Makemigration with django4.0.6 and python3.10.5 doesn't work

Using Django Mystery Errors
1

I’m currently coding a blog as a side project, whenever I make a considerable modification in my models, I cannot migrate.

This is my model

from ckeditor.fields import RichTextField
from django.contrib.auth.models import User
from django.db import models
from django.template.defaultfilters import slugify
from django.urls import reverse


class Tag(models.Model):
    name = models.CharField(max_length=255, default="Uncategorized")

    class Meta:
        ordering = ['name']

    def __str__(self):
        return self.name

    def get_absolute_url(self):
        return reverse('blog:home')


class Post(models.Model):
    ACTIVE = 'active'
    DRAFT = 'draft'

    CHOICE_STATUS = (
        (ACTIVE, 'Active'),
        (DRAFT, 'Draft')
    )

    title = models.CharField(max_length=255)
    title_color = models.CharField(max_length=50, default="white")
    header_image = models.ImageField(upload_to='images/headers', null=True, blank=True)
    author = models.ForeignKey(User, on_delete=models.CASCADE)
    table_content = RichTextField(default="CONTENTS", blank=True, null=True)
    body = RichTextField(blank=True, null=True)
    snippet = models.CharField(max_length=255, default="")
    date_published = models.DateTimeField(auto_now_add=True)
    status = models.CharField(max_length=10, choices=CHOICE_STATUS, default=DRAFT)
    slug = models.SlugField()
    tag = models.ManyToManyField(Tag)

    def __str__(self):
        return self.title + ' | ' + self.author.get_full_name()

    def get_absolute_url(self):
        return reverse('blog:article_details', args=(str(self.id), self.slug))

    @property
    def date(self):
        return self.date_published.date()

    def save(self, *args, **kwargs):
        if not self.slug:
            self.slug = slugify(self.title)
        return super().save(*args, **kwargs)


class PostPicture(models.Model):
    name = models.CharField(max_length=255, default="")
    files = models.FileField(upload_to="images/post")

    def __str__(self):
        return self.name

Now, in my model, I had the class named Category and decided I don’t need it anymore and just renamed it Tag.

When I make migrations, I have this error

LinuxTux@LinuxTux-MBP blog % python3 manage.py makemigrations
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/django/db/backends/utils.py", line 89, in _execute
    return self.cursor.execute(sql, params)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/django/db/backends/sqlite3/base.py", line 477, in execute
    return Database.Cursor.execute(self, query, params)
sqlite3.OperationalError: no such table: blog_tag

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/Users/LinuxTux/developer/PycharmProjects/blog_project/manage.py", line 22, in <module>
    main()
  File "/Users/LinuxTux/developer/PycharmProjects/blog_project/manage.py", line 18, in main
    execute_from_command_line(sys.argv)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/django/core/management/__init__.py", line 446, in execute_from_command_line
    utility.execute()
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/django/core/management/__init__.py", line 440, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/django/core/management/base.py", line 414, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/django/core/management/base.py", line 455, in execute
    self.check()
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/django/core/management/base.py", line 487, in check
    all_issues = checks.run_checks(
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/django/core/checks/registry.py", line 88, in run_checks
    new_errors = check(app_configs=app_configs, databases=databases)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/django/core/checks/urls.py", line 14, in check_url_config
    return check_resolver(resolver)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/django/core/checks/urls.py", line 24, in check_resolver
    return check_method()
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/django/urls/resolvers.py", line 480, in check
    for pattern in self.url_patterns:
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/django/utils/functional.py", line 49, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/django/urls/resolvers.py", line 696, in url_patterns
    patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/django/utils/functional.py", line 49, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/django/urls/resolvers.py", line 689, in urlconf_module
    return import_module(self.urlconf_name)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1050, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1027, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1006, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 688, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 883, in exec_module
  File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
  File "/Users/LinuxTux/developer/PycharmProjects/blog_project/blog_project/urls.py", line 21, in <module>
    import blog.views
  File "/Users/LinuxTux/developer/PycharmProjects/blog_project/blog/views.py", line 8, in <module>
    from .forms import UpdateForm, PostForm
  File "/Users/LinuxTux/developer/PycharmProjects/blog_project/blog/forms.py", line 7, in <module>
    for item in choices:
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/django/db/models/query.py", line 320, in __iter__
    self._fetch_all()
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/django/db/models/query.py", line 1507, in _fetch_all
    self._result_cache = list(self._iterable_class(self))
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/django/db/models/query.py", line 168, in __iter__
    return compiler.results_iter(
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/django/db/models/sql/compiler.py", line 1312, in results_iter
    results = self.execute_sql(
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/django/db/models/sql/compiler.py", line 1361, in execute_sql
    cursor.execute(sql, params)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/django/db/backends/utils.py", line 103, in execute
    return super().execute(sql, params)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/django/db/backends/utils.py", line 67, in execute
    return self._execute_with_wrappers(
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/django/db/backends/utils.py", line 80, in _execute_with_wrappers
    return executor(sql, params, many, context)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/django/db/backends/utils.py", line 84, in _execute
    with self.db.wrap_database_errors:
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/django/db/utils.py", line 91, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/django/db/backends/utils.py", line 89, in _execute
    return self.cursor.execute(sql, params)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/django/db/backends/sqlite3/base.py", line 477, in execute
    return Database.Cursor.execute(self, query, params)
django.db.utils.OperationalError: no such table: blog_tag

