How to use a MySQL database both remotely and locally

I cannot find the best solution for my problem. I made a C++ application which runs on a Kiosk under Ubuntu that needs to store and retrieve data from a MySQL database and these same data need to be accessed from a remote web application. These are the requirements: - The kiosk is connected to Internet, but we cannot assume that internet is always available - The kiosk need to always access to database because the users can access the kiosk services only after the login (user data are stored in the database) - the remote web application needs to insert or modify data stored in the database At the moment, I'm using a local MySQL database installed in the Kiosk with PhpMyAdmin and the application directly access the local data. Then, I used cron to upload the database once a day, then I import the database on my server in order to be accessed by the remote web application. This is really a bad solution, so I would like to find another one. What do you suggest? I would like to have a database on my server and let the remote web application directly use it and receive updates from the Kiosk.