[MySQL] 여러 개의 서브 쿼리를 이용하기

https://www.hackerrank.com/challenges/the-company/problem

New Companies | HackerRank

조인을 이용한 풀이는 나중에 해볼 것

select C.company_code, C.founder,
  (select count(distinct LM.lead_manager_code) 
   from Lead_Manager as LM 
   where LM.company_code = C.company_code),
  (select count(distinct SM.senior_manager_code) 
   from Senior_Manager as SM 
   where SM.company_code = C.company_code),
  (select count(distinct M.manager_code) 
   from Manager as M 
   where M.company_code = C.company_code),
  (select count(distinct E.employee_code) 
   from Employee as E 
   where E.company_code = C.company_code)
from Company as C
order by C.company_code;