Basic SQL Questions | Dataford Interview Questions

Answer basic SQL questions without using window functions.

Using the transactions table, write a PostgreSQL query that returns the five customers with the highest total amount from completed transactions.

Output

One row per customer, with columns customer_name and total_amount.
Include only completed transactions.
Sort by total_amount descending, then customer_name ascending to break ties.
Return at most five rows.

transactions

Column	Type	Description
transaction_idPK	INT	Unique transaction identifier
customer_name	VARCHAR(100)	Customer associated with the transaction
status	VARCHAR(20)	Transaction status
amount	DECIMAL(10,2)	Transaction amount

Your question is Basic SQL Questions. Start with the requirements and the one table 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.

Answer basic SQL questions without using window functions.

Using the transactions table, write a PostgreSQL query that returns the five customers with the highest total amount from completed transactions.

One row per customer, with columns customer_name and total_amount.
Include only completed transactions.
Sort by total_amount descending, then customer_name ascending to break ties.
Return at most five rows.

transactions

Column	Type	Description
transaction_idPK	INT	Unique transaction identifier
customer_name	VARCHAR(100)	Customer associated with the transaction
status	VARCHAR(20)	Transaction status
amount	DECIMAL(10,2)	Transaction amount

Your question is Basic SQL Questions. Start with the requirements and the one table 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.