oracle某些sql计算

    select rdc.city_code          as city_id,
           rdc.city_name,
           rdc.DIS_FAIL_ORDER_NUM as RES_PREE_FAILURE_NUM,
           --以下是计算最近的整分时间
           to_char(sysdate, ‘hh24‘) || ‘:‘ ||
           CASE trunc(to_char(sysdate, ‘mi‘) / 15, 0)
             WHEN 0 THEN
              ‘00‘
             WHEN 1 THEN
              ‘15‘
             WHEN 2 THEN
              ‘30‘
             WHEN 3 THEN
              ‘45‘
             ELSE
              ‘00‘
           END as HOUR_MIN
      from res_dis_city rdc
     where rdc.create_date =
           (select max(t.create_date) from res_dis_city t);