不可能将新的用户元素迁移到django表中

Question

我面临着无法将新用户值迁移到数据库表的问题。起初related_name上有错误，但我修复了它，现在这个值不能为零，同时，如果我写null=True，那么用户将来就不能显示在记录中。

class Writehelp(models.Model):
users = models.ForeignKey(User,on_delete = models.CASCADE,related_name='helpedman',null=False,verbose_name='Автор')
titles = models.CharField(max_length=200, verbose_name='Заголовок', blank=True)
descriptions = models.TextField(blank=True, verbose_name='Описание')
createdtimes = models.DateField(auto_now_add=True, db_index=True, verbose_name='Дата создания')
prices = models.DecimalField(max_digits=10, decimal_places=2, null=True, blank=True, verbose_name='Цена')
course = models.IntegerField(null=True, blank=True, verbose_name='Курс')
semestr = models.IntegerField(null=True, blank=True, verbose_name='Семестр')
subjects = models.CharField(max_length=200, null=True, blank=True, verbose_name='Предмет')
institutes = models.CharField(max_length=200, null=True, blank=True, verbose_name='Институт')

然而，当我迁移这个模型时，没有出现任何问题：

class UploadFile(models.Model):
user = models.ForeignKey(User,on_delete = models.CASCADE,related_name='file_created' ,verbose_name='Автор')
title = models.CharField(max_length=200, verbose_name='Заголовок',blank=True)
# uploadedfile = models.FileField(upload_to='files/',null=True, verbose_name='Файл')
description = models.TextField(blank=True, verbose_name='Описание')
createdtime = models.DateField(auto_now_add=True, db_index=True, verbose_name='Дата создания')
price = models.DecimalField(max_digits=10, decimal_places=2, null=True, blank=True, verbose_name='Цена')
number_course = models.IntegerField(null=True, blank=True, verbose_name='Курс')
number_semestr = models.IntegerField(null=True, blank=True, verbose_name='Семестр')
subjectt = models.CharField(max_length=200, null=True,blank=True,verbose_name='Предмет')
type_materials = models.CharField(max_length=200,null=True,blank=True, verbose_name='Тип работы')
institute = models.CharField(max_length=200, null=True,blank=True, verbose_name='Институт')

Answer 1

将defult=None添加到UploadFile模型中的uploadedfile字段。