SQL Server:超过5列的动态数据透视表

Question

我正在努力想弄清楚如何在SQL Server 2008中使用多列来创建动态数据透视图.

我的示例表如下:

ID  YEAR  TYPE  TOTAL   VOLUME
DD1 2008    A   1000    10
DD1 2008    B   2000    20
DD1 2008    C   3000    30
DD1 2009    A   4000    40
DD1 2009    B   5000    50
DD1 2009    C   6000    60
DD2 2008    A   7000    70
DD2 2008    B   8000    80
DD2 2008    C   9000    90
DD2 2009    A   10000   100
DD2 2009    B   11000   110
DD2 2009    C   12000   120

而我正在尝试如下:

ID  2008_A_TOTAL    2008_A_VOLUME   2008_B_TOTAL    2008_B_VOLUME   2008_C_TOTAL    2008_C_VOLUME   2009_A_TOTAL    2009_A_VOLUME   2009_B_TOTAL    2009_B_VOLUME   2009_C_TOTAL    2009_C_VOLUME
DD1 1000            10              2000            20              3000            30              4000            40              5000            50              6000            60
DD2 7000            70              8000            80              9000            90              10000           100             11000           110             12000           120

我的SQL Server 2008查询如下创建表:

CREATE TABLE ATM_TRANSACTIONS 
(
 ID varchar(5),
 T_YEAR varchar(4),
 T_TYPE varchar(3), 
 TOTAL int,
 VOLUME int
);

INSERT INTO ATM_TRANSACTIONS
(ID,T_YEAR,T_TYPE,TOTAL,VOLUME)

VALUES
('DD1','2008','A',1000,10),
('DD1','2008','B',2000,20),
('DD1','2008','C',3000,30),
('DD1','2009','A',4000,40),
('DD1','2009','B',5000,50),
('DD1','2009','C',6000,60),
('DD2','2008','A',7000,70),
('DD2','2008','B',8000,80),
('DD2','2008','C',9000,90),
('DD2','2009','A',10000,100),
('DD2','2009','B',11000,110),
('DD2','2009','C',1200,120);

该T_Year列可能在将来发生变化,但该T_TYPE列通常是已知的,所以我不确定我是否可以将SQL Server中的PIVOT函数与动态代码结合使用？

我试着按照这里的例子:

http://social.technet.microsoft.com/wiki/contents/articles/17510.t-sql-dynamic-pivot-on-multiple-columns.aspx

但我最终得到了奇怪的结果.

Answer 1

为了获得结果,在应用PIVOT函数以获得最终结果之前,您需要首先查看Total和Volume列中的数据的取消.我的建议是首先编写查询的硬编码版本,然后将其转换为动态SQL.

UNPIVOT进程将这些多列转换为行.有几种方法可以使用UNPIVOT,你可以使用UNPIVOT功能,也可以使用CROSS APPLY.取消数据的代码将类似于:

select id, 
    col = cast(t_year as varchar(4))+'_'+t_type+'_'+col, 
    value
from ATM_TRANSACTIONS t
cross apply
(
    select 'total', total union all
    select 'volume', volume
) c (col, value);

这为您提供以下格式的数据:

+-----+---------------+-------+
| id  |      col      | value |
+-----+---------------+-------+
| DD1 | 2008_A_total  |  1000 |
| DD1 | 2008_A_volume |    10 |
| DD1 | 2008_B_total  |  2000 |
| DD1 | 2008_B_volume |    20 |
| DD1 | 2008_C_total  |  3000 |
| DD1 | 2008_C_volume |    30 |
+-----+---------------+-------+

然后你可以应用PIVOT功能:

select ID, 
    [2008_A_total], [2008_A_volume], [2008_B_total], [2008_B_volume],
    [2008_C_total], [2008_C_volume], [2009_A_total], [2009_A_volume]
from
(
    select id, 
        col = cast(t_year as varchar(4))+'_'+t_type+'_'+col, 
        value
    from ATM_TRANSACTIONS t
    cross apply
    (
        select 'total', total union all
        select 'volume', volume
    ) c (col, value)
) d
pivot
(
    max(value)
    for col in ([2008_A_total], [2008_A_volume], [2008_B_total], [2008_B_volume],
                [2008_C_total], [2008_C_volume], [2009_A_total], [2009_A_volume])
) piv;

现在你有了正确的逻辑,你可以将它转换为动态SQL:

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

select @cols = STUFF((SELECT ',' + QUOTENAME(cast(t_year as varchar(4))+'_'+t_type+'_'+col) 
                    from ATM_TRANSACTIONS t
                    cross apply
                    (
                        select 'total', 1 union all
                        select 'volume', 2
                    ) c (col, so)
                    group by col, so, T_TYPE, T_YEAR
                    order by T_YEAR, T_TYPE, so
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 
        ,1,1,'')

set @query = 'SELECT id,' + @cols + ' 
            from 
            (
                select id, 
                    col = cast(t_year as varchar(4))+''_''+t_type+''_''+col, 
                    value
                from ATM_TRANSACTIONS t
                cross apply
                (
                    select ''total'', total union all
                    select ''volume'', volume
                ) c (col, value)
            ) x
            pivot 
            (
                max(value)
                for col in (' + @cols + ')
            ) p '

execute sp_executesql @query;

这会给你一个结果:

+-----+--------------+---------------+--------------+---------------+--------------+---------------+--------------+---------------+--------------+---------------+--------------+---------------+
| id  | 2008_A_total | 2008_A_volume | 2008_B_total | 2008_B_volume | 2008_C_total | 2008_C_volume | 2009_A_total | 2009_A_volume | 2009_B_total | 2009_B_volume | 2009_C_total | 2009_C_volume |
+-----+--------------+---------------+--------------+---------------+--------------+---------------+--------------+---------------+--------------+---------------+--------------+---------------+
| DD1 |         1000 |            10 |         2000 |            20 |         3000 |            30 |         4000 |            40 |         5000 |            50 |         6000 |            60 |
| DD2 |         7000 |            70 |         8000 |            80 |         9000 |            90 |        10000 |           100 |        11000 |           110 |         1200 |           120 |
+-----+--------------+---------------+--------------+---------------+--------------+---------------+--------------+---------------+--------------+---------------+--------------+---------------+