找出10次考试中成绩连续下滑3次的学生

问题：从10次考试中，找出考试成绩连续下滑3次的学生姓名？

解法：

SQL> with tb as(
  2  select 'aspen' sname,to_date('20100111','yyyymmdd')ttime,100 score from dual
  3  union all
  4  select 'aspen',to_date('20100211','yyyymmdd'),90 from dual
  5  union all
  6  select 'aspen',to_date('20100311','yyyymmdd'),80 from dual
  7  union all
  8  select 'aspen',to_date('20100411','yyyymmdd'),82 from dual
  9  union all
 10  select 'aspen',to_date('20100511','yyyymmdd'),81 from dual
 11  union all
 12  select 'aspen',to_date('20100611','yyyymmdd'),79 from dual
 13  union all
 14  select 'aspen',to_date('20100711','yyyymmdd'),77 from dual
 15  union all
 16  select 'aspen',to_date('20100811','yyyymmdd'),70 from dual
 17  union all
 18  select 'scott',to_date('20100111','yyyymmdd'),70 from dual
 19  union all
 20  select 'scott',to_date('20100211','yyyymmdd'),60 from dual
 21  union all
 22  select 'scott',to_date('20100311','yyyymmdd'),90 from dual
 23  )
 24  select distinct sname
 25  from
 26    (select sname,
 27    ttime,
 28    score,
 29    row_number() over(partition by sname order by ttime) rn
 30    from tb) t
 31  where level>=4
 32  start with rn=rn
 33  connect by prior score>score and prior rn=rn-1
 34  /

SNAME
-----
aspen

原帖：http://topic.csdn.net/u/20110314/15/5a7c8ca2-a0db-461c-b21b-07a74383341a.html?82160