How to count the amount of objects in a django joined table?

[hykyd]

My problem is simple: I have **Users** who own **Assets** or **Assets** which belong to Users If you prefer and I cannot make it to retrieve the number (count) of **Assets** each **User** has. I know this might be sound silly to most of you but I am new to python/django (coming from PHP/MySQL) and I do not know how things work here. I do not want to be engaged with raw SQL - this would be my last choice If nothing else works. 

(*) I have removed all non-related raws from the code

**Users**

    class Users(models.Model):

        firstname = models.CharField(max_length=100)

        lastname = models.CharField(max_length=100)

**Assets**

    class Assets(models.Model):

        serial = models.CharField(unique=True, max_length=100)

        user = models.ForeignKey('Users', blank=True, null=True)

    

        # this is what I am playing with to retrieve the number of assets each user owns

        @classmethod

            def user_assets(self):

                return Assets.objects.filter(user=user).count()

**views.py** 

    class UserList(ListView):

        model = Users

        def get_context_data(self, **kwargs):

            context = super(UserList, self).get_context_data(**kwargs)

            context['user_assets'] = self.model.user_assets()

            return context

**template** 

    {% for user in object_list %}

         <tr>

             <td>{{ user.id }}</td>

             <td>

                 {{ user_assets }}

             </td>

         </tr>

    {% endfor %}

How can I get that number? I have read about aggregations, annotations and filters but can't really get it.

I am looking for a simple solution by using class based views and easily expandable (I may want to add other models later)

[Lucas Magnum]

{% for user in object_list %}

         <tr>

             <td>{{ user.id }}</td>

             <td>

                 Number of assets: {{ user.assets_set.count }}

             </td>

        </tr>

    {% endfor %}

[]'s

Lucas Magnum.

2014-02-03 hykyd <chrisv...@gmail.com>:

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[shmengie]

This might be what you're looking for.  One caveat, tho, the queryset should be .ordered_by('user')

{% regroup object_list by user as user_list %}
{% for user in userlist_list %}
  <tr>
    <td>{{ user.user.id }} {{user.list|length}}</td>

    <td>

      {% for asset in user.list %}
        {{ asset.serial }}
      {% endfor %}