Help me in solving SQW44 problem

help
,
1

My issue

help me to solve this problem

My code

/* Write a query to do the following
- We need to output the following - 'connection_id', 'origin', 'destination', 'cost_category'.  
- 'cost_category' is the alias for the column which stores the values 'High cost', 'Medium cost', 'Low cost'
- Cost of operating a truck is the alias - running_cost = distance x cost_per_distance. 
- **Hint** you will need to JOIN the tables 'Network' and 'Truck' and then apply relevant conditions
- **Hint** you will need to use CASE / WHEN to identify the 'cost_category' */
SELECT
    connection_id,
    origin,
    destination,
    CASE
        WHEN distance * cost_per_distance > 800 THEN 'High cost'
        WHEN distance * cost_per_distance > 600 THEN 'Medium cost'
        ELSE 'Low cost'
    END AS cost_category
FROM
    Network
JOIN
    Truck ON Network.truck_id = Truck.truck_id
WHERE
    Truck.truck_type = 'Trailer';

Learning course: Learn Data Analytics using SQL and Python
Problem Link: Practice Problem in - CodeChef