缩短Python Django DB查询

Question

We have m2m relationship between E and U models:

class E(models.Model):
    us = models.ManyToManyField('U', related_name='events', symmetrical=False)

class U(models.Model):
    pass

Now we want to remove all links for U with pk=2.

I wrote this code: U.events.through.objects.filter(u=2).delete() .

Can this code be shortened/simplified?

Answer 1

You could do something like:

U.objects.get(pk=2).events.clear()

There are some useful examples in the Django documentation:

https://docs.djangoproject.com/en/2.0/topics/db/examples/many_to_many/

As a side note, you don't need symmetrical=False on your many to many definition. Quoting from the Django documentation:

Only used in the definition of ManyToManyFields on self.

See:

https://docs.djangoproject.com/en/2.0/ref/models/fields/#django.db.models.ManyToManyField.symmetrical