Save The Change

Save The Change takes this:

>>> lancelot = Knight.objects.get(name="Sir Lancelot")
>>> lancelot.favorite_color = "Blue"

And does this:

UPDATE "roundtable_knight"
SET "favorite_color" = 'Blue'

Instead of this:

UPDATE "roundtable_knight"
SET "name" = 'Sir Lancelot',
    "from" = 'Camelot',
    "quest" = 'To seek the Holy Grail.',
    "favorite_color" = 'Blue',
    "epithet" = 'The brave',
    "actor" = 'John Cleese',
    "full_name" = 'John Marwood Cleese',
    "height" = '6''11"',
    "birth_date" = '1939-10-27',
    "birth_union" = 'UK',
    "birth_country" = 'England',
    "birth_county" = 'Somerset',
    "birth_town" = 'Weston-Super-Mare',
    "facial_hair" = 'mustache',
    "graduated" = true,
    "university" = 'Cambridge University',
    "degree" = 'LL.B.',


Install Save The Change just like everything else:

$ pip install django-save-the-change


Just add SaveTheChange to your model:

from django.db import models
from save_the_change.mixins import SaveTheChange

class Knight(SaveTheChange, models.model):

And that’s it! Keep using Django like you always have, Save The Change will take care of you.

How It Works

Save The Change overloads __setattr__ and keeps track of what fields have changed from their stored value in your database. When you call save(), Save The Change passes those changed fields through Django’s update_fields kwarg, and Django does the rest, sending only those fields back to the database.


Save The Change can’t help you with ManyToManyFields nor reverse relations, as those aren’t handled through save(). But everything else’ll work.


Save The Change also comes with a second mixin, TrackChanges. Adding TrackChanges to your model will expose a few new properties and methods for tracking and manually reverting changes to your model before you save it.

You can also use UpdateTogetherModel in place of Model to add the new field update_together to your model’s Meta, which allows you to specify that certain fields are dependent on the values of other fields in your model.

Developer Interface


1.1.0 (05/16/2014)

  • Add proper support for ForeignKeys (thanks to Brandon Konkle and Brian Wilson).
  • Add update_together field to model Meta, via UpdateTogetherModel.

1.0.0 (09/08/2013)

  • Initial release.