Difference between revisions of "SELECT from WORLD Tutorial"

From SQLZOO
Jump to: navigation, search
 
(14 intermediate revisions by 8 users not shown)
Line 14: Line 14:
 
</div>
 
</div>
  
==World Country Profiles==
+
==Country Profile==
 
In this tutorial you will use the SELECT command on the table <code>World</code>:
 
In this tutorial you will use the SELECT command on the table <code>World</code>:
  
Line 28: Line 28:
 
==Warming up==
 
==Warming up==
 
<div class='qu'>
 
<div class='qu'>
[[Read_the_notes_about_this_table. |Read the notes about this table.]] Observe the result of running a simple SQL command.
+
[[Read_the_notes_about_this_table. |Read the notes about this table.]] Observe the result of running a simple SQL command.  
 
<source lang='sql' class='def'>
 
<source lang='sql' class='def'>
 
SELECT name, continent, population FROM world
 
SELECT name, continent, population FROM world
Line 41: Line 41:
 
[[WHERE_filters |How to use WHERE to filter records.]]
 
[[WHERE_filters |How to use WHERE to filter records.]]
 
<div class='qu'>
 
<div class='qu'>
Show the name for the countries  that have a population of at least 200 million. (200 million is 200000000, there are eight zeros)
+
Show the name for the countries  that have a population of at least 200 million.
 +
200 million is 200000000, there are eight zeros.
 
<source lang='sql' class='def'>
 
<source lang='sql' class='def'>
 
SELECT name FROM world
 
SELECT name FROM world
Line 55: Line 56:
  
 
<div class='qu'>
 
<div class='qu'>
Give the name and the per capita GDP for those countries with a population of at least 200 million.  
+
Give the <code>name</code> and the '''per capita GDP''' for those countries with a <code>population</code> of at least 200 million.  
 
<div title="HELP:How to calculate per capita GDP" class='hint'>
 
<div title="HELP:How to calculate per capita GDP" class='hint'>
 
per capita GDP is the GDP divided by the population GDP/population  
 
per capita GDP is the GDP divided by the population GDP/population  
Line 69: Line 70:
  
 
<div class='qu'>
 
<div class='qu'>
Show the <code>name</code> and <code>population</code> in millions for the countries of 'South America'
+
Show the <code>name</code> and <code>population</code> in millions for the countries of the <code>continent</code> 'South America'.
 
Divide the population by 1000000 to get population in millions.  
 
Divide the population by 1000000 to get population in millions.  
 
<source lang='sql' class='def'>
 
<source lang='sql' class='def'>
Line 92: Line 93:
  
 
<div class='qu'>
 
<div class='qu'>
Identify the countries which have names including the word 'United'
+
Show the countries which have a <code>name</code> that includes the word 'United'
 
<source lang='sql' class='def'>
 
<source lang='sql' class='def'>
 
</source>
 
</source>
Line 102: Line 103:
 
</div>
 
</div>
 
<div>
 
<div>
<div class="lsclear">Clear your results</div>
 
 
<p><div class="quizlink">[[BBC QUIZ]]</div></p>
 
<p><div class="quizlink">[[BBC QUIZ]]</div></p>
 
</div>
 
</div>
Line 108: Line 108:
 
<ul>
 
<ul>
 
   <li>You can play a game:
 
   <li>You can play a game:
   [http://sqlzoo.net/~andrew/brain/bt.htm Find the duplicate]
+
   [http://sqlzoo.net/brain/bt.htm Find the duplicate]
 
   </li>
 
   </li>
 
   <li>You can to continue practising the the same techniques
 
   <li>You can to continue practising the the same techniques

Latest revision as of 01:11, 19 March 2015

namecontinentarea populationgdp
AfghanistanAsia6522302550010020343000000
AlbaniaEurope28748 2831741 12960000000
AlgeriaAfrica2381741 37100000 188681000000
AndorraEurope46878115 3712000000
AngolaAfrica1246700 20609294 100990000000
...

Country Profile

In this tutorial you will use the SELECT command on the table World:

Summary

Warming up

Read the notes about this table. Observe the result of running a simple SQL command.

SELECT name, continent, population FROM world
SELECT name, continent, population FROM world

Large Countries

How to use WHERE to filter records.

Show the name for the countries that have a population of at least 200 million. 200 million is 200000000, there are eight zeros.

SELECT name FROM world
WHERE population>250000000
SELECT name FROM world
WHERE population>200000000


Give the name and the per capita GDP for those countries with a population of at least 200 million.

per capita GDP is the GDP divided by the population GDP/population

 
SELECT name, gdp/population FROM world
  WHERE population > 200000000

Show the name and population in millions for the countries of the continent 'South America'. Divide the population by 1000000 to get population in millions.

 
SELECT name, population/1000000 FROM world
  WHERE continent='South America'

Show the name and population for 'France', 'Germany', 'Italy'

 
SELECT name, population FROM world
  WHERE name IN ('France','Germany','Italy')

Show the countries which have a name that includes the word 'United'

 
SELECT name FROM world
  WHERE name LIKE '%United%'

What Next