请教各位，如果我想查询一个时间字段的 2011-12-09 号的 7点到8点的前10条 、 9点到10点的前10条 、11点到12点的前10条 等等，总共30条，这个SQL咋写？
------解决方案--------------------
select t.*,t.rownum from tablename t where time >= '2011-12-09 07%' and time <= '2011-12-09 08%' and t.rownum<=10
UNION ALL
select t.*,t.rownum from tablename t where time >= '2011-12-09 09%' and time <= '2011-12-09 10%' and t.rownum<=10
UNION ALL
select t.*,t.rownum from tablename t where time >= '2011-12-09 11%' and time <= '2011-12-09 12%' and t.rownum<=10
------解决方案--------------------
- SQL code
select * from (select row_number() over (partition by trunc(time_data,'hh') order by time_data) rn,t.* from twhere sign(time_data-to_date('2009-12-09 07','yyyy-mm-dd hh24'))+sign(time_data-to_date('2009-12-09 08','yyyy-mm-dd hh24'))=0 or sign(time_data-to_date('2009-12-09 09','yyyy-mm-dd hh24'))+sign(time_data-to_date('2009-12-09 10','yyyy-mm-dd hh24'))=0 or ...)t2where t2.rn <=10