https://leetcode.com/problems/queries-quality-and-percentage/description/
My SQL, Oracle
SELECT query_name, ROUND(SUM(rating / position) / COUNT(rating), 2) as quality,
ROUND(COUNT(CASE WHEN rating < 3 THEN 1 END) / COUNT(rating) * 100, 2) as poor_query_percentage
FROM Queries
WHERE query_name IS NOT NULL
GROUP BY query_name
특별할건없고 NULL 체크 및 적절한 계산 공식을 사용하면 된다.
