The database name comes from the MySQL service's variables (MYSQL_DATABASE, with MYSQLDATABASE and MYSQL_URL built for connecting), and our MySQL service runs the official mysql Docker image. You can modify the deployment following the image's Docker Hub instructions, which explain how that variable behaves on a database that already has data. The dashboard's Database tab reads whichever database MYSQLDATABASE (falling back to MYSQL_DATABASE) names.

Changing the template's variables, image or start command makes the database yours to manage, as noted on our MySQL page. Services that connect through those variables need to point at the new name after the change.