Question

我想在我的 html 模板中显示其父项下的所有子对象。如何在 Django 中做到这一点？

#html

{%for i in contact %}
  {% if not i.parent %}#shwing only parent objects
       ticket #parent_id{{i.message}}
       #here I want to list all child object of my parent   
  {%endif%}     
  {%endfor%}

这是我的models.py：

class Contact(models.Model):
       user = models.ForeignKey(settings.AUTH_USER_MODEL,on_delete=models.CASCADE,null=True,blank=True,related_name='contact_user')
       name = models.CharField(max_length=250)
       email = models.EmailField(max_length=500)
       message = models.CharField(max_length=2000,blank=True,null=True)
       parent =models.ForeignKey('self', on_delete=models.CASCADE,
                            null=True, blank=True, related_name='contact_parent')
       sno = models.AutoField(primary_key=True,)

这是我的views.py

def UserProfileView(request):
   userinfo = UserManagement.objects.filter(username=request.user)
   userprofile = UserProfile.objects.filter(user=request.user)
   contact = Contact.objects.filter(user=request.user)
    
    
   form = TicketForm(request.POST or None)
   if request.method == "POST":
       if form.is_valid():
          form.instance.user = request.user
          messages.add_message(request, messages.INFO,'You ticket submitted sucessfully')
          form.save() 
          return redirect('members:user-profile-private')

   else:
        form = TicketForm()


   context={"userinfo":userinfo,"userprofile":userprofile,"form":form,"contact":contact}
   return render(request,"members/privateprofile.html",context)

Answer 1

我认为您正在寻找以下内容：

查询：

Contact.objects.filter(parent__isnull=True)

模板：

{% for parent in contact %}
    <h1>{{ parent.name }}</h1>
    {% if parent.contact_parent.count %}
        <ul>
        {% for child in parent.contact_parent.all %}
            <li>{{ child.name }}</li>
        {% endfor %}
        </ul>
    {% endif %}
{% endfor %}

此外，我认为您应该将 related_name 更改为类似 contact_children 或仅 children，记住这应该代表 OneToMany 关系中的字段的相反内容，例如：

parent = models.ForeignKey(
    "self",
    on_delete=models.CASCADE,
    null=True,
    blank=True,
    related_name="contact_children", # opposite of field
)

为了避免在模板中进行过多查询，您可以使用 prefetch_related：

Contact.objects.prefetch_related('contact_children').filter(parent__isnull=True)

和模板：

{% for parent in contact %}
    <h1>{{ parent.name }}</h1>
    {% if parent.contact_children.count %}
        <ul>
        {% for child in parent.contact_children.all %}
            <li>{{ child.name }}</li>
        {% endfor %}
        </ul>
    {% endif %}
{% endfor %}

看起来更容易理解吧？

Django如何在HTML模板中将所有评论显示为子父关系？

1 个答案: