Algorithm
Problem Name: Sql -
In this HackerRank Functions in SQL problem solution,
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: 
Code Examples
#1 Code Example with MySQL
Code -
MySQL
select sum(City.Population) from City INNER JOIN Country on City.CountryCode = Country.Code Where Country.Continent = 'Asia';