django error: NOT NULL constraint failed - django

Question

I am getting this error while I was trying to make two forms (with two models) and process that in the view. My SongForm is not saving its data in database while AlbumForm is perfectly saving its data.
views.py-
def formm(request):
if request.method=='POST':
songform = SongForm(request.POST)
albumform=AlbumForm(request.POST)
if songform.is_valid() and albumform.is_valid():
songform.save()
albumform=albumform.save(commit=False)
albumform.date=timezone.now()
albumform.save()
return redirect("result")
forms.py-
from django import forms
from . models import Album,Song
class SongForm(forms.ModelForm):
class Meta:
model=Song
fields=('song_title','genre')
class AlbumForm(forms.ModelForm):
class Meta:
model=Album
fields=('album_title',)
models.py-
from __future__ import unicode_literals
from django.db import models
class Album(models.Model):
album_title=models.CharField(max_length=50)
date=models.DateTimeField(blank=True,null=True)
def __str__(self):
return self.album_title
class Song(models.Model):
song_title=models.CharField(max_length=50)
genre=models.CharField(max_length=50)
album=models.ForeignKey(Album,on_delete=models.CASCADE)
def __str__(self):
return self.song_title
formmpage.html-
{% extends "musicapp/basepage.html" %}
{% block content %}
<form method="POST" class="post-form">
{% csrf_token %}
{{ songform.as_p }}
{{ albumform.as_p }}
<button type="submit" class="btn btn-info">POST</button>
</form>
{% endblock %}
Do correct me, where actually I am doing wrong. I guess it is in my views.py.

Answer 1

It looks as if you should be setting the song's album before you save it.
if songform.is_valid() and albumform.is_valid():
album = albumform.save(commit=False)
album.date = timezone.now()
album.save()
song = songform.save(commit=False)
song.album = album
song.save()
return redirect("result")
Note that I changed the code to album=albumform.save(commit=False), since the save() method returns a model instance, not a form instance.

Answer 2

Ok,I was certain this was the issue but i've used the code you've given me and I get an integrity error due to the fact that your Song model has a Foreign Key to the Album model without null=True it won't allow you to create a new Song without an Album model.
There has to be some kind of business logic to know whether a song belongs to an album. In my opinon you should have these 2 in separate endpoints.
When creating a Song you should be able to select from a list albums that it may or may not belong to based on a genre.
Anyways, you can get past this with just adding null=True on the the album Foreign key attribute in your Song model.