更新时间:2023-01-29 12:20:31
A c0> 用于将数据从一列旋转到多列.
A PIVOT
used to rotate the data from one column into multiple columns.
在您的示例中,这是一个STATIC Pivot,表示您对要旋转的列进行了硬编码:
For your example here is a STATIC Pivot meaning you hard code the columns that you want to rotate:
create table temp
(
id int,
teamid int,
userid int,
elementid int,
phaseid int,
effort decimal(10, 5)
)
insert into temp values (1,1,1,3,5,6.74)
insert into temp values (2,1,1,3,6,8.25)
insert into temp values (3,1,1,4,1,2.23)
insert into temp values (4,1,1,4,5,6.8)
insert into temp values (5,1,1,4,6,1.5)
select elementid
, [1] as phaseid1
, [5] as phaseid5
, [6] as phaseid6
from
(
select elementid, phaseid, effort
from temp
) x
pivot
(
max(effort)
for phaseid in([1], [5], [6])
)p
这是具有工作版本的 SQL演示.
这也可以通过动态PIVOT完成,您可以在其中动态创建列列表并执行PIVOT.
This can also be done through a dynamic PIVOT where you create the list of columns dynamically and perform the PIVOT.
DECLARE @cols AS NVARCHAR(MAX),
@query AS NVARCHAR(MAX);
select @cols = STUFF((SELECT distinct ',' + QUOTENAME(c.phaseid)
FROM temp c
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
,1,1,'')
set @query = 'SELECT elementid, ' + @cols + ' from
(
select elementid, phaseid, effort
from temp
) x
pivot
(
max(effort)
for phaseid in (' + @cols + ')
) p '
execute(@query)
两者的结果:
ELEMENTID PHASEID1 PHASEID5 PHASEID6
3 Null 6.74 8.25
4 2.23 6.8 1.5