SQL服务器上 - 选择TOP 5行每个FK
https://stackoverflow.com/questions/1450603
-
11-09-2019 - |
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我有以下查询，看起来最多的前5名的产品的匹配搜索。每个产品与相关联的商店
SELECT TOP 5 * FROM产品 P，商店S其中p.ShopId = s.ShopId和p.ProductName LIKE '％圣诞节％'
我需要扩展这一点，以便它返回我的前5名的产品的在每个 商店的。
任何人都可以让我知道了如何查询可以修改实现这一目标？ - 即选择在TOP 5的产品匹配 “％圣诞节％”每个店（而不是其示出了TOP 5的产品匹配 “％圣诞％” 跨所有商店当前）。
解决方案
您实际上是缺少一个ORDER BY，使TOP有意义的，或基于ROW_NUMBER任何解决方案，它需要一个ORDER BY。
SELECT
*
FROM
Shops s
CROSS APPLY (
SELECT TOP 5
*
FROM
Products p
WHERE
p.ShopId = s.ShopId AND p.ProductName LIKE '%christmas%'
ORDER BY --added on edit
???
) X
其他提示
尝试这种情况：
select * from (
select *, rn = row_number() over (partition by s.ShopId order by p.ProductName)
from Products p, Shops s
where p.ShopId = s.ShopId AND p.ProductName LIKE '%christmas%'
) a where a.rn <= 5
尝试此
SELECT DISTINCT
A.Product_Group_code
,B.Sub_Product_Group_code
,A.Product_code
,A.Product_name
FROM dbo.A A
LEFT JOIN dbo.B B
ON A.Product_code = B.Product_code
WHERE B.Product_code IN
(
SELECT TOP 5 E.Product_code
FROM dbo.A D
LEFT JOIN dbo.B E
ON D.Product_code = E.Product_code
WHERE E.Sub_Product_Group_code = B.Sub_Product_Group_code
)
AND B.Sub_Product_Group_code IS NOT NULL
ORDER BY B.Sub_Product_Group_code,A.Product_name
下面是一个很好的解决方案我刚发现。
选择的前N行的每个组 阿尼罗兰，2008年3月13日
有对于每个类别多个行，并有一个愿望 按价格选择每个类别的只有前两（2）行。 例如，从以下数据：
RowID Category ID Description Price
1 Pot A1 Small Saucepan 21.50
2 Pot A2 1 Qt Saucepan 29.95
3 Pot A3 1.5 Qt Saucepan 33.95
4 Pot A4 Double Boiler 39.50
5 Pot A5 Stewpot 49.50
6 Pot A6 Pressure Cooker 79.95
7 Pan B1 8" Pie 6.95
8 Pan B2 8" Sq Cake 7.50
9 Pan B3 Bundt Cake 12.50
10 Pan B4 9x12 Brownie 7.95
11 Bowl C1 Lg Mixing 27.50
12 Bowl C2 Sm Mixing 17.50
13 Tools T1 14" Spatula 9.95
在期望的输出是：
RowID Category ID Description Price
11 Bowl C1 Lg Mixing 27.50
12 Bowl C2 Sm Mixing 17.50
9 Pan B3 Bundt Cake 12.50
10 Pan B4 9x12 Brownie 7.95
6 Pot A6 Pressure Cooker 79.95
5 Pot A5 Stewpot 49.50
13 Tools T1 14" Spatula 9.95
有几种方法来实现所希望的输出。 此演示提供了对SQL Server 2005 / SQL Server 2008的解决方案， 然后为SQL Server一个解决方案2000。
有两种解决方案创建采样数据
-- Suppress data loading messages
SET NOCOUNT ON
-- Create Sample Data using a Table Varable
DECLARE @MyTable table
( RowID int IDENTITY,
Category varchar(5),
[ID] varchar(5),
[Description] varchar(25),
Price decimal(10,2)
)
-- Load Sample Data
INSERT INTO @MyTable VALUES ( 'Pot', 'A1', 'Small Saucepan', 21.50 )
INSERT INTO @MyTable VALUES ( 'Pot', 'A2', '1 Qt Saucepan', 29.95 )
