Django Admin: Deleting Objects Doesn't Use the Correct Database in a Multi-Database Setup

Using Django The Admin
1

I have a Django project with multiple databases configured in settings.py. My User model is stored in the "members" database, and I can list and save objects correctly in Django Admin. However, deleting objects does not use the "members" database, and I get an error saying the table doesn’t exist.
django.db.utils.ProgrammingError: relation "login_history" does not exist LINE 1: ...rs"."premium_expired", "users"."location_id" FROM "login_his...

class MultiDBModelAdmin(admin.ModelAdmin):
    using = "members"

    def save_model(self, request, obj, form, change):
        # Tell Django to save objects to the 'members' database.
        obj.save(using=self.using)

    def delete_model(self, request, obj):
        # Tell Django to delete objects from the 'members' database
        obj._state.db = self.using
        obj.delete(using=self.using)
    
    def delete_queryset(self, request, queryset):
        queryset.using(self.using).delete()

    def get_queryset(self, request):
        # Tell Django to look for objects on the 'members' database.
        return super().get_queryset(request).using(self.using)

    def formfield_for_foreignkey(self, db_field, request, **kwargs):
        # Tell Django to populate ForeignKey widgets using a query
        # on the 'members' database.
        return super().formfield_for_foreignkey(
            db_field, request, using=self.using, **kwargs
        )

    def formfield_for_manytomany(self, db_field, request, **kwargs):
        # Tell Django to populate ManyToMany widgets using a query
        # on the 'members' database.
        return super().formfield_for_manytomany(
            db_field, request, using=self.using, **kwargs
        )
    
    def _save_related(self, request, form, formsets, change):
        """Ensure related objects are saved in the correct database."""
        for formset in formsets:
            formset.instance._state.db = self.using  # Force the database
        super()._save_related(request, form, formsets, change)

class MultiDBTabularInline(admin.StackedInline):
    using = "members"

    def get_queryset(self, request):
        # Tell Django to look for inline objects on the 'members' database.
        return super().get_queryset(request).using(self.using)

    def formfield_for_foreignkey(self, db_field, request, **kwargs):
        # Tell Django to populate ForeignKey widgets using a query
        # on the 'members' database.
        return super().formfield_for_foreignkey(
            db_field, request, using=self.using, **kwargs
        )

    def formfield_for_manytomany(self, db_field, request, **kwargs):
        # Tell Django to populate ManyToMany widgets using a query
        # on the 'members' database.
        return super().formfield_for_manytomany(
            db_field, request, using=self.using, **kwargs
        )

    def has_change_permission(self, request, obj = ...):
        return False

class LoginHistoryInline(MultiDBTabularInline):
    model = LoginHistoryRecord
    readonly_fields = [
        "id",
        "device",
        "login_date",
        "device_type",
    ]
    can_delete = False
    verbose_name = "Login history"
    verbose_name_plural = "Login history"


@admin.register(User)
class MemberAdmin(MultiDBModelAdmin):
    list_display = [
        "id",
    ]

How can I ensure that Django Admin deletes objects from the correct database (members) instead of the default database? Is there something else I need to override to make deletion work properly?

2

In the future, when asking for assistance with an error, please post the complete error with the full traceback.

Without the full error and traceback it’s tough to tell, but a common cause of this type of error is having created a new User model or moved the User model to a new database after having run the initial migration. (But I can’t be sure that that is the issue here without seeing the full error & traceback.)

I do see that you don’t have a using attribute on your LoginHistoryInline. Is that model also stored in the members database?

It would be helpful also if you posted your User and LoginHistoryRecord models.

Do you have a custom router defined for these models?

3

Thank you for your reply!

Here is my full traceback:

