HR-SQL Average Population of Each Continent

1 개요

HR-SQL Average Population of Each Continent

• https://www.hackerrank.com/challenges/average-population-of-each-continent/problem

해커랭크 SQL

문제	DB2	MS SQL	MySQL	Oracle
HR-SQL Basic Join e
HR-SQL Asian Population
HR-SQL African Cities
HR-SQL Average Population of Each Continent
HR-SQL The Report
HR-SQL Top Competitors
HR-SQL Ollivander's Inventory
HR-SQL Challenges
HR-SQL Contest Leaderboard

Africa 274439 
Asia 693038 
Europe 175138 
Oceania 109189 
South America 147435

2 MySQL

SELECT CO.CONTINENT, FLOOR(AVG(CI.POPULATION))
FROM CITY AS CI
JOIN COUNTRY AS CO ON CO.CODE = CI.COUNTRYCODE
GROUP BY CO.CONTINENT;

SELECT CO.CONTINENT, FLOOR(AVG(CI.POPULATION))
FROM CITY AS CI, COUNTRY AS CO
WHERE CO.CODE = CI.COUNTRYCODE
GROUP BY CO.CONTINENT;