Rolling Average Delivery Times SQL | Dataford Interview Questions

Write a SQL query to calculate the rolling average of delivery times over the last 30 days for Delivery Hero India.

Use completed deliveries with a non-null delivery duration. Treat the reporting date as the database's current date.

Output

One row per delivery date in the 30-day period.
Columns: delivery_date, daily_average_minutes, and rolling_average_minutes.
Include only dates with qualifying deliveries, ordered chronologically by delivery_date.

deliveries

Column	Type	Description
delivery_idPK	INT	Unique delivery identifier
delivered_at	TIMESTAMP	Timestamp when the order was delivered
delivery_minutes	INT	Elapsed delivery time in minutes
status	VARCHAR(20)	Current delivery status

Your question is Rolling Average Delivery Times SQL. 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.

Write a SQL query to calculate the rolling average of delivery times over the last 30 days for Delivery Hero India.

Use completed deliveries with a non-null delivery duration. Treat the reporting date as the database's current date.

One row per delivery date in the 30-day period.
Columns: delivery_date, daily_average_minutes, and rolling_average_minutes.
Include only dates with qualifying deliveries, ordered chronologically by delivery_date.

deliveries

Column	Type	Description
delivery_idPK	INT	Unique delivery identifier
delivered_at	TIMESTAMP	Timestamp when the order was delivered
delivery_minutes	INT	Elapsed delivery time in minutes
status	VARCHAR(20)	Current delivery status

Your question is Rolling Average Delivery Times SQL. 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.