擅长:python、mysql、java
<p>我想,你要找的是:</p>
<pre><code>from django.db.models import Count, Sum, Case, When, IntegerField
Item.objects.annotate(
count_subitems=Sum(
Case(When(subitems__created_at__lte=datetime.now(), then=1)),
output_field=IntegerField()
)
)
</code></pre>