How to refer to oneself in a ForeignKeyField?-CodePudding

I'm trying to create a foreignkey that refers to another object in the same model.

from peewee import *

class Domain(Model):
    owner = CharField(max_length=40)
    resolves_to = CharField(max_length=40)
    name = CharField(max_length=26)
    last_renewal = IntegerField(null=True) # null=True means that it is optional
    ending_date = IntegerField()
    active = BooleanField()
    parent = ForeignKeyField(Domain, null=True)

    class Meta:
        db_table = "domain"

but I get an error that Domain is not defined. Any help is much appreciated, thanks!

CodePudding user response：

You use the string literal 'self', as is specified in the documentation on ForeignKeys:

To create a recursive relationship – an object that has a many-to-one relationship with itself – use models.ForeignKey('self', on_delete=models.CASCADE).

You thus can implement this with:

from django.db import models

class Domain(models.Model):
    # …
    parent = models.ForeignKey('self', null=True, on_delete=models.CASCADE)

    class Meta:
        db_table = 'domain'