Db2 11.1

By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.

create table test (id int, dat_from date, dat_to date, notes varchar(200))
insert into test values(1, '01.01.2022', '01.02.2022', 'First')
insert into test values(1, '01.01.2022', '01.02.2022', 'Second')
insert into test values(2, '01.01.2022', '01.03.2022', 'First')
insert into test values(2, '01.01.2022', '01.03.2022', 'Second')
insert into test values(2, '01.01.2022', '01.03.2022', 'Third')
select id, min(dat_from), max(dat_to), listagg(notes, ',')
from test
group by id


ID
2
3
4


1
2022-01-01
2022-02-01
First,Second

2
2022-01-01
2022-03-01
First,Second,Third

ID	2	3	4
1	2022-01-01	2022-02-01	First,Second
2	2022-01-01	2022-03-01	First,Second,Third