django admin error on updation of data - mysql

Question

When I update/delete some content through views.py file i.e via the website, everything works fine but when I try to update some data through admin panel i get this error:
IntegrityError at /admin/library/student/
(1452, 'Cannot add or update a child row: a foreign key constraint fails (kt2.django_admin_log, CONSTRAINT django_admin_log_user_id_52fdd58701c5f563_fk_auth_user_id FOREIGN KEY (user_id) REFERENCES auth_user (id))')
where kt2 is the name of my database.
Please help and also let me know if you need the code.
models.py
# Create your models here.
from django.db import models
from django.contrib.auth.models import AbstractUser
# Create your models here.
class Student(AbstractUser):
roll_number = models.CharField(max_length=30,unique=True)
student_name = models.CharField(max_length=200)
branch = models.CharField(max_length=20)
sem = models.IntegerField()
pic = models.ImageField(null=True,blank=True)
due_fine = models.IntegerField(default=0)
USERNAME_FIELD='roll_number'
REQUIRED_FIELDS=['username','email']
def __str__(self):
return self.student_name
class Author(models.Model):
author_name = models.CharField(max_length=200,primary_key=True)
def __str__(self):
return self.author_name
class Quantity(models.Model):
q_id=models.AutoField(primary_key=True)
book_name=models.CharField(max_length=200)
list_of_authors=models.ManyToManyField(Author)
qty = models.IntegerField(default=1)
class Meta:
verbose_name_plural = 'Quantity'
# unique_together=(('book_name','list_of_authors'),)
def __str__(self):
return self.book_name
class LastFiveIssues(models.Model):
lfi_id=models.AutoField(primary_key=True)
one_st=models.CharField(max_length=30,blank=True,null=True)
two_st=models.CharField(max_length=30,blank=True,null=True)
three_st=models.CharField(max_length=30,blank=True,null=True)
four_st=models.CharField(max_length=30,blank=True,null=True)
five_st=models.CharField(max_length=30,blank=True,null=True)
issue_one_date=models.DateField(blank=True,null=True)
issue_two_date=models.DateField(blank=True,null=True)
issue_three_date=models.DateField(blank=True,null=True)
issue_four_date=models.DateField(blank=True,null=True)
issue_five_date=models.DateField(blank=True,null=True)
return_one_date=models.DateField(blank=True,null=True)
return_two_date=models.DateField(blank=True,null=True)
return_three_date=models.DateField(blank=True,null=True)
return_four_date=models.DateField(blank=True,null=True)
return_five_date=models.DateField(blank=True,null=True)
class Meta:
verbose_name_plural='last five issues'
class Publisher(models.Model):
publisher_name = models.CharField(max_length=200,primary_key=True)
def __str__(self):
return self.publisher_name
class Book(models.Model):
last_five_issues=models.OneToOneField(LastFiveIssues)
publisher_book=models.ForeignKey(Publisher)
authors = models.ForeignKey(Quantity)
student = models.ForeignKey(Student)
book_id = models.CharField(primary_key=True,max_length=30)
is_issued = models.BooleanField(default=False)
dep_book = models.CharField(max_length=20)
book_name = models.CharField(max_length=200)
date_of_issue = models.DateField(default = '1900-1-1')
return_date = models.DateField(default='1900-1-1')
book_added_on = models.DateField(default='1900-1-1')
placed_at_shelf=models.CharField(max_length=200,blank=True,null=True)
edition_of_book = models.IntegerField()
rare_book = models.BooleanField(default=False)
claim_one=models.CharField(max_length=30,blank=True,null=True)
claim_two=models.CharField(max_length=30,blank=True,null=True)
claim_three=models.CharField(max_length=30,blank=True,null=True)
def __str__(self):
return self.book_name