SQL Query with Complex Joins | Dataford Interview Questions

Write a SQL query with some tricky joins (HackerRank SQL question).

Asked in the HackerRank online test stage. Using the provided customers, orders, and payments tables, return customers with at least one order dated on or after 2025-01-01. Include successful payment totals while retaining qualifying orders that have no successful payment.

Output

One row per qualifying customer with customer_id, customer_name, order_count, and successful_payment_amount.
Sort by successful_payment_amount descending, then customer_id ascending.

Schema

customers

Column	Type	Description
customer_idPK	INT	Unique customer identifier
customer_name	VARCHAR(100)	Customer display name

orders

Column	Type	Description
order_idPK	INT	Unique order identifier
customer_id	INT	Customer associated with the order
order_date	DATE	Date the order was placed
order_amount	NUMERIC(10,2)	Original order amount

payments

Column	Type	Description
payment_idPK	INT	Unique payment identifier
order_id	INT	Order associated with the payment
status	VARCHAR(20)	Payment processing status
amount	NUMERIC(10,2)	Payment amount

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Problem