Django多表操作

from django.db import models

# Create your models here.

#不用创建ID，Django自动创建主键


class Book(models.Model):
    title=models.CharField(max_length=32,unique=True)
    price=models.DecimalField(max_digits=8,decimal_places=2,null=True)# 999999.99
    pub_date=models.DateField()
    publish=models.ForeignKey(to="Publish",to_field="id",on_delete=models.CASCADE)
django2.0需要写cascade
    authors=models.ManyToManyField(to="Author")
　　这里authors只是属性，不是字段，为了创建多对多关联表


    def __str__(self):
        return self.title

class Publish(models.Model):
    name=models.CharField(max_length=32)
    email=models.CharField(max_length=32)
    addr=models.CharField(max_length=32)


class Author(models.Model):
    name=models.CharField(max_length=32)
    age=models.IntegerField()
    这个不用# ad=models.ForeignKey(to="AuthorDetail",to_field="id",on_delete=models.CASCADE,unique=True)
    ad=models.OneToOneField(to="AuthorDetail",to_field="id",on_delete=models.CASCADE,)
　　用这个


class AuthorDetail(models.Model):
    gf=models.CharField(max_length=32)
    tel=models.CharField(max_length=32)