✅ 🔥 MySQL || ⚡easy solution
\nselect employee_id from employees \nwhere employee_id not in (select employee_id from salaries)\nunion\nselect employee_id from salaries\nwhere employee_id no
```\nselect employee_id from employees \nwhere employee_id not in (select employee_id from salaries)\nunion\nselect employee_id from salaries\nwhere employee_id not in (select employee_id from employees)\norder by 1\n```
['Union Find', 'MySQL']