SELECT basics/es

world

name	continent	area	population	gdp
Afghanistan	Asia	652230	25500100	20343000000
Albania	Europe	28748	2831741	12960000000
Algeria	Africa	2381741	37100000	188681000000
Andorra	Europe	468	78115	3712000000
Angola	Africa	1246700	20609294	100990000000
....

Presentamos la tabla world de países

The example uses a WHERE clause to show the population of 'France'. Note that strings (pieces of text that are data) should be in 'single quotes';

Modify it to show the population of Germany

SELECT population FROM world
  WHERE name = 'France'

SELECT population FROM world
  WHERE name = 'Germany'

Scandinavia

Checking a list The word IN allows us to check if an item is in a list. The example shows the name and population for the countries 'Brazil', 'Russia', 'India' and 'China'.

Show the name and the population for 'Sweden', 'Norway' and 'Denmark'.

SELECT name, population FROM world
  WHERE name IN ('Brazil', 'Russia', 'India', 'China');

SELECT name, population FROM world
  WHERE name IN ('Sweden','Norway', 'Denmark');

Just the right size

Which countries are not too small and not too big? BETWEEN allows range checking (range specified is inclusive of boundary values). The example below shows countries with an area of 250,000-300,000 sq. km. Modify it to show the country and the area for countries with an area between 200,000 and 250,000.

SELECT name, area FROM world
  WHERE area BETWEEN 250000 AND 300000

SELECT name, area FROM world
  WHERE area BETWEEN 200000 AND 250000

• SELECT Quiz
• You are ready for tutorial one:SELECT statements with WHERE.