After having downloaded the source code, and tinkering with it for a while, I can safely say that the "add student" feature works like a charm! It's able to store the name, sem, mobile, and address information in the SQLite3 Database. However, I seem to encounter a problem when trying to delete users and search users. It won't open the Message Box, but you are able to see the status tip if you hover over the "delete" and "search" buttons.

I hope this can be fixed by the awesome creator who coded this simple PyQt app!