[SQL] 해커랭크 Average Population of Each Continent

문제

Given the CITY and COUNTRY tables, query the names of all the continents (COUNTRY.Continent) and their respective average city populations (CITY.Population) rounded down to the nearest integer.

Note: CITY.CountryCode and COUNTRY.Code are matching key columns.
Input Format
The CITY and COUNTRY tables are described as follows:

 

https://www.hackerrank.com/challenges/average-population-of-each-continent/problem?isFullScreen=true

Average Population of Each Continent | HackerRank

문제 풀이

SELECT country.continent
     , FLOOR(AVG(city.population))
FROM city
     INNER JOIN country ON city.countrycode = country.code
GROUP BY country.continent

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SQL을 독학하시는 분들에게 도움이 되길 바라며,

혹 더 좋은 방법이 있거나 오류가 있다면 편하게 말씀 부탁드립니다.