SQL ZOO 练习 —— SELECT within SELECT Tutorial

This tutorial looks at how we can use SELECT statements within SELECT statements to perform more complex queries.

1.List each country name where the population is larger than that of ‘Russia’.

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

SELECT name FROM world
  WHERE population >
     (SELECT population FROM world
      WHERE name='Russia')

2.Show the countries in Europe with a per capita GDP greater than ‘United Kingdom’.

SELECT name FROM world
WHERE continent = 'Europe' AND name IN
   (SELECT name FROM world 
    WHERE gdp/population > 
            (SELECT gdp/population FROM world WHERE name = 'United Kingdom' ) )

3.List the name and continent of countries in the continents containing either Argentina or Australia. Order by name of the country.

SELECT name,continent FROM world 
WHERE continent IN