Relation does not exist in django admin site after migrations

Question

I'm getting a "relation does not exist error" when attempting to access a model page on my django admin site. Accessing the user model from the admin site works normally.

Environment:


Request Method: GET
Request URL: http://127.0.0.1:8000/admin/web_app/work/

Django Version: 2.0.4
Python Version: 3.6.4
Installed Applications:
['django.contrib.admin',
 'django.contrib.auth',
 'web_app.apps.WebsiteConfig',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles']
Installed Middleware:
['django.middleware.security.SecurityMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware']



Traceback:

File "C:\Users\danie\Envs\Prolitfic\lib\site-packages\django\db\backends\utils.py" in _execute
  85.                 return self.cursor.execute(sql, params)

The above exception (relation "web_app_work" does not exist
LINE 1: SELECT COUNT(*) AS "__count" FROM "web_app_work"
                                          ^
) was the direct cause of the following exception:

File "C:\Users\danie\Envs\Prolitfic\lib\site-packages\django\core\handlers\exception.py" in inner
  35.             response = get_response(request)

File "C:\Users\danie\Envs\Prolitfic\lib\site-packages\django\core\handlers\base.py" in _get_response
  128.                 response = self.process_exception_by_middleware(e, request)

File "C:\Users\danie\Envs\Prolitfic\lib\site-packages\django\core\handlers\base.py" in _get_response
  126.                 response = wrapped_callback(request, *callback_args, **callback_kwargs)

File "C:\Users\danie\Envs\Prolitfic\lib\site-packages\django\contrib\admin\options.py" in wrapper
  574.                 return self.admin_site.admin_view(view)(*args, **kwargs)

File "C:\Users\danie\Envs\Prolitfic\lib\site-packages\django\utils\decorators.py" in _wrapped_view
  142.                     response = view_func(request, *args, **kwargs)

File "C:\Users\danie\Envs\Prolitfic\lib\site-packages\django\views\decorators\cache.py" in _wrapped_view_func
  44.         response = view_func(request, *args, **kwargs)

File "C:\Users\danie\Envs\Prolitfic\lib\site-packages\django\contrib\admin\sites.py" in inner
  223.             return view(request, *args, **kwargs)

File "C:\Users\danie\Envs\Prolitfic\lib\site-packages\django\utils\decorators.py" in _wrapper
  62.             return bound_func(*args, **kwargs)

File "C:\Users\danie\Envs\Prolitfic\lib\site-packages\django\utils\decorators.py" in _wrapped_view
  142.                     response = view_func(request, *args, **kwargs)

File "C:\Users\danie\Envs\Prolitfic\lib\site-packages\django\utils\decorators.py" in bound_func
  58.                 return func.__get__(self, type(self))(*args2, **kwargs2)

File "C:\Users\danie\Envs\Prolitfic\lib\site-packages\django\contrib\admin\options.py" in changelist_view
  1570.             cl = self.get_changelist_instance(request)

File "C:\Users\danie\Envs\Prolitfic\lib\site-packages\django\contrib\admin\options.py" in get_changelist_instance
  705.             self,

File "C:\Users\danie\Envs\Prolitfic\lib\site-packages\django\contrib\admin\views\main.py" in __init__
  77.         self.get_results(request)

File "C:\Users\danie\Envs\Prolitfic\lib\site-packages\django\contrib\admin\views\main.py" in get_results
  175.         result_count = paginator.count

File "C:\Users\danie\Envs\Prolitfic\lib\site-packages\django\utils\functional.py" in __get__
  36.         res = instance.__dict__[self.name] = self.func(instance)

File "C:\Users\danie\Envs\Prolitfic\lib\site-packages\django\core\paginator.py" in count
  85.             return self.object_list.count()

File "C:\Users\danie\Envs\Prolitfic\lib\site-packages\django\db\models\query.py" in count
  387.         return self.query.get_count(using=self.db)

File "C:\Users\danie\Envs\Prolitfic\lib\site-packages\django\db\models\sql\query.py" in get_count
  491.         number = obj.get_aggregation(using, ['__count'])['__count']

File "C:\Users\danie\Envs\Prolitfic\lib\site-packages\django\db\models\sql\query.py" in get_aggregation
  476.         result = compiler.execute_sql(SINGLE)

File "C:\Users\danie\Envs\Prolitfic\lib\site-packages\django\db\models\sql\compiler.py" in execute_sql
  1067.             cursor.execute(sql, params)

File "C:\Users\danie\Envs\Prolitfic\lib\site-packages\django\db\backends\utils.py" in execute
  100.             return super().execute(sql, params)

File "C:\Users\danie\Envs\Prolitfic\lib\site-packages\django\db\backends\utils.py" in execute
  68.         return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)

File "C:\Users\danie\Envs\Prolitfic\lib\site-packages\django\db\backends\utils.py" in _execute_with_wrappers
  77.         return executor(sql, params, many, context)

File "C:\Users\danie\Envs\Prolitfic\lib\site-packages\django\db\backends\utils.py" in _execute
  85.                 return self.cursor.execute(sql, params)

