Related object reference does not work without importing the related model itself

Question

I have 2 models in my app -

In models/parent.py I have -

 from django.db import models
 class Parent(models.Model): 
       class Meta:
          db_table = "parent_table"
       start_date = models.DateField()
       end_date = models.DateField()

In models/child.py I have -

from django.db import models
from models.parent import Parent
class Child(models.Model): 
   class Meta:
      db_table = "child_table"
   some_ref = models.ForeignField(Parent)

Now in models/parent.py I am defining a property as -

@property
def referred_values(self):
 return self.child_set.all()

It gives me error -

AttributeError: 'Parent' object has no attribute 'child_set'

But if I import Child class in any file in my app, it works fine. Is this an expected behaviour or am I missing something here?

Thanks in advance.

Answer 1

It is good to set related_name directly

some_ref = models.ForeignField(Parent, related_name='childs')

and use childs insted of child_set (more English)

Also you can use:

 some_ref = models.ForeignField(to='parent_app.Parent', related_name='childs')

and you do not need import Parent to Child models

Also:

class Parent(models.Model): 

insted of

 class Parent:

But in your probrem, I think you forget add Child to models/__init__.py