第四章、Django之模型层---创建模型
一、写models.py
from django.db import models
# Create your models here.
"""
你在写orm语句的时候 跟你写sql语句一样
不要想着一次性写完
写一点查一点看一点
"""
class Book(models.Model):
title = models.CharField(max_length=32)
price = models.DecimalField(max_digits=8,decimal_places=2)
publish_date = models.DateField(auto_now_add=True)
# 书籍与出版社 是一对多关系
publish = models.ForeignKey(to=\'Publish\')
# 书籍与作者 是多对多
authors = models.ManyToManyField(to=\'Author\')
"""
authors虚拟字段
1.告诉orm自动帮你创建第三张关系表
2.orm查询的时候 能够帮助你更加方便的查询
"""
def __str__(self):
return self.title
class Publish(models.Model):
name = models.CharField(max_length=32)
addr = models.CharField(max_length=64)
def __str__(self):
return self.name
"""return返回的数据必须是字符串类型"""
class Author(models.Model):
name = models.CharField(max_length=32)
age = models.IntegerField()
# author_detail = models.ForeignKey(unique=True,to=\'AuthorDetail\')
author_detail = models.OneToOneField(to=\'AuthorDetail\')
def __str__(self):
return self.name
class AuthorDetail(models.Model):
phone = models.BigIntegerField()
addr = models.CharField(max_length=64)
def __str__(self):
return self.addr