django 外键的增删改查，一对多和多对多

1.一对一和一多对多是一样的，多对多不太一样

 

 

2.增 post (一对多）

class BookView(APIView):


    def post (self,request,*args,**kwargs):
        publish=Publish.objects.filter(pk=1).first()
        author=Author.objects.filter(pk=1)
        Book.objects.create(book_name="红楼",publish=publish) # 自动关联出版社，publish_id ,publish  也可以
        #方法2，新增数据
        book_objects=Book(book_name="aa",publish=publish)
        book_objects.save()
        # 删除
        Publish.objects.filter(pk=2).delete()
        # 修改
        Book.objects.filter(pk=1).update(publish_id=1)