连接在一起group by就行了where都不用 select d1.dept_no,d1.dept_name,t.title,count(t.title) from departments d1 join dept_emp d2 on (d1.dept_no=d2.dept_no) join titles t on (d2.emp_no=t.emp_no) group by dept_no,dept_name,title order by d1.dept_no asc,title asc