求助，关于分组求最大值的问题， 在线等
id jiquid date price
101101012012-07-10 00:00:00.0006.71
101101012012-08-10 00:00:00.000NULL
101101012012-08-13 00:00:00.0007.01
101101012012-09-01 00:00:00.0007.03
101101012012-09-11 00:00:00.0007.46
102102012012-07-10 00:00:00.000NULL
102102012012-08-10 00:00:00.0007.02
103103152012-07-10 00:00:00.0006.93
108108012012-07-11 00:00:00.0007.28
108108012012-09-11 00:00:00.0007.72
109109012012-07-11 00:00:00.0006.88
109109012012-08-10 00:00:00.0007.19
109109012012-09-11 00:00:00.0007.63
112112012012-07-31 00:00:00.0007.05
112112012012-08-01 00:00:00.0007.36
112112012012-08-10 00:00:00.0007.36
112112012012-08-11 00:00:00.0007.80
201201012012-07-10 00:00:00.0006.96
201201012012-08-10 00:00:00.0007.27
201201012012-09-11 00:00:00.0007.71
202202012012-07-10 00:00:00.0006.94
202202012012-08-10 00:00:00.0007.25
203203012012-07-10 00:00:00.0007.07
203203012012-08-10 00:00:00.0007.38
206206012012-07-10 00:00:00.000NULL
206206012012-09-10 00:00:00.000NULL
301301012012-07-11 00:00:00.0007.26
301301012012-08-10 00:00:00.0007.58
301301012012-09-11 00:00:00.0008.02
302302012012-07-10 00:00:00.0007.16
303303012012-07-10 00:00:00.0007.96
303303012012-08-10 00:00:00.0008.27
303303012012-09-11 00:00:00.0008.71
402402012012-07-10 00:00:00.0006.97
402402012012-08-10 00:00:00.0007.28
402402012012-09-11 00:00:00.0007.72
403403012012-08-10 00:00:00.0007.28
404404012012-07-11 00:00:00.0006.94
404404012012-08-10 00:00:00.0007.25
404404012012-09-11 00:00:00.0007.68
501501012012-07-10 00:00:00.0006.92
501501012012-08-10 00:00:00.0007.23
501501012012-09-11 00:00:00.0007.67
502502012012-07-24 00:00:00.0006.90
502502012012-09-11 00:00:00.0007.65
503503012012-07-10 00:00:00.0007.26
503503012012-08-10 00:00:00.0007.26
503503012012-09-11 00:00:00.0007.70
603603012012-07-10 00:00:00.0007.03
603603012012-08-10 00:00:00.0007.34
603603012012-09-11 00:00:00.0007.78
数据如上。
以id为分组，求出每个id中date最大的行
想了半天没想出来…
谢谢…
[解决办法]
--1select * from tb as t where not exists(select 1 from tb where id=t.id and date>t.date)--2select * from tb as t where date(select max(date) from tb where id=t.id )--3select * from (select *,row_id=row_number() over(partition by id order by date desc) from tb) as t where row_id=1
[解决办法]
--> --> (Roy)生成測試數據if not object_id('Tempdb..#T') is null drop table #TGoCreate table #T([ID] int,[Name] nvarchar(1),[Memo] nvarchar(2))Insert #Tselect 1,N'A',N'A1' union allselect 2,N'A',N'A2' union allselect 3,N'A',N'A3' union allselect 4,N'B',N'B1' union allselect 5,N'B',N'B2'Go--Name相同ID最大的记录:方法1:Select * from #T a where not exists(select 1 from #T where Name=a.Name and ID>a.ID)方法2:select a.* from #T a join (select max(ID)ID,Name from #T group by Name) b on a.Name=b.Name and a.ID=b.ID order by ID方法3:select * from #T a where ID=(select max(ID) from #T where Name=a.Name) order by ID方法4:select a.* from #T a join #T b on a.Name=b.Name and a.ID<=b.ID group by a.ID,a.Name,a.Memo having count(1)=1 方法5:select * from #T a group by ID,Name,Memo having ID=(select max(ID)from #T where Name=a.Name)方法6:select * from #T a where (select count(1) from #T where Name=a.Name and ID>a.ID)=0方法7:select * from #T a where ID=(select top 1 ID from #T where Name=a.name order by ID desc)方法8:select * from #T a where ID!<all(select ID from #T where Name=a.Name)方法9(注:ID为唯一时可用):select * from #T a where ID in(select max(ID) from #T group by Name)--SQL2005:方法10:select ID,Name,Memo from (select *,max(ID)over(partition by Name) as MinID from #T a)T where ID=MinID方法11:select ID,Name,Memo from (select *,row_number()over(partition by Name order by ID desc) as MinID from #T a)T where MinID=1生成结果2:/*ID Name Memo----------- ---- ----3 A A35 B B2(2 行受影响)*/