CODEWITHSUNDEEP
pythondjango
Maede
Maede

Reputation: 182

delete from many to many field but not from related model

Here is my code in django,


class Comment(models.Model):
    text = models.CharField(max_length=400)
    writer = models.ForeignKey(Email, on_delete=models.DO_NOTHING)
    replied_to = models.ManyToManyField('self', related_name='replied')
    class Meta:
        db_table = 'Comment'

when I add an instance of comment to replied_to, It adds to parent but replied instance keeps a pointer to related object in its replied_to field. Is there a way to remove pointer to related Comment without removing reply instace from parent?

Upvotes: 2

Views: 76

Answers (1)

willeM_ Van Onsem
willeM_ Van Onsem

Reputation: 476557

Yes, you can use the .remove(..) method here:

mycomment.replied_to.remove(othercomment)

This will not remove othercomment from the database, but it will no longer be part of the replied_to in the ManyToManyField.

Note that by default ManyToManyField relations to self are symmetrical. That means that if one comment is in the replied_to of another comment, then the other comment's replied_to also contains the first comment. You can set the symmetrical=… parameter [Django-doc] to False to make it assymetrical:

class Comment(models.Model):
    text = models.CharField(max_length=400)
    writer = models.ForeignKey(Email, on_delete=models.DO_NOTHING)
    replied_to = models.ManyToManyField('self', symmetrical=False, related_name='replied')
    class Meta:
        db_table = 'Comment'

Upvotes: 2

Related Questions