I created a data model in Django which has many to one relation (N topics to 1 user) like this:
from django.db import models
from django.contrib.auth.models import User
# Create your models here.
class Topic(models.Model):
content = models.CharField(max_length=2000)
pub_date = models.DateTimeField('date published')
author = models.ForeignKey(User)
When I try to load the data model in the admin page, I get this error:
Exception Value:
no such column: talk_comment.author_id
Did I miss something in the data model?
Thanks.
You forgot to actually modify/create the tables in database (manually, with South or manage.py syncdb).
You can't modify the table with syncdb . you need to use South Migrations
Its really very good and you can even revert back to previous migration in case of some problem
Related
I created a custom user model just like the docs said, when I ran the makemigrations I went to the folder of migrations and deleted the first name and last name columns inside the 0001_initial.py and then I ran the migrate command, but when I ran the createsuperuser command it throwed an error in the terminal that django.db.utils.OperationalError: no such column: myapp_usermodel.first_name
How can I fix this?
I want to delete the first name and last name columns because I'm not using them
EDIT: this is the user model
from django.db import models
from django.utils.translation import gettext_lazy as _
from django.contrib.auth.models import AbstractUser
# Create your models here.
class usermodel(AbstractUser):
email = models.EmailField(max_length=60)
username = models.CharField(max_length=20, unique=True)
password = models.CharField(max_length=20)
def __str__(self):
return self.username
I went to the folder of migrations and deleted the first name and last name columns inside the 0001_initial.py
You shouldn't do that. This will indeed prevent Django from creating the columns. But now it will each time query under the impression that the columns are there. Furthermore if you make migrations again, it will try to add extra columns.
You should simply use the method resolution order (MRO) and set the field to None:
class usermodel(AbstractUser):
first_name = None
last_name = None
def __str__(self):
return self.username
You probably also better remove the table in the database and the migration file and make migrations again, and migrate the database.
(Django 1.10.) I'm trying to follow this advice on extending the user model using OneToOneField. In my app 'polls' (yes, I'm extending the app made in the 'official' tutorial) I want to store two additional pieces of information about each user, namely, a string of characters and a number.
In my models.py I now have the following:
from django.contrib.auth.models import User
class Employee(models.Model):
user = models.OneToOneField(User, on_delete=models.CASCADE)
stopien = models.CharField(max_length=100)
pensum = models.IntegerField()
and in admin.py the following:
from django.contrib.auth.admin import UserAdmin as BaseUserAdmin
from django.contrib.auth.models import User
from polls.models import Employee
class EmployeeInline(admin.StackedInline):
model = Employee
can_delete = False
verbose_name_plural = 'employee'
class UserAdmin(BaseUserAdmin):
inlines = (EmployeeInline, )
admin.site.unregister(User)
admin.site.register(User, UserAdmin)
When adding a user using the admin panel my two new fields display correctly. However, when I click 'save', or if I don't add any user and just click on the name of my sole admin user in the admin panel, I get the following error:
OperationalError at /admin/auth/user/1/change/
no such table: polls_employee
I see some questions and answers related to similar problems, but they seem to be relevant for older version of Django. Could anyone give me a tip as to what I should do? Ideally I'd want my two additional fields display in the admin panel, though I suspect this might be a task for the future.
I have to confess I do not understand this paragraph from the documentation just following the advice I'm using:
These profile models are not special in any way - they are just Django models that happen to have a one-to-one link with a User model. As such, they do not get auto created when a user is created, but a django.db.models.signals.post_save could be used to create or update related models as appropriate.
Do I need to tie this 'post-save' to some element of the admin panel?
I'd be very greatful for any help!
You need run makemigrations to create a migration for your new model, and then migrate to run the migration and create the database table.
./manage.py makemigrations
./manage.py migrate
After customizing my user model in Django Oscar, I received the following error message:
IntegrityError at /
insert or update on table "basket_basket" violates foreign key constraint "basket_basket_owner_id_74ddb970811da304_fk_auth_user_id"
DETAIL: Key (owner_id)=(5) is not present in table "auth_user".
To customize my user model, I followed the instructions here.
First, I wrote the following models.py file, located within my project directory at apps/user/models.py.
from django.db import models
from oscar.apps.customer.abstract_models import AbstractUser
from django.contrib.postgres.fields import ArrayField
class User(AbstractUser):
acct_bal = models.DecimalField(max_digits=10, decimal_places=2, default=0.00)
purchased_items = ArrayField(models.IntegerField(), default=list)
The idea is that I want the user to have an account balance (which I will use for payment later) as well as a list of product numbers representing items that have already been purchased.
After making models.py, I edited the installed apps as follows:
INSTALLED_APPS = [...
'shopworld.apps.user',
] + get_core_apps()
And then put this at the bottom of my settings.py:
AUTH_USER_MODEL = 'user.User'
I then did ./manage.py migrate, but for some reason I am getting this error message. I also tried dropping the django_admin_log table as suggested here, but it did not work. Any help would be greatly appreciated.
I fixed this - the issue was that I was trying to migrate to a custom user model after already having done migrations with auth_user. This meant that auth_user didn't update correctly. I had to flush and re-sync the database, so that the initial migration captured the custom user model.
