Nested SELECT quiz
bbc
name region area population gdp
Afghanistan South Asia 652225 26000000  
Albania Europe 28728 3200000 6656000000
Algeria Middle East 2400000 32900000 75012000000
Andorra Europe 468 64000  
Bangladesh South Asia 143998 152600000 67144000000
United Kingdom Europe 242514 59600000 2022824000000
...
1. Select the code that shows the name, region and population of the smallest country in each region

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

 SELECT region, name, population FROM bbc WHERE population <= ALL (SELECT population FROM bbc WHERE population>0)

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

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

 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 population>0)

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

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

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

 SELECT name,region,population FROM bbc x WHERE 500000 < 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 y.region = x.region AND y.name != x.name)

SELECT name, region FROM bbc x

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

SELECT name, region FROM bbc x

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

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

 SELECT name, region FROM bbc x WHERE population < ALL (SELECT population/3 FROM bbc y WHERE 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-A
Andorra
Albania
Austria
Bulgaria
Table-B
France Europe
Germany Europe
Russia Europe
Turkey Europe
Table-C
France
Germany
Andorra
Albania
Table-D
France
Germany
Russia
Turkey
Table-E
France
Germany
Russia
Turkey
Brazil
United States of USA
Canada
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 > ALL (SELECT MAX(gdp) FROM bbc WHERE region = 'Africa' AND gdp=0)

SELECT name FROM bbc

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

SELECT name FROM bbc

 WHERE gdp > ALL (SELECT MIN(gdp) FROM bbc WHERE region = 'Africa')

SELECT name FROM bbc

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

SELECT name FROM bbc

 WHERE gdp > ALL (SELECT gdp FROM bbc WHERE region = 'Africa' AND gdp<>NULL)
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='Denmark')

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

SELECT name FROM bbc

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

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

SELECT name FROM bbc

 WHERE population = (SELECT population FROM bbc WHERE name='Russia')

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

SELECT name FROM bbc

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

   AND population > (SELECT population FROM bbc WHERE name='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-A
Afghanistan
Bhutan
Nepal
Sri Lanka
The Maldives
Table-B
Bangladesh
India
Pakistan
Table-C
China
India
Table-D
Brazil
Bangladesh
China
India
Table-E
France
Germany
Russia
Trukey

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