使用django自带的user做外键的方法

# Product / models.py
from django.db import models
from django.contrib.auth import settings


class Product(models.Model):
  productName = models.CharField('产品名称', max_length=20)
  productDescription = models.CharField('产品描述', max_length=100)
  producer = models.ForeignKey(settings.AUTH_USER_MODEL, verbose_name='负责人',             on_delete=models.SET_NULL,blank=True, null=True)
  createTime = models.DateTimeField('创建时间', auto_now=True)

  class Meta:
    verbose_name = '产品管理'
    verbose_name_plural = '产品管理'

  def __str__(self):
    return self.productName

from django.contrib.auth.models import AbstractUser
from django.db import models

class NewUser(AbstractUser):
	new_field = models.CharField(max_length=100)

AUTH_USER_MODEL = "app.NewUser"

# django.contrib.auth.base_user
class AbstractBaseUser(models.Model):
  password = models.CharField(_('password'), max_length=128)
  last_login = models.DateTimeField(_('last login'), blank=True, null=True)

  is_active = True

  REQUIRED_FIELDS = []

  # Stores the raw password if set_password() is called so that it can
  # be passed to password_changed() after the model is saved.
  _password = None

  class Meta:
    abstract = True

  def __str__(self):
    return self.get_username()

  def save(self, *args, **kwargs):
    super().save(*args, **kwargs)
    if self._password is not None:
      password_validation.password_changed(self._password, self)
      self._password = None

  def get_username(self):
    """Return the username for this User."""
    return getattr(self, self.USERNAME_FIELD)

  def clean(self):
    setattr(self, self.USERNAME_FIELD, self.normalize_username(self.get_username()))

  def natural_key(self):
    return (self.get_username(),)

  @property
  def is_anonymous(self):
    """
    Always return False. This is a way of comparing User objects to
    anonymous users.
    """
    return False

  @property
  def is_authenticated(self):
    """
    Always return True. This is a way to tell if the user has been
    authenticated in templates.
    """
    return True

  def set_password(self, raw_password):
    self.password = make_password(raw_password)
    self._password = raw_password

  def check_password(self, raw_password):
    """
    Return a boolean of whether the raw_password was correct. Handles
    hashing formats behind the scenes.
    """
    def setter(raw_password):
      self.set_password(raw_password)
      # Password hash upgrades shouldn't be considered password changes.
      self._password = None
      self.save(update_fields=["password"])
    return check_password(raw_password, self.password, setter)

  def set_unusable_password(self):
    # Set a value that will never be a valid hash
    self.password = make_password(None)

  def has_usable_password(self):
    """
    Return False if set_unusable_password() has been called for this user.
    """
    return is_password_usable(self.password)

  def get_session_auth_hash(self):
    """
    Return an HMAC of the password field.
    """
    key_salt = "django.contrib.auth.models.AbstractBaseUser.get_session_auth_hash"
    return salted_hmac(key_salt, self.password).hexdigest()

  @classmethod
  def get_email_field_name(cls):
    try:
      return cls.EMAIL_FIELD
    except AttributeError:
      return 'email'

  @classmethod
  def normalize_username(cls, username):
    return unicodedata.normalize('NFKC', username) if isinstance(username, str) else username