更新时间:2023-02-15 18:30:25
您可以使用以下命令将row_number()
应用于记录:
You could use the following which applies a row_number()
to the records:
select DateTimeID,
[1] as Wavelength1,
[2] as Wavelength2,
SensorId
from
(
select [DateTimeID], [Wavelength], [SensorID],
row_number() over(partition by DateTimeID, SensorId
order by DateTimeID) rn
from yourtable
) src
pivot
(
max(Wavelength)
for rn in ([1], [2])
) piv
请参见带有演示的SQL提琴.
如果您将有未知数量的wavelength
值,则可以使用动态SQL生成此值:
If you will have an unknown number of wavelength
values, then you can use dynamic SQL to generate this:
DECLARE @cols AS NVARCHAR(MAX),
@query AS NVARCHAR(MAX)
select @cols = STUFF((SELECT distinct ',' + QUOTENAME('Wavelength'+cast(rn as varchar(50)))
from
(
select row_number() over(partition by DateTimeID, SensorId
order by DateTimeID) rn
from yourtable
) src
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
,1,1,'')
set @query = 'SELECT DateTimeID,' + @cols + ', SensorId from
(
select [DateTimeID], [Wavelength], [SensorID],
''Wavelength''+cast(row_number() over(partition by DateTimeID, SensorId
order by DateTimeID) as varchar(50)) rn
from yourtable
) x
pivot
(
max(Wavelength)
for rn in (' + @cols + ')
) p '
execute(@query)
请参见带有演示的SQL小提琴