sutun veri yapisi her satirda ayni olmali
tum when case ler string dondurmeli

bir satirda branch integer
sonraki satirda string dondurdugu icin olabilir

her alt sorgu icin case yazmak yerine mevcut case blogunun disina tek seferde yazabilirsiniz

genel bir ornek

create table branches(
  branch_id int,
  branch_name varchar(50)
);

insert into branches (branch_id,branch_name) values (1,'test1');
insert into branches (branch_id,branch_name) values (2,'test2');
insert into branches (branch_id,branch_name) values (3,'test3');
insert into branches (branch_id,branch_name) values (4,'test4');

select
case
  when branch_id = 1 then 'dukkan1'  
  when branch_id = 2 then 'dukkan2'  
  when branch_id = 3 then 'dukkan3'  
  when branch_id = 4 then cast((select branch_id from branches where branch_id=1) as varchar(100))
  else ''
end ,
cast((select branch_id from branches where branch_id=1) as varchar(100))
from branches