Top Customers by Total Spend | Dataford Interview Questions

Given a dataset of customer transactions, write a SQL query to find the top 5 customers by total spend.

Use the provided customer and transaction data. Include transaction amounts in the total, treating missing amounts as zero. Return customers with transactions, ordered from highest total spend to lowest, with customer name ascending as the tie-breaker.

Output

One row per customer, with columns customer_name and total_spent.
Return only the five highest-spending customers.
Order by total_spent descending, then customer_name ascending.

Schema

customers

Column	Type	Description
customer_idPK	INT	Unique customer identifier
customer_name	VARCHAR(100)	Customer's full name
email	VARCHAR(255)	Customer email address

transactions

Column	Type	Description
transaction_idPK	INT	Unique transaction identifier
customer_id	INT	Customer associated with the transaction
amount	DECIMAL(12,2)	Transaction amount
transaction_date	DATE	Date the transaction occurred

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