3308. Find Top Performing Driver 🔒

Description

Table: Drivers

+--------------+---------+
| Column Name  | Type    |
+--------------+---------+
| driver_id    | int     |
| name         | varchar |
| age          | int     |
| experience   | int     |
| accidents    | int     |
+--------------+---------+
(driver_id) is the unique key for this table.
Each row includes a driver's ID, their name, age, years of driving experience, and the number of accidents they’ve had.

Table: Vehicles

+--------------+---------+
| vehicle_id   | int     |
| driver_id    | int     |
| model        | varchar |
| fuel_type    | varchar |
| mileage      | int     |
+--------------+---------+
(vehicle_id, driver_id, fuel_type) is the unique key for this table.
Each row includes the vehicle's ID, the driver who operates it, the model, fuel type, and mileage.

Table: Trips

+--------------+---------+
| trip_id      | int     |
| vehicle_id   | int     |
| distance     | int     |
| duration     | int     |
| rating       | int     |
+--------------+---------+
(trip_id) is the unique key for this table.
Each row includes a trip's ID, the vehicle used, the distance covered (in miles), the trip duration (in minutes), and the passenger's rating (1-5).

Uber is analyzing drivers based on their trips. Write a solution to find the top-performing driver for each fuel type based on the following criteria:

1. A driver's performance is calculated as the average rating across all their trips. Average rating should be rounded to 2 decimal places.
2. If two drivers have the same average rating, the driver with the longer total distance traveled should be ranked higher.
3. If there is still a tie, choose the driver with the fewest accidents.

Return the result table ordered by fuel_type in ascending order.

The result format is in the following example.

 

Example:

Input:

Drivers table:

+-----------+----------+-----+------------+-----------+
| driver_id | name     | age | experience | accidents |
+-----------+----------+-----+------------+-----------+
| 1         | Alice    | 34  | 10         | 1         |
| 2         | Bob      | 45  | 20         | 3         |
| 3         | Charlie  | 28  | 5          | 0         |
+-----------+----------+-----+------------+-----------+

Vehicles table:

+------------+-----------+---------+-----------+---------+
| vehicle_id | driver_id | model   | fuel_type | mileage |
+------------+-----------+---------+-----------+---------+
| 100        | 1         | Sedan   | Gasoline  | 20000   |
| 101        | 2         | SUV     | Electric  | 30000   |
| 102        | 3         | Coupe   | Gasoline  | 15000   |
+------------+-----------+---------+-----------+---------+

Trips table:

+---------+------------+----------+----------+--------+
| trip_id | vehicle_id | distance | duration | rating |
+---------+------------+----------+----------+--------+
| 201     | 100        | 50       | 30       | 5      |
| 202     | 100        | 30       | 20       | 4      |
| 203     | 101        | 100      | 60       | 4      |
| 204     | 101        | 80       | 50       | 5      |
| 205     | 102        | 40       | 30       | 5      |
| 206     | 102        | 60       | 40       | 5      |
+---------+------------+----------+----------+--------+

Output:

+-----------+-----------+--------+----------+
| fuel_type | driver_id | rating | distance |
+-----------+-----------+--------+----------+
| Electric  | 2         | 4.50   | 180      |
| Gasoline  | 3         | 5.00   | 100      |
+-----------+-----------+--------+----------+

Explanation:

• For fuel type Gasoline, both Alice (Driver 1) and Charlie (Driver 3) have trips. Charlie has an average rating of 5.0, while Alice has 4.5. Therefore, Charlie is selected.
• For fuel type Electric, Bob (Driver 2) is the only driver with an average rating of 4.5, so he is selected.

The output table is ordered by fuel_type in ascending order.

Solutions

Solution 1: Equi-join + Grouping + Window Function

We can use equi-join to join the Drivers table with the Vehicles table on driver_id, and then join with the Trips table on vehicle_id. Next, we group by fuel_type and driver_id to calculate each driver's average rating, total mileage, and total accident count. Then, using the RANK() window function, we rank the drivers of each fuel type in descending order of rating, descending order of total mileage, and ascending order of total accident count. Finally, we filter out the driver ranked 1 for each fuel type.

MySQL

# Write your MySQL query statement below
WITH
    T AS (
        SELECT
            fuel_type,
            driver_id,
            ROUND(AVG(rating), 2) rating,
            SUM(distance) distance,
            SUM(accidents) accidents
        FROM
            Drivers
            JOIN Vehicles USING (driver_id)
            JOIN Trips USING (vehicle_id)
        GROUP BY fuel_type, driver_id
    ),
    P AS (
        SELECT
            *,
            RANK() OVER (
                PARTITION BY fuel_type
                ORDER BY rating DESC, distance DESC, accidents
            ) rk
        FROM T
    )
SELECT fuel_type, driver_id, rating, distance
FROM P
WHERE rk = 1
ORDER BY 1;

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