Merge pull request #2 from pankaj892/pankaj892-patch-2

Added solution for sql basic join

Author: pankaj892

SQL/average-population.sql

@@ -0,0 +1,10 @@
+-- Average Population of Each Continent
+-- 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
+-- https://www.hackerrank.com/challenges/average-population-of-each-continent/problem
+
+SELECT country.continent, FLOOR(AVG(city.population))
+FROM city
+INNER JOIN country ON city.countrycode = country.code
+GROUP BY country.continent;