django Cannot set values on a ManyToManyField which specifies an intermediary model. Use Manager instead

Question

i am working on saving on the same form two tables - having a m2m relation. I don\'t succeed, my error persists with something like: Cannot set values on a ManyToManyField w

Answer 1

As specified in https://docs.djangoproject.com/en/2.1/topics/db/models/

"Unlike normal many-to-many fields, you can’t use add(), create(), or set() to create relationships"

This means for django version 2.1 ,these methods are impossible. But the same page of django 2.2 documentation https://docs.djangoproject.com/en/2.2/topics/db/models/ tells that:

"You can also use add(), create(), or set() to create relationships, as long as you specify through_defaults for any required fields"

So just update the django to 2.2 or newer versions to use the above methods and while creating objects give the argument 'through_defaults' as a python dictionary with keys as your extra field names and values as their default values.