Exercise 4.05 – writing case statements

Your company wants to run analysis on the country data of the world database to determine the size of the countries. They have asked you to create a query that categorizes countries based on the following criteria:

• If a country has a population under 100,000, it is small.
• If a country has a population between 100,000 and 500,000, it is medium.
• In all other cases, the country is large.

To achieve this, we can use a case statement. Here are the steps to write the query:

1. Open MySQL Workbench and create a new query window.
2. First, it is helpful to determine the cases that our query has. There are three cases to consider:
   • WHEN population < 100,000, THEN 'small'
   • WHEN population < 500,000, THEN 'medium'
   • ELSE 'large'
3. Next, we will put these cases into a formal case statement. This will give us the following query:

   SELECT Name, CASE WHEN population < 100000 THEN 'small...