SQL: Subqueries With Aggregates | Dataford Interview Questions

Write a SQL query using subqueries to filter a dataset based on an aggregated condition.

Use the provided customers and transactions tables. Return customers whose total transaction amount is greater than the average total transaction amount across customers with valid transactions. Exclude unmatched transactions.

Output

One row per qualifying customer.
Columns: customer_id, customer_name, and total_amount.
Sort by total_amount descending, then customer_id ascending.

Schema

customers

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

transactions

Column	Type	Description
transaction_idPK	INT	Unique transaction identifier
customer_id	INT	Customer associated with the transaction
amount	DECIMAL(10,2)	Transaction amount

Your question is SQL: Subqueries With Aggregates. Start with the requirements and the two tables in the Question tab.

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Problem