MySQL 8.0

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CREATE table brands (
id int(11),
brand_name varchar(20));

CREATE TABLE models (
id int(11),
idBrand int(11),
model_name varchar(20));
insert into brands values(1, 'A_brand')
insert into brands values(2, 'B_brand')
insert into models values(1, 1, 'M1')
insert into models values(2, 1, 'M2')
insert into models values(3, 2, 'M3')
insert into models values(4, 2, 'M4')
insert into models values(5, 2, 'M5')
select b.id, max(brand_name), group_concat(model_name)
from brands b join models m
on b.id = m.idBrand
group by b.id;


id
max(brand_name)
group_concat(model_name)


1
A_brand
M1,M2

2
B_brand
M3,M4,M5


select brand_name, group_concat(model_name) model_name
from brands b join models m
on b.id = m.idBrand
group by brand_name;


brand_name
model_name


A_brand
M1,M2

B_brand
M3,M4,M5