New Companies

• 문제
  
• 정답

SELECT C.company_code, 
        C.founder, 
        COUNT(DISTINCT LM.lead_manager_code), 
        COUNT(DISTINCT SM.senior_manager_code), 
        COUNT(DISTINCT M.manager_code), 
        COUNT(DISTINCT E.employee_code)
FROM COMPANY C
LEFT JOIN LEAD_MANAGER LM ON C.company_code = LM.company_code
LEFT JOIN SENIOR_MANAGER SM ON LM.lead_manager_code = SM.lead_manager_code
LEFT JOIN MANAGER M ON SM.senior_manager_code = M.senior_manager_code
LEFT JOIN Employee E ON M.manager_code = E.manager_code
GROUP BY C.company_code, C.founder
ORDER BY C.company_code

• 결과