SQL ZOO练习——SELECT from WORLD Tutorial

1. Read the notes about this table. Observe the result of running this SQL command to show the name, continent and population of all countries.

SELECT name, continent, population 
FROM world

2. How to use WHERE to filter records. Show the name for the countries that have a population of at least 200 million. 200 million is 200000000, there are eight zeros.

SELECT name 
FROM world
WHERE population >= 200000000

3. Give the name and the per capita GDP for those countries with a population of at least 200 million.

SELECT name, gdp/population 
FROM world
WHERE population > 200000000

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