Question

我正在研究一个django项目。我有两个表，它们是组和组活动。组存储有关所创建组的信息。 GroupActivity存储与组相关的所有活动。例如，一个名为Welcome的组将存储在组表中，其中包含有关该组的信息。如果将成员添加到组中，则会在组活动表中显示活动记录。我想创建一个系统，允许我抓住某人所属的所有组，并为每个组抓取该用户所属的每个组所发生的最后一个活动。我尝试使用两个不同的查询并使用两个for循环，但它根本不起作用。任何人都可以帮助我..这是我的代码

以下是表格：

class Group(models.Model):
    name = models.CharField(max_length = 25)
    description = models.CharField(max_length = 250, null=True)
    created_by = models.ForeignKey(User, default=1, on_delete=models.CASCADE)
    created = models.DateTimeField(auto_now_add=True)

class GroupActivity(models.Model):
    user = models.ForeignKey(User, on_delete=models.CASCADE)
    group = models.ForeignKey(Group, on_delete=models.CASCADE)
    expense = models.ForeignKey(Expense, null=True, on_delete=models.CASCADE)
    bundle = models.ForeignKey(Bundle, on_delete=models.CASCADE, null=True)
    description = models.CharField(max_length=200, default='some action')
    host = models.CharField(max_length=100, null=True)
    reference = models.IntegerField(default=0)
    category = models.SmallIntegerField(default = 1)
    created = models.DateTimeField(auto_now_add=True)

以下是我在views.py文件中的内容：

# ensure someone is logged in
@login_required(login_url='/login/')
# groups home page
def groups_home(request):
    # grab the logged in user
    user = request.user
    # grab all of the groups you are a member of
    groups = Member.objects.filter(user = user).all()
    # everythin that is going to be passed to the html template
    activities = GroupActivity.ojects.order_by('group').desc()
    parameters = {
        'groups':groups,
        'activities':activities,
    }
    return render(request, 'groups/groups.html', parameters)

这是html模板：

      {% for group in groups %}
        <p>
          <a href="{% url 'group_home' group.group.name|slugify group.group.id %}">{{ group.group.name }}</a>
        </p>
      {% endfor %}

示例：

two groups = Bros and Sisters 
activity = Bros => josh was added
                => steve was added 
                => josh sent steve a message 
           Sisters => jessica added jenny 
                   => jessica added julie 
                   => jessica added stephanie

I want to grab the two groups = Bros and Girls
I want to grab the actviities = josh sent steve a message 
                              = jessica added stephanie

我想像应用程序主屏幕中的whatsapp组一样显示组和最后一个活动。

任何人都可以帮助我。

Answer 1

而不是直接查询活动，你可以使用后向关系，在模板中使用这样的东西

{% for group in groups %}
    <p>
      <a href="{% url 'group_home' group.group.name|slugify group.group.id %}">{{ group.group.name }}</a>
    </p>
    {% for act in group.activity_set.all %}
        {{ act.description }}
    {% endfor %}
  {% endfor %}

有关详情，请参阅django docs中的this页面。

抓取与数组中项目相关的每个项目的第一个对象 - DJango

1 个答案: