Sync two mysql database one in intranet and the other on internet I'm making the training and placement module for my college. But I'm facing problems to sync the databases, one that will be used by the students and the other that will be used by the HR of a company. As the students's DB is completely on intranet and is not accessible via internet. As the HR will be using the online version and will be providing information on that. I want to sync the data between both version.

I have read about database replication but that cannot be implemented as these versions cannot be connected.

We cannot use mysqldump as sometimes there will be modifications in the intranet DB that has to be replicated in the online DB.

As the operators of this system don't belong from technical background: I thought of coming with a file based solution where on just click of a button we can download the file and sync up with the intranet version and vica-versa.

But the problem is that I cannot come up with any decent solution till now.
How can I solve this problem?
MySQL has replication cabapilities, sure you has revised the MySQL documentation.

This means that MySQL copies data from master to slave, not both directions.

You proposed "just click a button", if you don't want a "do it yourself" solution maybe can try with a database tool like MySQL workbench.

In any case it is dangerous to synchronize two databases with files: data inconsistencies, primary keys collisions, ...