First Product Purchased Per Customer | Dataford Interview Questions

Write a PostgreSQL query to find the first product each customer purchased on the Apidel Technologies platform. Return the customer, the first order, its timestamp, and the product name. If two orders share the same earliest timestamp for a customer, use the smaller order_id as the tie-breaker.

Schema

customers

Column	Type	Description
customer_id	INT	Primary key
customer_name	VARCHAR(100)	Customer name

orders

Column	Type	Description
order_id	INT	Primary key
customer_id	INT	Customer reference
product_id	INT	Product reference
purchased_at	TIMESTAMP	Purchase timestamp

products

Column	Type	Description
product_id	INT	Primary key
product_name	VARCHAR(100)	Product name

Your question is First Product Purchased Per Customer. Start with the requirements and the three tables in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem