1. Learn
    2. /
  2. Courses
    3. /
  3. SQL for Joining Data

Exercise

Inner join (2)

Instead of writing the full table name, you can use table aliasing as a shortcut. For tables you also use AS to add the alias immediately after the table name with a space. Check out the aliasing of cities and countries below.

SELECT c1.name AS city, c2.name AS country
FROM cities AS c1
INNER JOIN countries AS c2
ON c1.country_code = c2.code;

Notice that to select a field in your query that appears in multiple tables, you'll need to identify which table/table alias you're referring to by using a . in your SELECT statement.

You'll now explore a way to get data from both the countries and economies tables to examine the inflation rate for both 2010 and 2015.

Sometimes it's easier to write SQL code out of order: you write the SELECT statement after you've done the JOIN.

Instructions

100 XP
  • Join the tables countries (left) and economies (right) aliasing countries AS c and economies AS e.
  • Specify the field to match the tables ON.
  • From this join, SELECT:
    • c.code, aliased as country_code.
    • name, year, and inflation_rate, not aliased.