SELECT de.dept_no, e.emp_no, salary FROM employees e # join 就完事儿了 JOIN dept_emp de ON e.emp_no = de.emp_no JOIN dept_manager dm ON de.dept_no = dm.dept_no JOIN salaries s ON e.emp_no = s.emp_no WHERE s.to_date = '9999-01-01' AND e.emp_no NOT IN (SELECT emp_no FROM dept_manager) #非领导条件 ORDER BY de.dept_no, salary DESC # 隐藏条件