hive 計算年齡

--effective_date 可以是當前日期，也可以是數據中中數據的創建日期

--計算年齡
, if(
  datediff(ui.effective_date , CONCAT(substr(ui.effective_date , 0, 4), substr(uip.user_birthday, 5, 7)))>=0,
  (substr(ui.effective_date , 0, 4) - substr(uip.user_birthday, 0, 4)),
  (substr(ui.effective_date , 0, 4) - substr(uip.user_birthday, 0, 4) - 1)
) as uip_user_age