我该如何解决这个错误：django.db.utils.IntegrityError: NOT NULL constraint failed答案

【问题标题】：How do i solve this error : django.db.utils.IntegrityError: NOT NULL constraint failed我该如何解决这个错误：django.db.utils.IntegrityError: NOT NULL constraint failed
【发布时间】：2020-10-27 04:38:40
【问题描述】：

我正在为我的愿望清单按钮/视图编写单元测试，并且我正在尝试检查我的图书 ISBN 和用户 ID 是否在我按下按钮后添加到愿望清单中。我试过了，但它一直给我标题中所述的错误。

这是我的代码：

#tests.py
class wishlist_view_test(TestCase):
    @classmethod
    def setUpTestData(cls):
        books.objects.create(ISBN = "976354890", bookName = "testingbook1", bookVersion = "1",bookAuthor = "Carlie Presley", bookPublisher = "TeamBananaMonkey1")
        retailer.objects.create(retailer= "Amazon", sellerID = 1)
        retailer_book.objects.create(condition = "new", reviews = "4.5", ID= 1, bookType = "hardcover", ISBN_id= "976354890", sellerID_id = 1, price = 177.98)

    def test_wishlist_button(self):
        user = User.objects.create_user(username='user1', password='djangolife')
        self.client.login(username='user1', password='djangolife')
        response1 = self.client.post(reverse('TextSearch:wishlist',args=("976354890",)))
        self.assertEqual(str(wishlist.objects.filter(userid_id= user.id),'<QuerySet [..........]>')

#html code
<form action="{% url 'TextSearch:wishlist' book.pk %}" method="post">
    {% csrf_token %}
    <input type="hidden" value="{{book.pk}}" name="isbn">
    <input type="submit" value="Add to wishlist★">

#views.py
class wishlistView(TemplateView):
    template_name = 'TextSearch/wishlist.html'
    model = wishlist
    def post(self, request, pk):
        isbn = self.request.POST.get('isbn')
        current_user = request.user
        book = wishlist(userid_id = current_user.id, ISBN_id = isbn)
        book.save()
        return render(request, 'TextSearch/wishlist.html')

#models.py
class wishlist (models.Model):
    userid = models.ForeignKey(User, on_delete= models.CASCADE)
    ISBN = models.ForeignKey(books, on_delete = models.CASCADE)

class books (models.Model):
    ISBN = models.CharField(max_length=255, primary_key=True)
    bookName = models.CharField(max_length=255)
    bookVersion = models.CharField(max_length=255)
    bookAuthor = models.CharField(max_length=255)
    bookPublisher = models.CharField(max_length=255, default ='NULL')

