E-commerce: Customers Who Placed an Order (IN Subquery)

SQL coding challenge · Difficulty: easy · +50 XP

Problem

Your loyalty program wants to email every customer who has placed at least one order. Find them using an IN subquery (not a JOIN).

Tables

Table: Customer

| customer_id | name | email |
| --- | --- | --- |
| 1 | Prince | prince@gmail.com |
| 2 | Mohit | mohit@gmail.com |
| 3 | Rahul | rahul@gmail.com |
| 4 | Krishna | krishna@gmail.com |

Table: Orders

| order_id | customer_id | order_date | total_amount |
| --- | --- | --- | --- |
| 101 | 1 | 2024-05-01 | 1500 |
| 102 | 2 | 2024-05-02 | 2300 |
| 103 | 3 | 2024-05-03 | 1800 |
| 104 | 4 | 2024-05-04 | 2700 |
| 105 | 1 | 2024-05-05 | 1100 |

Expected Output

| customer_id | name |
| --- | --- |
| 1 | Prince |
| 2 | Mohit |
| 3 | Rahul |
| 4 | Krishna |

Return: customer_id, name, email
Must use an IN subquery (not a JOIN)
Sort by customer_id ascending