[MySQL] Simple and easy Implementation
```\nselect  employee_id\nfrom Employees\nwhere employee_id not in(select employee_id\n                        from Salaries)\n             union\nselect  emplo
```\nselect  employee_id\nfrom Employees\nwhere employee_id not in(select employee_id\n                        from Salaries)\n             union\nselect  employee_id\nfrom  Salaries\nwhere employee_id not in(select employee_id\n                        from Employees)\norder by employee_id;
['Union Find', 'MySQL']