text: from django.db import models
  
  
  class CommonModel(models.Model):
      """ 模型公共类 """
      is_valid = models.BooleanField('是否有效', default=True)
      created_at = models.DateTimeField('创建时间', auto_now_add=True)
      updated_at = models.DateTimeField('修改时间', auto_now=True)
  
      class Meta:
          abstract = True
  