Can not delete document object using mongoengine

Question

I am working with mongoDB 4.2 using python 3.7 and library mongoengine 0.18.2. So, I want to delete a document but I got lookup error.

ODM:

from mongoengine import Document
from mongoengine.fields import *

class Myparent(Document):
  fieldfoo = IntField()
  fieldbar = IntField()


class Mychild(Document):
  fieldfoo = StringField()
  myparent = ReferenceField('Myparent')

Now, when I want to delete a child:

  item = Mychild.objects.get(id=123456)
  item.delete()

I got this error:

site-packages/mongoengine/queryset/transform.py", line 60, in query
    fields = _doc_cls._lookup_field(parts)
site-packages/mongoengine/base/document.py", line 1032, in _lookup_field
    raise LookUpError('Cannot resolve field "%s"' % field_name)
mongoengine.errors.LookUpError: Cannot resolve field "myparent"

Any clue? Thanks

Answer 1

The id you are providing is not a valid id. Mongo supports 12 byte binary BSON type format which is definitely not 123456 . If your id is correct then you can do the following:

item=Mychild.objects(pk='some_id')

Whatever is returned in item will be a list but id is unique so you can write it as:

item=Mychild.objects(pk='some_id').first()

item.delete()