from django.db import models class Author(models.Model): name = models.CharField(max_length=100) age = models.IntegerField() friends = models.ManyToManyField('self', blank=True) def __str__(self): return self.name class Publisher(models.Model): name = models.CharField(max_length=255) num_awards = models.IntegerField() def __str__(self): return self.name class Book(models.Model): isbn = models.CharField(max_length=9) name = models.CharField(max_length=255) pages = models.IntegerField() rating = models.FloatField() price = models.DecimalField(decimal_places=2, max_digits=6) authors = models.ManyToManyField(Author) contact = models.ForeignKey(Author, models.CASCADE, related_name='book_contact_set') publisher = models.ForeignKey(Publisher, models.CASCADE) pubdate = models.DateField() def __str__(self): return self.name class Store(models.Model): name = models.CharField(max_length=255) books = models.ManyToManyField(Book) original_opening = models.DateTimeField() friday_night_closing = models.TimeField() def __str__(self): return self.name class DepartmentStore(Store): chain = models.CharField(max_length=255) def __str__(self): return '%s - %s ' % (self.chain, self.name) class Employee(models.Model): # The order of these fields matter, do not change. Certain backends # rely on field ordering to perform database conversions, and this # model helps to test that. first_name = models.CharField(max_length=20) manager = models.BooleanField(default=False) last_name = models.CharField(max_length=20) store = models.ForeignKey(Store, models.CASCADE) age = models.IntegerField() salary = models.DecimalField(max_digits=8, decimal_places=2) def __str__(self): return '%s %s' % (self.first_name, self.last_name) class Company(models.Model): name = models.CharField(max_length=200) motto = models.CharField(max_length=200, null=True, blank=True) ticker_name = models.CharField(max_length=10, null=True, blank=True) description = models.CharField(max_length=200, null=True, blank=True) def __str__(self): return 'Company(name=%s, motto=%s, ticker_name=%s, description=%s)' % ( self.name, self.motto, self.ticker_name, self.description, ) class Ticket(models.Model): active_at = models.DateTimeField() duration = models.DurationField() def __str__(self): return '{} - {}'.format(self.active_at, self.duration)