[해커랭크 SQL] Aggregation - Japan Population

❓ Question
https://www.hackerrank.com/challenges/japan-population

Japan Population | HackerRank

❗ Answer

SELECT SUM(population)
    FROM city
    WHERE countrycode = 'JPN';

📌 Discussion

• where 절에서 조건에 맞는 레코드만 추출 후 sum 집계