Editing Player Ratings

I've been trying to edit player ratings using DB Commander but I can't seem to get the number values that I've entered to save on the DBF. The values I enter remain there while I'm still in the program, but once I exit the values are reset back to what they were originally. How do I save any edits that I make upon exiting the program?

DB Commander should save changes automatically, but you can also click the tick icon on the bar under the databases.

I can get the changes I've made to save in DBC now after I exit the program, but my changes don't show up in the game itself. Also once I open the game the changes in DBC get reset again. Do I have to export the file, or should DB Commander just alter the DBF itself?

DB Commander should just save the changes automatically, there's no need to export anything. Are you editing a saved roster or the files in currentdb/workingdb? You should always modify a saved roster as you can reload it with the changes you've made.