[StrataScratch] Popularity Percentage [MySQL]

https://platform.stratascratch.com/coding/10284-popularity-percentage?code_type=3 

StrataScratch

코드

WITH friends AS (
    SELECT user1 p1, user2 p2
    FROM facebook_friends
    UNION
    Select user2 p1, user1 p2
    FROM facebook_friends
)
 
SELECT p1, COUNT(*) / (
    SELECT COUNT(*)
    FROM facebook_friends
) * 100
FROM friends
GROUP BY p1
ORDER BY p1;