There are many ways with which AEM enables integration with an external database. One of the most common ways to integrate a database is by using Apache Sling Connection Pooled DataSource configuration properties through the configMgr.
The first step is to download and deploy the appropriate MySql drivers in AEM.
Create Apache Sling Connection Pooled DataSource and provide the properties as specified in the screen shot below. The database schema is provided to you as part of this tutorial assets.