Change the order in which Django migrate app during testing - python

I am using the custom user model which inherits from the AbstractBaseUser class. When I try to migrate after makemigrations command
django.db.utils.ProgrammingError: relation "custom_user_users" does not exist
This is happening since Django is trying to migrate other apps first which depends upon the custom user model. Even I tried to changing the order of the app which contains the custom user model in INSTALLED_APP but no luck.
I know I can force fully migrate custom_user model first then let Django migrate all other models. This solves the problem but during running test it runs the migration in order which Django decides.
How can I alter the order in which apps are migrated during test ? Any other way to solve this dependency problem ?
I am using Django 1.8

Put your your apps before Django apps in INSTALLED_APP in settings.py file

https://pypi.python.org/pypi/django-test-without-migrations adds a --nomigrations flag to manage.py test. Works like a charm.

Related

modify max_length models python django

I'm working on a python-django project.
If a have a class where one of its attributes have
max_length=100
how can I change to
max_length=5000
? for instance...
Thank you!
Basically when you edit a field on a Model you need to makemigrations and migrate for changes to take effect in database.
python manage.py makemigrations <optional_appname(If not provided it affects all apps.)>
python manage.py migrate <optional_appname>

Migration error on Django + django-oauth-toolkit

I have an django application with version 2.2.13 and django oauth toolkit 1.0.0. In the effort to update to Django 3.0, I need to update the django-oauth-toolkit, but every version after version 1.0.0, I run into a migration problem because my application (oauth2) extends the abstract application (AbstractApplication) model from the oauth2_provider (from django-oauth-toolkit).
from oauth2_provider.models import AbstractApplication
class Application(AbstractApplication):
# there are more fields added here
pass
This custom oauth application (oauth2) has 28 migrations that were generate inside the project itself.
When we try to run all migrations from scratch (we do this on our CI Server), we get an error trying to run migration 0001 for the app oauth2_provider
ValueError: Related model 'oauth2.Application' cannot be resolved.
There is an issue similar to my problem open on the project, https://github.com/jazzband/django-oauth-toolkit/issues/778, but workaround provided does not work, and I have not found other solution to it.
Thanks.
when you swap the application model,
you should create and run the migration defining the swapped
application model prior to setting OAUTH2_PROVIDER_APPLICATION_MODEL.
It is possible to force your migration providing the custom model to run in the right order by adding:
run_before = [
('oauth2_provider', '0001_initial'),
]
to the migration class.
You can find more details here

