SQL Server 2008报告：组的最大总和

我在报表设计器中有这样的表格：

Category:       1     2       3      4   Total
Max Amount:     x     y       z      c     ?

我需要得到Max Amount的总和,但是表达式不允许我取Sum(Max(amount)),并且对此单元格禁用add total.

最大金额行是一个表达式,它取每个类别的最大值.源数据有重复的值,所以我只取最大值.例如：

Category    Amount
    1         4.6
    1         4.6
    1         4.6
    2          5
    3          4

表中的其他列是不同的,但数量将是相同的,所以我不仅可以选择不同的值.

解决方法

也许是这样的：

SELECT
    SUM(t1.maxAmout)
FROM
(
    SELECT
        MAX(t.Amout) AS maxAmout,t.Category
    FROM
        yourTable AS t
    GROUP BY
        t.Category
) AS t1

你也可以这样做.如果您使用的是sql server 2005：

SELECT
    pvt.[1],pvt.[2],pvt.[3],(
        pvt.[1]+
        pvt.[2]+
        pvt.[3]
    ) AS Total
FROM
(
    SELECT
        t.Category,t.Amout
    FROM
        yourTable AS t
) AS SourceTable
PIVOT
(
    MAX(Amout)
    FOR Category IN([1],[2],[3])
) AS pvt

编辑

如果您有1000个类别.然后动态支点将是最佳解决方案.像这样：

测试数据

CREATE TABLE #T
    (
        Category INT,Amout FLOAT
    )

INSERT INTO #T
VALUES
    (1,4.6),(1,(2,5),(3,4)

唯一的列名称

DECLARE @cols VARCHAR(MAX)
DECLARE @colsTotal VARCHAR(MAX)
;WITH CTE
AS
(
    SELECT
        ROW_NUMBER() OVER(PARTITION BY t.Category ORDER BY t.Amout) AS RowNbr,t.*
    FROM
        #T AS t
)
SELECT  @cols = COALESCE(@cols + ','+QUOTENAME(Category),QUOTENAME(Category)),@colsTotal=COALESCE(@colsTotal + '+ISNULL('+QUOTENAME(Category)+',0)','ISNULL('+QUOTENAME(Category)+',0)')
FROM 
    CTE
WHERE
    CTE.RowNbr=1
ORDER BY 
    Category

动态枢轴

DECLARE @query NVARCHAR(4000)=
N'SELECT
    '+@cols+',(
        '+@colsTotal+'
    ) AS Total
FROM
(
    SELECT
        t.Category,t.Amout
    FROM
        #T AS t
) AS SourceTable
PIVOT
(
    MAX(Amout)
    FOR Category IN('+@cols+')
) AS pvt'

EXECUTE(@query)