I wouldn't use OAuth, it's overkill and commonly implemented wrong both in pkg form and as user of said pkg. Opening a port to any DB for remote use, also a bad idea.
Use a tool that was designed to DO what you are asking. Dropbox. ~sqlite.lock, problem solved, you won't get fired for doing stupid things.
If it must be on server, use SSH and port forward. This solution also won't get you fired for doing stupid things.
Even a database, like CouchDB, that is REST, recommends the SSH solution.