Analyzing track length
Previously, you used a subquery to find the average length of songs, in milliseconds, for each genre. Now, you're going to do something similar with a common table expression, but this time, with a bit more attention to detail. Let's get to it!
This exercise is part of the course
Data Manipulation in Snowflake
Exercise instructions
- Write a common table expression with the name
track_lengths
to retrieve thename
field fromstore.genre
, as well as thegenre_id
andmilliseconds
from thestore.track
table. - Find the average
track_length
, in seconds, for each genre using thetrack_lengths
common table expression. - Sort the results by the average track length, from longest to shortest.
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
-- Create a CTE named track_lengths
___ ___ ___ (
SELECT
genre.name,
track.genre_id,
track.milliseconds / 1000 AS num_seconds
FROM store.track
JOIN store.genre ON track.genre_id = genre.genre_id
)
SELECT
track_lengths.name,
-- Find the average length of each track in seconds
___(___.___) AS avg_track_length
FROM ___
GROUP BY track_lengths.name
-- Sort the results by average track_length
___;