我正在使用 Django 的内置用户模型。

***回溯错误***

Traceback (most recent call last):
  File "C:\Users\ytann\Desktop\textbooks-for-less-9-website-design\textbooks-for-less-9-website-design\TextSearch\tests.py", line 67, in test_wishlist_button
    response1 = self.client.post(reverse('TextSearch:wishlist',args=("976354890",)))
  File "C:\Users\ytann\Desktop\python\lib\site-packages\django\test\client.py", line 741, in post
    response = super().post(path, data=data, content_type=content_type, secure=secure, **extra)
  File "C:\Users\ytann\Desktop\python\lib\site-packages\django\test\client.py", line 404, in post
    return self.generic('POST', path, post_data, content_type,
  File "C:\Users\ytann\Desktop\python\lib\site-packages\django\test\client.py", line 470, in generic
    return self.request(**r)
  File "C:\Users\ytann\Desktop\python\lib\site-packages\django\test\client.py", line 709, in request
    self.check_exception(response)
  File "C:\Users\ytann\Desktop\python\lib\site-packages\django\test\client.py", line 571, in check_exception
    raise exc_value
  File "C:\Users\ytann\Desktop\python\lib\site-packages\django\core\handlers\exception.py", line 47, in inner
    response = get_response(request)
  File "C:\Users\ytann\Desktop\python\lib\site-packages\django\core\handlers\base.py", line 179, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "C:\Users\ytann\Desktop\python\lib\site-packages\django\views\generic\base.py", line 70, in view
    return self.dispatch(request, *args, **kwargs)
  File "C:\Users\ytann\Desktop\python\lib\site-packages\django\views\generic\base.py", line 98, in dispatch
    return handler(request, *args, **kwargs)
  File "C:\Users\ytann\Desktop\textbooks-for-less-9-website-design\textbooks-for-less-9-website-design\TextSearch\views.py", line 25, in post
    book.save()
  File "C:\Users\ytann\Desktop\python\lib\site-packages\django\db\models\base.py", line 753, in save
    self.save_base(using=using, force_insert=force_insert,
  File "C:\Users\ytann\Desktop\python\lib\site-packages\django\db\models\base.py", line 790, in save_base
    updated = self._save_table(
  File "C:\Users\ytann\Desktop\python\lib\site-packages\django\db\models\base.py", line 895, in _save_table
    results = self._do_insert(cls._base_manager, using, fields, returning_fields, raw)
  File "C:\Users\ytann\Desktop\python\lib\site-packages\django\db\models\base.py", line 933, in _do_insert
    return manager._insert(
  File "C:\Users\ytann\Desktop\python\lib\site-packages\django\db\models\manager.py", line 85, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
  File "C:\Users\ytann\Desktop\python\lib\site-packages\django\db\models\query.py", line 1249, in _insert
    return query.get_compiler(using=using).execute_sql(returning_fields)
  File "C:\Users\ytann\Desktop\python\lib\site-packages\django\db\models\sql\compiler.py", line 1397, in execute_sql
    cursor.execute(sql, params)
  File "C:\Users\ytann\Desktop\python\lib\site-packages\django\db\backends\utils.py", line 66, in execute
    return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
  File "C:\Users\ytann\Desktop\python\lib\site-packages\django\db\backends\utils.py", line 75, in _execute_with_wrappers
    return executor(sql, params, many, context)
  File "C:\Users\ytann\Desktop\python\lib\site-packages\django\db\backends\utils.py", line 84, in _execute
    return self.cursor.execute(sql, params)
  File "C:\Users\ytann\Desktop\python\lib\site-packages\django\db\utils.py", line 90, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "C:\Users\ytann\Desktop\python\lib\site-packages\django\db\backends\utils.py", line 84, in _execute
    return self.cursor.execute(sql, params)
  File "C:\Users\ytann\Desktop\python\lib\site-packages\django\db\backends\sqlite3\base.py", line 413, in execute
    return Database.Cursor.execute(self, query, params)
django.db.utils.IntegrityError: NOT NULL constraint failed: User_wishlist.ISBN_id

** 编辑 ** 我觉得做 self.client.post 有问题，但我似乎无法弄清楚问题出在哪里

【问题讨论】：

请将您的models.py 和您的回溯错误的详细版本附加到您的问题中。
我添加了我的 models.py，但是我会添加我的回溯错误的详细版本。
在 ISBN 中添加 null=True
@RaghavSharma 但是视图功能通常可以正常工作，我假设我的测试类中的某个地方有一个我根本找不到的错误？
你能在 book.save() 之前打印这本书吗？我怀疑你的帖子返回空值

标签： python django django-testing django-tests

【解决方案1】：

在 test.py 中使用这个：

response1 = self.client.post(reverse('TextSearch:wishlist',kwargs={'isbn': '976354890'}))

代替：

response1 = self.client.post(reverse('TextSearch:wishlist',args=("976354890",)))

【讨论】：

嗨，当我这样做时它仍然不起作用，它无法识别 isbn。但是当我使用 {'pk' : '976354890'} 时，它会运行，但会出现与以前相同的错误。
您可能在 url.py 中使用了 pk，因此您应该从 view.py 中的 request.POST 获取 pk。这意味着这样做：isbn = self.request.POST.get('pk')
如果正确，请在模板中使用：<input type="hidden" value="{{book.pk}}" name="pk">
是的，我把它改成了你所说的，仍然不起作用:(
使用这个response1 = self.client.post(reverse('TextSearch:wishlist'), {'isbn': '976354890'})