I am developing a native application which calls a PHP Script by using POST-requests. The PHP script interacts with a MySQL Community Server which is under the license GPL. It reads, inserts and deletes data from a MySQL database just on the server where it is installed and returns results to the native application.
Do I have to publish the PHP code for the web app which interacts with MySQL because of GPL? That would be a security risk because the whole database structure and access would be visible. Or do I not have to publish the code of the web app because it is not the part of the application that would be distributed?
The native application will be distributed (for free) but the whole project would not be open source.