Django 1.7 - makemigrations not detecting changes

As the title says, I can't seem to get migrations working.
The app was originally under 1.6, so I understand that migrations won't be there initially, and indeed if I run python manage.py migrate I get:
Operations to perform:
Synchronize unmigrated apps: myapp
Apply all migrations: admin, contenttypes, auth, sessions
Synchronizing apps without migrations:
Creating tables...
Installing custom SQL...
Installing indexes...
Running migrations:
No migrations to apply.
If I make a change to any models in myapp, it still says unmigrated, as expected.
But if I run python manage.py makemigrations myapp I get:
No changes detected in app 'myapp'
Doesn't seem to matter what or how I run the command, it's never detecting the app as having changes, nor is it adding any migration files to the app.
Is there any way to force an app onto migrations and essentially say "This is my base to work with" or anything? Or am I missing something?
My database is a PostgreSQL one if that helps at all.
If you're changing over from an existing app you made in django 1.6, then you need to do one pre-step (as I found out) listed in the documentation:
python manage.py makemigrations your_app_label
The documentation does not make it obvious that you need to add the app label to the command, as the first thing it tells you to do is python manage.py makemigrations which will fail. The initial migration is done when you create your app in version 1.7, but if you came from 1.6 it wouldn't have been carried out. See the 'Adding migration to apps' in the documentation for more details.
This may happen due to the following reasons:
You did not add the app in INSTALLED_APPS list in settings.py
(You have to add either the app name or the dotted path to the subclass of AppConfig in apps.py in the app folder, depending on the version of django you are using). Refer documentation: INSTALLED_APPS
You don't have migrations folder inside those apps. (Solution: just create that folder).
You don't have __init__.py file inside migrations folder of those apps. (Solution: Just create an empty file with name __init__.py)
You don't have an __init__.py file inside the app folder. (Solution: Just create an empty file with name __init__.py)
You don't have a models.py file in the app
Your Python class (supposed to be a model) in models.py doesn't inherit django.db.models.Model
You have some semantic mistake in definition of models in models.py
Note:
A common mistake is to add migrations folder in .gitignore file. When cloned from remote repo, migrations folder and/or __init__.py files will be missing in local repo. This causes problem.
Migration files are supposed to be included in the repo. read here. If your team frequently faces migration issues you may consider ignoring migration files as follows:
I suggest to gitignore migration files by adding the following lines to .gitignore file
*/migrations/*
!*/migrations/__init__.py
Remember, it is not recommended to gitignore migration files as per django documentation
Ok, looks like I missed an obvious step, but posting this in case anyone else does the same.
When upgrading to 1.7, my models became unmanaged (managed = False) - I had them as True before but seems it got reverted.
Removing that line (To default to True) and then running makemigrations immediately made a migration module and now it's working. makemigrations will not work on unmanaged tables (Which is obvious in hindsight)
My solution was not covered here so I'm posting it. I had been using syncdb for a project–just to get it up and running. Then when I tried to start using Django migrations, it faked them at first then would say it was 'OK' but nothing was happening to the database.
My solution was to just delete all the migration files for my app, as well as the database records for the app migrations in the django_migrations table.
Then I just did an initial migration with:
./manage.py makemigrations my_app
followed by:
./manage.py migrate my_app
Now I can make migrations without a problem.
Agree with #furins. If everything seems to be in order and yet this problem arises, checkout if there is any property method with same title as the attribute which you are trying to add in the Model class.
Remove method with similar name as attribute you are adding.
manage.py makemigrations my_app
manage.py migrate my_app
Add the methods back.
This is kind of a stupid mistake to make, but having an extra comma at the end of the field declaration line in the model class, makes the line have no effect.
It happens when you copy paste the def. from the migration, which itself is defined as an array.
Though maybe this would help someone :-)
Maybe I am too late but did you try to have a migrations folder in your app with a __init__.py file in it?
Maybe this will help someone. I was using a nested app. project.appname and I actually had project and project.appname in INSTALLED_APPS. Removing project from INSTALLED_APPS allowed the changes to be detected.
The answer is on this stackoverflow post, by cdvv7788 Migrations in Django 1.7
If it is the first time you are migrating that app you have to use:
manage.py makemigrations myappname Once you do that you can do:
manage.py migrate If you had your app in database, modified its model
and its not updating the changes on makemigrations you probably havent
migrated it yet. Change your model back to its original form, run the
first command (with the app name) and migrate...it will fake it. Once
you do that put back the changes on your model, run makemigrations and
migrate again and it should work.
I was having the exact same trouble and doing the above worked perfectly.
I had moved my django app to cloud9 and for some reason I never caught the initial migration.
Following worked for me:
Add the app name to settings.py
use 'python manage.py makemigrations'
use 'python manage.py migrate'
Worked for me: Python 3.4, Django 1.10
People like me who don't like migrations can use steps below.
Remove changes what you want to sync.
Run python manage.py makemigrations app_label for the initial migration.
Run python manage.py migrate for creating tables before you make changes.
Paste changes which you remove at first step.
Run 2. and 3. steps.
If you confused any of these steps, read the migration files. Change them to correct your schema or remove unwanted files but don't forget to change next migration file's dependencies part ;)
I hope this will help someone in future.
You want to check the settings.py in the INSTALLED_APPS list and make sure all the apps with models are listed in there.
Running makemigrations in the project folder means it will look to update all the tables related to all the apps included in settings.py for the project. Once you include it, makemigrations will automatically include the app (this saves a lot of work so you don't have to run makemigrations app_name for every app in your project/site).
Just in case you have a specific field that does not get identified by makemigrations: check twice if you have a property with the same name.
example:
field = django.db.models.CharField(max_length=10, default = '', blank=True, null=True)
# ... later
#property
def field(self):
pass
the property will "overwrite" the field definition so changes will not get identified by makemigrations
Adding this answer because only this method helped me.
I deleted the migrations folder run makemigrations and migrate.
It still said: No migrations to apply.
I went to migrate folder and opened the last created file,
comment the migration I wanted(It was detected and entered there)
and run migrate again.
This basically editing the migrations file manually.
Do this only if you understand the file content.
Make sure your model is not abstract. I actually made that mistake and it took a while, so I thought I'd post it.
Did u use schemamigration my_app --initial after renaming old migration folder? Try it. Might work. If not - try to recreate the database and make syncdb+migrate. It worked for me...
In my case I needed to add my model to the _init_.py file of the models folder where my model was defined:
from myapp.models.mymodel import MyModel
I had mistakely deleted folder of migrations from my project directory.
Solution is to create __init__.py file in the migrations folder, and then,
python manage.py makemigrations
python manage.py migrate
Had the same problem
Make sure whatever classes you have defined in models.py, you must have to inherit models.Model class.
class Product(models.Model):
title = models.TextField()
description = models.TextField()
price = models.TextField()
I had the same problem with having to run makemigrations twice and all sorts of strange behaviour. It turned out the root of the problem was that I was using a function to set default dates in my models so migrations was detecting a change every time I ran makemigrations. The answer to this question put me on the right track: Avoid makemigrations to re-create date field
I recently upgraded Django from 1.6 to 1.8 and had few apps and migrations for them. I used south and schemamigrations for creating migrations in Django 1.6, which is dropped in Django 1.8.
When I added new models after upgrade, the makemigrations command wasn't detecting any changes. And then I tried the solution suggested by #drojf (1st answer), it worked fine, but failed to apply fake initial migration (python manage.py --fake-initial). I was doing this as my tables (old tables) were already created.
Finally this worked for me, removed new models (or model changes) from models.py and then had to delete (or rename for safety backup) migrations folder of all apps and run python manage.py makemigrations for all apps, then did python manage.py migrate --fake-initial. This worked like a charm. Once initial migration is created for all apps and fake initial migrated, then added new models and followed regular process of makemigrations and migrate on that app. The changes were detected now and everything went fine.
I just thought of sharing it here, if someone faces same problem (having schemamigrations of south for their apps), it might help them :)
Maybe that can help someone, I had the same problem.
I've already created two tables with the serializer class and the views.
So when I wanted to updated, I had this error.
I followed this steps:
I made .\manage.py makemigrations app
I executed .\manage.py migrate
I erased both tables of my models.py
I erased all reference to my tables from serializer and view class.
I executed step 1 and 2.
I retrieved my changes just in the models.py
I executed again step 5.
I restored all my changes.
If you're working with Pycharm, local history is very helpfull.
Maybe this will help someone.
I've deleted my models.py and expected makemigrations to create DeleteModel statements.
Remember to delete *.pyc files!
./manage makemigrations
./manage migrate
Migrations track changes to DB so if youre changing from unmanaged to managed, you'll need to make sure that youre database table is up to date relating to the Model you're dealing with.
If you are still in dev mode, I personally decided to delete the migration files in my IDE as well as in the django_migrations table relating to my Model and rerun the above command.
REMEMBER: if you have a migration that ends with _001 in your IDE & _003 in your database. Django will only see if you have a migration ending with _004 for anything to update.
The 2 (code & db migrations) are linked and work in tandem.
Happy coding.
You may need to fake the initial migrations using the command below
python manage.py migrate --fake-initial
Remove changes what you want to sync.
Run python manage.py makemigrations app_label for the initial migration.
Run python manage.py migrate for creating tables before you make changes.
Paste changes which you remove at first step.
Run 2. and 3. steps
Added this answer because none of other available above worked for me.
In my case something even more weird was happening (Django 1.7 Version), In my models.py I had an "extra" line at the end of my file (it was a blank line) and when I executed the python manage.py makemigrations command the result was: "no changes detected".
To fix this I deleted this "blank line" that was at the end of my models.py file and I did run the command again, everything was fixed and all the changes made to models.py were detected!
First this solution is applicable to those who are facing the same issue during deployment on heroku server, I was facing same issue.
To deploy, there is a mandatory step which is to add django_heroku.settings(locals()) in settings.py file.
Changes:
When I changed the above line to django_heroku.settings(locals(), databases=False), it worked flawlessly.
I have encountered this issue, the command
python manage.py makemigrations
worked with me once I saved the changes that I made on the files.
One of the cause may be You didn't register your models in admin.py file .
First register your models in admin.py file then do the migrations.

