Mock database design for Twidder, a social networking app that has nothing at all to do with a social networking app of a similar name.

twidder_models.py

from django.db import models


class User(models.Model):
    # Django's auth framework provides its own very 
    # capable user model, but we'll make our own
    
    # assuming English/Western-style names –
    # first name/last name distinction doesn't apply in all cultures
    first_name = models.CharField(max_length=64)
    last_name = models.CharField(max_length=64)
    
    email = models.EmailField()
    username = models.CharField(max_length=20)
    password = models.PasswordField() # this isn't actually a thing but 
                                      # we're going to pretend it is
    following = models.ManyToManyField('self') 
        # Django automatically creates an intermediary table for us to 
        # handle many-to-many relations
    

class Message(models.Model):
    user = models.ForeignKey('User')
    text = models.CharField(max_length=120)
    created = models.DateTimeField(auto_now_add=True)