django.db.utils.IntegrityError: NOT NULL constraint failed: main

I am creating a telegram bot which is a database. If '@usename == None' it returns django.db.utils.IntegrityError: NOT NULL constraint failed: main_profile.name What should I do ?

Models.py

from django.db import models


class Profile(models.Model):
    external_id = models.PositiveIntegerField(
        verbose_name='User ID',
        unique=True,
    )
    name = models.TextField(
        verbose_name='User name',
        default='None'
    )

    def __str__(self):
        return f' ID: {self.external_id} | Username: {self.name}'

    class Meta:
        verbose_name = 'Profile'


class Message(models.Model):
    profile = models.ForeignKey(
        to='main.Profile',
        verbose_name='Profile',
        on_delete=models.PROTECT,
        null=True,
    )
    text = models.TextField(
        verbose_name='Text',
    )

Forms.py

from django import forms
from .models import Profile


class ProfileForm(forms.ModelForm):

    class Meta:
        model = Profile
        fields = (
            'external_id',
            'name',
        )
        widgets = {
            'name': forms.TextInput
        }

CodePudding user response：

You need to delete the last few migrations, you can do all except the 0001_initial.py. Then just go and do python manage.py makemigrations your_app_name and then python manage.py migrate and it should be solved

CodePudding user response：

You should take a look at the answer above, this problem is almost always related to migration stuff, but in case it don't, I guess that in the name field of your Profile model, if you don't specify the constraint null=True, by default it would be False so it is saying that you are obliged to give a value (!= to an empty string), so:

if you are doing something like this:

def home_view(request):
    context ={}
  
    form = ProfileForm(request.POST)

    if form.is_valid():

        form.save()

    context['form']= form

    return render(request, "home.html", context)

When the the form class receives the request if the name input has no data in it, it would look like {"name" : ""}, and becouse the request object have the name key first it not going to use the default='None' and then is going to pass it to the create method in the form, and based on the constraint defined for that particular field, the db transaction would rise the django.db.utils.IntegrityError becouse at DB level, that field is not allowed to be NULL

Django docs:

"Field.null : If True, Django will store empty values as NULL in the database. Default is False."