The task is as follows:
The client database is stored on the local machine. It should periodically (with changes, apparently) be copied to the hosting (MySQL is there).
The second part of. Customers have cards (magnetic or with bar codes) with which you can pay. There is a ticket office. It is necessary that when reading a card, a certain amount is deducted from the account in the database.
Very little idea how to organize it. Is there any ready software for this?
Can you recommend something worthwhile?