Django多对多关系对象更新

# 更新文章
@login_required(login_url='/userprofile/login/')
def article_update(request, id):
    """
    更新文章的视图函数
    通过POST方法提交表单，更新title、body字段
    :param request:
    :param id: 文章的id
    :return:
    """
    article = ArticlePost.objects.get(id=id)

    # 过滤非作者的用户
    if request.user != article.author:
        return HttpResponse('抱歉，你无权修改这篇文章。')

    if request.method == 'POST':
        article_post_form = ArticlePostForm(data=request.POST)
        if article_post_form.is_valid():
            article.title = request.POST['title']
            article.body = request.POST['body']

            if request.POST['column'] != 'none':
                article.column = ArticleColumn.objects.get(id=request.POST['column'])
            else:
                article.column = None

            article.tags.set(*request.POST['tags'].split(','))  #就是此行代码，非常重要

            article.save()

            # article_post_form.save_m2m()

            return redirect('article:article_detail', id=id)
        else:
            return HttpResponse('表单内容有误，请重新填写。')
    else:
        article_post_form = ArticlePostForm()
        columns = ArticleColumn.objects.all()
        tags = article.tags.all()
        tags = ','.join([tag.name for tag in tags])
        context = {
            'article': article,
            'article_post_form': article_post_form,
            'columns': columns,
            'tags': tags
        }
        return render(request, 'article/update.html', context)

核心代码就是文中的article.tags.set(*request.POST['tags'].split(','))这一句。