Population Census in SQL | HackerRank Solution

Hello coders, today we are going to solve Population Census HackerRank Solution in SQL.

Population Census

Contents

Problem

Given the CITY and COUNTRY tables, query the sum of the populations of all cities where the CONTINENT is ‘Asia’.

Note: CITY.CountryCode and COUNTRY.Code are matching key columns.

Input Format

The CITY and COUNTRY tables are described as follows:

FieldType
IDNUMBER
NAMEVARCHAR2(17)
COUNTRYCODEVARCHAR2(3)
DISTRICTVARCHAR2(20)
POPULATIONNUMBER
CITY
FieldType
CODEVARCHAR2(3)
NAMEVARCHAR2(44)
CONTINENTVARCHAR2(13)
REGIONVARCHAR2(25)
SURFACEAREANUMBER
INDEPYEARVARCHAR2(5)
POPULATIONNUMBER
LIFEEXPECTANCYVARCHAR2(4)
GNPNUMBER
GNPOLDVARCHAR2(9)
LOCALNAMEVARCHAR2(44)
GOVERNMENTFORMVARCHAR2(44)
HEADOFSTATEVARCHAR2(32)
CAPITALVARCHAR2(4)
CODE2VARCHAR2(2)
COUNTRY

Solution – Population Census in SQL

MySQL

select sum(city.population) from country 
left join city on country.code = city.countrycode
where country.continent = 'Asia'

Disclaimer: The above Problem (Population Census) is generated by Hacker Rank but the Solution is Provided by CodingBroz. This tutorial is only for Educational and Learning Purpose.

1 thought on “Population Census in SQL | HackerRank Solution”

  1. SELECT sum(city.population)
    FROM city
    INNER JOIN country
    ON city.countrycode = country.code where continent=’asia’;

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