문제1부서별 직무의 사원수를 계산하는 쿼리문을 작성하세요.select c.dept_name, d.title, count(a.emp_no) as employee_count from employees as a join dept_emp as b on a.emp_no = b.emp_nojoin departments as c on b.dept_no = c.dept_nojoin titles as d on a.emp_no = d.emp_nogroup by c.dept_no, d.titleorder by b.dept_no;