sql-server - SQL Server 枢轴 : Displaying row values to column headers

Question

我有一个表格(项目)，其格式如下:

ITEMNO | WEEKNO | VALUE  
A1234  |   1    |  805  
A2345  |   2    |  14.50  
A3547  |   2    |  1396.70  
A2208  |   1    |  17.65  
A4326  |   6    |  19.99

这是一个表格，显示给定一周内商品的销售额。

结果或我想以表格格式显示的是一行中的项目编号，然后是每周包含值的列，例如

ITEMNO | WK1 | WK2 | WK3 | WK4 | WK5  ...etc up to 52  
A1234  | 805 | 345 | 234 | 12  | 10   ...etc up to 52  
A2345  |  23 | 12  | 456 | 34  | 99   ...etc up to 52  
A3456  | 234 | 123 | 34  | 25  | 190  ...etc up to 52  

虽然我有 52 岁……所以我只有最多第 9 周的数据，但这会随着时间的推移而增加。

所以基本上我想要显示的是作为列标题的周数值。

这可能吗...虽然我很想通过代码/(asp.net)获取数据并正确显示，但我想知道是否可以在SQL中像这样显示它？

有谁知道或认为这可能是最好的方法？

Answer 1

使用静态 SQL 和动态 SQL 有两种方法可以做到这一点:

静态枢轴:

SELECT P.ItemNo, IsNull(P.[1], 0) as Wk1, IsNull(P.[2], 0) as Wk2
    , IsNull(P.[3], 0) as Wk3, IsNull(P.[4], 0) as Wk4
    , IsNull(P.[5], 0) as Wk5, IsNull(P.[6], 0) as Wk6
    , IsNull(P.[7], 0) as Wk7, IsNull(P.[8], 0) as Wk8
    , IsNull(P.[9], 0) as Wk9
FROM
(
    SELECT ItemNo, WeekNo, [Value]
    FROM dbo.Items
) I
PIVOT
(
    SUM([Value])
    FOR WeekNo IN ([1], [2], [3], [4], [5], [6], [7], [8], [9])
) as P

动态枢轴:

DECLARE
@cols AS NVARCHAR(MAX),
@y    AS INT,
@sql  AS NVARCHAR(MAX);

-- Construct the column list for the IN clause
SET @cols = STUFF(
(SELECT N',' + QUOTENAME(w) AS [text()]
FROM (SELECT DISTINCT WeekNo AS W FROM dbo.Items) AS W
ORDER BY W
FOR XML PATH('')),
1, 1, N'');


-- Construct the full T-SQL statement
-- and execute dynamically
SET @sql = N'SELECT *
            FROM (SELECT ItemNo, WeekNo, Value
                    FROM dbo.Items) AS I
            PIVOT(SUM(Value) FOR WeekNo IN(' + @cols + N')) AS P;';

EXEC sp_executesql @sql;
GO