Django：随机排序(order_by(‘？’))进行额外的查询

[情况1]

views.py

from sampleapp.models import SampleModel
from django.core.cache import cache

def get_filtered_data():

    result = cache.get("result")

    # make cache if result not exists
    if not result:
         result = SampleModel.objects.filter(field_A="foo")
         cache.set("result",result)

    return render_to_response('template.html',locals(),context_instance=RequestContext(request))

template.html

{% for case in result %}
  <p>{{ case.field_A}}</p>
  {% endfor %}

在这种情况下,缓存生成后没有生成查询.我用django_debug_toolbar检查了它.

[案例2]

views.py – 添加了一行结果= result.order_by(‘？’)

from sampleapp.models import SampleModel
from django.core.cache import cache

def get_filtered_data():

    result = cache.get("result")

    # make cache if result not exists
    if not result:
         result = SampleModel.objects.filter(field_A="foo")
         cache.set("result",result)

    result = result.order_by('?')

    return render_to_response('template.html',context_instance=RequestContext(request))

template.html – 与上一个相同

在这种情况下,即使我缓存了已过滤的查询,它也会生成新的查询.

如何在没有额外查询集的情况下调整随机排序？

>制作缓存时我无法输入order_by(‘？’).
(例如result = SampleModel.objects.filter(field_A =“foo”).order_by(‘？’))
因为它甚至可以缓存随机顺序.
>它与’django queryset是懒惰’有关吗？

提前致谢.