from django.db import modelsclass Electrics(models.Model):"""id  name1   日立冰箱2   三星电视3   小天鹅洗衣机"""name = models.CharField(max_length=32)class Foods(models.Model):"""id   name1    面包2    烤鸭"""name = models.CharField(max_length=32)class Clothes(models.Model):name = models.CharField(max_length=32)class Coupon(models.Model):"""id     name            Electrics        Foods           Clothes        more...1     通用优惠券       null              null            null          2     冰箱满减券         2               null            null3     面包狂欢节        null              1              null"""name = models.CharField(max_length=32)electric_obj = models.ForeignKey(to='Electrics', null=True)food_obj = models.ForeignKey(to='Foods', null=True)cloth_obj = models.ForeignKey(to='Clothes', null=True)

from django.db import models
from django.contrib.contenttypes.models import ContentType
from django.contrib.contenttypes.fields import GenericForeignKeyclass Electrics(models.Model):name = models.CharField(max_length=32)coupons = GenericRelation(to='Coupon')  # 用于反向查询，不会生成表字段def __str__(self):return self.nameclass Foods(models.Model):name = models.CharField(max_length=32)coupons = GenericRelation(to='Coupon')def __str__(self):return self.nameclass Clothes(models.Model):name = models.CharField(max_length=32)coupons = GenericRelation(to='Coupon')def __str__(self):return self.nameclass Coupon(models.Model):name = models.CharField(max_length=32)content_type = models.ForeignKey(to=ContentType) # step 1 添加一个字段，关联ContentType表中的某一个表object_id = models.PositiveIntegerField() # step 2 添加一个id字段，就是‘某一张’表在ContentType里的对应的idcontent_object = GenericForeignKey('content_type', 'object_id') # step 3 不会添加字段，只是为了插入或者查询时使用def __str__(self):return self.name

from django.shortcuts import render, HttpResponse
from app01 import models
from django.contrib.contenttypes.models import ContentTypedef test(request):if request.method == 'GET':# ContentType表对象有model_class() 方法，取到对应modelcontent = ContentType.objects.filter(app_label='app01', model='electrics').first()  # 表名小写cloth_class = content.model_class() # cloth_class 就相当于models.Electricsres = cloth_class.objects.all()print(res)# 为三星电视(id=2)创建一条优惠记录s_tv = models.Electrics.objects.filter(id=2).first()models.Coupon.objects.create(name='电视优惠券', content_object=s_tv)  #直接用content_object属性添加，无需给contenttype和object_id字段分别赋值
<br>　　　　# 查询优惠券（id=1）绑定了哪些商品coupon_obj = models.Coupon.objects.filter(id=1).first()prod = coupon_obj.content_objectprint(prod)# 查询三星电视(id=2)的所有优惠券res = s_tv.coupons.all() print(res)# 查询obj的所有优惠券：如果没有定义反向查询字段，通过如下方式：content = ContentType.objects.filter(app_label='app01', model='model_name').first()res = models.OftenAskedQuestion.objects.filter(content_type=content,object_id=obj.pk).all() <br>　　　　<br><br>　　　　return HttpResponse('....')