[SQL][sqlzoo] SUM and COUNT

SUM and COUNT                                                                                                       

SUM and COUNT - SQLZOO

1.Total world population

SELECT SUM(population)
FROM world

2.List of continents

select distinct continent
from world

3.GDP of Africa

select sum(gdp) 
from world 
where continent ='africa'

4.Count the big countries

select count(name) 
from world 
where area>=1000000

5.Baltic states population

select sum(population) 
from world 
where name in('Estonia', 'Latvia', 'Lithuania')

6.Counting the countries of each continent

SELECT continent,COUNT(name) 
FROM world 
GROUP BY continent

7.Counting big countries in each continent

select continent,count(population) 
from world 
where population >=10000000 
group by continent

 

8.Counting big continents

SELECT continent 
FROM world 
GROUP BY continent 
HAVING SUM(population) >= 100000000

SUM and COUNT Quiz                                                                                              

1.

 SELECT SUM(population) FROM bbc WHERE region = 'Europe'

2.

 SELECT COUNT(name) FROM bbc WHERE population < 150000

3.

AVG(), COUNT(), MAX(), MIN(), SUM()

4.

No result due to invalid use of the WHERE function

5.

 SELECT AVG(population) FROM bbc WHERE name IN ('Poland', 'Germany', 'Denmark')

6.

 SELECT region, SUM(population)/SUM(area) AS density FROM bbc GROUP BY region

7.

SELECT name, population/area AS density FROM bbc WHERE population = (SELECT MAX(population) FROM bbc)

8.

Table-D

Americas	732240
Middle East	13403102
South America	17740392
South Asia	9437710