SQL for Average Booking Value | Dataford Interview Questions

Write a SQL query to find the average booking value per customer from the transactions table.

Use all transaction rows. Null booking values should not contribute to the average, but customers whose transactions all have null values should remain in the output.

Output

One row per customer.
Columns: customer_id and average_booking_value.
Round the average to two decimal places and sort by customer_id ascending.

Schema

transactions

Column	Type	Description
transaction_idPK	INT	Unique identifier for the transaction
customer_id	INT	Identifier of the customer associated with the transaction
booking_value	NUMERIC(10,2)	monetary value of the booking

Your question is SQL for Average Booking Value. 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.

Problem