如何保存外键？

Question

我想上传多张图片。在

class IssuePanel(models.Model):
    issue = models.ForeignKey(ComicIssue, on_delete=models.CASCADE)
    panel = models.FileField(upload_to='comic_issues_files/panels/')
    date_uploaded = models.DateTimeField(auto_now_add=True)

在遵循了github上django multiupload存储库的示例之后，我将讨论这个问题表单.py在

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在视图.py在

class ComicIssueCreate(LoginRequiredMixin, CreateView):
    model = ComicIssue
    slug_field = 'comicseries_id'
    form_class = PanelsForm

    def form_valid(self, form):
        obj = form.save(commit=False)
        obj.title = ComicSeries.objects.get(id=self.kwargs['pk'])
        obj.user = self.request.user
        obj.save()
        return redirect('comics:series_detail', pk=obj.title.id, slug=obj.title.slug)

在网址.py在

url(r'^comic/issue/(?P<pk>[0-9]+)/add/$', views.ComicIssueCreate.as_view(), name='comic-issue-add'),

但是，我得到了这个错误 整合度错误at/comic/issue/21/add/ NOT NULL约束失败：漫画_ComicsSue.title_id在

class ComicIssue(models.Model):
user = models.ForeignKey(User, on_delete=models.CASCADE, 
        null=True, blank=True, verbose_name='Uploaded by: '
    )
title = models.ForeignKey(ComicSeries, on_delete=models.CASCADE, verbose_name='Series Title')
issue = models.CharField(verbose_name='Issue Number', max_length=500)
issue_title = models.CharField(verbose_name='Issue Title', max_length=1000)
issue_cover = models.ImageField(verbose_name='Issue cover', upload_to='comic_issues', height_field=None, width_field=None, max_length=None)
issue_description = models.TextField(verbose_name='Description')
issue_file = models.FileField(verbose_name='Issue file', upload_to='comic_issues_files', max_length=100,
    help_text='File in pdf or as single image', null=True, blank=True
)
date_added = models.DateTimeField(auto_now_add=True, null=True)
is_favorite = models.BooleanField(default=False)
issue_slug = models.SlugField(default='')

class Meta:

    verbose_name = 'Comic Issue'
    verbose_name_plural = 'Comic Issues'

def __str__(self):
    return '{}: {} issue number - {}'.format(self.title.title, self.issue_title, self.issue)

def save(self, *args, **kwargs):
    self.issue_slug = slugify(self.issue_title)
    super(ComicIssue, self).save(*args, **kwargs)

def get_absolute_url(self):
    return reverse('comics:issue_detail', kwargs={'issue_slug':self.issue_slug,'pk': self.pk})

ComicIssue模型中的此功能是否存在问题，因为它也在错误页面上突出显示：

def save(self, commit=False, *args, **kwargs):
        self.issue_slug = slugify(self.issue_title)
        super(ComicIssue, self).save(*args, **kwargs)

我正在从url传递标题_id。它正在其他型号上工作，但不是这个型号。如何保存外键？在

Answer 1

不管commit值是多少，您都将表单保存在表单的save方法中。第一行是instance = super(PanelsForm, self).save()，它将尝试保存ComicIssue实例，即使在您的视图中，您编写了obj = form.save(commit=False)。在

您可以做两件事：在初始化时将title和user传递给表单，这样表单就可以在保存期间处理对它们的分配。或者将表单的save方法更改为：

def save(self, commit=False):
    instance = super(PanelsForm, self).save(commit=commit)
    if commit:
        for each in self.cleaned_data['panels']:
            IssuePanel.objects.create(panel=each, issue=instance)
    return instance

然后视图需要调用表单的save()方法两次（注意，表单的instance是通过引用传递的，因此在视图中更改它也会更改表单的instance）：

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