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 worldWHERE name='Russia')

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

Per Capita GDP
The per capita GDP is the gdp/population

select name from world where (gdp/population) > (select gdp/population from world where name='United Kingdom') and continent='Europe';

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 (select continent from world where name in ('Argentina','Australia')) order by name;

4.Which country has a population that is more than Canada but less than Poland? Show the name and the population.

select name,population from world where population > (select population from world where name='Canada') and population < (select population from world where name='Poland');

5.Germany (population 80 million) has the largest population of the countries in Europe. Austria (population 8.5 million) has 11% of the population of Germany.

Show the name and the population of each country in Europe. Show the population as a percentage of the population of Germany.

The format should be Name, Percentage for example:

namepercentage

Albania	3%
Andorra	0%
Austria	11%
…	…

Decimal places
You can use the function ROUND to remove the decimal places.
Percent symbol %
You can use the function CONCAT to add the percentage symbol.

select name,concat(round(population/(select population from world where name='Germany')*100,0),'%') from world where continent='Europe';

6.Which countries have a GDP greater than every country in Europe? [Give the name only.] (Some countries may have NULL gdp values)

select name from world where gdp > all(select gdp from world where continent='Europe'and gdp>0);

7.Find the largest country (by area) in each continent, show the continent, the name and the area:

SELECT continent, name, area FROM world as x WHERE area >= ALL(SELECT areaFROM world yWHERE y.continent=x.continentorder by continentAND area>0);

8.List each continent and the name of the country that comes first alphabetically.

select continent,name from (select continent,name, row_number() over(partition by continent order by name)as afrom worldorder by continent) as newtable where newtable.a=1; select continent,name from world x where x.name=(select y.name from world y where y.continent=x.continent order by name limit 1); select continent, name from world a where name <= all(select name from world b where a.continent=b.continent)

9.Find the continents where all countries have a population <= 25000000. Then find the names of the countries associated with these continents. Show name, continent and population.

select name,continent,population from world a where 25000000>ALL(select population from world b where a.continent=b.continent);

10.Some countries have populations more than three times that of any of their neighbours (in the same continent). Give the countries and continents.

select name,continent from world a where (a.population/3)>=all(select population from world b where a.continent=b.continent and a.name<>b.name and b.population>0);

總結

以上是生活随笔為你收集整理的SQLZOO:SELECT within SELECT Tutorial的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。