from django.db import models
# Create your models here.classPublisher(models.Model):
name = models.CharField(max_length=20)
address = models.CharField(max_length=50)
city = models.CharField(max_length=20)
country = models.CharField(max_length=20)
website = models.URLField()
classAuthor(models.Model):
name = models.CharField(max_length=20)# varchar(20)
age = models.IntegerField()# int
email = models.EmailField(null=True)# varchar(254)允许为空classBook(models.Model):
title = models.CharField(max_length=30)# varchar(30)
publication_date = models.DateField(default=datetime.datetime.now())# date