A PIVOT https://msdn.microsoft.com/en-us/library/ms177410.aspx用于将数据从一列旋转到多列。
对于您的示例,这里是一个 STATIC Pivot ,这意味着您对要旋转的列进行硬编码:
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
这里有一个SQL Demo https://data.stackexchange.com/stackoverflow/query/521090有工作版本。
这也可以通过动态数据透视表来完成,您可以在动态数据透视表中动态创建列列表并执行数据透视表。
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