OperationalError: table "django_session" already exists - python

I have applied all solutions I could find, but still I got an operational error and also when I run project it gives error like:
You have 1 unapplied migration(s).....
I had applied all migrations.
I tried this solution:
Delete all files under migrations directory except init.py (successfully)
run $python manage.py makemigrations <appname> (successfully)
run $python manage.py sqlmigrate <appname> 001 (Successfully)
run $python manage.py migrate (Failed: operational error)
Because of 4th failure I got a statement of migrations while I ran project
What should I do?
Below is my code:
urls.py
urlpatterns = [ url(r'^$', views.index,name='index'), url(r'.*signup/$' , views.signup.as_view(), name='signup'), ]
models.py
class PatientSignup(models.Model):
Pname = models.CharField()
forms.py:
class PatientSignupForm(forms.ModelForm):
forms.CharField() # add other fileds
views.py:
class signup(TemplateView):
temp = 'personal/signup.html'
def get(self, request):
psform = PatientSignupForm()
data = PatientSignup.objects.all()
args = {'psform': psform, 'data': data}
return render(request, self.temp, args)
def post(self, request):
psform = PatientSignupForm(request.POST)
if psform.is_valid():
psform.save()
cd = psform.cleaned_data
args = {'psform': psform, 'data': data}
return render(request, self.temp, args)
Template code:
<form method="post">
{ % csrf_token %}
<div>
{{psform.as_p}}
<button type="submit"/>
</div>
</form>

Step 0) Delete the database and create it again or delete all entries in the table django_migrations and try again the migrations.

You are trying to apply migrations on already created database field. You could have run migrate --fake command, but in your case, it seems that you have multiple migrations to migrate. First of all, delete your current db by creating a backup of it. Now type,
python manage.py makemigrations app_name
At this point, you have created migration files, enter following command,
python manage.py migrate
This should have solved your migrations issue. Thanks

Related

django.db.utils.OperationalError: no such table: django_site_id_seq

I got this error when running command python manage.py test for testing purpose.
I tried after delete my pycache and migration files and db.sqlite3 then run the python manage.py makemigrations and python manage.py migrate again as well.
But still got the same error...
Here is my test.py
from rest_framework.test import APITestCase
from django.urls import reverse
from rest_framework import status
# Create your tests here.
class UserTest(APITestCase):
def setUp(self):
register_url = reverse('user:register')
data = {
"username":"Tester",
"email":"tester#gmail.com",
"password":"tester123",
"mobile_number":"03322917356"
}
self.client.post(register_url, data, format='json')
def test_user_can_register(self):
register_url = reverse('user:register')
data = {
"username":"Tester1",
"email":"tester1#gmail.com",
"password":"tester123",
"mobile_number":"03322911356"
}
response = self.clent.post(register_url , data , format='json')
self.assertEqual(response.status_code ,status.HTTP_201_CREATED)
Try switching to postgresql, to see if it is a database issue always good to try something else. if that doesn’t work then I would get an existing example that does work and compare it from there to what you have. tbh unless you have your code opensource it is difficult to debug something like this without speculation as a lot of different systems are affected when ensuring migrations are applied. Check your migrations files to see if those are indeed correct. they should be under /migrations
Have you added your app in settings.py to installed apps?
In hour installed app comment out django sites. Do makemigrations and migrate. Then reactivate django sites and do the migration stuff again

Apply a migration to Django Flatpage model

I would like to use the modeltranslation package in a Django application that uses the flatpages app.
I installed both, followed the model translation docs, and created a translation.py file, which I put in the main app (where all the global stuff lies), as I can't put it directly in the flat pages app (Django code is a requirement and is not committed to VCS).
# django/main/translation.py
from modeltranslation.translator import translator, TranslationOptions
from django.contrib.flatpages.models import FlatPage
class FlatPageTranslationOptions(TranslationOptions):
fields = ('title', 'content')
translator.register(FlatPage, FlatPageTranslationOptions)
Then I ran python manage.py makemigrations, and it created a migration file in the flatpages app /usr/local/lib/python3.8/site-packages/django/contrib/flatpages/migrations/0002_auto_20211118_1558.py. It would be again in the Django code, so I tried to simply move it to the main app at django/main/migrations/0002_flatpages_translations.py (there is already an unrelated 0001_initial.py migration, which has no dependencies):
from django.db import migrations, models
class Migration(migrations.Migration):
dependencies = [
('flatpages', '0001_initial'),
]
operations = [
migrations.AddField(
model_name='flatpage',
name='content_en',
field=models.TextField(blank=True, null=True, verbose_name='content'),
),
migrations.AddField(
model_name='flatpage',
name='content_fr',
field=models.TextField(blank=True, null=True, verbose_name='content'),
),
migrations.AddField(
model_name='flatpage',
name='title_en',
field=models.CharField(max_length=200, null=True, verbose_name='title'),
),
migrations.AddField(
model_name='flatpage',
name='title_fr',
field=models.CharField(max_length=200, null=True, verbose_name='title'),
),
]
And... when I finally try to run the migration (python manage.py migrate), I got this error:
CommandError: Conflicting migrations detected; multiple leaf nodes in the migration graph: (0001_initial, 0002_flatpages_translations in main).
To fix them run 'python manage.py makemigrations --merge'
I tried the --merge flag, but got another error: ValueError: Could not find common ancestor of ['0001_initial', '0002_flatpages_translations']
Is it possible to achieve what I want to do?
Found a solution, so I post it here if someone has the same problem. According Django documentation, you can specify the package where migration modules can be found on a per-app basis.
So, in settings.py, add:
MIGRATION_MODULES = {
'flatpages': 'main.migrations.flatpages',
}
Then move the migration file 0002_flatpages_translations.py in django/main/migrations/flatpages/. In the case of the flatpages app, you will also need to copy the 0001_initial.py migration file from the flatpage app, inside this directory.
And you're good, Django now searches the migrations for the flatpages app in your new directory.

how solve this proplem on models django?

Finished creating the models file, typed python manage.py makemigrations main and I get a reply back, 'no installed app with label 'main'. when I do python manage.py migrate, it says Apply all migrations: admin, auth, contenttypes, sessions. I even spent considerable time double checking my spelling and it is correct. Any ideas on how I can fix it?
your app.py must look like this:
from django.apps import AppConfig
class MainConfig(AppConfig):
name = 'main'
verbose_name = 'Some Name'
You need to add your app main to the INSTALLED_APPS setting [Django-doc] in the settings.py:
# settings.py
INSTALLED_APPS = [
# …,
'main'
]

How to remove an app from a django projects (and all its tables)

I want to remove an app from a django project.
I want to remove
the tables of the app
the content-types
foreign-key usages of these content-types
Running manage.py migrate app_to_remove zero does not work:
django.db.migrations.migration.IrreversibleError:
Operation <RunPython <function forwards_func at 0x7ff76075d668>> in
fooapp.0007_add_bar is not reversible
I guess there are several migrations which are not reversible ...
First: Remove references in the code
remove app_to_remove from settings.INSTALLED_APPS
remove other references in urls.py or other places
Second: Clean the database
Create an empty migration for your django-project:
manage.py makemigrations your_django_project --empty
Edit the file. Here is a template:
# -*- coding: utf-8 -*-
from __future__ import unicode_literals
from django.db import migrations, models
class Migration(migrations.Migration):
dependencies = [
('your_django_project', '0001_initial'),
]
operations = [
migrations.RunSQL('''
drop table if exists app_to_remove_table1;
drop table if exists app_to_remove_table2;
....
delete from auth_permission where content_type_id in (select id from django_content_type where app_label = '{app_label}');
delete from django_admin_log where content_type_id in (select id from django_content_type where app_label = '{app_label}');
delete from django_content_type where app_label = '{app_label}';
delete from django_migrations where app='{app_label}';
'''.format(app_label='app_to_remove'))
]
Run the migration, run tests.
About "drop if exists": You have two cases:
The production system: You want to drop the tables.
New development systems: These systems never had this app, and they don't have this table :-)
Note: this guide is successful with Django 3.1.1 and Python 3.8.2
Can you try this solution to clean your database and migrations first
Step 1: Delete your table from the file your_app/models.py but leave the file itself
Step 2: Check your register in the file admin.py if you have
Step 3: create migration:
manage.py makemigrations your_app
Step 4: migrate into database:
manage.py migrate
you can see the result in my example
Step 5: delete all the files in the folder your_app/migrations
Step 6: Remove migrations in the table django_migrations
python manage.py migrate --fake your_app zero
Check migrations:
python manage.py showmigrations
Step 7: Then you can remove the app completely,check reference,INSTALLED_APPS

Django south cannot see any field in submodule

I have such folder system:
project_name:
plugins
link
templates
cms_plugin.py
models.py
view.py
....
gallery
...
I want to use migration for link module, but when I do:
./manage schemamigration --initial plugins.link
south creates an empty file initial.py (models.py is not empty, and syncdb works well with it).
import datetime
from south.db import db
from south.v2 import SchemaMigration
from django.db import models
class Migration(SchemaMigration):
def forwards(self, orm):
pass
def backwards(self, orm):
pass
models = {
}
complete_apps = ['link']
If I change something in models.py - south says:
./manage.py schemamigration --auto plugins.link
Nothing seems to have changed.
I try to add app_label = 'cmsplugin', and run south with app_label:
./manage.py schemamigration --initial cmsplugin.link
but it give me the same result,
What am I doing wrong? How to create migrations for submodules?

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