[Django]-In Django, how do you make a model refer to itself?

by

92👍

✅

http://docs.djangoproject.com/en/dev/ref/models/fields/#foreignkey

To create a recursive relationship —
an object that has a many-to-one
relationship with itself — use
models.ForeignKey('self').

So you have it right. It’s usually faster to determine if code will do what you want by running it 🙂

👤Jonny Buchanan

5👍

I believe you can even exclude the app name which would look like:

ref_employee= models.ForeignKey('Employee',null=True,blank=True)
👤Stryker

4👍

You can reference other models by name (using a string, including
package), instead of by the class directly:

So, if your Employee class is in the hr app:

class Employee(models.model):
   other_employee = models.ForeignKey('hr.models.Employee', null=True, blank=True)
👤nelhage

3👍

Yes, this is correct but consider writing 'null=True' because if you don’t mention that, your database recursively creates a joint table.

👤AMIN

0👍

A constraint forcing id and ref_employee_id to have separate values is outside the scope of Django’s ORM. You will need to add said constraint at the database level, via SQL in syncdb or manually.

👤Ignacio Vazquez-Abrams

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