如何创建一个查询来过滤一列等于另一列同一个表的行？

Say I have a model that looks like:

说我的模型看起来像：

class StockRequest(models.Model):
    amount_requested = models.PositiveIntegerField(null=True)
    amount_approved = models.PositiveIntegerField(null=True)

Is there any way to make a django query that would show me all requests where there is some relationship between amount_requested and amount_approved on a particular object/row?

有没有办法制作一个django查询，它会向我显示特定对象/行上的amount_requested和amount_approved之间存在某种关系的所有请求？

In SQL it would be as simple as:

在SQL中，它将如下所示：

select * from stockrequest where amount_requested = amount_approved;

要么

select * from stockrequest where amount_requested = amount_approved;

In Django, I'm not sure if it can be done, but I would imagine something like the below (NOTE: syntax completely made up and does not work).

在Django中，我不确定它是否可以完成，但我会想象下面的内容（注意：语法完全组成并且不起作用）。

StockRequest.objects.filter(amount_requested="__amount_approved")

3 个解决方案

#1

from django.db.models import F
StockRequest.objects.filter(amount_requested=F("amount_approved"))

http://docs.djangoproject.com/en/dev/topics/db/queries/#filters-can-reference-fields-on-the-model

#2

Yes, you can. You can use the built in "F" object to do this.

是的你可以。您可以使用内置的“F”对象来执行此操作。

The syntax would be:

语法是：

from django.db.models import F
StockRequest.objects.filter(amount_requested=F("amount_approved"))

要么

StockRequest.objects.filter(amount_requested__gt=F("amount_approved"))

Note: I found the answer immediately after I finished writing the question up. Since I hadn't seen this on Stack Overflow anywhere, I am leaving it up with this answer.

注意：我在写完问题后立即找到答案。由于我没有在任何地方看到Stack Overflow，我将这个答案留给我。

#3

Check docs on the F() function:

检查F（）函数上的文档：

#1

from django.db.models import F
StockRequest.objects.filter(amount_requested=F("amount_approved"))