Background coupon management

Back end

Create a new sub app

Create another one in the project coupons Subapplication
In the project settings.py Register the sub application in the file
stay coupons Create in subapplication urls.py File configuration routing
And then in coupons Write in your own sub application

Write model classes

Generate migration files for migration
Note that foreign key bound tables should be imported

from django.db import models
from goods.models import SKUS
from users.models import User
# Create your models here.
# Coupon type 
class CouponType(models.Model):
    type_name=models.CharField(' Coupon type ',max_length=30)
    def __str__(self):
        return self.type_name
    class Meta:
        db_table='coupon_type'

#y Coupon 
class Coupon(models.Model):
    name=models.CharField(' Coupon name ',max_length=100)
    brief=models.TextField(' Coupon introduction ',default='')
    coupon_type=models.ForeignKey(CouponType,on_delete=models.CASCADE,verbose_name=' Coupon type ',null=True,blank=True)
    good=models.ForeignKey(SKUS,on_delete=models.CASCADE,verbose_name=' goods ',null=True,blank=True)
    coupon_num=models.IntegerField(' Number ',default=0)
    start_time=models.DateTimeField(' Starting time ')
    over_time=models.DateTimeField(' End use time ')
    start_get_time=models.DateTimeField(' Start time of ticket collection ')
    end_get_time=models.DateTimeField(' End time of receipt ')
    remark=models.CharField(' remarks ',max_length=300)
    def __str__(self):
        return self.name
    class Meta:
        db_table='coupon'
# Coupon -- type -- Specific value 
class CouponTypeValue(models.Model):
    coupon=models.ForeignKey(Coupon,on_delete=models.CASCADE,verbose_name=' Coupon ')
    coupon_type=models.ForeignKey(CouponType,on_delete=models.CASCADE,verbose_name=' Coupon type ')
    value=models.IntegerField(' Coupon value ',default=0)
    def __str__(self):
        # return ' Coupon name - type -value'
        return f'{
      self.coupon.name}-{
      self.coupon_type.type_name}-{
      self.value}'
    class Meta:
        db_table='coupon_type_value'

# User ticket collection form 
class UserGetCoupon(models.Model):
    STATUS=(
        (0,' not used '),
        (1,' Already used '),
        (2,' Has expired ')
    )
    user=models.ForeignKey(User,on_delete=models.CASCADE,verbose_name=' user ')
    coupon=models.ForeignKey(Coupon,on_delete=models.CASCADE,verbose_name=' Coupon ')
    status=models.SmallIntegerField(' Using a state ',default=0,choices=STATUS)
    get_time=models.DateTimeField(' Voucher collection time ',auto_now_add=True)
    user_time=models.DateTimeField(' Use your time ',null=True,blank=True)
    def __str__(self):
        # return ' user name - Coupon name - Using a state '
        return '%s-%s-%s'%(self.user.username,self.coupon.name,self.get_status_display())
    class Meta:
        db_table='user_get_coupon'

Write a serializer

Create in subapplication serializers.py file

from rest_framework import serializers
from .models import *

class CouponSer(serializers.ModelSerializer):
    good_name=serializers.SerializerMethodField(read_only=True)
    def get_good_name(self,obj):
        if obj.good:
            return obj.good.name
        else:
            return ' Non item coupons '
    coupon_type_name=serializers.SerializerMethodField(read_only=True)
    def get_coupon_type_name(self,obj):
        return obj.coupon_type.type_name
    class Meta:
        model=Coupon
        fields='__all__'
        read_only_fields=['id']
#  Serializer of coupon type 
class CouponTypeSer(serializers.ModelSerializer):

    class Meta:
        model=CouponType
        fields='__all__'
        read_only_fields=['id']

Write view classes

from django.shortcuts import render
from rest_framework.viewsets import ModelViewSet
from rest_framework.response import Response
from .models import *
from .serializers import *
from rest_framework.generics import ListAPIView
# Create your views here.
from rest_framework.pagination import PageNumberPagination
class MyPagination(PageNumberPagination):
    page_size = 3
    max_page_size = 5
    page_query_param = 'page'
    page_size_query_param = 'pageSize'
#  View of coupon 
class CouponViewSet(ModelViewSet):
    queryset = Coupon.objects.all()
    serializer_class = CouponSer
    lookup_field = 'pk'
    lookup_url_kwarg = 'pk'
    pagination_class = MyPagination
    # rewrite destroys Delete method 
    def destroy(self, request, *args, **kwargs):
        obj = self.get_object()
        ser = " Huawei " in obj.name
        if not ser:
            return Response({
    "code": 400, "msg": " Delete Huawei "})
        obj.delete()
        return Response({
    "code": 200, "msg": " Delete successful "})
    # rewrite create Method 
    def create(self, request, *args, **kwargs):
        print(request.data)
        name = request.data.get("name")
        repe = self.get_queryset().filter(name=name).first()
        if repe:
            return Response({
    "code": 400, "msg": " Coupon already exists "})
        try:
            ser = self.get_serializer(data=request.data)
            ser.is_valid()
            ser.save()
        except Exception as e:
            print(e)
            return Response({
    "code": 400, "msg": " Create failure "})
        return Response({
    "code": 201, "msg": " Add success "})
#  View of coupon types 
class CouponTypeAPIView(ListAPIView):
    queryset = CouponType.objects.all()
    serializer_class = CouponTypeSer
    lookup_field = 'pk'
    lookup_url_kwarg = 'pk'

Configure the routing

# from django.contrib import admin
from django.urls import path
from rest_framework import routers
from .views import *
urlpatterns = [
    # Load all coupon types 
    path('types/',CouponTypeAPIView.as_view())
]
router=routers.SimpleRouter()
router.register('coupon',CouponViewSet)
urlpatterns+=router.urls