Question

我正在创建一个网站，允许用户关注股票并根据他们关注的内容查看文章。注册后，用户选择他们想要关注的股票。

def follow_stocks_post_registration(request):
        all_stocks = Stock.objects.all()

        if request.method == 'POST':
            stocks_user_selected = request.POST.getlist('stocks_selected')
            user_profile = request.user.profile
            for stock_name in stocks_user_selected:
                stock = Stock.objects.get(name=stock_name)
                user_profile.followed_stocks.add(stock)

models.py：

class Stock(models.Model):
    name = models.CharField(max_length = 50)
    ticker = models.CharField(max_length = 50)

    def __str__(self):
        return self.name

class Profile(models.Model):
    user = models.OneToOneField(User, on_delete=models.CASCADE)
    followed_stocks = models.ManyToManyField(Stock, blank=True)

    def __str__(self):
        return self.user.username

    @receiver(post_save, sender=User)
    def update_user_profile(sender, instance, created, **kwargs):
        if created:
            Profile.objects.create(user=instance)
        instance.profile.save()

在视图中，stocks_user_selected = request.POST.getlist('stocks_selected')获取正确的股票列表，但user_profile.followed_stocks.add(stock)未成功向用户followed_stocks添加任何股票。我不确定是什么错？

Answer 1

将对象添加到.save()后，您需要调用ManyToManyField方法。此外，您应该在一个查询中过滤stocks，而不是逐个获取它们。

def follow_stocks_post_registration(request):
    all_stocks = Stock.objects.all()

    if request.method == 'POST':
        stocks_user_selected = request.POST.getlist('stocks_selected')
        user_profile = Profile.objects.get(user=request.user)
        for stock in Stock.objects.filter(name__in=stocks_user_selected):
            user_profile.followed_stocks.add(stock)
            user_profile.save()

Add（）方法不保存多个到多个字段

1 个答案: