This tutorial focuses on how to wire your web application to a MySQL database so you can Create, Read, Update, and Delete (CRUD) information in a database via a Vaadin web application. The idea is to show you how to connect a template project downloaded from https://start.vaadin.com to a database so you can replicate it to your own needs. This is not about best practices (for Vaadin, Spring, or MySQL) but to help you get started fast.
You can find the code used in this tutorial from GitHub.