Django之content_type
什么是content type:django内置的一个组件,这个组件帮忙做连表的操作。(混搭连表)
适用场景:适用于一张表与多张表同时做关联的时候。直接导入就可以使用了。
关联数据库说有的表;让我们可以快速插入数据,并且用反向查找能快速查找到数据。
models.py文件建立表
from django.db import models # Create your models here. from django.contrib.contenttypes.fields import GenericForeignKey,GenericRelation from django.contrib.contenttypes.models import ContentType class Course(models.Model): ''' 普通课程 ''' title=models.CharField(max_length=32) # 仅用于反向查找 price_policy_list=GenericRelation('PricePolicy') class DegreeCourse(models.Model): ''' 学位课程 ''' title=models.CharField(max_length=32) # 仅用于反向查找 price_policy_list=GenericRelation('PricePolicy') class PricePolicy(models.Model): ''' 价钱策略 ''' price = models.IntegerField() period = models.IntegerField() content_type=models.ForeignKey(ContentType,verbose_name='关联的表名称') object_id=models.IntegerField(verbose_name='关联的表中的数据行的ID') content_object=GenericForeignKey('content_type','object_id') # 1. 为学位课“Python全栈”添加一个价格策略:一个月 9.9 """ obj = DegreeCourse.objects.filter(title='Python全栈').first() # obj.id cobj = ContentType.objects.filter(model='course').first() # cobj.id PricePolicy.objects.create(price='9.9',period='30',content_type_id=cobj.id,object_id=obj.id) """
views.py文件,进行数据插入和查看
from django.shortcuts import render,HttpResponse # Create your views here. from app01 import models def test(request): # 1 为学位课python添加一个价格策略:一个月9.9 # obj1=models.DegreeCourse.objects.filter(title='python').first() # models.PricePolicy.objects.create(price=9.9,period=30,content_object=obj1) # # obj1 = models.DegreeCourse.objects.filter(title='python').first() # models.PricePolicy.objects.create(price=19.9, period=60, content_object=obj2) # # obj1 = models.DegreeCourse.objects.filter(title='python').first() # models.PricePolicy.objects.create(price=29.9, period=90, content_object=obj3) # # 2 为学位课rest framework添加一个价格策略:一个月9.9 # obj1=models.Course.objects.filter(title='rest framework').first() # models.PricePolicy.objects.create(price=9.9,period=30,content_object=obj1) # # obj2 = models.Course.objects.filter(title='rest framework').first() # models.PricePolicy.objects.create(price=19.9, period=60, content_object=obj2) # # obj3 = models.Course.objects.filter(title='rest framework').first() # models.PricePolicy.objects.create(price=29.9, period=90, content_object=obj3) # 3 根据课程的ID获取课程,并获取该课程的所有价格策略 course=models.Course.objects.filter(id=1).first() price_policys=course.price_policy_list.all() print(price_policys) return HttpResponse('ok')