old_contents: from django.db import models
  
  from django.contrib.auth.models import User
  # Create your models here.
  
  
  class CompletedCourse(models.Model):
      """
      Model for completed studies
      """
      student = models.ForeignKey(User, related_name='completed_courses') 
      code = models.CharField(max_length=11)
      name = models.CharField(max_length=100)
      cr = models.IntegerField()
      ocr = models.IntegerField()
      grade = models.CharField(max_length=5)
      date = models.DateField()
      teacher = models.CharField(max_length=60)
      
  class Teacher(models.Model):
      """
      should be updated for the teachers to combine them with course information
      """
      name = models.CharField(max_length = 30)
  
new_contents: from django.db import models
  
  from django.contrib.auth.models import User
  # Create your models here.
  
  
  class CompletedCourse(models.Model):
      """
      Model for completed studies
      """
      student = models.ForeignKey(User, related_name='completed_courses')
      code = models.CharField(max_length=11)
      name = models.CharField(max_length=100)
      cr = models.IntegerField(null=True)
      ocr = models.IntegerField(null=True)
      grade = models.CharField(max_length=5)
      date = models.DateField()
      teacher = models.CharField(max_length=60)
  
  class Teacher(models.Model):
      """
      should be updated for the teachers to combine them with course information
      """
      name = models.CharField(max_length = 30)
  
subject: Allow null values for ocr and cr fields of CompletedCourse