Rebuilding Django development server database
You should delete the migrations folder inside your app folder. You should also delete the database file, if there is one (for SQLite there is a file called db.sqlite3 in the root project folder, but I'm not sure how this works for MySQL). Then run makemigrations and migrate.
I'm trying to reset my django database so I've run manage.py sqlflush and run that output in MySQL. 
I've then run manage.py flush.  I think this should clear everything.
I've then run manage.py makemigrations which seemed to identify all tables that would need building but when I run manage.py migrate it says nothing needs doing and so I now don't have any tables when I run my app.