How can I make a Django model read-only?

Question

Is it possible to make a Django model read only? No creating, updating etc.

N.B. this question is different to:

Make a Django model read-only? (this question allows creation of new records)

Whole model as read-only (only concerns the Django admin interface - I'd like the model to be read only throughout the whole app)

Answer 1

Override the save and delete methods for the model. How are you planning to add objects to your model?

def save(self, *args, **kwargs):      return  def delete(self, *args, **kwargs):      return 

Answer 2

Database Routers

To take more precautions that your model is read-only, you can use the DATABASE_ROUTERS setting to disable writing on a per model basis:

# settings.py DATABASE_ROUTERS = ('dbrouters.MyCustomRouter', )   # dbrouters.py class MyCustomRouter(object):     def db_for_write(self, model, **hints):         if model == MyReadOnlyModel:             raise Exception("This model is read only. Shame!")          return None 

I would consider this an insurance policy, and not the primary way to solve the problem. Mikael's answer, for example, is great but doesn't cover all cases because some Django operations bypass delete and save methods.

See Juan José Brown's answer in Django - how to specify a database for a model? for a more detailed description of using a database router.

Setting permissions on database user

However, even the database router approach seems to have loopholes, i.e. there are ways to send SQL from Django that bypasses your router code. To be absolutely sure of making something readonly, you should set the permissions on the database user. This question describes how to set up a readonly postgreql user, which could then be the database user set by Django in settings.DATABASES.