！！请教个sql语句。。
有一个表tmp
date name used
2012/10/17 8:00:00 db1 20
2012/10/17 8:30:00 db1 23
2012/10/17 9:00:00 db1 32
2012/10/18 8:00:00 db1 15
2012/10/18 8:30:00 db1 18
2012/10/18 9:00:00 db1 21
2012/10/18 9:30:00 db1 25
求环比增长量，本次采集的时间点与上次采集的时间点相比used的增长量，请教sql语句
求同比增长量，今天采集数据的时间点与昨天采集的相同的时间点相比used的增长量，请教sql语句，
对这一个表操作。。
[解决办法]
with t1 as( select '2012/10/17 8:00:00' c1,'db1' name,20 used from dual union all select '2012/10/17 8:30:00' c1,'db1' name,23 used from dual union all select '2012/10/17 9:00:00' c1,'db1' name,32 used from dual union all select '2012/10/18 8:00:00' c1,'db1' name,15 used from dual union all select '2012/10/18 8:30:00' c1,'db1' name,18 used from dual union all select '2012/10/18 9:00:00' c1,'db1' name,21 used from dual union all select '2012/10/18 10:00:00' c1,'db1' name,14 used from dual union all select '2012/10/19 8:00:00' c1,'db1' name,23 used from dual union all select '2012/10/19 10:00:00' c1,'db1' name,17 used from dual)select c1,name,used, round(used-lag(used) over(partition by name order by rownum),2) z1, round(used-lag(used) over(partition by to_char(to_date(c1,'yyyy/mm/dd hh24:mi:ss'),'hh24:mi:ss') order by c1),2) z2from t1order by to_date(c1,'yyyy/mm/dd hh24:mi:ss') c1 name used z1 z2---------------------------1 2012/10/17 8:00:00 db1 20 2 2012/10/17 8:30:00 db1 23 3 3 2012/10/17 9:00:00 db1 32 9 4 2012/10/18 8:00:00 db1 15 -17 -55 2012/10/18 8:30:00 db1 18 3 -56 2012/10/18 9:00:00 db1 21 3 -117 2012/10/18 10:00:00 db1 14 -7 8 2012/10/19 8:00:00 db1 23 9 89 2012/10/19 10:00:00 db1 17 -6 3
