select 产品ID from tb k where 产品ID in(select top 2 产品ID from tb where k.品牌=品牌 order by 销量 desc)
select Distinct [产品ID],[品牌] from tb t where ( select count(*) from tb where t.[品牌]=[品牌] and t.[销量]>[销量] )<2
select Distinct [产品ID],[品牌] from tb t where ( select count(*) from tb where t.[品牌]=[品牌] and t.[销量]<[销量])<2
---测试数据--- if object_id('[tb]') is not null drop table [tb] go create table [tb]([产品ID] varchar(2),[品牌] varchar(1),[销量] int) insert [tb] select 'A1','A',10 union all select 'A2','A',8 union all select 'A3','A',9 union all select 'B1','B',10 union all select 'B2','B',8 union all select 'B3','B',9
---查询--- select 产品ID from (select 产品ID,品牌,sum(销量) as 总销量 from tb group by 产品ID,品牌) a where (select count(1) from (select 产品ID,品牌,sum(销量) as 总销量 from tb group by 产品ID,品牌) b where b.品牌=a.品牌 and b.总销量>=a.总销量 )<=2---结果--- 产品ID ---- A1 A3 B1 B3(4 行受影响) 如果你给的销售汇总表,可以用楼上几位的,如果是销售明细表,最好用sum先合计再取前2位
--------------------------------- -- 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) */
bancxc 达人:你的代码很正确,但我有点不懂.麻烦解释一下
3楼的啊 我自己有时候都想不明白 大概意思:就是把外部查询和子查询中品牌向通的产品作比较, 如果子查询中有t.[销量]<[销量]的则Count(*), 如果t.[销量]最大,则没有t.[销量]<[销量]的,那么count(*)=0 <2 则符合条件 如果t.[销量]第二大,那么t.[销量]<[销量]的只有一个,count(*)=1 也小于2 就这两条符合条件 select Distinct [产品ID],[品牌] from tb t where ( select count(*) from tb where t.[品牌]=[品牌] and t.[销量]<[销量])<2 你自己琢磨琢磨吧 这个我觉得很难理解 我当时费老大劲才想明白的
from tb k
where 产品ID in(select top 2 产品ID from tb where k.品牌=品牌 order by 销量 desc)
from tb t
where (
select count(*)
from tb
where t.[品牌]=[品牌] and t.[销量]>[销量]
)<2
from tb t
where ( select count(*)
from tb where t.[品牌]=[品牌] and t.[销量]<[销量])<2
if object_id('[tb]') is not null drop table [tb]
go
create table [tb]([产品ID] varchar(2),[品牌] varchar(1),[销量] int)
insert [tb]
select 'A1','A',10 union all
select 'A2','A',8 union all
select 'A3','A',9 union all
select 'B1','B',10 union all
select 'B2','B',8 union all
select 'B3','B',9
---查询---
select 产品ID
from
(select 产品ID,品牌,sum(销量) as 总销量 from tb group by 产品ID,品牌) a
where
(select count(1)
from (select 产品ID,品牌,sum(销量) as 总销量 from tb group by 产品ID,品牌) b
where b.品牌=a.品牌 and b.总销量>=a.总销量
)<=2---结果---
产品ID
----
A1
A3
B1
B3(4 行受影响)
如果你给的销售汇总表,可以用楼上几位的,如果是销售明细表,最好用sum先合计再取前2位
-- 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)
*/
大概意思:就是把外部查询和子查询中品牌向通的产品作比较,
如果子查询中有t.[销量]<[销量]的则Count(*),
如果t.[销量]最大,则没有t.[销量]<[销量]的,那么count(*)=0 <2 则符合条件
如果t.[销量]第二大,那么t.[销量]<[销量]的只有一个,count(*)=1 也小于2 就这两条符合条件
select Distinct [产品ID],[品牌]
from tb t
where ( select count(*)
from tb where t.[品牌]=[品牌] and t.[销量]<[销量])<2
你自己琢磨琢磨吧 这个我觉得很难理解 我当时费老大劲才想明白的