SQL Server 2012

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CREATE TABLE T
	([產品] varchar(1), [文件階段] varchar(3), [文件編號] int)
;
	
INSERT INTO T
	([產品], [文件階段], [文件編號])
VALUES
	('A', 'DR1', 111),
	('A', 'DR2', 222),
	('B', 'DR1', 456),
	('B', 'DR2', 789),
	('C', 'DR2', 888),
	('D', 'DR1', 999)
;
6 rows affected

select * from T


產品
文件階段
文件編號


A
DR1
111

A
DR2
222

B
DR1
456

B
DR2
789

C
DR2
888

D
DR1
999


select 
產品,
max(case when [文件階段] = 'DR1' then [文件編號] end) as [DR1文件階段],
max(case when [文件階段] = 'DR2' then [文件編號] end) as [DR2文件階段]
from T
group by 產品


產品
DR1文件階段
DR2文件階段


A
111
222

B
456
789

C
null
888

D
999
null


Warning: Null value is eliminated by an aggregate or other SET operation.