pytho/django

#Admins.py
from django.contrib import admin
from .models import users, libary, loan

admin.site.register(users)
admin.site.register(libary)
admin.site.register(loan)

#Models.py
from django.db import models
from django.utils import timezone

class users(models.Model):
    IdOfUser = models.AutoField(primary_key = True)
    first_name = models.CharField(max_length = 50)
    surname = models.CharField(max_length = 50)

    def published(self):
        self.save()

    def __str__(self):
        return self.first_name + "  " + self.surname

class libary(models.Model):
    IdOfBook = models.AutoField(primary_key = True)
    NameOfBook = models.CharField(max_length = 50)
    Author = models.CharField(max_length = 50)

    def published(self):
        self.save()

    def __str__(self):
        return self.NameOfBook +"   "+ self.Author

class loan(models.Model):
    IdOfUser= models.ForeignKey(users, on_delete = models.CASCADE)
    IdOfBook = models.ForeignKey(libary, on_delete = models.CASCADE)

    def published(self):
        self.save()