INSERT INTO @MyTable VALUES ( 'Pot', 'A3', '1.5 Qt Saucepan', 33.95 )
INSERT INTO @MyTable VALUES ( 'Pot', 'A4', 'Double Boiler', 39.50 )
INSERT INTO @MyTable VALUES ( 'Pot', 'A5', 'Stewpot', 49.50 )
INSERT INTO @MyTable VALUES ( 'Pot', 'A6', 'Pressure Cooker', 79.95 )
INSERT INTO @MyTable VALUES ( 'Pan', 'B1', '8"" Pie', 6.95 )
INSERT INTO @MyTable VALUES ( 'Pan', 'B2', '8"" Sq Cake', 7.50 )
INSERT INTO @MyTable VALUES ( 'Pan', 'B3', 'Bundt Cake', 12.50 )
INSERT INTO @MyTable VALUES ( 'Pan', 'B4', '9x12 Brownie', 7.95 )
INSERT INTO @MyTable VALUES ( 'Bowl', 'C1', 'Lg Mixing', 27.50 )
INSERT INTO @MyTable VALUES ( 'Bowl', 'C2', 'Sm Mixing', 17.50 )
INSERT INTO @MyTable VALUES ( 'Tools', 'T1', '14"" Spatula', 9.95 )
Return to Top
的SQL Server 2005 / SQL Server 2008中的解决方案
--Query to Retrieve Desired Data
SELECT
RowID,
Category,
[ID],
[Description],
Price
FROM (SELECT
ROW_NUMBER() OVER ( PARTITION BY Category ORDER BY Price DESC ) AS 'RowNumber',
RowID,
Category,
[ID],
[Description],
Price
FROM @MyTable
) dt
WHERE RowNumber <= 2
-- Results
RowID Category ID Description Price
11 Bowl C1 Lg Mixing 27.50
12 Bowl C2 Sm Mixing 17.50
9 Pan B3 Bundt Cake 12.50
10 Pan B4 9x12 Brownie 7.95
6 Pot A6 Pressure Cooker 79.95
5 Pot A5 Stewpot 49.50
13 Tools T1 14" Spatula 9.95
Return to Top
的SQL Server 2005 / SQL Server 2008中使用的CTE解 （添加：雅各塞巴斯蒂安）
-- Define a CTE with the name "dt"
;WITH dt AS (
SELECT
ROW_NUMBER() OVER ( PARTITION BY Category ORDER BY Price DESC ) AS 'RowNumber',
RowID,
Category,
[ID],
[Description],
Price
FROM @MyTable
)
-- and select the data from the CTE
SELECT
RowID,
Category,
[ID],
[Description],
Price
FROM dt
WHERE RowNumber <= 2
-- Results
RowID Category ID Description Price
11 Bowl C1 Lg Mixing 27.50
12 Bowl C2 Sm Mixing 17.50
9 Pan B3 Bundt Cake 12.50
10 Pan B4 9x12 Brownie 7.95
6 Pot A6 Pressure Cooker 79.95
5 Pot A5 Stewpot 49.50
13 Tools T1 14" Spatula 9.95
Return to Top
SQL 2000解
--Query to Retrieve Desired Data
SELECT DISTINCT
RowID,
Category,
[ID],
[Description],
Price
FROM @MyTable t1
WHERE RowID IN (SELECT TOP 2
RowID
FROM @MyTable t2
WHERE t2.Category = t1.Category
ORDER BY Price DESC
)
ORDER BY
Category,
Price DESC
-- Results
RowID Category ID Description Price
11 Bowl C1 Lg Mixing 27.50
12 Bowl C2 Sm Mixing 17.50
9 Pan B3 Bundt Cake 12.50
10 Pan B4 9x12 Brownie 7.95
6 Pot A6 Pressure Cooker 79.95
5 Pot A5 Stewpot 49.50
13 Tools T1 14" Spatula 9.95
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