Top Drivers by Monthly Rating | Dataford Interview Questions

Task

Uber wants a monthly leaderboard of driver quality. Write a PostgreSQL query that returns the top 10 drivers by average rating for the last month, using a fixed reporting date of 2026-06-01.

Requirements

Only include rides with ride_status = 'completed'.
Use the last-month window starting on 2026-05-01 and ending before 2026-06-01.
Exclude completed rides where rating is NULL.
Return driver_name, avg_rating rounded to 2 decimals, and completed_rides.
Sort by avg_rating descending, then completed_rides descending, then driver_name ascending.
Return at most 10 rows.

Input Tables

`drivers`

column	type	description
driver_id	INT	Unique driver identifier
driver_name	VARCHAR(100)	Driver display name

`rides`

column	type	description
ride_id	INT	Unique ride identifier
driver_id	INT	Driver assigned to the ride
ride_date	DATE	Date of the ride
rating	DECIMAL(3,2)	Passenger rating for the ride
ride_status	VARCHAR(20)	Ride status such as completed or canceled

Problem

Task

Uber wants a monthly leaderboard of driver quality. Write a PostgreSQL query that returns the top 10 drivers by average rating for the last month, using a fixed reporting date of 2026-06-01.

Requirements

Only include rides with ride_status = 'completed'.
Use the last-month window starting on 2026-05-01 and ending before 2026-06-01.
Exclude completed rides where rating is NULL.
Return driver_name, avg_rating rounded to 2 decimals, and completed_rides.
Sort by avg_rating descending, then completed_rides descending, then driver_name ascending.
Return at most 10 rows.

Input Tables

`drivers`

column	type	description
driver_id	INT	Unique driver identifier
driver_name	VARCHAR(100)	Driver display name

`rides`

column	type	description
ride_id	INT	Unique ride identifier
driver_id	INT	Driver assigned to the ride
ride_date	DATE	Date of the ride
rating	DECIMAL(3,2)	Passenger rating for the ride
ride_status	VARCHAR(20)	Ride status such as completed or canceled

Problem

Task

Uber wants a monthly leaderboard of driver quality. Write a PostgreSQL query that returns the top 10 drivers by average rating for the last month, using a fixed reporting date of 2026-06-01.

Requirements

Only include rides with ride_status = 'completed'.
Use the last-month window starting on 2026-05-01 and ending before 2026-06-01.
Exclude completed rides where rating is NULL.
Return driver_name, avg_rating rounded to 2 decimals, and completed_rides.
Sort by avg_rating descending, then completed_rides descending, then driver_name ascending.
Return at most 10 rows.

Input Tables

`drivers`

column	type	description
driver_id	INT	Unique driver identifier
driver_name	VARCHAR(100)	Driver display name

`rides`

column	type	description
ride_id	INT	Unique ride identifier
driver_id	INT	Driver assigned to the ride
ride_date	DATE	Date of the ride
rating	DECIMAL(3,2)	Passenger rating for the ride
ride_status	VARCHAR(20)	Ride status such as completed or canceled

Problem

Task

Uber wants a monthly leaderboard of driver quality. Write a PostgreSQL query that returns the top 10 drivers by average rating for the last month, using a fixed reporting date of 2026-06-01.

Requirements

Only include rides with ride_status = 'completed'.
Use the last-month window starting on 2026-05-01 and ending before 2026-06-01.
Exclude completed rides where rating is NULL.
Return driver_name, avg_rating rounded to 2 decimals, and completed_rides.
Sort by avg_rating descending, then completed_rides descending, then driver_name ascending.
Return at most 10 rows.

Input Tables

`drivers`

column	type	description
driver_id	INT	Unique driver identifier
driver_name	VARCHAR(100)	Driver display name

`rides`

column	type	description
ride_id	INT	Unique ride identifier
driver_id	INT	Driver assigned to the ride
ride_date	DATE	Date of the ride
rating	DECIMAL(3,2)	Passenger rating for the ride
ride_status	VARCHAR(20)	Ride status such as completed or canceled