use world;
select * from City;
select CountryCode, count(CountryCode) as Count_of_Codes
from city GROUP BY CountryCode ORDER BY CountryCode DESC;

select CountryCode, sum(Population) as TotalPopulation
from city GROUP BY CountryCode ORDER BY TotalPopulation DESC;

select CountryCode, District, sum(Population) as TotalPopulation
from city where (CountryCode="IND" or CountryCode="CHN")
GROUP BY CountryCode, District ORDER BY TotalPopulation DESC;