如何在django中创建基于父查询集的预取查询集

# models.py
class ParentModel(models.Model):
    name = models.CharField(max_length=100)

class ChildModel(models.Model):
    parent = models.ForeignKey(ParentModel, on_delete=models.CASCADE)
    name = models.CharField(max_length=100)

# views.py
def my_view(request):
    parents = ParentModel.objects.all().prefetch_related('childmodel_set')
    return render(request, 'my_template.html', {'parents': parents})

# my_template.html
{% for parent in parents %}
    <h2>{{ parent.name }}</h2>
    {% for child in parent.childmodel_set.all %}
        <p>{{ child.name }}</p>
    {% endfor %}
{% endfor %}