For this example, we are going to work with an in-memory database, which will make things simpler for us. In the source code of the book, I have left a couple of comments to show you how to generate a SQLite file, so I hope you'll explore that option as well.
You can find a free database browser for SQLite at sqlitebrowser.org. If you are not satisfied with it, you will be able to find a wide range of tools, some free, some not free, that you can use to access and manipulate a database file.
Before we dive into the code, allow me to briefly introduce the concept of a relational database.
A relational database is a database that allows you to save data following the relational model, invented in 1969 by Edgar F. Codd. ...
