Top Taskers by Category | Dataford Interview Questions

TaskRabbit wants to identify the highest-earning taskers in each service category. Write a SQL query that ranks taskers by revenue from completed bookings during the previous calendar month, using September 15, 2026 as the reporting reference date.

Output

Return one row per qualifying tasker and category, with category_name, tasker_id, tasker_name, total_revenue, and revenue_rank.
Include only completed bookings from August 2026, excluding bookings with missing tasker or category matches.
Return the top three taskers in each category, with ties broken by the lower tasker_id.
Sort by category_name, then revenue_rank, then tasker_id.
NULL booking amounts are ignored by SUM; taskers with only NULL amounts remain eligible with a NULL total revenue.

Schema

taskers

Column	Type	Description
tasker_idPK	INT	Unique Tasker identifier
tasker_name	VARCHAR(100)	Tasker display name
service_area	VARCHAR(100)	Primary service area

categories

Column	Type	Description
category_idPK	INT	Unique task category identifier
category_name	VARCHAR(100)	Task category name

bookings

Column	Type	Description
booking_idPK	INT	Unique booking identifier
tasker_id	INT	Tasker assigned to the booking
category_id	INT	Category associated with the booking
amount	DECIMAL(10,2)	Booking revenue amount
status	VARCHAR(20)	Booking status
completed_at	TIMESTAMP	Timestamp when the booking was completed

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