It is possible to shift between a MySQL and a a SQLite database.
Roel has put this on the Forum :
Backup your MySQL calendar database via the admin's database page and download the backup file.
Install LuxCal 4.4.0L (SQLite) in any web-accessible folder.
From the toolbox section of the downloaded zip-file upload the file "lctools.php"
Start this file with your browser (so URL: www.yourplace.xxx/calendar/lctools.php)
Select the last action: "Import calendar backup file of a previous LuxCal version"
As source file select the backup file of your MySQL backup.
Select the destination calendar.
Hit the Import button.
It shows how to shift from a MySQL to a SQLite database.
You can of course also do the opposite.