solution_sql_zoo/sum_and_count.sql at master · thegeekscript/solution_sql_zoo · GitHub

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-- SUM and COUNT


-- 1.
-- Show the total population of the world.


-- world(name, continent, area, population, gdp)


SELECT SUM(population)
FROM world
;


-- 2.
-- List all the continents - just once each.


SELECT DISTINCT(continent)
FROM world
;


-- 3.
-- Give the total GDP of Africa


SELECT SUM(gdp)
FROM world
WHERE continent = 'Africa'
;


-- 4.
-- How many countries have an area of at least 1000000


SELECT COUNT(name)
FROM world
WHERE area >= 1000000
;


-- 5.
-- What is the total population of ('France','Germany','Spain')


SELECT SUM(population)
FROM world
WHERE name IN('France','Germany','Spain')
;


-- 6.
-- For each continent show the continent and number of countries.


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


-- 7.
-- For each continent show the continent and number of countries with populations of at least 10 million.


SELECT continent, COUNT(name)
FROM world
WHERE population >= 10000000
GROUP BY(continent)
;


-- 8.
-- List the continents that have a total population of at least 100 million.

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