Admin previliges for python, django , sqlite

I am new to python and begginer.
Is it necessary to have admin permissions for installing and working with Python , Django , Sqlite.. I have got all the softwares installed bt dont think i have admin previliges . While i am using command
syncdb
I am getting the result as 0 fixtures. But i am not able to create db with the above piece of code.
Being admin or not has no effect at syncdb stage.
Is your DB already there? if yes, then changes in django models doesn't support migrations out of the box. So for example, if you have created DB and then changed your models.pyrunning syncdb now will not change your model.
There is a pluggable app for Django that does exactly that though, and it works great. It's called South.

django syncdb and an updated model

I have recently updated my model, added a BooleanField to it however when I do python manage.py syncdb, it doesn't add the new field to the database for the model. How can I fix this ?
From Django 1.7 onwards
Django has built in support for migrations - take a look at the documentation.
For Django 1.6 and earlier
Django doesn't support migrations out of the box. There is a pluggable app for Django that does exactly that though, and it works great. It's called South.
Django currently does not do this automatically. Your options are:
Drop the table from the database, then recreate it in new form using syncdb.
Print out SQL for the database using python manage.py sql (appname), find the added line for the field and add it manually using alter table SQL command. (This will also allow you to choose values of the field for your current records.)
Use South (per Dominic's answer).
Follow these steps:
Export your data to a fixture using the dumpdata management command
Drop the table
Run syncdb
Reload your data from the fixture using the loaddata management command
As suggested in top answer, I tried using South, and after an hour of frustration with obscure migration errors decided to go with Django Evolution instead.
I think it's easier to get started with than South, and it worked perfectly the first time I typed ./manage.py evolve --hint --execute, so I'm happy with it.
Havent used django in a while, but i seem to remember that syncdb does perform alter commands on db tables. you have to drop the table then run again and it will create again.
edit: sorry does NOT perform alter.
In django 1.6
At first we have run - python manage.py sql <app name>
Then we have to run - python manage.py syncdb
If you run Django with Apache and MySQL, restart apache after making migration with makemigrations.

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