Question

我有一个像这样的简单查询..

USE AdventureWorks;
GO

SELECT DaysToManufacture, AVG(StandardCost) AS AverageCost 
FROM Production.Product
GROUP BY DaysToManufacture; 



DaysToManufacture  AverageCost  
0                  5.0885  
1                  223.88  
2                  359.1082  
4                  949.4105

一个简单的转轴给了我

SELECT 'AverageCost' AS Cost_Sorted_By_Production_Days,   
[0], [1], [2], [3], [4]  
FROM  
(SELECT DaysToManufacture, StandardCost   
    FROM Production.Product) AS SourceTable  
PIVOT  
(  
AVG(StandardCost)  
FOR DaysToManufacture IN ([0], [1], [2], [3], [4]) 
) AS PivotTable;

给我

Cost_Sorted_By_Production_Days   0                     1                     2                     3                     4

AverageCost                    5.0885                223.88                359.1082              NULL                  949.4105

但是数据透视查询中的值是硬编码..我想从子查询中获取这些值..

select DaysToManufacture FROM Production.Product GROUP BY DaysToManufacture;

但是pivot不允许我从子查询中获取值，除了编写动态生成的查询之外，还有什么方法可以做到这一点吗？

Answer 1

没有。这只能使用动态查询来完成。我真的很想知道是否有办法。

有些示例使用COALESCE快速Google search创建列列表。但是，我更喜欢使用STUFF创建列列表。但是我确实找到了这篇关于使用CTE's and dynamic pivots的文章，这篇文章可能也是赞助的

Answer 2

要从子查询中获取值，我们可以使用动态查询。我做了一些研究并找到了解决方案。

DECLARE @query VARCHAR(4000)
DECLARE @days VARCHAR(2000)
SELECT  @days = STUFF(( SELECT DISTINCT
                        '],[' + ltrim(str(DaysToManufacture))
                        FROM    Product
                        ORDER BY '],[' + ltrim(str(DaysToManufacture))
                        FOR XML PATH('')
                        ), 1, 2, '') + ']'

SET @query =
'SELECT ''AverageCost'' AS Cost_Sorted_By_Production_Days,'   +
@days + 
'FROM  (SELECT DaysToManufacture, StandardCost FROM Product) AS SourceTable  
PIVOT  
(  
AVG(StandardCost)  
FOR DaysToManufacture IN (' + @days +  ')) AS PivotTable;'  

EXECUTE (@query)

感谢.NET Technologies

Pivot - SQL - 来自SubQuery的值

2 个答案: