Django管理錯誤而刪除

Question

我有一個奇怪的錯誤：

TypeError at /admin/wall/articles/ 
__str__ returned non-string (type Articles) 

我有一個模型文章。 我只是試圖從Django的管理面板中刪除我的數據庫的一些文章。我說它很好奇，因爲它只發生在一些物體上。我可以刪除大部分文章，但由於某些原因，如果我刪除它們，數據庫中的某些條目會返回錯誤。這不適用於我的其他模型。

這是phpMyAdmin的顯示在我的桌子「公司章程」的所有條目的截圖：

例如，我有ID 70條目在Django管理潘內爾我無法刪除它，我有一個錯誤。爲了測試重新創建確切的條目（請參閱ID 75），我可以從django admin pannel中刪除此條目。

爲什麼我可以刪除一些內容但不是全部？

這是我的models.py：

from django.db import models 
from start.models import Games 
from django.contrib.auth.models import User 
from tinymce.models import HTMLField 

# Create your models here. 

def user_directory_path_articles(instance, filename): 
    return 'media/user/user_{0}/articles/{1}/'.format(instance.user.id, filename) 

def user_directory_path_comments(instance, filename): 
    return 'media/user/user_{0}/comments/{1}/'.format(instance.user.id, filename) 

def validate_file_extension(value): 
    import os 
    from django.core.exceptions import ValidationError 
    ext = os.path.splitext(value.name)[1] # [0] returns path+filename 
    valid_extensions = ['.jpg', '.png'] 
    if not ext.lower() in valid_extensions: 
     raise ValidationError(u'Merci d\'utiliser le format JPG ou PNG') 

class Articles(models.Model): 
    title = models.CharField(max_length=50, null=False, verbose_name="Titre") 
    text = HTMLField() 
    image = models.FileField(upload_to='media/articles/', validators=[validate_file_extension], blank=True, null=True, verbose_name="Image de présentation") 
    games = models.ForeignKey(Games, verbose_name="Jeux", blank=True, null=True) 
    author = models.ForeignKey(User, verbose_name="Auteur") 
    is_statut = models.BooleanField(default=True, verbose_name="Statut") 
    date = models.DateTimeField(auto_now_add=True, auto_now=False, verbose_name="Date de création") 
    update = models.DateTimeField(auto_now=True, verbose_name="Dernière modification") 

    def __str__(self): 
     return self.title 

class Comments(models.Model): 
    text = models.CharField(max_length=300, null=False) 
    image = models.FileField(upload_to=user_directory_path_comments, validators=[validate_file_extension], blank=True, null=True) 
    articles = models.ForeignKey(Articles, verbose_name="Article", null=False, related_name='comments') 
    author = models.ForeignKey(User, verbose_name="Auteur") 
    in_answer_to = models.ForeignKey('self', verbose_name="En réponse au commentaire", blank=True, null=True, on_delete=models.CASCADE) 
    date = models.DateTimeField(auto_now_add=True, auto_now=False, verbose_name="Date de création") 
    update = models.DateTimeField(auto_now=True, verbose_name="Dernière modification") 

    def __str__(self): 
     return self.text 

class Like(models.Model): 
    articles = models.ForeignKey(Articles, verbose_name="Article", null=True, blank=True) 
    user = models.ForeignKey(User, verbose_name="Auteur", null=False) 

    def __str__(self): 
     return self.articles 

class Up(models.Model): 
    comments = models.ForeignKey(Comments, verbose_name="Commentaire", null=True, blank=True) 
    user = models.ForeignKey(User, verbose_name="Auteur", null=False) 

這是我的admin.py：

from django.contrib import admin 
from .models import Articles, Comments 

# Register your models here. 

class ArticlesAdmin(admin.ModelAdmin): 
    list_display = ('date', 'title', 'author', 'games', 'is_statut', 'update') 


    fieldsets = (
     ('Général', { 
      'fields': ('title', 'author', 'is_statut') 
      }), 
     ('Choisir une image de présentation', { 
      'fields': ('image',)}),  
     ('Contenu de l\'article', { 
      'fields': ('text',)}), 
     ('En rapport avec le jeu :', { 
      'fields': ('games',)}), 
    ) 
admin.site.register(Articles, ArticlesAdmin) 

