Having a model like below
from django.contrib.auth.models import User # has migrations in 1.7
class MyProxyUser(User):
class Meta:
proxy = True
in an app without migrations gives the following error when running the tests:
django.db.migrations.state.InvalidBasesError: Cannot resolve bases for [<ModelState: 'django_proxy_model_problems.MyProxyUser'>]
This can happen if you are inheriting models from an app with migrations (e.g. contrib.auth)
in an app with no migrations; see https://docs.djangoproject.com/en/1.7/topics/migrations/#dependencies for more
Having read both
https://docs.djangoproject.com/en/1.8/topics/migrations/#dependencies
https://docs.djangoproject.com/en/1.8/topics/db/models/#proxy-models
I can't figure out what I should be doing to resolve this problem (manage.py makemigrations reports No changes detected)
The problem can be reproduced by running tox -e py27-django17 using this github repo
This can be reproduced with Django 1.7 & 1.8, but works fine with 1.4
Run manage.py makemigrations <app_label>. Django won't create a migration folder if it doesn't exist, unless you explicitly specify the app label. That is because apps without migrations are (still) supported.
If the migrations folder exists within the app, and has an __init__.py file (even on Python 3), Django will pick up the app as a migrated app, and create the migrations with just manage.py makemigrations.
Related
I built a Django 1.9 project locally with sqlite3 as my default database. I have an application named Download which defines the DownloadedSongs table in models.py:
models.py
from __future__ import unicode_literals
from django.db import models
class DownloadedSongs(models.Model):
song_name = models.CharField(max_length = 255)
song_artist = models.CharField(max_length = 255)
def __str__(self):
return self.song_name + ' - ' + self.song_artist
Now, in order to deploy my local project to Heroku, I added the following lines at the bottom of my settings.py file:
import dj_database_url
DATABASES['default'] = dj_database_url.config()
My application has a form with a couple of text fields, and on submitting that form, the data gets inserted into the DownloadedSongs table. Now, when I deployed my project on Heroku and tried submitting this form, I got the following error:
Exception Type: ProgrammingError at /download/
Exception Value: relation "Download_downloadedsongs" does not exist
LINE 1: INSERT INTO "Download_downloadedsongs" ("song_name", "song_a...
This is how my requirements.txt file looks like:
beautifulsoup4==4.4.1
cssselect==0.9.1
dj-database-url==0.4.1
dj-static==0.0.6
Django==1.9
django-toolbelt==0.0.1
gunicorn==19.6.0
lxml==3.6.0
psycopg2==2.6.1
requests==2.10.0
static3==0.7.0
Also, I did try to run the following commands as well:
heroku run python manage.py makemigrations
heroku run python manage.py migrate
However, the issue still persists. What seems to be wrong here?
Make sure your local migration folder and content is under git version control.
If not, add, commit & push them as follows (assuming you have a migrations folder under <myapp>, and your git remote is called 'heroku'):
git add <myapp>/migrations/*
git commit -m "Fix Heroku deployment"
git push heroku
Wait until the push is successful and you get the local prompt back.
Then log in to heroku and there execute migrate.
To do this in one execution environment, do not launch these as individual heroku commands, but launch a bash shell and execute both commands in there: (do not type the '~$', this represents the Heroku prompt)
heroku run bash
~$ ./manage.py migrate
~$ exit
You must not run makemigrations via heroku run. You must run it locally, and commit the result to git. Then you can deploy that code and run those generated migrations via heroku run python manage.py migrate.
The reason is that heroku run spins up a new dyno each time, with a new filesystem, so any migrations generated in the first command are lost by the time the second command runs. But in any case, migrations are part of your code, and must be in version control.
As Heroku's dynos don't have a filesystem that persists across deploys, a file-based database like SQLite3 isn't going to be suitable. It's a great DB for development/quick prototypes, though. https://stackoverflow.com/a/31395988/784648
So between deploys your entire SQLite database is going to be wiped, you should move onto a dedicated database when you deploy to heroku I think. I know heroku has a free tier for postgres databases which I'd recommend if you just want to test deployment to heroku.
python manage.py makemigrations
python manage.py migrate
python manage.py migrate --run-syncdb
this worked for me.
I know this is old, but I had this issue and found this thread useful.
