Django Saving form with two foreign keys - django

Question

I am attempting to save a form that submits data (project note comments) linked to another model (project notes) via foreign key (project notes). Project notes are linked via foreign key to another model (projects). I thought I would only need to consider the immediate relationship (project notes). However from the error I am getting, I also need to process the relationship from project notes to project.
The error:
IntegrityError at /projects/note/1/add_project_note_comment/
insert or update on table "company_project_projectnotes" violates foreign key constraint "company_project_proj_project_id_478f433c_fk_company_p"
DETAIL: Key (project_id)=(0) is not present in table "company_project_project".
The models:
class Project(models.Model):
title = models.CharField(max_length= 200)
description = tinymce_models.HTMLField()
def __str__(self):
return self.title
def get_absolute_url(self):
return reverse ('project_detail', args=[str(self.id)])
class ProjectNotes(models.Model):
title = models.CharField(max_length=200)
body = tinymce_models.HTMLField()
date = models.DateField(auto_now_add=True)
project = models.ForeignKey(Project, default=0, blank=True, on_delete=models.CASCADE, related_name='notes')
def __str__(self):
return self.title
class ProjectNoteComments(models.Model):
body = tinymce_models.HTMLField()
date = models.DateField(auto_now_add=True)
projectnote = models.ForeignKey(ProjectNotes, default=0, blank=True, on_delete=models.CASCADE, related_name='notes')
The view:
class ProjectNotesCommentCreateView(CreateView):
model = ProjectNotes
template_name = 'company_accounts/add_project_note_comment.html'
fields = ['body']
def form_valid(self, form):
projectnote = get_object_or_404(ProjectNotes, id=self.kwargs.get('pk'))
comment = form.save(commit=False)
comment.projectnote = projectnote
comment.save()
return super().form_valid(form)
def get_success_url(self):
return reverse('project_detail', args=[self.kwargs.get('pk')])
The URL pattern:
path('note/<int:pk>/add_project_note_comment/', ProjectNotesCommentCreateView.as_view(), name='add_project_note_comment'),
The template:
{% extends 'base.html' %}
{% load crispy_forms_tags %}
{% block content %}
<h1>Add Comment</h1>
<form action="" method="post">
{% csrf_token %}
{{ form.media }}
{{ form|crispy }}
<input type="submit" value="save">
</form>
{% endblock content %}
Any ideas on how to get this to work?

Answer 1

You won't have a relationship with pk field of the ProjectNoteComments with the ProjectNote model and the related names are same for both models, you might want to fix that.
Moreover, you are delaying commiting the form only for ProjectNote, but you also have to handle it for Project model too through backward referencing projectnote__project (related names may cause problem at this place.