Understanding the database structure

If you don't have MySQL installed, head over to the MySQL link (https://dev.mysql.com/downloads/installer) to install it and populate it with the world database, if it is not already available. The appendix will also guide you on how to run the queries using MySQL Workbench and MySQL command-line tool. 

The world database schema is depicted in the following diagram:

The database schema is simple, containing three tables as follows:

• city: List of cities mapped to the three character country coded in the country table.
• country: List of countries where the primary key is the three character country code. There is a column that has the ISO country code.
• countrylanguage: List of languages mapped to the country with one of the languages of the country marked as official.