SQL ZOO练习——SELECT within SELECT

最近在练习SQL上学习，把结果发上来存个档。

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

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
  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