I have a models folder that has a few models in files that are already in the DB. I have just added another file/model but it is not being added to the DB when I run syncdb. I've tried manage.py validate and it is running fine. I have also run the code and it only fails when it tries to save with "table does not exist".
the original structure was like this:
/models
-- __init__.py
-- file1.py
-- file2.py
and __init__.py looked like:
from file1 import File1Model
from file2 import File2Model
I added file3.py
/models
-- __init__.py
-- file1.py
-- file2.py
-- file3.py
and modified __init__.py
from file1 import File1Model
from file2 import File2Model
from file3 import File3Model
And the contents of file3 (names may have been changed to protect the innocent, but besides that its the exact file):
UPDATE: just tried adding a primary key since the id field may have been messing with the automatically added integer primary key id. Also tried a few variations but no dice.
from django.db import models
from django.contrib.auth.models import User
class File3Model(models.Model):
user = models.OneToOneField(User)
token = models.CharField(max_length=255, blank=False, null=False)
id = models.CharField(primary_key=True, max_length=255)
class Admin:
pass
class Meta:
app_label = 'coolabel'
def __unicode__(self):
return self.user.username
#staticmethod
def getinstance(user, token, id):
try:
instance = File3Model.objects.get(pk=id)
if instance.token != token:
instance.token = token
instance.save()
return instance
except:
pass
instance = File3Model()
instance.user = user
instance.token = token
instance.id = id
instance.save()
return instance
So in this example, File1Model and File2Model are already in the DB and remain in the DB after syncdb. However, File3Model is not added even after rerunning syncdb. Is there any way to figure out why the new model isn't being added??
If you define the model outside of models.py, you have to set the app_label attribute on the models Meta class.
Edit: The app_label has to refer to an app in your INSTALLED_APPS setting. It should probably match the name of the app that the models directory is in, unless you've got a really good reason to do otherwise. That seems to have been your problem here.
class File3Model(models.Model):
foo = models.CharField(...)
...
class Meta:
app_label = "my_app"
Note that syncdb will never remove any tables from the db. The other tables were probably created with syncdb before the models.py was replaced with the directory structure.
set app_label to my app solves my problem.
Why did you split you models and having models folder instead of placing models in models.py ?
In my own project there are about 10 models live in models.py and I'm fine with it.
You can also try manage.py syncdb --all.
And I think its better to keep all models in one single file and import them like from my_app.models import model_name instead of keeping in mind to import necessary model into models/__init__.py. By the way you avoid many problems and long lined imports and don't care about where some_model lives among models/*.py files.
Thanks,
Sultan
BOOM!
I was using a different app_label for the new model but it has to be the same across the model group.
The other models labels were "mediocrelabel" and my new model had the label "coolabel". I changed the new model's label to "mediocrelabel" and now they are being added to the DB correctly.
Thanks for your help, folks!
edit: I wasn't clear before, I am saving my object in the django admin panel, not in a view. Even when I save the object with no many-to-many relationships I still get the error.
I have a model called TogglDetails that has a ForeignKey relationship with the standard django User model and a MayToManyField relationship with a model named Tag. I have registered my models with django admin but when I try to save a TogglDetails instance I get the error in the title.
Here are my models:
class Tag(models.Model):
name = models.CharField(max_length=30)
def __unicode__(self):
return self.name
class TogglDetails(models.Model):
token = models.CharField(max_length=100)
user = models.ForeignKey(User)
tags = models.ManyToManyField(Tag, blank=True, null=True)
def __unicode__(self):
return self.user.username
class Meta:
verbose_name_plural = "toggl details"
As far as I can tell, there should be no issues with my models and django admin should just save the instance without any issues. Is there something obvious that I have missed?
I am using Django 1.3
The answer to my question was this: Postgres sequences without an 'owned by' attribute do not return an id in Django 1.3
The sequences in my postgres database did not have the "Owned by" attribute set and so did not return an id when a new entry was saved to the db.
As stated by other users:
Postgres sequences without an 'owned by' attribute do not return an id in Django 1.3
The sequences in my postgres database did not have the "Owned by" attribute set and so did not return an id when a new entry was saved to the db
In addition:
This is most likely caused by a backwards incompatible change that renders some primary key types in custom models beyond reach for Django 1.3. See Django trac tickets https://code.djangoproject.com/ticket/13295 and http://code.djangoproject.com/ticket/15682 for more information.
I solved the problem by running the follow commands for the affected tables/sequences.
Specifically running the command:
manage.py dbshell
ALTER SEQUENCE tablename_colname_seq OWNED BY tablename.colname;
change tablename_colname_seq and tablename.colname
Don't let us guess and add the Error message to your question, this gives most information about where it fails.
Have you imported the User model?
from django.contrib.auth.models import User
I've had this problem as well and the only thing I could do was make the M2M fields blank and not set them until I hit Save and Continue Editing.
I think this just may be a framework wart, as you will notice the User section of the Admin site also has a very strict "You can only edit these fields until you save the model".
So my recommendation is to adopt that scheme, and hide the M2M form field until the model has a Primary Key.
I tried Django 1.3 using CPython, with different database setups. I copy-pasted the models from the question, and did some changes: first I added
from django.contrib.auth.models import User
at the top of the file and I put the reference to Tag between quotes. That shouldn't make any difference. Further, I created the following admin.py:
from django.contrib import admin
import models
admin.site.register(models.Tag)
admin.site.register(models.TogglDetails)
For Sqlite3, the problem described doesn't occur, neither for MySQL. So I tried PostgreSQL, with the postgresql_psycopg2 back end. Same thing: I can't reproduce the error.
So as far as I can figure, there's nothing wrong with the code in the question. The problem must be elsewhere.