_id field is not working

[programacion webdecero]

I want to use the _id field of mongodb as primary key, but when I create an object it keeps adding the default 'id' field. This is my model code:

class UserMongo(models.Model):

_id = models.ObjectIdField(primary_key=True, db_column='_id')

username = models.CharField(max_length=25)

email = models.EmailField()

password = models.CharField(max_length=25)

objects = UserMongoManager()

def __str__(self):

return "{} {}".format(self._id, self.username)

And this what I get when creating the object from postman:

{

"_id": 27,

"username": "user13",

"email": "use...@mail.com",

"password": "password13"

}

In compass I see this data:

{
    "_id": {
        "$oid": "6232240214afce2f3a4c0e13"
    },
    "id": 27,
    "username": "user13",
    "email": "use...@mail.com",
    "password": "password13"
}