方法一 NOT IN+子查询
select emp_no
from employees
where emp_no not in (select emp_no from dept_manager);
方法二 左连接去中
SELECT e.emp_no
FROM employees e
left join dept_manager d ON e.emp_no = d.emp_no
where d.emp_no is NULL;
select emp_no
from employees
where emp_no not in (select emp_no from dept_manager);
SELECT e.emp_no
FROM employees e
left join dept_manager d ON e.emp_no = d.emp_no
where d.emp_no is NULL;
牛客博客，记录你的成长
京公网安备 11010502036488号