django：当2个字段具有相同值时过滤queryset

Question

I have a model which has 2 fields like, 我有一个模型，其中包含2个字段，

pickup_station_id = models.IntegerField(null=True)
drop_station_id = models.IntegerField(null=True)

I want a filter in admin which can filter the queryset based on, 我想要admin中的过滤器，该过滤器可以根据以下内容过滤查询集：

How can I get a queryset based on these conditions? 如何根据这些条件获取查询集？

I mean, something like this, 我的意思是，像这样

Mymodel.objects.filter(pickup_station_id==drop_station_id)

Mymodel.objects.filter(pickup_station_id!=drop_station_id)

Answer 1

You can refer to a f ield with an F -expression [Django-doc] . 你可以参考A F ield与F -expression [Django的DOC] 。 So we can write it like: 所以我们可以这样写：

from django.db.models import F

Mymodel.objects.filter(pickup_station_id=F('drop_station_id'))

We can negate a q uery by using a Q -object [Django-doc] : 我们可以通过使用否定 A Q uery Q -object [Django的DOC] ：

from django.db.models import F, Q

Mymodel.objects.filter(~Q(pickup_station_id=F('drop_station_id')))

Here the tilde ( ~ ) means we negate the condition that the Q object represents. 这里的波浪号（ ~ ）表示我们否定了Q对象表示的条件。