是否可以使用 SQL Server 使用相同的数据透视列进行多个数据透视
我正面临以下挑战.我需要在同一列上旋转表数据两次.这是数据的截图.
I am facing the following challenge. I need to rotate table data twice over the same column. Here's a screenshot of the data.
我想为每个项目 ID 设置一行,其中包含每年的购买价值和销售价值.我尝试通过选择年份"列两次,对其进行格式化,以便每个销售年份以S"为前缀,每个采购年份以P"开头,并使用 2 个枢轴围绕 2 年列旋转.这是 SQL 查询(用于 SQL Server 2008):
I want to have one row for each Item ID containing both the purchasing value and the selling value for each year. I tried doing this by selecting the "year" column twice, formatting it a bit so each selling year gets prefixed with a "S" and each purchasing year begins with a "P", and using 2 pivots to rotate around the 2 year columns. Here's the SQL query (used in SQL Server 2008):
SELECT [Item ID],
[P2000],[P2001],[P2002],[P2003],
[S2000],[S2001],[S2002],[S2003]
FROM
(
SELECT [Item ID]
,'P' + [Year] AS YearOfPurchase
,'S' + [Year] AS YearOfSelling
,[Purchasing value]
,[Selling value]
FROM [ItemPrices]
) AS ALIAS
PIVOT
(
MIN ([Purchasing value]) FOR [YearOfPurchase] in ([P2000],[P2001],[P2002],[P2003])
)
AS pvt
PIVOT
(
MIN ([Selling value]) FOR [YearOfSelling] in ([S2000],[S2001],[S2002],[S2003])
)
AS pvt2
结果并不是我所希望的(见下图):
The result is not exactly what I was hoping for (see image below):
如您所见,每个项目 ID 仍然不止一行.有没有办法将行数减少到每个项目正好一个?这样看起来有点像下面的 Excel 截图?
As you can see, there are still more than one row for each item ID. Is there a way to reduce the number of rows to exactly one per item? So that it looks a bit like the Excel screenshot below?
推荐答案
我的建议是同时应用 UNPIVOT
和 PIVOT
函数来获得结果.
My suggestion would be to apply both the UNPIVOT
and the PIVOT
functions to get the result.
UNPIVOT
会将 PurchasingValue
和 SellingValue
列转换为行.完成此操作后,您可以将数据转换为结果.
The UNPIVOT
will turn the PurchasingValue
and SellingValue
columns into rows. Once this is done, then you can pivot the data into your result.
代码将是:
select *
from
(
select itemid,
case
when col = 'PurchasingValue' then 'P'
when col = 'SellingValue' then 'S'
end + cast(year as varchar(4)) new_col,
value
from yourtable
unpivot
(
value
for col in ([PurchasingValue], [SellingValue])
) unpiv
) src
pivot
(
max(value)
for new_col in (P2000, P2001, P2002, P2003,
S2000, S2001, S2002, S2003)
) piv;
请参阅 SQL Fiddle with Demo.结果是:
| ITEMID | P2000 | P2001 | P2002 | P2003 | S2000 | S2001 | S2002 | S2003 |
--------------------------------------------------------------------------
| 1 | 1000 | 1100 | 1200 | 1300 | 900 | 990 | 1080 | 1170 |
| 2 | 500 | 550 | 600 | 650 | 450 | 495 | 540 | 585 |
在 SQL Server 2008+ 中,您可以使用 CROSS APPLY
和 VALUES
以及 PIVOT
函数:
In SQL Server 2008+ you can use CROSS APPLY
with VALUES
along with the PIVOT
function:
select *
from
(
select itemid,
col+cast(year as varchar(4)) new_col,
value
from yourtable
cross apply
(
VALUES
(PurchasingValue, 'P'),
(SellingValue, 'S')
) x (value, col)
) src
pivot
(
max(value)
for new_col in (P2000, P2001, P2002, P2003,
S2000, S2001, S2002, S2003)
) piv
请参阅 SQL Fiddle with Demo
相关文章