SQL Server 2017

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CREATE TABLE aa (
  a1 varchar(20), -- 日期
  a2 varchar(20), -- 時間
  a3 varchar(20), -- DeviceName
  a4 float        -- pH  
);

INSERT INTO aa VALUES 
('2024-11-12','00:21','100',8.19),
('2024-11-12','03:51','100',8.19),
('2024-11-12','00:21','101',7.31),
('2024-11-12','03:51','101',7.28);

SELECT *
FROM aa;


a1
a2
a3
a4


2024-11-12
00:21
100
8.19

2024-11-12
03:51
100
8.19

2024-11-12
00:21
101
7.31

2024-11-12
03:51
101
7.28


SELECT a1,a2,'pH-'+a3 AS a3,a4
FROM aa;


a1
a2
a3
a4


2024-11-12
00:21
pH-100
8.19

2024-11-12
03:51
pH-100
8.19

2024-11-12
00:21
pH-101
7.31

2024-11-12
03:51
pH-101
7.28


SELECT *
FROM (
  SELECT a1,a2,'pH-'+a3 AS a3,a4
  FROM aa
) AS X
PIVOT
(
  SUM(a4)
  FOR a3 IN 
  ([pH-100], [pH-101])
) AS PVT
ORDER BY a1,a2;


a1
a2
pH-100
pH-101


2024-11-12
00:21
8.19
7.31

2024-11-12
03:51
8.19
7.28

a1	a2	a3	a4
2024-11-12	00:21	100	8.19
2024-11-12	03:51	100	8.19
2024-11-12	00:21	101	7.31
2024-11-12	03:51	101	7.28

a1	a2	a3	a4
2024-11-12	00:21	pH-100	8.19
2024-11-12	03:51	pH-100	8.19
2024-11-12	00:21	pH-101	7.31
2024-11-12	03:51	pH-101	7.28