模型里的 抽象类 表继承

# 主表
class Base(models.Model):
    create_time = models.DateTimeField(auto_now_add=True)   #创建时间
    update_time = models.DateTimeField(auto_now=True)   #更新时间
    class Meta:
        abstract = True   #一定要写

class Stu(Base,models.Model):
    name = models.CharField(max_length=32)
    img = models.CharField(max_length=255)
    duo = models.ManyToManyField(to='Kc',related_name='sss')#
    class Meta:
        db_table='stu'