DoorDash Schema SQL and Python | Dataford Interview Questions

SQL questions based on DoorDash data schema, python leet code medium

Using the DoorDash-style tables provided, write a PostgreSQL query for Seattle restaurants. Include restaurants without qualifying deliveries and consider only completed orders delivered during the first quarter of 2024.

Output

One row per Seattle restaurant, with restaurant_name, completed_delivery_count, and avg_delivery_minutes.
Sort by completed delivery count descending, then restaurant name ascending.
Return NULL for the average when no qualifying delivery has a measurable duration.

Schema

restaurants

Column	Type	Description
restaurant_idPK	INT	Unique restaurant identifier
restaurant_name	VARCHAR(100)	Restaurant display name
city	VARCHAR(80)	Restaurant city

orders

Column	Type	Description
order_idPK	INT	Unique order identifier
restaurant_id	INT	Restaurant that received the order
customer_id	INT	Customer identifier
order_placed_at	TIMESTAMP	Timestamp when the order was placed
order_status	VARCHAR(30)	Current order status

deliveries

Column	Type	Description
delivery_idPK	INT	Unique delivery identifier
order_id	INT	Order associated with the delivery
dasher_id	INT	Dasher identifier
picked_up_at	TIMESTAMP	Timestamp when the order was picked up
delivered_at	TIMESTAMP	Timestamp when the order was delivered
delivery_status	VARCHAR(30)	Current delivery status

Your question is DoorDash Schema SQL and Python. Start with the requirements and the three tables 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