在 Django 中查询自引用表

Question

I have a model which references itself so that I have a parent / child relationship between users in the db. A parent can have multiple children, but a child can only have one parent.

Firstly, is this the correct way to define the model:

class User(models.Model):
   name = models.CharField(max_length=50)
   parent = models.ForeignKey('self')

Secondly, I need to query the model and return all the children of a particular parent. I have read some articles on tree structures where queries can be more complicated. But given I only need one layer deep, will this return all the children:

children = User.objects.get(parent=PARENT_ID)

where PARENT_ID is obviously the id of the parent

Answer 1

Yes, you can use like your code.

and Yes again, but little bit different.

children = User.objects.filter(parent__id=PARENT_ID)

You can find children with parent__id

Note; remember parent _ _ id , not parent_id!