Objejctive-C - SQLite not writing to database file during unit testing

I have an iOS application that uses SQLite as its database. For some reason, when I'm running unit tests involving SQLite operations, the created *.sqlite file will always be empty, but my class method calls to retrieve information from it will work just fine.

I've tested my application using the simulator and the resulting .sqlite file contains information by calling the same methods that the unit test is calling.

Is there a difference between running SQLite operations via the simulator/device, and via unit tests?