Nested SELECT Quiz

bbc table

Link

1. Select the code that shows the name, region and population of the smallest country in each region

   SELECT region, name, population 
   FROM bbc x 
   WHERE population <= ALL (SELECT population 
                           FROM bbc y 
                           WHERE y.region=x.region 
                               AND population>0)

2. Select the code that shows the countries belonging to regions with all populations over 50000

   SELECT name,region,population 
   FROM bbc x 
   WHERE 50000 < ALL (SELECT population 
                   FROM bbc y 
                   WHERE x.region=y.region 
                   AND y.population>0)

3. Select the code that shows the countries with a less than a third of the population of the countries around it

   SELECT name,region 
   FROM bbc x 
   WHERE population < ALL (SELECT population/3 
                   FROM bbc y 
                   WHERE x.region=y.region 
                   AND y.name != x.name)

4. Select the result that would be obtained from the following code:

   SELECT name FROM bbc
    WHERE population >
          (SELECT population
             FROM bbc
            WHERE name='United Kingdom')
      AND region IN
          (SELECT region
             FROM bbc
            WHERE name = 'United Kingdom')

Table-D
France
Germany
Russia
Turkey

5. Select the code that would show the countries with a greater GDP than any country in Africa (some countries may have NULL gdp values).

   SELECT name FROM bbc
    WHERE gdp > (SELECT MAX(gdp) FROM bbc WHERE region = 'Africa')

6. Select the code that shows the countries with population smaller than Russia but bigger than Denmark

   SELECT name FROM bbc
    WHERE population < (SELECT population FROM bbc WHERE name='Russia')
      AND population > (SELECT population FROM bbc WHERE name='Denmark')

7. Select the result that would be obtained from the following code:

   SELECT name FROM bbc
    WHERE population > ALL
          (SELECT MAX(population)
             FROM bbc
            WHERE region = 'Europe')
      AND region = 'South Asia'

Table-B
Bangladesh
Pakistan
Pakistan