--------------------------------- -- 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) */
Select TerritoryID,SubTotal,SalesPersonID,SalesOrderID FROM SalesOrderHeader AS SO1 WHERE SubTatal >= ( SELECT Min(SubTatal) FROM SalesOrderHeader AS SO2 WHERE SO1.TerritoryID=SO2.TerritoryID AND SO1.SubTotal<=SO2.SubTotal HAVING COUNT(*)<=5 ) ORDER BY TerritoryID,SubTotal DESC--首先拆开来看, --1.主查询.主查询的意思是大于某个SubTatal的记录,并且按照TerritoryID升序,SubTotal降序排列. Select TerritoryID,SubTotal,SalesPersonID,SalesOrderID FROM SalesOrderHeader AS SO1 WHERE SubTatal >= ( --子查询部分 ) ORDER BY TerritoryID,SubTotal DESC--2.子查询 找出最小的Subtotal的值,并且要满足TerritoryID和主查询的相等,SubTotal要大于等于主查询的SubTotal的前5笔记录中的最小值. SELECT Min(SubTatal) FROM SalesOrderHeader AS SO2 WHERE SO1.TerritoryID=SO2.TerritoryID AND SO1.SubTotal<=SO2.SubTotal HAVING COUNT(*)<=5
Select TerritoryID,SubTotal,SalesPersonID,SalesOrderID FROM SalesOrderHeader AS SO1 WHERE SubTatal >= (SELECT Min(SubTatal) FROM SalesOrderHeader AS SO2 WHERE SO1.TerritoryID=SO2.TerritoryID AND SO1.SubTotal<=SO2.SubTotal HAVING COUNT(*)<=5 ) ORDER BY TerritoryID,SubTotal DESC你的意思是解释一下这个查询的思想吗?首先从SalesOrderHeader表(SO2)当中根据SO1.TerritoryID=SO2.TerritoryID,SO1.SubTotal<=SO2.SubTotal和HAVING COUNT(*)<=5这三个条件查找出最小的SubTatal.然后从SalesOrderHeader表(SO1)当中根据条件SubTatal>=刚才SO2表当中查找出的SubTatal,再按照TerritoryID,SubTotal这两个字段的降序排序,最后查找出TerritoryID,SubTotal,SalesPersonID,SalesOrderID
1 1 135653 23 6558
2 1 135620 14 7676
3 1 127761 302 7056
4 1 124051 303 7022
5 1 120585 26 7555
6 2 178000 65 7685
7 2 175526 456 1569
8 2 170025 125 7540
9 2 165200 15 7450
10 2 152024 245 7710
11 3 185500 210 6330
12 3 175000 250 5666
13 3 170520 36 7011
14 3 165520 95 6522
15 3 160030 75 7100
TerritoryID 为区域号码 SubTotal为销售总量
SalesPersonID员工号 SalesOrderID订单数量
题目不明确,可以说有好几种方法,没必要这样些,我希望你把他分才成两个sql语句,
先求出没个销售区的销售总量,然后排序就简单多了。
这只是我个人的写法。
-- 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)
*/
FROM SalesOrderHeader AS SO1
WHERE SubTatal >=
(
SELECT Min(SubTatal)
FROM SalesOrderHeader AS SO2
WHERE SO1.TerritoryID=SO2.TerritoryID
AND SO1.SubTotal<=SO2.SubTotal
HAVING COUNT(*)<=5
)
ORDER BY TerritoryID,SubTotal DESC--首先拆开来看,
--1.主查询.主查询的意思是大于某个SubTatal的记录,并且按照TerritoryID升序,SubTotal降序排列.
Select TerritoryID,SubTotal,SalesPersonID,SalesOrderID
FROM SalesOrderHeader AS SO1
WHERE SubTatal >=
(
--子查询部分
)
ORDER BY TerritoryID,SubTotal DESC--2.子查询 找出最小的Subtotal的值,并且要满足TerritoryID和主查询的相等,SubTotal要大于等于主查询的SubTotal的前5笔记录中的最小值.
SELECT Min(SubTatal)
FROM SalesOrderHeader AS SO2
WHERE SO1.TerritoryID=SO2.TerritoryID
AND SO1.SubTotal<=SO2.SubTotal
HAVING COUNT(*)<=5
Select TerritoryID,SubTotal,SalesPersonID,SalesOrderID
FROM SalesOrderHeader AS SO1
WHERE SubTatal >=
(SELECT Min(SubTatal)
FROM SalesOrderHeader AS SO2
WHERE SO1.TerritoryID=SO2.TerritoryID
AND SO1.SubTotal<=SO2.SubTotal
HAVING COUNT(*)<=5
)
ORDER BY TerritoryID,SubTotal DESC你的意思是解释一下这个查询的思想吗?首先从SalesOrderHeader表(SO2)当中根据SO1.TerritoryID=SO2.TerritoryID,SO1.SubTotal<=SO2.SubTotal和HAVING COUNT(*)<=5这三个条件查找出最小的SubTatal.然后从SalesOrderHeader表(SO1)当中根据条件SubTatal>=刚才SO2表当中查找出的SubTatal,再按照TerritoryID,SubTotal这两个字段的降序排序,最后查找出TerritoryID,SubTotal,SalesPersonID,SalesOrderID