将日期转换为列的行 - SQL Server 2008

Question

我需要一些关于PIVOT表的帮助或者以我需要的方式获得结果。

我有一张这样的桌子。

+---------------+--------------+----------+-----------+---------------+-----------------------------------------+-----------------+---------------+------------------+----------+-------+------------+--------------+------------+-------------------+----------------+----------+-------------------+ 
|  Client_Id | Project_Id | Hotel_Id | Room_Type | Room_Category |    Allotment_Date    | Number_Of_Rooms | Number_Booked | Number_Available | Overbook | Price | Dep_Amount | Full_Payment | Admin_Only | HotelAllotment_Id | Price_Excl_VAT | VAT_Code | Charge_Dep_Amount | 
+---------------+--------------+----------+-----------+---------------+-----------------------------------------+-----------------+---------------+------------------+----------+-------+------------+--------------+------------+-------------------+----------------+----------+-------------------+ 
|  DEFAULT |  TEMPLATE |  2423 |  276 |    |      2010-12-05 00:00:00 |   99999 |    1 |   99998 |  0 | 33000 |   0 |   1 |   0 |   279611 |    0 |   |     0 | 
|  DEFAULT |  TEMPLATE |  2423 |  276 |    |      2010-12-06 00:00:00 |   99999 |    1 |   99998 |  0 | 33000 |   0 |   1 |   0 |   279612 |    0 |   |     0 | 
|  DEFAULT |  TEMPLATE |  2423 |  276 |    |      2010-12-07 00:00:00 |   99999 |    1 |   99998 |  0 | 33000 |   0 |   1 |   0 |   279613 |    0 |   |     0 | 
|  DEFAULT |  TEMPLATE |  2424 |  276 |    |      2010-12-05 00:00:00 |   99999 |    1 |   99998 |  0 | 22000 |  22000 |   0 |   0 |   279590 |    0 |   |     0 | 
|  DEFAULT |  TEMPLATE |  2424 |  276 |    |      2010-12-06 00:00:00 |   99999 |    1 |   99998 |  0 | 22000 |  22000 |   0 |   0 |   279591 |    0 |   |     0 | 
|  DEFAULT |  TEMPLATE |  2424 |  276 |    |      2010-12-07 00:00:00 |   99999 |    1 |   99998 |  0 | 22000 |  22000 |   0 |   0 |   279592 |    0 |   |     0 | 
+---------------+--------------+----------+-----------+---------------+-----------------------------------------+-----------------+---------------+------------------+----------+-------+------------+--------------+------------+-------------------+----------------+----------+-------------------+ 

我需要这样显示数据，以获得列中的日期和每天预订的数量。

+---------------+--------------+----------+-----------+---------------+------------+------------+--------------+ 
|  Client_Id | Project_Id | Hotel_Id | Room_Type | Room_Category | 2010-12-05 | 2010-12-06 | 2010-12-07 | 
+---------------+--------------+----------+-----------+---------------+------------+------------+--------------+ 
|  DEFAULT |  TEMPLATE |  2423 |  276 |    |   1 |   1 |   1 | 
|  DEFAULT |  TEMPLATE |  2424 |  276 |    |   1 |   1 |   1 | 
+---------------+--------------+----------+-----------+---------------+------------+------------+--------------+ 

我需要这个由HOTEL_ID，Room_Type和Room_Category（如果有的话）

我需要这是动态的，因为日期，可以更改进行分组。

我尝试使用简单的透视表，没有运气。

任何帮助将是伟大的。

Answer 1

您可以使用PIVOT函数在写动态版本之前得到结果我建议先写一个静态版本。

如果你有值的数量有限，那么你可以硬编码的所有dates的是列标题：

select client_id, project_id, hotel_id, 
    room_type, room_category, 
    [2010-12-05], [2010-12-06], [2010-12-07] 
from 
(
    select client_id, project_id, hotel_id, 
    room_type, room_category, 
    allotment_date, number_booked 
    from yourtable 
) d 
pivot 
(
    sum(number_booked) 
    for allotment_date in ([2010-12-05], [2010-12-06], [2010-12-07]) 
) p; 

见SQL Fiddle with Demo。但是，如果你的值将是未知的，那么你将需要创建一个SQL字符串，以使用动态SQL执行。

DECLARE @cols AS NVARCHAR(MAX), 
    @query AS NVARCHAR(MAX) 

select @cols = STUFF((SELECT ',' + QUOTENAME(convert(varchar(10), allotment_date, 120)) 
        from yourtable 
        group by allotment_date 
        order by allotment_date 
      FOR XML PATH(''), TYPE 
      ).value('.', 'NVARCHAR(MAX)') 
     ,1,1,'') 

set @query = 'SELECT client_id, project_id, hotel_id, 
       room_type, room_category,' + @cols + ' 
      from 
      (
       select client_id, project_id, hotel_id, 
       room_type, room_category, 
       allotment_date, number_booked 
       from yourtable 
      ) x 
      pivot 
      (
       sum(number_booked) 
       for allotment_date in (' + @cols + ') 
      ) p ' 

execute sp_executesql @query; 

