Updated answer for Django migrations without south plugin:

Like T.T suggested in his answer, my previous answer was for south migration plugin, when Django hasn’t any schema migration features.
Now (works in Django 1.9+):

T.T wrote:

You can try this!

python manage.py makemigrations

python manage.py migrate --run-syncdb

Outdated for south migrations plugin

As I can see you done it all in wrong order, to fix it up your should
complete this checklist (I assume you can’t delete sqlite3 database
file to start over):

1. Grab any SQLite GUI tool (i.e. http://sqliteadmin.orbmu2k.de/)
2. Change your model definition to match database definition (best approach is to comment new fields)
3. Delete migrations folder in your model
4. Delete rows in south_migrationhistory table where app_name match your application name (probably homework)
5. Invoke: ./manage.py schemamigration <app_name> --initial
6. Create tables by ./manage.py migrate <app_name> --fake (--fake will skip SQL execute because table already exists in your database)
7. Make changes to your app’s model
8. Invoke ./manage.py schemamigration <app_name> --auto
9. Then apply changes to database: ./manage.py migrate <app_name>

Steps 7,8,9 repeat whenever your model needs any changes.