Difference between revisions of "SUM and COUNT Quiz"

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{Select the statement that shows the sum of population of all countries in 'Europe'
 
{Select the statement that shows the sum of population of all countries in 'Europe'
 
|type="()"}
 
|type="()"}
−
-A. SELECT name, population FROM bbc WHERE region = 'Europe'
+
- SELECT name, population FROM bbc WHERE region = 'Europe'
−
-B. SELECT population FROM bbc WHERE region = 'Europe' SUM BY region
+
- SELECT population FROM bbc WHERE region = 'Europe' SUM BY region
−
+C. SELECT SUM(population) FROM bbc WHERE region = 'Europe'
+
+ SELECT SUM(population) FROM bbc WHERE region = 'Europe'
−
-D. SELECT SUM(population FROM bbc WHERE region = 'Europe')
+
- SELECT SUM(population FROM bbc WHERE region = 'Europe')
−
-E. SUM population FROM bbc WHERE region = 'Europe'
+
- SUM population FROM bbc WHERE region = 'Europe'
  
 
{Select the statement that shows the number of countries with population smaller than 150000
 
{Select the statement that shows the number of countries with population smaller than 150000
 
|type="()"}
 
|type="()"}
−
+A. SELECT COUNT(name) FROM bbc WHERE population < 150000
+
+ SELECT COUNT(name) FROM bbc WHERE population < 150000
−
-B. SELECT COUNT(population < 150000) FROM bbc
+
- SELECT COUNT(population < 150000) FROM bbc
−
-C. SELECT name FROM bbc WHERE population < 150000
+
- SELECT name FROM bbc WHERE population < 150000
−
-D. SELECT population AS COUNT FROM bbc WHERE population < 150000
+
- SELECT population AS COUNT FROM bbc WHERE population < 150000
−
-E. SELECT SUM() FROM bbc WHERE population < 150000
+
- SELECT SUM() FROM bbc WHERE population < 150000
  
 
{Select the full set of SQL aggregate functions
 
{Select the full set of SQL aggregate functions
 
|type="()"}
 
|type="()"}
−
-A. AVG(), COUNT(), FIRST(), LAST(), SUM()
+
- AVG(), COUNT(), FIRST(), LAST(), SUM()
−
-B. AVG(), COUNT(), MAX(), MEDIAN(), MIN(), ROUND(), SUM()
+
- AVG(), COUNT(), MAX(), MEDIAN(), MIN(), ROUND(), SUM()
−
+C. AVG(), COUNT(), FIRST(), LAST(), MAX(), MIN(), SUM()
+
+ AVG(), COUNT(), FIRST(), LAST(), MAX(), MIN(), SUM()
−
-D. AVG(), COUNT(), MAX(), MIN(), SUM()
+
- AVG(), COUNT(), MAX(), MIN(), SUM()
−
-E. COUNT(), SUM()
+
- COUNT(), SUM()
  
 
{Select the statement that shows the average population of 'Poland', 'Germany' and 'Denmark'
 
{Select the statement that shows the average population of 'Poland', 'Germany' and 'Denmark'

Revision as of 15:34, 6 August 2012

SUM and COUNT 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
...

1. Select the statement that shows the sum of population of all countries in 'Europe'

SELECT name, population FROM bbc WHERE region = 'Europe'
SELECT population FROM bbc WHERE region = 'Europe' SUM BY region
SELECT SUM(population) FROM bbc WHERE region = 'Europe'
SELECT SUM(population FROM bbc WHERE region = 'Europe')
SUM population FROM bbc WHERE region = 'Europe'

2. Select the statement that shows the number of countries with population smaller than 150000

SELECT COUNT(name) FROM bbc WHERE population < 150000
SELECT COUNT(population < 150000) FROM bbc
SELECT name FROM bbc WHERE population < 150000
SELECT population AS COUNT FROM bbc WHERE population < 150000
SELECT SUM() FROM bbc WHERE population < 150000

3. Select the full set of SQL aggregate functions

AVG(), COUNT(), FIRST(), LAST(), SUM()
AVG(), COUNT(), MAX(), MEDIAN(), MIN(), ROUND(), SUM()
AVG(), COUNT(), FIRST(), LAST(), MAX(), MIN(), SUM()
AVG(), COUNT(), MAX(), MIN(), SUM()
COUNT(), SUM()

4. Select the statement that shows the average population of 'Poland', 'Germany' and 'Denmark'

A. SELECT AVG(population) FROM bbc WHERE name = ('Poland', 'Germany', 'Denmark')
B. SELECT AVG(population) FROM bbc WHERE name IN ('Poland', 'Germany', 'Denmark')
C. SELECT AVG(population) FROM bbc WHERE name LIKE ('Poland', 'Germany', 'Denmark')
D. SELECT AVG(population) FROM bbc WHERE name LIKE (Poland, Germany, Denmark)
E. SELECT population FROM bbc WHERE name IN ('Poland', 'Germany', 'Denmark')

5. Select the statement that shows the medium population density of each region

A. SELECT region, AVG(population/area) AS density FROM bbc
B. SELECT region, COUNT(population)/COUNT(area) AS density FROM bbc GROUP BY region
C. SELECT region, SUM(population)/COUNT(area) AS density FROM bbc GROUP BY region
D. SELECT region, SUM(population)/SUM(area) AS density FROM bbc HAVING region
E. SELECT region, SUM(population)/SUM(area) AS density FROM bbc GROUP BY region

6. Select the statement that shows the name and population density of the country with the largest population

A. SELECT name, density AS population/area FROM bbc WHERE population = MAX(population)
B. SELECT name, density AS population/area FROM bbc WHERE population = (SELECT MAX(population) FROM bbc)
C. SELECT name, MAX (population) FROM bbc WHERE population / (SELECT area FROM bbc)
D. SELECT name, population/area AS density FROM bbc WHERE population = (SELECT MAX(population) FROM bbc)
E. SELECT name, population/area AS density FROM bbc WHERE population > (SELECT MAX(population) FROM bbc)

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