Find Dashers With Late Deliveries | Dataford Interview Questions

Find dashers with late deliveries

Use the provided dasher and delivery records. Treat a completed delivery as late when its delivery timestamp is later than its promised timestamp. Exclude canceled deliveries and records missing either timestamp.

Output

One row per dasher with at least one late delivery.
Return dasher_id, dasher_name, late_delivery_count, and average_minutes_late.
Order by late delivery count descending, average minutes late descending, then dasher name ascending.

Schema

dashers

Column	Type	Description
dasher_idPK	INT	Unique identifier for the dasher
dasher_name	VARCHAR(100)	Dasher's display name

deliveries

Column	Type	Description
delivery_idPK	INT	Unique identifier for the delivery
dasher_id	INT	Dasher assigned to the delivery
status	VARCHAR(20)	Delivery status
promised_at	TIMESTAMP	Promised delivery timestamp
delivered_at	TIMESTAMP	Actual delivery timestamp

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