The code is giving output but it is showing that it is not matching the instructions. I have written the code according to the instructions but don't know what is missing.
Modify the case statement's such that when the elevation is less than 250, the elevation_tier column returns 'Low', when between 250 and 1749 it returns 'Medium', and when greater than or equal to 1750 it returns 'High'.
Be sure to alias the conditional statement as elevation_tier, in your query.
select case when elevation < 250 then 'Low' when elevation between 250 and 1749 then 'medium' when elevation >= 1749 then 'High' else 'Unknown' end as elevation_tier, elevation, count(*) from airports group by 1;