: Data Scientist
Category: Data Manipulation (SQL/Python)
Difficulty: Medium
Interview Round: Onsite
orders
+----------+--------------+------------+--------+
| order_id | customer_id | order_date | amount |
+----------+--------------+------------+--------+
| 1 | 101 | 2024-01-05 | 250.00 |
| 2 | 102 | 2024-01-07 | 125.50 |
| 3 | 101 | 2024-01-10 | 80.00 |
| 4 | 103 | 2024-01-11 | 300.00 |
| 5 | 104 | 2024-01-15 | 150.00 |
+----------+--------------+------------+--------+
##### Scenario
SQL screening – answer four basic queries on a single orders table
##### Question
Count how many orders each customer has made. Return the total revenue generated per day. Find the customer(s) with the highest single order amount. Select all orders whose amount is above the overall average.
##### Hints
GROUP BY, ORDER BY, HAVING and window functions might help.
Quick Answer: This question evaluates proficiency in SQL data manipulation, specifically aggregation, grouping, filtering, and identification of extrema within a single-table orders dataset.