File "C:\Users\danie\Envs\Prolitfic\lib\site-packages\django\db\utils.py" in __exit__
  89.                 raise dj_exc_value.with_traceback(traceback) from exc_value

File "C:\Users\danie\Envs\Prolitfic\lib\site-packages\django\db\backends\utils.py" in _execute
  85.                 return self.cursor.execute(sql, params)

Exception Type: ProgrammingError at /admin/web_app/work/
Exception Value: relation "web_app_work" does not exist
LINE 1: SELECT COUNT(*) AS "__count" FROM "web_app_work"

Here is my model:

class Work(models.Model):
    work_id = models.AutoField(primary_key=True)
    writer_id = models.ForeignKey(
        Writer,
        on_delete=models.SET_NULL,
        null = True,
        verbose_name = "Author")
    content = models.TextField()
    title = models.CharField(max_length=100)
    views = models.IntegerField(default=0)
    num_ratings = models.IntegerField(verbose_name = "Number of Ratings", default=0)
    ratings_sum = models.IntegerField(verbose_name = "Sum of Ratings", default=0)
    ratings_avg = models.IntegerField(verbose_name = "Rating Score", default=0)
    date_created = models.DateTimeField(auto_now_add=True)
    read_count = models.IntegerField(default=0)

    def get_absolute_url(self):
        return reversed('story', args=[str(self.work_id)])

    def __string__(self):
        return self.title

and my migration file:

from django.db import migrations, models
import django.db.models.deletion


class Migration(migrations.Migration):

    initial = True

    dependencies = [
    ]

    operations = [
        migrations.CreateModel(
            name='Comment',
            fields=[
                ('text', models.TextField()),
                ('ratings_sum', models.IntegerField(default=0, verbose_name='Sum of Ratings')),
                ('num_ratings', models.IntegerField(default=0, verbose_name='Number of Ratings')),
                ('ratings_avg', models.IntegerField(default=0, verbose_name='Rating Score')),
                ('date_created', models.DateTimeField(auto_now_add=True)),
                ('comment_id', models.AutoField(primary_key=True, serialize=False)),
            ],
        ),
        migrations.CreateModel(
            name='Work',
            fields=[
                ('work_id', models.AutoField(primary_key=True, serialize=False)),
                ('content', models.TextField()),
                ('title', models.CharField(max_length=100)),
                ('views', models.IntegerField(default=0)),
                ('num_ratings', models.IntegerField(default=0, verbose_name='Number of Ratings')),
                ('ratings_sum', models.IntegerField(default=0, verbose_name='Sum of Ratings')),
                ('ratings_avg', models.IntegerField(default=0, verbose_name='Rating Score')),
                ('date_created', models.DateTimeField(auto_now_add=True)),
                ('read_count', models.IntegerField(default=0)),
            ],
        ),
        migrations.CreateModel(
            name='Writer',
            fields=[
                ('writer_id', models.AutoField(primary_key=True, serialize=False)),
                ('writer_name', models.CharField(max_length=100)),
            ],
        ),
        migrations.AddField(
            model_name='work',
            name='writer_id',
            field=models.ForeignKey(null=True, on_delete=django.db.models.deletion.SET_NULL, to='web_app.Writer', verbose_name='Author'),
        ),
        migrations.AddField(
            model_name='comment',
            name='work_id',
            field=models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='web_app.Work'),
        ),
        migrations.AddField(
            model_name='comment',
            name='writer_id',
            field=models.ForeignKey(null=True, on_delete=django.db.models.deletion.SET_NULL, to='web_app.Writer', verbose_name='Commenter'),
        ),
    ]

Things I've already tried:

• Migrating individual apps

• Migrating from scratch(deleting all migrations and pycache of web_app and migrations folders)

• Changing the work model

• Commenting out the urls and views, migrating, then uncommenting them

Answer 1

I fixed my issue by following the steps listed in this guide:

https://micropyramid.com/blog/how-to-create-initial-django-migrations-for-existing-schema/

Step1: Empty the django_migrations table:

Just go to your corresponding database terminals and delete all the records from you django_migrations table with

delete from django_migrations;

Step2: Remove all the files in migrations folders in each and every app of your project.

Go to terminal and run remove all files in migrations folder with

rm -rf <app>/migrations/

Step3: Reset the migrations for the "built-in" apps:

Reset all the migrations of the Django's built-in apps like admin with the command

python manage.py migrate --fake

Step4: Create initial migrations for each and every app:

For each app run:

python manage.py makemigrations <app>. 

Note: Take care of dependencies (models with ForeignKey's should run after their parent model).

Step5: Final step is to create fake initial migrations:

To create initial fake migrations just run

python manage.py migrate --fake-initial

After the above steps I was able to run makemigrations and migrate normally.

Answer 2

Ok, once I got the same problem and for solving that I deleted all migrations and pycache of that app except init.py This happened because your makemigrations command worked properly but your migrate doesn't migrate any thing.