What is the ID of the longest song, please?
select f_id from files order by duration desc limit 1
What is the artist name of that song?
select artist_name from files order by duration desc limit 1
What is the duration of that song?
select duration from files order by duration desc limit 1
What about the shortest song?
select duration from files order by duration limit 1
What is the average duration of all songs?
select avg ( duration ) from files