mysql | easy | using union
\nselect employee_id \nfrom Salaries\nwhere employee_id not in (select employee_id from Employees)\nunion\nselect employee_id \nfrom Employees\nwhere employee_i
```\nselect employee_id \nfrom Salaries\nwhere employee_id not in (select employee_id from Employees)\nunion\nselect employee_id \nfrom Employees\nwhere employee_id not in (select employee_id from Salaries)\norder by employee_id\n```
['Union Find', 'MySQL']