To sum up, the error can also appear when executing the migrations (which is supposed to create the needed relations in the DB), because recent versions of Django check your urls.py before doing the migrations. In my case - and in many others' it seems, loading urls.py meant loading the views, and some views were class-based and had an attribute defined through get_object_or_404:
class CustomView(ParentCustomView):
phase = get_object_or_404(Phase, code='C')
This is what was evaluated before the migrations actually ran, and caused the error. I fixed it by turning my view's attribute as a property:
class CustomView(ParentCustomView):
#property
def phase(self):
return get_object_or_404(Phase, code='C')
You'll know quite easily if this is the problem you are encountering, as the Traceback will point you towards the problematic view.
Also this problem might not appear in development because you have migrated before creating the view.
I deployed a website on python anywhere. Then I planed on adding an extra model for more functionality. I added that model offline and it works fine but when I made changes to the deployed website the bash console didn't detect any migrations. I thought there was something wrong with the model so I added some sample models to check but even those weren't getting detected when I used
python manage.py makemigrations
the same happened when I used
python manage.py migrate I read up the docs but there isn't a problem with the code
I have trouble with my makemigrations command.
Note: I have successfully make migrations till now, so it is not the first time I try to make migrations on this project.
I have my project in INSTALLED_APPS.
Problem: For some reason project stop detecting any changes in my models.
Inside my project models.py I have:
from myproject.myfolder import myModel1
from myproject.myfolder import myModel2
from myproject.myfolder import myModel3
if a add new models as myModel4 class and import it inside models.py and I try to
python mamange.py makemigrations environment=local
I get No changes detected
I know there are a lot of posts of making the initial migrations, so I even try
python manage.py makemigrations myproject environment=local
I even try to delete all files in __pycache__ but it doesn't work for me.
I even try to delete database and create new one, and it doesn't work either.
EDIT:
Because I delete the database and make it new again, database is empty, but I still get same message.
I just ran into an issue like this. In my case, the problem was that I had installed, through pip, the stable version of the package that I was developing, and Django was importing the stable version rather than my development version. To check if this is the case with you, try adding a syntax error to models.py. If makemigrations doesn't trigger the syntax error, then you'll know that your version is not even being loaded by the python interpreter.
If your model is not inheriting from django model then, you will see aforementioned error. Make sure that your custom model inherits from django models.Model, something like this.
from django.db import models
class Posts(models.Model):
...
Deleting the DB and creating new one will never work since it refer the previous migration files. Delete all previous migration files and pycache files except init. Then try running these.
python manage.py migrate --fake-initial
python manage.py makemigrations
python manage.py migrate
This worked for me
According to the Django docs, if I want to create an initial migration for an app, I should do:
$ python manage.py makemigrations my_app
However, if I do that in my project, I get:
No changes detected in app 'my_app'
even though there are no migrations for my_app yet - the my_app/migrations/ folder only has an __init__.py file.
I do NOT have managed = False in my model. The model classes in question don't even have a Meta class defined. What else can prevent Django from detecting model changes?
How does Django detect if/when there are changes?
Update:
I should add that migrations for this particular app worked fine back when I was using South migrations. It's only after upgrading to Django 1.7, and built-in migrations, that it can no longer figure out if/when there are model changes for that particular app (migrations for other apps work fine).
A little late, but having just hit this after creating a brand new app, it suddenly dawned on me that I hadn't added the new app to the INSTALLED_APPS in the settings.py.
INSTALLED_APPS = (
...
my_app,
...
)
Doing that and then re-running python manage.py makemigrations my_app generated the initial migration.
You might want to look for a "migrations" directory somewhere in your virtualenv home directory or on your path.
I ran a few times into some similar issue, when trying to migrate an app from South to Django 1.7 migrations. For some reason, Django wouldn't find the correct migrations folder, and so would create the migration into an unlikely location such as <virtualenv>/bin/myapp/migrations dir (when using django-admin.py). So everytime I'd run makemigrations Django would find this "stale" migration, and display the No changes detected in app 'my_app' message.
Sorry if I'm vague on the specifics, I'll update next time I run into this issue.
I have Django 1.7 running on Heroku. I've made a change to the models.py file (added a column to a table) but Django doesn't seem to be able to detect this. When I run
python manage.py makemigrations appname
it responds No changes detected in app.
I've tried deleting the appname/migrations folder, but that doesn't help.
Is there a way to get Django to rescan the database and check for differences? This was easy with South.
https://docs.djangoproject.com/en/1.7/topics/migrations/#the-commands
Have you tried
python manage.py migrate
It seems the migrate is "responsible for applying migrations, as well as unapplying and listing their status."