Question

每次我尝试删除帖子时，我都会不断收到此错误，但是删除按钮以前曾起作用。我认为它与on_delete属性有关，但是我几次更改了它的值，但仍然无法正常工作。

// models.py

from django.db import models
from django.conf import settings
from django.urls import reverse


User = settings.AUTH_USER_MODEL

class PostManager(models.Manager):
    def search(self, query):
        qs = self.get_queryset().filter(title__icontains=query)
        if qs:
            return qs
        return None

    def get_by_id(self, id):
        qs = self.get_queryset().filter(id=id)
        if qs.count() == 1:
            return qs.first()
        else:
            return None     


# Create your models here.
class PostModel(models.Model):
    user = models.ForeignKey(User, default=1, on_delete=models.CASCADE)
    title = models.CharField(max_length=50)
    message = models.TextField()
    date = models.DateTimeField(auto_now_add=True)
    likes = models.ManyToManyField(User, blank=True, related_name='post_likes')


    def __str__(self):
        return self.title

    objects = PostManager()

    def get_total_likes(self):
        return self.likes.count()   

    def get_absolute_url(self):
        return reverse("birdpost:detail", kwargs={"id": self.id})

    def get_like_url(self):
        return reverse("birdpost:like-toggle", kwargs={"id": self.id})

    def get_delete_url(self):
        return reverse("birdpost:delete_post", kwargs={"id": self.id})

// views.py

def del_post(request, id):
    obj = get_object_or_404(PostModel, id=id)
    if request.user != obj.user:
        print("Ooh no looks like this post is not yours... ")
    else:
        obj.delete()

    return redirect("home")

环境：

请求方法：GET 请求网址：http://localhost:8000/post/4/delete

Django版本：2.2.1 的Python版本：3.6.8 已安装的应用程序：

['django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'accounts',
 'birdpost',
 'search']

已安装的中间件：

['django.middleware.security.SecurityMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware']

跟踪：

File "/home/grey/Desktop/python/birds/virtualenv/lib/python3.6/site-packages/django/db/backends/base/base.py" in _commit
  240.                 return self.connection.commit()

The above exception (FOREIGN KEY constraint failed) was the direct cause of the following exception:

File "/home/grey/Desktop/python/birds/virtualenv/lib/python3.6/site-packages/django/core/handlers/exception.py" in inner
  34.             response = get_response(request)

File "/home/grey/Desktop/python/birds/virtualenv/lib/python3.6/site-packages/django/core/handlers/base.py" in _get_response
  115.                 response = self.process_exception_by_middleware(e, request)

File "/home/grey/Desktop/python/birds/virtualenv/lib/python3.6/site-packages/django/core/handlers/base.py" in _get_response
  113.                 response = wrapped_callback(request, *callback_args, **callback_kwargs)

File "/home/grey/Desktop/python/birds/src/birdpost/views.py" in del_post
  104.      obj.delete()

File "/home/grey/Desktop/python/birds/virtualenv/lib/python3.6/site-packages/django/db/models/base.py" in delete
  919.         return collector.delete()

File "/home/grey/Desktop/python/birds/virtualenv/lib/python3.6/site-packages/django/db/models/deletion.py" in delete
  318.                             sender=model, instance=obj, using=self.using

File "/home/grey/Desktop/python/birds/virtualenv/lib/python3.6/site-packages/django/db/transaction.py" in __exit__
  240.                         connection.commit()

File "/home/grey/Desktop/python/birds/virtualenv/lib/python3.6/site-packages/django/db/backends/base/base.py" in commit
  262.         self._commit()

File "/home/grey/Desktop/python/birds/virtualenv/lib/python3.6/site-packages/django/db/backends/base/base.py" in _commit
  240.                 return self.connection.commit()

File "/home/grey/Desktop/python/birds/virtualenv/lib/python3.6/site-packages/django/db/utils.py" in __exit__
  89.                 raise dj_exc_value.with_traceback(traceback) from exc_value

File "/home/grey/Desktop/python/birds/virtualenv/lib/python3.6/site-packages/django/db/backends/base/base.py" in _commit
  240.                 return self.connection.commit()

Exception Type: IntegrityError at /post/4/delete
Exception Value: FOREIGN KEY constraint failed

Answer 1

尝试删除默认值= 1。我不知道是否要在没有选择字段的情况下设置默认值。

Answer 2

我像@ Na'aman Hirschfeld所说的那样删除了default = 1，并删除了我所有的迁移和数据库。现在一切正常。

当我尝试删除帖子时，不断收到“ IntegrityError FOREIGN KEY约束失败”

2 个答案: