책 항상 잘보고 있습니다. 감사합니다!

밑에 같이 오류가 나는대 계속 코드 봐도 도져히 모르겠습니다..!

---오류내용---
IntegrityError at /pybo/question/create/
NOT NULL constraint failed: pybo_question.create_data
Request Method: POST
Request URL: http://localhost:8000/pybo/question/create/
Django Version: 4.0.3
Exception Type: IntegrityError
Exception Value:
NOT NULL constraint failed: pybo_question.create_data
Exception Location: C:\venvs\mysite\Lib\site-packages\django\db\backends\sqlite3\base.py, line 477, in execute
Python Executable: C:\venvs\mysite\Scripts\python.exe
Python Version: 3.11.0
Python Path:
['c:\projects\mysite',
'C:\Users\gawky\AppData\Local\Programs\Python\Python311\python311.zip',
'C:\Users\gawky\AppData\Local\Programs\Python\Python311\DLLs',
'C:\Users\gawky\AppData\Local\Programs\Python\Python311\Lib',
'C:\Users\gawky\AppData\Local\Programs\Python\Python311',
'C:\venvs\mysite',
'C:\venvs\mysite\Lib\site-packages']
Server time: Wed, 23 Nov 2022 00:47:16 +0900

---views.py 코드작성내용------

from django.shortcuts import render, get_object_or_404, redirect
from django.utils import timezone
from .models import Question
from .form import QuestionForm


def index(request):
    question_list = Question.objects.order_by('-create_data')
    context = {'question_list':question_list}
    return render(request,'pybo/question_list.html',context)

def detail(request, question_id):
    question = get_object_or_404(Question, pk=question_id)
    context = {'question': question}
    return render(request, 'pybo/question_detail.html', context)

def answer_create(request, question_id):
    question = get_object_or_404(Question, pk=question_id)
    question.answer_set.create(content=request.POST.get('content'),create_data=timezone.now())
    return redirect('pybo:detail',question_id=question.id)

def question_create(request):
    if request.method == 'POST':
        form = QuestionForm(request.POST)
        if form.is_valid():
            question = form.save(commit=False)
            question.create_date = timezone.now()
            question.save()
            return redirect('pybo:index')
    else:
        form = QuestionForm()
    context = {'form': form}
    return render(request, 'pybo/question_form.html', context)