mysql----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