from django.db import models
from django.contrib.contenttypes.fields import GenericForeignKey,GenericRelation,ContentType
class Post(models.Model):"""帖子表"""title = models.CharField(max_length=72)# 查看一个对象的全部评论用comments，创建时用GenericRelationcomments=GenericRelation('Comment')
class Picture(models.Model):"""图片表"""image = models.ImageField()comments = GenericRelation('Comment')class Comment(models.Model):"""评论表"""content = models.TextField()# post = models.ForeignKey(Post, null=True, blank=True, on_delete=models.CASCADE)# picture = models.ForeignKey(Picture, null=True, blank=True, on_delete=models.CASCADE)# 外键关联ContentType（其中有所有的表）content_type=models.ForeignKey(ContentType,on_delete=models.DO_NOTHING)# 关联数据的主键，具体某一行的id（例如具体某一个帖子的id）object_id=models.PositiveSmallIntegerField()# GenericForeignKey字段创建，在数据库中不会存在该字段content_object=GenericForeignKey('content_type','object_id')

from django.shortcuts import render,HttpResponse
from app01 import models
from django.contrib.contenttypes.fields import ContentType
# Create your views here.
def Test(request):# 创建测试数据 方式一# content_type_pic_obj=ContentType.objects.filter(model='picture').first()# picture_obj=models.Picture.objects.filter(id=1).first()# models.Comment.objects.create(content='图片好看2',content_type=content_type_pic_obj,object_id=picture_obj.id)# models.Comment.objects.create(content='图片好看3',content_type=content_type_pic_obj,object_id=picture_obj.id)# models.Comment.objects.create(content='图片好看4',content_type=content_type_pic_obj,object_id=picture_obj.id)# content_type_post_obj = ContentType.objects.filter(model='post').first()# post_obj_1 = models.Post.objects.filter(title='散文1').first()# post_obj_2 = models.Post.objects.filter(title='散文2').first()# models.Comment.objects.create(content='散文写的好', content_type=content_type_post_obj, object_id=post_obj_1.id)# models.Comment.objects.create(content='散文写的好2', content_type=content_type_post_obj, object_id=post_obj_1.id)# models.Comment.objects.create(content='散文写的好3', content_type=content_type_post_obj, object_id=post_obj_2.id)# 创建测试数据方式二# picture_obj = models.Picture.objects.filter(image='default_avatar.jpg').first()# models.Comment.objects.create(content_object=picture_obj,content='图片一般般')# post_obj_1 = models.Post.objects.filter(title='散文1').first()# models.Comment.objects.create(content_object=post_obj_1, content='文章一般般')# 查询一个对象的所有评论comment_list=models.Post.objects.filter(id=1).first().comments.all()print(comment_list)return HttpResponse('...')

"""django_contenttypes编写models URL ConfigurationThe `urlpatterns` list routes URLs to views. For more information please see:https://docs.djangoproject.com/en/2.0/topics/http/urls/
Examples:
Function views1. Add an import:  from my_app import views2. Add a URL to urlpatterns:  path('', views.home, name='home')
Class-based views1. Add an import:  from other_app.views import Home2. Add a URL to urlpatterns:  path('', Home.as_view(), name='home')
Including another URLconf1. Import the include() function: from django.urls import include, path2. Add a URL to urlpatterns:  path('blog/', include('blog.urls'))
"""
from django.contrib import admin
from django.urls import path
from app01 import views
urlpatterns = [path('admin/', admin.site.urls),path('test/', views.Test),
]