Saving related model objects

Posted by iHeartDucks on Stack Overflow See other posts from Stack Overflow or by iHeartDucks
Published on 2010-05-09T18:12:47Z Indexed on 2010/05/09 18:18 UTC
Read the original article Hit count: 231

Filed under:

django

|

django-models

I have two related models (one to many) in my django app and When I do something like this

ObjBlog = Blog()
objBlog.name = 'test blog'

objEntry1 = Entry()
objEntry1.title = 'Entry one'

objEntry2 = Entry()
objEntry2.title = 'Entry Two'

objBlog.entry_set.add(objEntry1)
objBlog.entry_set.add(objEntry2)

I get an error which says "null value in column and it violates the foreign key not null constraint".

None of my model objects have been saved. Do I have to save the "objBlog" before I could set the entries? I was hoping I could call the save method on objBlog to save it all.

NOTE: I am not creating a blog engine and this is just an example.

© Stack Overflow or respective owner

Related posts about django

Overriding the save() method of a model that uses django-mptt

as seen on Stack Overflow - Search for 'Stack Overflow'
I've been using django-mptt in my project for a while now, it's fabulous. Recently, I've found a need to override a model's save() method that uses mptt, and I'm getting an error when I try to save a new instance of that model: Exception Type: ValueError at /admin/scrivener/page/add/ Exception Value:… >>> More
Where is meta.local_fields set in django.db.models.base.py ?

as seen on Stack Overflow - Search for 'Stack Overflow'
I'm getting the error: Exception Value: (1110, "Column 'about' specified twice") As I was reviewing the Django error page, I noticed that the customizations the model User, seem to be appended to the List twice. This seems to be happening here in django/db/model/base.py in base_save(): values… >>> More
Deploying Django on EC2 using Bitnami Djangostack: WSGI script cannot be loadded

as seen on Stack Overflow - Search for 'Stack Overflow'
I've been struggling to deploy Django application on Amazon EC2 using Bitnami Djangostack for the last couple of days. When I go to http://dewey.io I see the default bitnami page (/opt/bitnami/apache2/htdocs/index.html), however, when I open http://dewey.io/portnoy, I get 'Internal Server Error'… >>> More
Internal Server Error with mod_wsgi [django] on windows xp

as seen on Stack Overflow - Search for 'Stack Overflow'
when i run development server it works very well, even an empty project runing in mod_wsgi i have no problem but when i want to put my own project i get an Internal Server Error (500) in my apache conf i put WSGIScriptAlias /codevents C:/django/apache/CODEvents.wsgi <Directory "C:/django/apache"> Order… >>> More
Internal Server Error with mod_wgsi [django] on windows xp

as seen on Stack Overflow - Search for 'Stack Overflow'
when i run development server it works very well, even an empty project runing in mod_wsgi i have no problem but when i want to put my own project i get an Internal Server Error (500) in my apache conf i put WSGIScriptAlias /codevents C:/django/apache/CODEvents.wsgi <Directory "C:/django/apache"> Order… >>> More

Related posts about django-models

how to import csv data into django models

as seen on Stack Overflow - Search for 'Stack Overflow'
i have some csv data and i want to export into django models the example of csv data 1;"02-01-101101";"Worm Gear HRF 50";"Ratio 1 : 10";"input shaft, output shaft, direction A, color dark green"; 2;"02-01-101102";"Worm Gear HRF 50";"Ratio 1 : 20";"input shaft, output shaft, direction A, color dark… >>> More
Subclassed django models with integrated querysets

as seen on Stack Overflow - Search for 'Stack Overflow'
Like in this question, except I want to be able to have querysets that return a mixed body of objects: >>> Product.objects.all() [<SimpleProduct: ...>, <OtherProduct: ...>, <BlueProduct: ...>, ...] I figured out that I can't just set Product.Meta.abstract to true or otherwise… >>> More
List display names from django models

as seen on Stack Overflow - Search for 'Stack Overflow'
I have an object: POP_CULTURE_TYPES = ( ('SG','Song'), ('MV', 'Movie'), ('GM', 'Game'), ('TV', 'TV'), ) class Pop_Culture(models.Model): name = models.CharField(max_length=30, unique=True) type = models.CharField(max_length=2, choices = POP_CULTURE_TYPES, blank=True,… >>> More
Best way to re-use the same django models and admin for multiple apps

as seen on Stack Overflow - Search for 'Stack Overflow'
Given a reference app ( called guide), how can I create additional apps that will reuse the same model/admin/views than guide - the motivation behind is to be able to individually control each subapp. guide guideApp1 exact same models/admin/views than guide guideApp2 exact same models/admin/views… >>> More
Generate unique hashes for django models

as seen on Stack Overflow - Search for 'Stack Overflow'
I want to use unique hashes for each model rather than ids. I implemented the following function to use it across the board easily. import random,hashlib from base64 import urlsafe_b64encode def set_unique_random_value(model_object,field_name='hash_uuid',length=5,use_sha=True,urlencode=False): … >>> More