#34165: migrate management command does not respect database parameter when 
adding
Permissions.
------------------------------+------------------------------------
     Reporter:  Vasanth       |                    Owner:  nobody
         Type:  Bug           |                   Status:  new
    Component:  contrib.auth  |                  Version:  4.1
     Severity:  Normal        |               Resolution:
     Keywords:                |             Triage Stage:  Accepted
    Has patch:  0             |      Needs documentation:  0
  Needs tests:  0             |  Patch needs improvement:  0
Easy pickings:  0             |                    UI/UX:  0
------------------------------+------------------------------------

Comment (by David Wobrock):

 Replying to [comment:10 Mariusz Felisiak]:
 > Replying to [comment:8 David Wobrock]:
 > > I think `bulk_create` already sets the `_state.db` to the value passed
 in `.using()`, right?
 >
 > Yes, but it's a different issue, strictly related with `Permission` and
 its `content_type`. `get_content_type()` is trying to find a content type
 using `obj._state.db` so when we create a `Permission()` without
 `._state.db` it will first try to find a content type in the default db.

 Okay, I understand the issue now, thanks for the details!!

 First thing, it makes me wonder why we require to have a DB attribute set,
 at a moment where we are not (yet) interacting with the DB.
 So we are currently checking, when setting the `content_type` FK, that the
 router allows this relation. I guess one option is to not do that for not-
 saved model instances.
 Would it make sense to defer this to when we start interacting with the
 DB? But it brings a whole other lot of changes and challenges, like
 changing a deep behaviour of FKs and multi-tenancy :/

 Apart from that, if we don't want to set directly the internal attribute
 `_state.db`, I guess we would need a proper way to pass the `db`/`using`
 to the model instantiation.
 What would be the most ''Django-y'' way?
 - Passing it through the model constructor => this has quite a large
 impact, as a keyword argument would possibly shadow existing field names:
 `Permission(..., db=using)`. Quite risky in terms of backward
 compatibility I guess.
 - Adding a method to `Model`? Something like: `Permission(...).using(db)`,
 which could perhaps then be re-used in other places also.

 What do you think ? :) Or am I missing other solutions?

-- 
Ticket URL: <https://code.djangoproject.com/ticket/34165#comment:11>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.

-- 
You received this message because you are subscribed to the Google Groups 
"Django updates" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
To view this discussion on the web visit 
https://groups.google.com/d/msgid/django-updates/010701852ef6b16c-5086918c-e150-45ed-b179-e9aa00151a69-000000%40eu-central-1.amazonses.com.

Reply via email to