[해커랭크 SQL] Basic Join - Population Census

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

Population Census | HackerRank

 

 

❗ Answer

SELECT SUM(city.population)
    FROM city
    INNER JOIN country
            ON city.countrycode = country.code
    WHERE country.continent = 'ASIA';

📌 Discussion

• INNER JOIN 후 조건을 걸어서 모든 인구를 합해주었다.