$Django content_type组件 缓存组件

1  content_type组件(只能方便插入添加)

需求:课程，学位课（不同的课程字段不一样），价格策略

#免费课
class Free_classes (models.Model):
    id = models.AutoField (primary_key=True)
    name = models.CharField (max_length=32)
    def __str__(self):
        return self.name

#学位课
class degree_course (models.Model):
    id = models.AutoField (primary_key=True)
    name = models.CharField (max_length=32)
    def __str__(self):
        return self.name

#周期价格
class Price (models.Model):
    id = models.AutoField (primary_key=True)
    period = models.CharField (max_length=32)
    price = models.DecimalField (max_digits=8, decimal_places=2)
    table_id = models.ForeignKey (to=ContentType)
    course_id = models.IntegerField ()

model设计