old_contents: from django.db import models
  from django.contrib.auth.models import User
  
  '''
  class Venue(models.Model):
      name = models.CharField(max_length=255)
  
  
  class Field(models.Model):
      name = models.CharField(max_length=255)
      venue = models.ForeignKey(Venue)
  
  
  class Reservation(models.Model):
      name = models.CharField(max_length=255)
      user = models.ForeignKey(User)
      field = models.ForeignKey(Field)
  
  '''
new_contents: from django.db import models
  from django.contrib.auth.models import User
  
  
  class Venue(models.Model):
      name = models.CharField(max_length=255)
  
  
  class Field(models.Model):
      name = models.CharField(max_length=255)
      venue = models.ForeignKey(Venue)
  
  
  class Reservation(models.Model):
      name = models.CharField(max_length=255)
      user = models.ForeignKey(User)
      field = models.ForeignKey(Field)
  
  
subject: test git in pycharm