5.5Django网络框架（5）：数据模型详解
@说明
- 本文通过一个趣味的电商系统案例，演示Django框架中数据模型的使用
- 本例源代码的GitHub地址：https://github.com/ouyangsuo/WhatsDjangoModel
@创建数据模型
- 在子应用目录MyApp中创建数据模型，代码如下
from django.db import models
# Create your models here.
class Buyer(models.Model):
bname = models.CharField(max_length=20, unique=True)
bgender = models.NullBooleanField(default=None)
bage = models.IntegerField(default=0)
def __str__(self):
return self.bname
class Account(models.Model):
amoney = models.FloatField(default=100)
ano = models.CharField(max_length=10, unique=True)
apwd = models.CharField(max_length=6,default='111111')
abuyer = models.OneToOneField(Buyer)
def __str__(self):
return self.ano
class Order(models.Model):
# ono = models.AutoField(primary_key=True,default=1)
odatetime = models.DateTimeField(auto_now_add=True)
omoney = models.FloatField(default=0)
omsg = models.CharField(max_length=200,null=True)
obuyer = models.ForeignKey(Buyer)
def __str__(self):
return "Order{obuyer="+self.obuyer.bname+",omoney="+str(self.omoney)+"}"
class Goods(models.Model):
gname = models.CharField(max_length=20, unique=True)
gtype = models.CharField(max_length=10)
gprice = models.FloatField(default=0)
ginfo = models.TextField()
gbuyers = models.ManyToManyField(Buyer)
def __str__(self):
return self.gname
@创建和注册后台数据管理类
from django.contrib import admin
# Register your models here.
from MyApp.models import *
class BuyerAdmin(admin.ModelAdmin):
# bname = models.CharField(max_length=20, unique=True)
# bgender = models.NullBooleanField(default=None)
# bage = models.IntegerField(default=0)
def tellBgender(self):
if self.bgender:
return '男'
else:
return '女'
list_display = ['bname',tellBgender,'bage']
search_fields = ['bname']
list_filter = ['bgender','bage']
class AccountAdmin(admin.ModelAdmin):
# amoney = models.FloatField(default=100)
# ano = models.CharField(max_length=10, unique=True)
# apwd = models.CharField(default='111111')
# abuyer = models.OneToOneField(Buyer)
list_display = ['ano','apwd','abuyer']
search_fields = ['ano']
list_filter = ['amoney']
class GoodsAdmin(admin.ModelAdmin):
# gname = models.CharField(max_length=20, unique=True)
# gtype = models.CharField(max_length=10)
# gprice = models.FloatField(default=0)
# ginfo = models.TextField()
# gbuyers = models.ManyToManyField(Buyer)
list_display = ['gname','gtype','gprice','ginfo']
search_fields = ['gname','gprice','gbuyers']
list_filter = ['gprice','gtype']
class MySite(admin.AdminSite):
site_header = '美剁购物系统'
site_title = '美剁'
mysite = MySite()
mysite.register(Buyer,BuyerAdmin)
mysite.register(Account,AccountAdmin)
mysite.register(Goods,GoodsAdmin)
@执行数据迁移
python manage.py makemigrations
python manage.py migrate@在管理后台插入买家、账户、商品数据
- 添加数据后的表内容为
@定义路由分发规则
- 在工程中将美剁meiduo/开头的路由全部交由MyAPP下的urls.py进行分发
from django.conf.urls import url, include
from django.contrib import admin
from MyApp.admin import mysite
urlpatterns = [
url(r'^admin/', mysite.urls),
# 将meiduo开头的路由交由MyApp.urls进行分发
url(r'^meiduo/', include('MyApp.urls')),
]- 定义应用MyApp内部的派发规则，主要实现增删改查和关联关系管理
from django.conf.urls import url, include
from django.contrib import admin
from MyApp import views
from MyApp.admin import mysite
urlpatterns = [
# 买家的增删改查路由
url(r'^addbuyer/', views.addBuyer),
url(r'^deletebuyer/', views.deleteBuyer),
url(r'^updatebuyer/', views.updateBuyer),
url(r'^querybuyer/', views.queryBuyer),
# 一对一：获取用户的账户信息
url(r'^getaccount/(\d+)/', views.getAccount),
# 多对多：购买商品，获取用户购买的所有商品，查询商品的所有买家
url(r'^buy/(\d+)/(\d+)/', views.buy),
url(r'^getbuyergoods/(\d+)/', views.getBuyerGoods),
url(r'^getgoodsbuyers/(\d+)/', views.getGoodsBuyers),
# 一对多：查询用户的所有订单
url(r'^getorders/(\d+)/', views.getOrders),
]@实现用户数据的增删改查
- 在应用目录MyApp下实现对用户的增删改查
# 添加以时间戳明明的新用户
def addBuyer(request):
b = Buyer()
b.bname = 'Buyer-' + str(int(time.time()))
b.save()
return HttpResponse('用户添加成功' + b.bname)
# 删除最后一个用户
def deleteBuyer(request):
b = Buyer.objects.last()
b.delete()
return HttpResponse('用户删除成功' + b.bname)
# 修改用户名称
def updateBuyer(request):
b = Buyer.objects.last()
b.bname = 'new' + b.bname
b.save()
return HttpResponse('用户修改成功' + b.bname)
# 查询所有用户
def queryBuyer(request):
bs = Buyer.objects.all()
ret = ''
for b in bs:
ret += b.bname + ";"
return HttpResponse('用户查询成功' + ret)- 在应用的views.py中实现关联关系的查询
# 一对一：获取用户的账户信息
def getAccount(request, bid):
b = Buyer.objects.get(pk=bid)
account = b.account
return HttpResponse(account.ano)
# 用户购买商品
def buy(request, bid, gid):
b = Buyer.objects.get(pk=bid)
g = Goods.objects.get(pk=gid)
g.gbuyers.add(b)
g.save()
o = Order()
o.obuyer = b
o.omoney = g.gprice
o.omsg = g.gname
o.save()
return HttpResponse(o)
# 一对多：查看用户的所有订单
def getOrders(request, bid):
b = Buyer.objects.get(pk=bid)
bos = b.order_set.all()
ret = ''
for o in bos:
ret += str(o.id) + ";"
return HttpResponse(ret)
# 多对多：查看用户购买的全部商品
def getBuyerGoods(request, bid):
b = Buyer.objects.get(pk=bid)
gs = b.goods_set
ret = ''
for g in gs:
ret += g.gname + ";"
return HttpResponse(ret)
# 多对多：查看商品的全部买家
def getGoodsBuyers(request, gid):
g = Goods.objects.get(pk=gid)
bs = g.gbuyers.all()
ret = ''
for b in bs:
ret += b.bname + ";"
return HttpResponse(ret)