Django IntegrityError: (1048, "Column 'user_id' cannot be null") - mysql

Question

This is my models.py
class Cfituser(models.Model):
user = models.OneToOneField(User)
socialid = models.IntegerField(null=True)
accesstoken = models.CharField(max_length=255L, null = True)
class Meta:
db_table = 'CfitUser'
def __str__(self):
return "%s's profile" % self.user
#receiver(post_save, sender=User)
def create_cfituser(sender, instance, created, **kwargs):
if created:
Cfituser.objects.get_or_create(user=instance)
This is my views.py
#api_view(['GET', 'POST'])
def users_create(request, format = None):
"""
List all users, or create a new user.
"""
if request.method == 'GET':
cfituser = Cfituser.objects.all()
serializer = CfituserSerializer(cfituser, many=True)
return Response(serializer.data)
elif request.method == 'POST':
serializer = CfituserSerializer(data=request.DATA)
if serializer.is_valid():
print serializer.data
user = User.objects.create_user(username = serializer.data['socialid'])
cfituser = Cfituser.objects.get(user = user)
cfituser.accesstoken = serializer.data['accesstoken']
cfituser.socialid = serializer.data['socialid']
cfituser.save()
serializer.save()
return Response(serializer.data, status=status.HTTP_201_CREATED)
else:
return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
Whenever there is a HTTP Post request, my database tables are filled in as expected but this error keeps popping up. I've tried almost every solution available on SO but I'm stuck with this.
I have tried user = models.OneToOneField(User, null = True) but this leads to two entries in my database table, one with user_id = NULL and one with user_id = actualvalue.
Any suggestions on how to fix this?

Answer 1

Saving by default commits the entry to the database, to prevent that, pass commit=False to save(), and then do your customizations.
serializer = serializer.save(commit=False)
user, created = User.objects.get_or_create(username = serializer.socialid)
cfituser, created = Cfituser.objects.get_or_create(user = user)
# cfituser.user = user This line is unnecessary
cfituser.accesstoken = serializer.accesstoken
cfituser.socialid = serializer.socialid
cfituser.save()
serializer.save()
You are also duplicating your efforts because your signal will also attempt to create a user. If you are on django 1.5, use customized user model; and for social registration/oauth, use django-social-auth.

Answer 2

OneToOneField means, in Cfituser.user the reverse side of the relation will directly return a single object(user.cfituser gives Cfituser). SO Cfituser.user must be unique through out the table(one and only one).
class Cfituser(models.Model):
user = models.OneToOneField(User)
socialid = models.IntegerField(null=True)
accesstoken = models.CharField(max_length=255L, null = True)
def __unicode__(self):
return "%s's profile" % self.user.username
def users_create(request, format = None):
"""
List all users, or create a new user.
"""
if request.method == 'GET':
cfituser = Cfituser.objects.all()
serializer = CfituserSerializer(cfituser, many=True)
return Response(serializer.data)
elif request.method == 'POST':
serializer = CfituserSerializer(data=request.DATA)
if serializer.is_valid():
print serializer.data
user = User.objects.create_user(username = serializer.data['socialid'])
Cfituser(user = user,accesstoken = serializer.data['accesstoken'],socialid = serializer.data['socialid']).save()
serializer.save()
return Response(serializer.data, status=status.HTTP_201_CREATED)
else:
return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)