How to create an object for a Django model with a many to many field?

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My model:

class Sample(models.Model):
    users = models.ManyToManyField(User)

I want to save both user1 and user2 in that model:

user1 = User.objects.get(pk=1)
user2 = User.objects.get(pk=2)
sample_object = Sample(users=user1, users=user2)
sample_object.save()

I know that's wrong, but I'm sure you get what I want to do. How would you do it ?

django-orm django-models django python
6 Answers

For future visitors, you can create an object and all of its m2m objects in 2 queries using the new bulk_create in django 1.4. Note that this is only usable if you don't require any pre or post-processing on the data with save() methods or signals. What you insert is exactly what will be in the DB

You can do this without specifying a "through" model on the field. For completeness, the example below creates a blank Users model to mimic what the original poster was asking.

from django.db import models

class Users(models.Model):
    pass

class Sample(models.Model):
    users = models.ManyToManyField(Users)

Now, in a shell or other code, create 2 users, create a sample object, and bulk add the users to that sample object.

Users().save()
Users().save()

# Access the through model directly
ThroughModel = Sample.users.through

users = Users.objects.filter(pk__in=[1,2])

sample_object = Sample()
sample_object.save()

ThroughModel.objects.bulk_create([
    ThroughModel(users_id=users[0].pk, sample_id=sample_object.pk),
    ThroughModel(users_id=users[1].pk, sample_id=sample_object.pk)
])
user_2167350

If someone is looking to do David Marbles answer on a self referring ManyToMany field. The ids of the through model are called: "to_'model_name_id" and "from_'model_name'_id".

If that doesn't work you can check the django connection.

user_80814470
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