在保存

Question

models.py

from django.db import models

class Author(models.Model):
    name = models.CharField(max_length=32)

class Article(models.Model):
    author = models.ForeignKey(Author, on_delete=models.SET_NULL, null=True)
    content = models.TextField()

forms.py

from django import forms
from .models import Article

class ArticleForm(forms.ModelForm):
    class Meta:
        model = Article
        fields = ['content']

在我的Web应用程序中，作者登录并撰写文章。很明显，当作者被提交ArticleForm时，他/她不需要填写ArticleForm中的作者字段，因为应用程序已经通过使用会话变量知道作者是谁。

这是我尝试添加作者的方式：

views.py

from django.shortcuts import render, redirect, get_object_or_404
from django.contrib.auth.decorators import login_required

from .models import Article
from .forms import ArticleForm

@login_required
def new_article(request):
    author_name = request.session['author_name']
    author = Author.objects.get(name=author_name)

    if request.method == 'POST':
        form = ArticleForm(request.POST)
        if form.is_valid():
            form.save(commit=False)
            form.author = author  # I suspect the mistake is here
            # I also tried form.author = author.id
            form.save()
            return redirect('success')
    else:
        form = ArticleForm()

    return render(request, 'writings/new_article.html', {'form': form})

当我查看数据库表时，author_id列始终为NULL。我的做法有什么问题？如何在保存ModelForm之前添加模型关系？

Answer 1

捕获从form.save(commit=False)返回的对象并修改它而不是表单。 EG：

if form.is_valid():
    article = form.save(commit=False)
    article.author = author
    article.save()
    return redirect('success')