使用PIVOT将数据从宽到高翻转 [英] Using PIVOT to Flip Data from Wide to Tall

问题描述

我有一张桌子很宽，我想将其转换成高桌子.数据当前位于以下位置:

I have a table that is rather wide that I would like to convert to tall. The data currently resides like this:

VEND   YEAR   I1_DOLS   I1_QTY   I2_DOLS   I2_QTY   I3_DOLS   I3_QTY ...
1234   2011   101587    508      203345    334      105938    257
1234   2012   257843    587      235883    247      178475    456
1011   2010   584737    432      587274    356      175737    563
1011   2011   517774    356      483858    456      481785    354

我想将其转换为如下所示的表:

I would like to convert this to a table that looks like this:

VEND   YEAR   MONTH   DOLS     QTY
1234   2011   1       101587   508
1234   2011   2       203345   334
1234   2011   3       105938   257
1234   2012   1       257843   587
1234   2012   2       235883   247
.
.
.

我认为我需要的是PIVOT，但我似乎无法弄清楚.

I assume that a PIVOT is what I need, but I can't seem to figure this out.

推荐答案

您可以使用CROSS APPLY (VALUES) 取消数据透视.这是一篇文章，说明如何完成此操作:

You can unpivot the data using CROSS APPLY (VALUES). Here is an article to explain how this is done:

http://www.sqlservercentral.com/articles/CROSS + APPLY + VALUES + UNPIVOT/91234/

基本上，代码是:

SELECT vend,
  year,
  month,
  dols, 
  qty
FROM YourTable t
CROSS APPLY 
(
    VALUES
        (1, I1_DOLS, I1_QTY),
        (2, I2_DOLS, I2_QTY),
        (3, I3_DOLS, I3_QTY)
) x (month, dols, qty);

请参见带有演示的SQL提琴

或者您可以使用UNION ALL查询:

select vend, year, 1 month, [I1_DOLS] Dols, [I1_QTY] Qty
from yourtable
union all
select vend, year, 2 month, [I2_DOLS] Dols, [I2_QTY] Qty
from yourtable
union all
select vend, year, 3 month, [I3_DOLS] Dols, [I3_QTY] Qty
from yourtable

请参见带有演示的SQL小提琴

或者甚至可以同时应用UNPIVOT和PIVOT函数来转换数据:

Or you can even apply both the UNPIVOT and the PIVOT function to transform the data:

select *
from
(
  select vend,
    year,
    replace(replace(replace(col, 'I', ''), '_Dols', ''), '_Qty', '') month,
    case when col like '%Dols%' then 'dols' else 'qty' end col_name,
    value
  from 
  (
    select vend, year, [I1_DOLS], [I1_QTY], [I2_DOLS], [I2_QTY], [I3_DOLS], [I3_QTY]
    from yourtable
  ) src
  unpivot
  (
    value
    for col in ([I1_DOLS], [I1_QTY], [I2_DOLS], [I2_QTY], [I3_DOLS], [I3_QTY])
  ) un
) unp
pivot
(
  max(value)
  for col_name in (dols, qty)
) piv

请参见带有演示的SQL小提琴.

这三个都将给出相同的结果:

All three will give the same result:

| VEND | YEAR | MONTH |   DOLS | QTY |
--------------------------------------
| 1234 | 2011 |     1 | 101587 | 508 |
| 1234 | 2011 |     2 | 203345 | 334 |
| 1234 | 2011 |     3 | 105938 | 257 |
| 1234 | 2012 |     1 | 257843 | 587 |
| 1234 | 2012 |     2 | 235883 | 247 |
| 1234 | 2012 |     3 | 178475 | 456 |
| 1011 | 2010 |     1 | 584737 | 432 |
| 1011 | 2010 |     2 | 587274 | 356 |
| 1011 | 2010 |     3 | 175737 | 563 |
| 1011 | 2011 |     1 | 517774 | 356 |
| 1011 | 2011 |     2 | 483858 | 456 |
| 1011 | 2011 |     3 | 481785 | 354 |

这篇关于使用PIVOT将数据从宽到高翻转的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！