django 在模板中分组

django group by in template

我正在尝试为我的用户记录记录更改的历史记录。 我有一个历史模型:

class History(models.Model):
concerning      = models.ForeignKey(User)
field           = models.CharField(max_length=30)
creation_date   = models.DateTimeField(auto_now_add=True)
author          = models.ForeignKey(User, related_name='autor_history_info')
action          = models.CharField(max_length=30)
new_value       = models.CharField(max_length=1000)

和历史视图:

def get_history(request):
changes = History.objects.all().filter(concerning=request.user).order_by('field')

return render(request, "get_history.html", {"changes" : changes)

和一个历史模板:

{%for change in changes %}
  <h1>{{change.field}} </h1>
  {{change.creation_date}} 
  {{change.author}}
  {{change.action}}
  to
  {{change.new_value}}
  <br>
{% endfor %}

不幸的是,我找不到分组的好方法,该方法将限制显示该字段一次,然后是下面的所有更改。如何通过分组来做到这一点?

使用 {% ifchanged %} 模板标签:

{% for change in changes %}

  {% ifchanged %}<h1>{{change.field}}</h1>{% endifchanged %}

  {{change.creation_date}} 
  {{change.author}}
  {{change.action}}
  to
  {{change.new_value}}
  <br>

{% endfor %}