Instruction
Nice job! Let's move on.
Exercise
Find the maximum amount of fuel consumed for all grouping combinations involving the country, car_size, and trip_type columns. Show the following columns in the query result: country, car_size, trip_type, and max_fuel_consumed. Replace all NULL values in the first three columns with a double dash --.
Stuck? Here's a hint!
To replace NULL values with --, use the COALESCE() function. Here's an example:
COALESCE(country, '--') AS country



