select case when to_char(sysdate, 'HH24:mi:ss') >= '08:00:00' and to_char(sysdate, 'HH24:mi:ss') <= '20:00:00' then '早8-晚8' else '晚8-早8' end from dual

DATE_TIME 是你表里的时间字段

SELECT

    *

FROM

    TABLE1

WHERE

    1 = 1

    AND ${IF(AND(LEFT(RIGHT(NOW(),8),2)>="08",LEFT(RIGHT(NOW(),8),2)<"20"),

            "SUBSTR(TO_CHAR(DATE_TIME,'YYYY-MM-DD HH24:MI:SS'),12,2) >= '08' AND SUBSTR(TO_CHAR(DATE_TIME,'YYYY-MM-DD HH24:MI:SS'),12,2) < '20'",

            "SUBSTR(TO_CHAR(DATE_TIME,'YYYY-MM-DD HH24:MI:SS'),12,2) < '08' OR SUBSTR(TO_CHAR(DATE_TIME,'YYYY-MM-DD HH24:MI:SS'),12,2) >= '20'"

        )}

select * from dual 

where 

(

--8点之后并且20点之前

substr(to_char(sysdate,'yyyymmdd hh24:mi:ss'),10,2) >= 8 and substr(to_char(sysdate,'yyyymmdd hh24:mi:ss'),10,2) <= 20 

--v_date筛选8-20

      and v_data between to_date(to_char(sysdate,'yyyymmdd')||'08:00:00','yyyymmdd hh24:mi:ss') and to_date(to_char(sysdate,'yyyymmdd')||'20:00:00','yyyymmdd hh24:mi:ss') 

)

or

 (

--20点之后并且8点之前

substr(to_char(sysdate,'yyyymmdd hh24:mi:ss'),10,2) > 20 and substr(to_char(sysdate,'yyyymmdd hh24:mi:ss'),10,2) < 8

--v_date筛选20点之后到8点之前

      and v_data between to_date(to_char(sysdate,'yyyymmdd')||'20:00:01','yyyymmdd hh24:mi:ss') and to_date(to_char(sysdate,'yyyymmdd')||'07:59:59','yyyymmdd hh24:mi:ss')

 )