Oracle SQL:Намерете дублиран CLIENTKEY и покажете един конкретен запис

Можете да използвате подзаявка, която присвоява класиране на всеки ред, така че там, където има дублиран ключ (един KB, един нещо друго), редът KB се класира по-високо; и след това филтрирайте това:

-- CTE for sample data
with your_table (clientkey, clientname, department, hostkey) as (
  select '0201967/6', 'PPBOP1BOP01-JO,BLOGS', 'KB', 'PPBOP1BOP01/MSC/PPBOP1BOP01/2/B1KI0' from dual
  union all
  select '0201967/6', 'PPBOP1BOP01-JO,BLOGS', 'BS', 'PPBOP1BOP01/MSC/PPBOP1BOP01/2/B1KI0' from dual
  union all
  select '0024028/2', 'PPBOP1BOP01-FOO,BAR', 'KB', 'PPBOP1BOP01/MSC/PPBOP1BOP01/2/B2KI0' from dual
  union all
  select '0024028/2', 'PPBOP1BOP01-FOO,BAR', 'BS', 'PPBOP1BOP01/MSC/PPBOP1BOP01/2/B2KI0' from dual
  union all
  select '1746947/1', 'BSM1BSM03-THING,BOB', 'BS', 'BSM1BSM03/BSHVS/BSM1BSM03/2/B1KI0' from dual
  union all
  select '1612105/1', 'WIBU1IBU03-TREE,GREEN', 'BS', 'WIBU1IBU03/SHVS/WIBU1IBU03/3/B1KI0' from dual
)
-- actual query
select clientkey, clientname, department, hostkey
from (
  select clientkey, clientname, department, hostkey,
    rank () over (partition by clientkey
      order by case when department = 'KB' then 0 else 1 end) as rnk
  from your_table
)
where rnk = 1;

CLIENTKEY CLIENTNAME            DE HOSTKEY                            
--------- --------------------- -- -----------------------------------
0024028/2 PPBOP1BOP01-FOO,BAR   KB PPBOP1BOP01/MSC/PPBOP1BOP01/2/B2KI0
0201967/6 PPBOP1BOP01-JO,BLOGS  KB PPBOP1BOP01/MSC/PPBOP1BOP01/2/B1KI0
1612105/1 WIBU1IBU03-TREE,GREEN BS WIBU1IBU03/SHVS/WIBU1IBU03/3/B1KI0 
1746947/1 BSM1BSM03-THING,BOB   BS BSM1BSM03/BSHVS/BSM1BSM03/2/B1KI0  

Това все пак ще позволи дубликати в други отдели, ако това може да се случи, и ще включва всички тези редове; ще изключи само дубликати за KB.