5

我有以下查询，它查找与搜索匹配的TOP 5产品。每个产品都与一个商店相关联

SELECT TOP 5 * FROM Products p, Shops s WHERE p.ShopId = s.ShopId AND p.ProductName LIKE '%christmas%'

我需要扩展它，以便它返回每个Shop中的 TOP 5 Products。

谁能让我知道如何修改查询以实现这一目标？- 即在每个商店中选择与“%christmas%”匹配的 TOP 5 产品（而不是当前显示所有商店中与“%chrismas%”匹配的 TOP 5 产品）。

4

4 回答 4

10

您实际上缺少一个 ORDER BY 以使 TOP 有意义，或者任何基于 ROW_NUMBER 的解决方案都需要一个 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
于 2009-09-20T08:59:59.157 回答
4

试试这个：

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
于 2009-09-20T09:00:52.260 回答
1

试试这个

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
于 2011-06-08T08:55:29.550 回答
1

这是我刚刚找到的一个很好的解决方案。

为每个组选择前 n 行 Arnie Rowland，2008 年 3 月 13 日

每个类别有多个行，并且希望按价格仅选择每个类别的前两 (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

所需的输出是：

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

有几种方法可以实现所需的输出。该演示提供了 SQL Server 2005 / SQL Server 2008 的解决方案，然后提供了 SQL Server 2000 的解决方案。

为两种解决方案创建示例数据

-- 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

SQL Server 2005 / SQL Server 2008 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

使用 CTE 的 SQL Server 2005 / SQL Server 2008 解决方案（添加者：Jacob Sebastian）

-- 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 解决方案

--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

From：为每个组选择 TOP n 行

于 2013-07-27T04:05:29.833 回答