這是我的錯誤頁面的追蹤，並感謝您的幫助：

Environment: 


Request Method: POST 
Request URL: http://*******:8000/admin/wall/articles/ 

Django Version: 1.11.2 
Python Version: 3.5.3 
Installed Applications: 
['django.contrib.admin', 
'django.contrib.auth', 
'django.contrib.contenttypes', 
'django.contrib.sessions', 
'django.contrib.messages', 
'django.contrib.staticfiles', 
'widget_tweaks', 
'tinymce', 
'start', 
'myaccount', 
'wall'] 
Installed Middleware: 
['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'] 



Traceback: 

File "/usr/local/lib/python3.5/dist-packages/django/core/handlers/exception.py" in inner 
    41.    response = get_response(request) 

File "/usr/local/lib/python3.5/dist-packages/django/core/handlers/base.py" in _get_response 
    187.     response = self.process_exception_by_middleware(e, request) 

File "/usr/local/lib/python3.5/dist-packages/django/core/handlers/base.py" in _get_response 
    185.     response = wrapped_callback(request, *callback_args, **callback_kwargs) 

File "/usr/local/lib/python3.5/dist-packages/django/contrib/admin/options.py" in wrapper 
    551.     return self.admin_site.admin_view(view)(*args, **kwargs) 

File "/usr/local/lib/python3.5/dist-packages/django/utils/decorators.py" in _wrapped_view 
    149.      response = view_func(request, *args, **kwargs) 

File "/usr/local/lib/python3.5/dist-packages/django/views/decorators/cache.py" in _wrapped_view_func 
    57.   response = view_func(request, *args, **kwargs) 

File "/usr/local/lib/python3.5/dist-packages/django/contrib/admin/sites.py" in inner 
    224.    return view(request, *args, **kwargs) 

File "/usr/local/lib/python3.5/dist-packages/django/utils/decorators.py" in _wrapper 
    67.    return bound_func(*args, **kwargs) 

File "/usr/local/lib/python3.5/dist-packages/django/utils/decorators.py" in _wrapped_view 
    149.      response = view_func(request, *args, **kwargs) 

File "/usr/local/lib/python3.5/dist-packages/django/utils/decorators.py" in bound_func 
    63.     return func.__get__(self, type(self))(*args2, **kwargs2) 

File "/usr/local/lib/python3.5/dist-packages/django/contrib/admin/options.py" in changelist_view 
    1568.     response = self.response_action(request, queryset=cl.get_queryset(request)) 

File "/usr/local/lib/python3.5/dist-packages/django/contrib/admin/options.py" in response_action 
    1286.    response = func(self, request, queryset) 

File "/usr/local/lib/python3.5/dist-packages/django/contrib/admin/actions.py" in delete_selected 
    37.   queryset, opts, request.user, modeladmin.admin_site, using) 

File "/usr/local/lib/python3.5/dist-packages/django/contrib/admin/utils.py" in get_deleted_objects 
    172.  to_delete = collector.nested(format_callback) 

File "/usr/local/lib/python3.5/dist-packages/django/contrib/admin/utils.py" in nested 
    232.    roots.extend(self._nested(root, seen, format_callback)) 

File "/usr/local/lib/python3.5/dist-packages/django/contrib/admin/utils.py" in _nested 
    216.    children.extend(self._nested(child, seen, format_callback)) 

File "/usr/local/lib/python3.5/dist-packages/django/contrib/admin/utils.py" in _nested 
    218.    ret = [format_callback(obj)] 

File "/usr/local/lib/python3.5/dist-packages/django/contrib/admin/utils.py" in format_callback 
    145.         force_text(obj)) 

File "/usr/local/lib/python3.5/dist-packages/django/utils/encoding.py" in force_text 
    76.      s = six.text_type(s) 

Exception Type: TypeError at /admin/wall/articles/ 
Exception Value: __str__ returned non-string (type Articles) 

Answer 1

問題出在您的Like模型中。如錯誤所述，該文章的__str__方法不返回字符串，而是返回Articles的實例。你應該確定實際返回一個字符串，例如self.articles.title。

這是刪除問題的原因是因爲刪除文章也會刪除所有指向它的對象，並且Django會在確認頁面中幫助顯示所有受影響的對象。

請注意，您的命名約定很混亂。你應該堅持爲你的模型單名：文章，評論。