SELECT  dr_id
  
        ,ds
FROM    study
WHERE   ds <= ‘20210621‘
AND     ds > ‘20210520‘and     dr_id=‘193589‘;
查出结果是：8条记录

 用 group by   dr_id=193589,有8人

SELECT dr_id

,COUNT(DISTINCT ds) AS online_30d

FROM alihealth_dw.dwd_alihosp_dr_online_df

WHERE ds <= ‘20210621‘

AND ds > ‘20210520‘

AND is_online_1d = ‘Y‘

and dr_id=‘193589‘

GROUP BY dr_id;