title: Django collection of instances of same model
body: <p>I'm new to Django
  I'm currently using django 3.2.6. I want make multiple instances of route_stop model and store in SchoolRouteStop.route_graph model.I don't want use ForeignKey because i want to make somthing like like nested dict.</p>
  <pre><code>from django.db import models
  
  
  class geo_fence(models.Model):
      radius = models.FloatField()
  
  class geo_location(models.Model):
      latitude = models.FloatField()
      longitude = models.FloatField()
  
  class address(models.Model):
      entity = models.fields.CharField(max_length=100)
      apt_plot = models.fields.CharField(max_length=100)
      street = models.fields.CharField(max_length=100)
      city = models.fields.CharField(max_length=100)
      state = models.fields.CharField(max_length=2) #state name in short code
      zip_code = models.fields.IntegerField()
  
  class route_stop(models.Model): # this for multiple bus stops
      route_stop_id =  models.fields.IntegerField()
      school_id = models.fields.CharField(max_length=100)
      route_number = models.fields.CharField(max_length=100)
      school_route_stop_uuid = models.fields.CharField(max_length=100, primary_key=True)
      registered_arrival_time = models.TimeField()
      time_from_src = models.FloatField()
      is_school = models.BooleanField(default=False)
      geo_fence = models.ForeignKey(geo_fence, on_delete =models.CASCADE)
      geo_location = models.ForeignKey(geo_location, on_delete = models.CASCADE)
      address = models.ForeignKey(address, on_delete = models.CASCADE)
  
  
  class SchoolRouteStop(models.Model):
      school_id = models.CharField(max_length=100)
      school_route_number = models.IntegerField()
      route_type = models.CharField(max_length=2)
      route_id = str(school_id)+'_'+str(school_route_number)+str(route_type)
      route_graph= models.ForeignKey(route_stop,related_name='School', on_delete = models.CASCADE)
      
  
  
  
  # Create your models here.
  </code></pre>