I also tried

python3 manage.py makemigrations blog

or

python3 manage.py makemigrations --dry-run --verbosity 3

or

python3.10 manage.py makemigrations --dry-run --verbosity 3

I also have the same error output when I run:

python3 manage.py test

I tried removing the database (db.sqlite3) and all the migrations folder + pycache folder, re-run the same command above, same error.

Am I the only one having this error ?

2

This type of error is frequently encountered when you have some module-level code referencing the table.

Do you have any other code in any file in your project that is still referencing Category?

3

Yes, I used class-based view. When I commented out every bit of code that could reference Category and run makemigrations again, it works, thanks to your advice. Does that mean there’s something wrong with it and I need to change my class-based view to a function-based view?

4

You’d have to show me your view for me to determine what’s wrong. I would likely say that you’re not doing something right in your view.

5

This is my old view

from django.contrib.auth.decorators import login_required
from django.db.models import Q
from django.shortcuts import render
from django.urls import reverse_lazy
from django.utils.decorators import method_decorator
from django.views.generic import ListView, DetailView, CreateView, UpdateView, DeleteView

from .forms import UpdateForm, PostForm
from .models import Post, Category


class HomeView(ListView):
    model = Post
    template_name = 'blog/index.html'
    ordering = ['-date_published']

    def context_data_filtering(self, post):
        context = super(HomeView, self).get_context_data()
        cat_list = Category.objects.all()
        context["cat_list"] = cat_list
        if len(post) >= 5:
            last_post = post[0]
            first_row = post[1:4]
            the_rest = post[4:]
        elif 5 > len(post) > 1:
            last_post = post[0]
            first_row = post[1:4]
            the_rest = None
        elif len(post) == 1:
            last_post = post[0]
            first_row = None
            the_rest = None
        else:
            last_post = None
            first_row = None
            the_rest = None
        context["last_post"] = last_post
        context["row"] = first_row
        context["rest"] = the_rest
        return context

    def get_context_data(self, *, object_list=None, **kwargs):
        if self.request.user.is_authenticated:
            post_user_logged = Post.objects.all().order_by('-date_published')
            return self.context_data_filtering(post_user_logged)
        else:
            post = Post.objects.filter(status='active').order_by('-date_published')
            return self.context_data_filtering(post)


class ArticleDetailView(DetailView):
    model = Post
    pk_url_kwarg = "pk"
    slug_url_kwarg = "slug"
    template_name = 'blog/articles_details.html'


@method_decorator(login_required, name='dispatch')
class AddPostView(CreateView):
    model = Post
    form_class = PostForm
    template_name = 'blog/add_post.html'

    @method_decorator(login_required)
    def dispatch(self, *args, **kwargs):
        return super().dispatch(*args, **kwargs)


@method_decorator(login_required, name='dispatch')
class UpdatePostView(UpdateView):
    model = Post
    form_class = UpdateForm
    template_name = 'blog/update_post.html'

    @method_decorator(login_required)
    def dispatch(self, *args, **kwargs):
        return super().dispatch(*args, **kwargs)


@method_decorator(login_required, name='dispatch')
class DeletePostView(DeleteView):
    model = Post
    template_name = 'blog/delete_post.html'
    success_url = reverse_lazy('blog:home')

    @method_decorator(login_required)
    def dispatch(self, *args, **kwargs):
        return super().dispatch(*args, **kwargs)


@method_decorator(login_required, name='dispatch')
class AddCategoryView(CreateView):
    model = Category
    template_name = 'blog/add_category.html'
    fields = '__all__'

    @method_decorator(login_required)
    def dispatch(self, *args, **kwargs):
        return super().dispatch(*args, **kwargs)


def category_view(request, cats):
    category_post = Post.objects.filter(category=cats.replace('-', ' '))
    return render(request, 'blog/categories.html', {'cats': cats.title().replace('-', ' '), 'category': category_post})


def search(request):
    query = request.GET.get('query', '')
    posts = Post.objects.filter(status=Post.ACTIVE).filter(
        Q(title__icontains=query) | Q(snippet__icontains=query) | Q(body__icontains=query))
    return render(request, 'blog/search.html', {'query': query, 'posts': posts})
6

It was probably the import statement at the top, if the model Category no longer existed.

7

I’ve tried making migrations on the server with the new view file updated(with the right import) with the tag model, same problem, I had to comment every other file using the app logic, push to server, makemigrations on server, uncomment, push to server again to make it work.

8

I’m not entirely sure I know exactly what the implications are of this phrase, but since you have it working, it sounds like the issue is moot.

9

I meant admin.py urls.py test.py forms.py view.py…