参见SQL Fiddle with Demo。这些给结果：

| CLIENT_ID | PROJECT_ID | HOTEL_ID | ROOM_TYPE | ROOM_CATEGORY | 2010-12-05 | 2010-12-06 | 2010-12-07 | 
|-----------|------------|----------|-----------|---------------|------------|------------|------------| 
| DEFAULT | TEMPLATE |  2423 |  276 |  (null) |   1 |   1 |   1 | 
| DEFAULT | TEMPLATE |  2424 |  276 |  (null) |   1 |   1 |   1 | 

Answer 2

编辑：关于这个“办法”进一步的讨论表明，这将是审慎的进入进一步的细节，以为什么这不应该永远作为可靠的代码。除了像SELECT *这样的显而易见的事情之外，沿着这条路走下去只会超过编译时间的限制。假设我们填入以下的@t_Date表变量（和方式，更好的方式）CTE：

Msg 8632, Level 17, State 2, Line 2

Internal error: An expression services limit has been reached. Please look for potentially complex expressions in your query, and try to simplify them.

注：

-- Thanks @AaronBertrand! 
    WITH cte_Date(DateVal) AS (
     SELECT TOP (10000) DATEADD(DAY, ROW_NUMBER() 
        OVER (ORDER BY s1.object_id), '19991231') 
     FROM sys.all_objects AS s1 
     CROSS JOIN sys.all_objects AS s2 
    ) 
    INSERT INTO @t_Date (DateVal) 
    SELECT DateVal 
    FROM cte_Date; 

不可避免的，我们将传达信息像在一些点以下运行即使是错误信息也可以总结为：@bluefeet和@Lamak或多或少地声明：“不要在数据层中这样做”。

因此，随着职位是：

@bluefeet和@Lamak是两个最优秀的数据库人们在计算器上的，所以你要听从他们的话。如果你真的需要这个测试，使用@ bluefeet的答案，因为你正在收到一个编译时错误，所以你可以在你的查询中加以干涉，并通过下面的例子来解决这个问题。请为了任何可能需要承担工作职责的人的利益，不要将此类代码移到生产环境。我只发布这个hack-fest解决方法，以便您可以测试您正在处理的任何理论，并通过适当的步骤进行后续跟踪，以使您的数据层更适合部署。

IF NOT EXISTS (SELECT 1 
       FROM sys.objects 
       WHERE name = 'yourtable' 
        AND type = 'U') 
BEGIN 
    --DROP TABLE dbo.yourtable; 
    CREATE TABLE dbo.yourtable 
    ( 
     [Client_Id] varchar(7), 
     [Project_Id] varchar(8), 
     [Hotel_Id] int, 
     [Room_Type] int, 
     [Room_Category] int, 
     [Allotment_Date] datetime, 
     [Number_Of_Rooms] int, 
     [Number_Booked] int, 
     [Number_Available] int, 
     [Overbook] int, 
     [Price] int, 
     [Dep_Amount] int, 
     [Full_Payment] int, 
     [Admin_Only] int, 
     [HotelAllotment_Id] int, 
     [Price_Excl_VAT] int, 
     [VAT_Code] int, 
     [Charge_Dep_Amount] INT 
    ); 

    DECLARE @t_Date TABLE 
    (
     DateVal  DATE 
    ); 

    WITH cte_Date AS (
     SELECT DateVal = CAST(GETDATE() AS DATE) 
     UNION ALL 
     SELECT DateVal = DATEADD(DAY, -1, DateVal) 
     FROM cte_Date 
     WHERE DateVal > '2002-01-01' 
    ) 
    INSERT INTO @t_Date (DateVal) 
    SELECT DateVal 
    FROM cte_Date 
    OPTION (MAXRECURSION 5000); 

    INSERT INTO dbo.yourtable([Client_Id], [Project_Id], [Hotel_Id], [Room_Type], [Room_Category], [Allotment_Date], 
     [Number_Of_Rooms], [Number_Booked], [Number_Available], [Overbook], [Price], [Dep_Amount], [Full_Payment], 
     [Admin_Only], [HotelAllotment_Id], [Price_Excl_VAT], [VAT_Code], [Charge_Dep_Amount]) 
    SELECT 'DEFAULT', 'TEMPLATE', 2423, 276, NULL, DateVal, 99999, 1, 99998, 0, 33000, 0, 1, 0, 279611, 0, NULL, 0 
    FROM @t_Date; 
END; 
GO 

SELECT COUNT(DISTINCT Allotment_date) 
FROM dbo.yourtable; 

DECLARE @cols AS NVARCHAR(MAX), 
     @query AS NVARCHAR(MAX) 

select @cols = STUFF((SELECT ',' + QUOTENAME(convert(varchar(10), allotment_date, 120)) 
        from yourtable 
        group by allotment_date 
        order by allotment_date 
      FOR XML PATH(''), TYPE 
      ).value('.', 'NVARCHAR(MAX)') 
     ,1,1,'') 

set @query = ' 
      SELECT * 
      FROM ( SELECT client_id, project_id, hotel_id, 
         room_type, room_category,' + @cols + ' 
        from 
        (
         select client_id, project_id, hotel_id, 
         room_type, room_category, 
         allotment_date, number_booked 
         from yourtable 
        ) x 
        pivot 
        (
         sum(number_booked) 
         for allotment_date in (' + @cols + ') 
        ) p) a;' 

execute sp_executesql @query; 
GO