关于python:peewee-定义-createdat-和-updatedat

class SearchEngineCheck(Model):    category = CharField()    track_source_id = IntegerField()    keyword = CharField()    clip_len = IntegerField(null=True)    has_error = BooleanField(default=False)    created_at = DateTimeField(        null=False,        constraints=[SQL('DEFAULT CURRENT_TIMESTAMP')],        help_text='应用数据库工夫'    )    updated_at = DateTimeField(        null=False,        constraints=[            SQL('DEFAULT CURRENT_TIMESTAMP'),            SQL('ON UPDATE CURRENT_TIMESTAMP'),        ]    )    class Meta:        database = db        table_name = 'parse_monitoring'        indexes = (            ('parsed_at', 'track_source_id'),        )