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  • 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')
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  • 原文地址:https://www.cnblogs.com/zycorn/p/10020490.html
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