python - Django - 注释字典在模板中无法正确显示

Question

我在 models.py 中得到了这些模型

class Rating(models.Model):
    stars = models.IntegerField()
    user_rating = models.ForeignKey(UserProfile, related_name="rater", on_delete=models.CASCADE)
    user_rated = models.ForeignKey(UserProfile, related_name="rated", on_delete=models.CASCADE)
    ride_number = models.ForeignKey(Ride, related_name="rider", on_delete=models.CASCADE)

class UserProfile(models.Model):
    user = models.ForeignKey(User)

以及我的看法

def user_view(request):
    avg = user_avg
    total = user_count

    context = {
        'avg': avg,
        'total': total
    }

    return render(request, 'rating/home.html', context)

def user_avg():
    avg = (Rating.objects
                    .values('user_rated').annotate(Avg('stars'))
                    .distinct())

    return avg

最后我的模板看起来像这样

  {% for rating in avg %}
  {{ avg }}
  {% endfor %}

现在它的渲染是这样的；

[{'user_rated': 1L, 'stars__avg': 3.2222}, {'user_rated': 2L, 'stars__avg': 3.625}] [{'user_rated': 1L, 'stars__avg': 3.2222}, {'user_rated': 2L, 'stars__avg': 3.625}] 

我尝试将模板更改为 {{ avg.user_lated }} 但它没有给我带来任何结果，所以我不确定我在这里做错了什么。如何获取用户平均评分的名称而不是 user_lated

Answer 1

模板中的这一行:

{{ avg }}

应更改为:

{{ rating.user_rated }}: {{ rating.stars__avg }}

完整模板:

{% for rating in avg %}
{{ rating.user_rated }}: {{ rating.stars__avg }}
{% endfor %}

您的 2 个错误:1 - 循环变量是 rating - 您应该使用它来访问循环中的数据，2 - 要访问 dict 中的数据，您应该使用点表示法，请检查文档。

文档:https://docs.djangoproject.com/en/2.0/topics/templates/#variables

Dictionary lookup, attribute lookup and list-index lookups are implemented with a dot notation:

{{ my_dict.key }}
{{ my_object.attribute }}
{{ my_list.0 }}

要在注释结果中获取用户名，您应该将其添加到查询中的值中:

# assuming that your UserProfile model have name field
avg = (Rating.objects.values(
    'user_rated', 'user_rated__name').annotate(Avg('stars')).distinct())

但要小心值和注释 - 顺序很重要，结果值取决于值列表:

文档:https://docs.djangoproject.com/en/2.0/topics/db/aggregation/#order-of-annotate-and-values-clauses

As with the filter() clause, the order in which annotate() and values() clauses are applied to a query is significant. If the values() clause precedes the annotate(), the annotation will be computed using the grouping described by the values() clause.