题解 | #获取所有非manager的员工emp_no#

SELECT e.emp_no FROM employees e WHERE e.emp_no not in (SELECT e.emp_no FROM employees e INNER  JOIN dept_manager d on e.emp_no = d.emp_no)

筛选在部门的员工：SELECT e.emp_no FROM employees e INNER JOIN dept_manager d on e.emp_no = d.emp_no

排除在部门的员工，就是不在部门的员工:SELECT e.emp_no FROM employees e WHERE e.emp_no not in (SELECT e.emp_no FROM employees e INNER JOIN dept_manager d on e.emp_no = d.emp_no)