MySQL 8.0

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select version();


version()


8.0.25


create table t1 
(Group1 varchar(10),
SG1 varchar(10),
Value1 varchar(10),
 Group2 varchar(10),
SG2 varchar(10),
Value2 varchar(10),
 Group3 varchar(10),
SG3 varchar(10),
Value3 varchar(10)
);
insert into t1
VALUES('A',10,5,'A',10,4,NULL,NULL,NULL),('B',20,2,NULL,NULL,NULL,'B',20,3),
('C',30,6,NULL,NULL,NULL,NULL,NULL,NULL)
select * from t1


Group1
SG1
Value1
Group2
SG2
Value2
Group3
SG3
Value3


A
10
5
A
10
4
null
null
null

B
20
2
null
null
null
B
20
3

C
30
6
null
null
null
null
null
null

Group1	SG1	Value1	Group2	SG2	Value2	Group3	SG3	Value3
A	10	5	A	10	4	null	null	null
B	20	2	null	null	null	B	20	3
C	30	6	null	null	null	null	null	null