[SQL]Hackerrank - New Companies

select c.company_code, c.founder,
count(distinct m.lead_manager_code),count(distinct m.senior_manager_code),
count(distinct m.manager_code),
count(distinct m.employee_code)
from company c inner join employee m 
on c.company_code=m.company_code 
group by c.company_code,c.founder 
order by c.company_code ;

振り返る