HR-SQL Population Density Difference

1 개요

HR-SQL Population Density Difference

• https://www.hackerrank.com/challenges/population-density-difference/problem

해커랭크 SQL

문제	DB2	MS SQL	MySQL	Oracle
HR-SQL Aggregation e
HR-SQL Revising Aggregations - The Count Function
HR-SQL Revising Aggregations - The Sum Function
HR-SQL Revising Aggregations - Averages
HR-SQL Average Population
HR-SQL Japan Population
HR-SQL Population Density Difference
HR-SQL The Blunder
HR-SQL Top Earners
HR-SQL Weather Observation Station 2
HR-SQL Weather Observation Station 13
HR-SQL Weather Observation Station 14
HR-SQL Weather Observation Station 15
HR-SQL Weather Observation Station 16
HR-SQL Weather Observation Station 17
HR-SQL Weather Observation Station 18
HR-SQL Weather Observation Station 19
HR-SQL Weather Observation Station 20

2 MySQL

SELECT MAX(POPULATION)-MIN(POPULATION) FROM CITY;

SELECT (SELECT MAX(POPULATION) FROM CITY)
- (SELECT MIN(POPULATION) FROM CITY);