Mongoengine: ListField EmbeddedDocumentField dosen't generate own _id field

[rturk]

I have the following model:

class Comment(EmbeddedDocument):
    comment = StringField()
    comment_id = ObjectIdField()

class Blog(Document):
    title = StringField(max_length=120, required=True)
    content = StringField(max_length=500, required=True)
    comments = ListField(EmbeddedDocumentField(Comment))

I need to be able to reference each comment. If I run the code below, the new comment will not have it's own _id field

comment = Comment(comment='New comment!!')
product.comments.append(comment)
product.save()

[rozza]

Hi, Embedded documents dont auto generate an id - so you need to provide one or set one as a default eg:

from bson import ObjectId

class Comment(EmbeddedDocument):
        comment = StringField()
        comment_id = ObjectIdField(default=ObjectId)

[felipemullen]

@rozza I know this is an old discussion here but I have a relevant question:

Is it possible to later query the embedded document similar to this

comment = Comment.objects.with_id(object_id='an_id_str')

or is it necessary to query from the parent class (Blog in this case)? I haven't been able to query the embedded document by id