比如有这些一些数据
c0,c1,c2
-------------
a,2,2003
b,3,2003
c,4,2003
a,1,2004
b,1,2004
c,2,2004我要取每一年的排名前2位的,谢谢
c0,c1,c2
-------------
a,2,2003
b,3,2003
c,4,2003
a,1,2004
b,1,2004
c,2,2004我要取每一年的排名前2位的,谢谢
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-- Author: liangCK 小梁
-- Title : 查每个分组前N条记录
-- Date : 2008-11-13 17:19:23
-----------------------------------> 生成测试数据: #T
IF OBJECT_ID('tempdb.dbo.#T') IS NOT NULL DROP TABLE #T
CREATE TABLE #T (ID VARCHAR(3),GID INT,Author VARCHAR(29),Title VARCHAR(39),Date DATETIME)
INSERT INTO #T
SELECT '001',1,'邹建','深入浅出SQLServer2005开发管理与应用实例','2008-05-10' UNION ALL
SELECT '002',1,'胡百敬','SQLServer2005性能调校','2008-03-22' UNION ALL
SELECT '003',1,'格罗夫Groff.J.R.','SQL完全手册','2009-07-01' UNION ALL
SELECT '004',1,'KalenDelaney','SQLServer2005技术内幕存储引擎','2008-08-01' UNION ALL
SELECT '005',2,'Alex.Kriegel.Boris.M.Trukhnov','SQL宝典','2007-10-05' UNION ALL
SELECT '006',2,'飞思科技产品研发中心','SQLServer2000高级管理与开发','2007-09-10' UNION ALL
SELECT '007',2,'胡百敬','SQLServer2005数据库开发详解','2008-06-15' UNION ALL
SELECT '008',3,'陈浩奎','SQLServer2000存储过程与XML编程','2005-09-01' UNION ALL
SELECT '009',3,'赵松涛','SQLServer2005系统管理实录','2008-10-01' UNION ALL
SELECT '010',3,'黄占涛','SQL技术手册','2006-01-01'--SQL查询如下:--按GID分组,查每个分组中Date最新的前2条记录
--1.字段ID唯一时:
SELECT * FROM #T AS T WHERE ID IN(SELECT TOP 2 ID FROM #T WHERE GID=T.GID ORDER BY Date DESC)--2.如果ID不唯一时:
SELECT * FROM #T AS T WHERE 2>(SELECT COUNT(*) FROM #T WHERE GID=T.GID AND Date>T.Date)--SQL Server 2005 使用新方法--3.使用ROW_NUMBER()进行排位分组
SELECT ID,GID,Author,Title,Date
FROM
(
SELECT rid=ROW_NUMBER() OVER(PARTITION BY GID ORDER BY Date DESC),*
FROM #T
) AS T
WHERE rid<=2--4.使用APPLY
SELECT DISTINCT b.*
FROM #T AS a
CROSS APPLY
(
SELECT TOP(2) * FROM #T WHERE a.GID=GID ORDER BY Date DESC
) AS b
--结果
/*ID GID Author Title Date
---- ----------- ----------------------------- --------------------------------------- -----------------------
003 1 格罗夫Groff.J.R. SQL完全手册 2009-07-01 00:00:00.000
004 1 KalenDelaney SQLServer2005技术内幕存储引擎 2008-08-01 00:00:00.000
005 2 Alex.Kriegel.Boris.M.Trukhnov SQL宝典 2007-10-05 00:00:00.000
007 2 胡百敬 SQLServer2005数据库开发详解 2008-06-15 00:00:00.000
009 3 赵松涛 SQLServer2005系统管理实录 2008-10-01 00:00:00.000
010 3 黄占涛 SQL技术手册 2006-01-01 00:00:00.000(6 行受影响)
*/
where c0 in(select top 2 with ties c0 from 表 where c2=t.c2 order by c1)
--> Author : wufeng4552
--> Date : 2009-11-06 16:39:04
if object_id('[tb]') is not null drop table [tb]
go
create table [tb] (c0 nvarchar(2),c1 int,c2 int)
insert into [tb]
select 'a',2,2003 union all
select 'b',3,2003 union all
select 'c',4,2003 union all
select 'a',1,2004 union all
select 'b',1,2004 union all
select 'c',2,2004
;with stone
as
(select *,cnt=row_number()over(partition by c2 order by c1 desc)from tb)
select * from stone where cnt<=2
/*
c0 c1 c2 cnt
---- ----------- ----------- --------------------
c 4 2003 1
b 3 2003 2
c 2 2004 1
a 1 2004 2
*/
from (select *, DENSE_RANK() OVER(partition by c2 ORDER BY c1 ) AS denserank from 表 t) t
where denserank=1 or denserank =2
insert into tb values('a',2,2003)
insert into tb values('b',3,2003)
insert into tb values('c',4,2003)
insert into tb values('a',1,2004)
insert into tb values('b',1,2004)
insert into tb values('c',2,2004)
goselect t.* from tb t where c1 in (select top 2 c1 from tb where c2 = t.c2 order by c1 desc) order by t.c2 , t.c1 desc
/*
c0 c1 c2
---------- ----------- -----------
c 4 2003
b 3 2003
c 2 2004
a 1 2004
b 1 2004(所影响的行数为 5 行)
*/select m.c0 , m.c1 , m.c2 from
(
select t.* , px = (select count(1) from tb where c2 = t.c2 and (c1 > t.c1 or (c1 = t.c1 and c0 > t.c0) )) + 1 from tb t
) m
where px <= 2
order by m.c2 , m.c1 desc
/*
c0 c1 c2
---------- ----------- -----------
c 4 2003
b 3 2003
c 2 2004
b 1 2004(所影响的行数为 4 行)
*/drop table tb