SQL Countries of the World Project on Codecademy

countries.sql

SELECT COUNT(id) FROM countries WHERE continent = 'Africa';

SELECT SUM(population) FROM population_years JOIN countries ON population_years.country_id = countries.id WHERE countries.continent = 'Oceania' AND year = 2005;

SELECT AVG(population) FROM population_years JOIN countries ON population_years.country_id = countries.id WHERE countries.continent = 'South America' AND year = 2003;

SELECT countries.name FROM population_years JOIN countries ON population_years.country_id = countries.id WHERE population_years.year = 2007 ORDER BY population ASC LIMIT 1;

SELECT AVG(population) FROM population_years JOIN countries ON population_years.country_id = countries.id WHERE countries.name = 'Poland';

SELECT * FROM countries WHERE name LIKE '%The%';

SELECT countries.continent, SUM(population) FROM population_years JOIN countries ON population_years.country_id = countries.id GROUP BY countries.continent;