Django-Content-type用法

from django.db import models
from django.contrib.contenttypes.models import ContentType
from django.contrib.contenttypes.fields import GenericRelation,GenericForeignKey

class  SuperCourse(models.Model):
    name = models.CharField(max_length=32,verbose_name="超级课名")
    course_policy = GenericRelation('CoursePolicy')

class NormalCourse(models.Model):
    name = models.CharField(max_length=32,verbose_name='普通课名')
    course_policy = GenericRelation('CoursePolicy')

class CoursePolicy(models.Model):
    price = models.IntegerField(verbose_name="价格")
    period = models.IntegerField(verbose_name="周期")
    object_id = models.IntegerField(verbose_name="课程id")
    table_name = models.ForeignKey(ContentType,verbose_name="关键在ContentType表里面的表名")
    # obj = GenericForeignKey('table_name',"object_id")
    obj = GenericForeignKey(ct_field=table_name,fk_field=object_id)