数据库结构备份

from django.db import models

# Create your models here.

class User(models.Model):
    username=models.CharField(max_length=32)
    password=models.CharField(max_length=32)
    role = models.ForeignKey("Role", on_delete=models.CASCADE)

class Role(models.Model):
    name=models.CharField(max_length=32)
class Province(models.Model):
    province = models.CharField(max_length=32)
class City(models.Model):
    city=models.CharField(max_length=32)
    province=models.ForeignKey("Province",on_delete=models.CASCADE)
class Customer(models.Model):
    long_name=models.CharField(max_length=32)
    short_name=models.CharField(max_length=32,null=True)
    address=models.CharField(max_length=64)
    register_time=models.DateField(auto_now_add=True)
    city=models.ForeignKey("City",on_delete=models.CASCADE)
    role=models.ForeignKey("Role",on_delete=models.CASCADE)
    user=models.ForeignKey("User",on_delete=models.CASCADE)

class Client(models.Model):
    name=models.CharField(max_length=32)
    SEX_CHOICES=(("F","女"),("M","男"))
    gender = models.CharField(max_length=2,choices=SEX_CHOICES,default="M")
    role_position=models.CharField(max_length=32)
    cellphone=models.CharField(max_length=32)
    telephone=models.CharField(max_length=32,null=True)
    qq=models.CharField(max_length=32,null=True)
    email=models.EmailField(null=True)
    register_time = models.DateField(auto_now_add=True)

    #一个外键链接 客户表
    customer=models.ForeignKey("Customer",on_delete=models.CASCADE)

class Visit(models.Model):
    content=models.TextField(max_length=32)
    client=models.ForeignKey("Client",on_delete=models.CASCADE)
    register_user=models.ForeignKey("User",on_delete=models.CASCADE)
    register_time = models.DateField(auto_now_add=True)