Traceback (most recent call last):
File "/usr/local/lib/python3.11/site-packages/django/contrib/staticfiles/handlers.py", line 80, in __call__
  return self.application(environ, start_response)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/django/core/handlers/wsgi.py", line 124, in __call__
  response = self.get_response(request)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/django/core/handlers/base.py", line 140, in get_response
  response = self._middleware_chain(request)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/django/core/handlers/exception.py", line 57, in inner
  response = response_for_exception(request, exc)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/django/core/handlers/exception.py", line 140, in response_for_exception
  response = handle_uncaught_exception(
             ^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/django/core/handlers/exception.py", line 181, in handle_uncaught_exception
  return debug.technical_500_response(request, *exc_info)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/django_extensions/management/technical_response.py", line 40, in null_technical_500_response
  raise exc_value.with_traceback(tb)
File "/usr/local/lib/python3.11/site-packages/django/core/handlers/exception.py", line 55, in inner
  response = get_response(request)
             ^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/django/core/handlers/base.py", line 197, in _get_response
  response = wrapped_callback(request, *callback_args, **callback_kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/contextlib.py", line 81, in inner
  return func(*args, **kwds)
         ^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/django/contrib/admin/options.py", line 688, in wrapper
  return self.admin_site.admin_view(view)(*args, **kwargs)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/django/utils/decorators.py", line 134, in _wrapper_view
  response = view_func(request, *args, **kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/django/views/decorators/cache.py", line 62, in _wrapper_view_func
  response = view_func(request, *args, **kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/django/contrib/admin/sites.py", line 242, in inner
  return view(request, *args, **kwargs)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/django/utils/decorators.py", line 46, in _wrapper
  return bound_method(*args, **kwargs)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/django/utils/decorators.py", line 134, in _wrapper_view
  response = view_func(request, *args, **kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/django/contrib/admin/options.py", line 2106, in delete_view
  return self._delete_view(request, object_id, extra_context)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/django/contrib/admin/options.py", line 2133, in _delete_view
  ) = self.get_deleted_objects([obj], request)
      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/django/contrib/admin/options.py", line 2101, in get_deleted_objects
  return get_deleted_objects(objs, request, self.admin_site)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/django/contrib/admin/utils.py", line 121, in get_deleted_objects
  collector.collect(objs)
File "/usr/local/lib/python3.11/site-packages/django/contrib/admin/utils.py", line 187, in collect
  return super().collect(objs, source_attr=source_attr, **kwargs)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/django/db/models/deletion.py", line 348, in collect
  if getattr(on_delete, "lazy_sub_objs", False) or sub_objs:
File "/usr/local/lib/python3.11/site-packages/django/db/models/query.py", line 412, in __bool__
  self._fetch_all()
File "/usr/local/lib/python3.11/site-packages/django/db/models/query.py", line 1881, in _fetch_all
  self._result_cache = list(self._iterable_class(self))
                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/django/db/models/query.py", line 91, in __iter__
  results = compiler.execute_sql(
            ^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/django/db/models/sql/compiler.py", line 1562, in execute_sql
  cursor.execute(sql, params)
File "/usr/local/lib/python3.11/site-packages/debug_toolbar/panels/sql/tracking.py", line 235, in execute
  return self._record(super().execute, sql, params)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/debug_toolbar/panels/sql/tracking.py", line 160, in _record
  return method(sql, params)
         ^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/django/db/backends/utils.py", line 102, in execute
  return super().execute(sql, params)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/django/db/backends/utils.py", line 67, in execute
  return self._execute_with_wrappers(
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/django/db/backends/utils.py", line 80, in _execute_with_wrappers
  return executor(sql, params, many, context)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/django/db/backends/utils.py", line 84, in _execute
  with self.db.wrap_database_errors:
File "/usr/local/lib/python3.11/site-packages/django/db/utils.py", line 91, in __exit__
  raise dj_exc_value.with_traceback(traceback) from exc_value
File "/usr/local/lib/python3.11/site-packages/django/db/backends/utils.py", line 89, in _execute
  return self.cursor.execute(sql, params)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/psycopg/cursor.py", line 732, in execute
  raise ex.with_traceback(None)
django.db.utils.ProgrammingError: relation "login_history" does not exist
LINE 1: ...rs"."premium_expired", "users"."location_id" FROM "login_his...

And here are my models:

class MembersManager(Manager):
    def get_queryset(self, *args, **kwargs):
        return super().get_queryset(*args, **kwargs).using("members")

class LoginHistoryRecord(models.Model):
    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
    user = models.ForeignKey("User", on_delete=models.CASCADE)
    device = models.ForeignKey("Device", on_delete=models.CASCADE)
    login_date = models.DateTimeField(default=timezone.now)
    device_type = models.CharField(max_length=255, default="web")
    
    objects = MembersManager()
    ...

class User(models.Model):
    id = models.BigIntegerField(primary_key=True)
    phone_number = models.CharField(max_length=14, unique=True)
    email = models.EmailField(max_length=255, unique=True, null=True, blank=True)
    ...
    objects = MembersManager()

I am not using a custom database router for my models. The database selection is handled directly in the Manager and Admin classes.
The admin panel displays the objects correctly, and I can save changes to them, after adding a custom Manager to my models, saving started working correctly on the "members" database. However, deleting still does not work.