a表三列：id为int类型，dt列为datetime类型，data列为int 类型
id dt data
1 2007-05-1 9:00:10 100
1 2007-05-1 9:04:10 101
1 2007-05-1 9:08:10 102
1 2007-05-2 9:01:10 103
1 2007-05-2 9:05:18 104
查询是这样的：
假设我要id 为1的数据，时间是5月1号和2号，离9点最近的数据
id dt today9 yesterday9
1 2007-05-1 9:00:10 100 103
帮着出出主意吧
------解决方案--------------------
declare @a table(id int, dt datetime,data int)
insert @a select 1 , '2007-05-1 9:00:10 ', 100
union all select 1 , '2007-05-1 9:04:10 ', 101
union all select 1 , '2007-05-1 9:08:10 ', 102
union all select 1 , '2007-05-2 9:01:10 ', 103
union all select 1 , '2007-05-2 9:05:18 ', 104
select id,dt,convert(varchar(10),dt,120) d,abs(datediff(ss,cast(convert(varchar(10),dt,120)+ ' 09:00:00 ' as datetime),dt) ) ti, data into #tmp from @a
select * from #tmp a where not exists(select 1 from #tmp where id=a.id and d=a.d and ti <a.ti)
drop table #tmp
------解决方案--------------------
try
Select
TOP 1
id,
dt,
data As today9,
(Select TOP 1 data From A Where id = T.id And DateDiff(dd, T.dt, dt) = 1 And Datepart(hh, dt) > =9 Order By dt) As tomorrow9
From A T
Where Datepart(hh, dt) > =9 And DateDiff(dd, dt, ' 2007-05-01 ') = 0
Order By dt
------解决方案--------------------
Create Table A
(id Int,
dt Datetime,
data Int)
Insert A Select 1, '2007-05-1 9:00:10 ', 100
Union All Select 1, '2007-05-1 9:04:10 ', 101
Union All Select 1, '2007-05-1 9:08:10 ', 102
Union All Select 1, '2007-05-2 9:01:10 ', 103
Union All Select 1, '2007-05-2 9:05:18 ', 104
GO
Select
TOP 1
id,
dt,
data As today9,
(Select TOP 1 data From A Where id = T.id And DateDiff(dd, T.dt, dt) = 1 And Datepart(hh, dt) > =9 Order By dt) As tomorrow9
From A T
Where Datepart(hh, dt) > =9 And DateDiff(dd, dt, ' 2007-05-01 ') = 0
Order By dt
GO
Drop Table A
--Result
/*
id dt today9 tomorrow9
1 2007-05-01 09:00:10.000 100 103
*/