Django2.0手册:Model class reference

This document covers features of the Model class.
For more information about models, see the complete list of Model
reference guides




Each non-abstract Model class must have a
Manager instance added to it.
Django ensures that in your model class you have at least a
default Manager specified. If you don’t add your own Manager,
Django will add an attribute objects containing default
Manager instance. If you add your own
Manager instance attribute, the default one does
not appear. Consider the following example:

from django.db import models

class Person(models.Model):
    # Add manager with another name
    people = models.Manager()

For more details on model managers see Managers
and Retrieving objects.